It turns out that a number of my web pages are about things related to aircraft so I've started this page for aircraft related things.
Wiki) was founded Aug. 7, 1789 and lasted until Sep, 18, 1947, aka: War Office.
U.S. Department of the Navy (Wiki:DoN) founded 30 Apr. 1798.
Near the end of World War I (Wiki: 1914 - 1918), Brig. General William " Billy " Mitchell (Wiki) became Chief of Air Service for the U.S. Army.
The Air Service was renamed the Army Air Corps (Wiki: USAAC) in 1926
On June 27, 1940 Truman formed the National Defense Research Committee (Wiki: NDRC), replaced by the OSRD. - Atomic bomb (Wiki), DUKW (Wiki), Project Pigeon (Wiki), Proximity Fuze (Wiki, China Lake), RADAR (Wiki, RWR).
The Army Air Forces (Wiki: USAAF, or AAF) was formed on 20 June 1941.
On 28 June 1941 EO8847 formed the Office of Scientific Research and Development (Wiki: OSRD).
On Sep, 18, 1947 the U.S. Department of Defense (Wiki: DOD) replaced the War Department.
On Sep, 18, 1947 the U.S. Department of the Army (Wiki: DOA) was formed.
On Sep, 18, 1947 the U.S. Department of the Air Force (Wiki: DAF) was formed.
On 18 Sep. 1947, Congress created the U.S. Air Force (Wiki: USAF) as an equal partner with the Army and Navy.
On 20 Dec. 2019 (FY2020 NDAA), Congress created the U.S. Space Force (Wiki: USSF).
Ref 9, Ref 13, Wiki), A-12 (Wiki) and SR-71 (Wiki) as well as to the altimeters they use.
A key consideration for heavier than air craft is called wing loading (Wiki). This determines stall speed which in turn relates to maximum altitude. Key factors in max altitude are air density, wing area and total aircraft weight.
An assumption made by the designers of the U-2 was that because it could fly so high that it would not be seen by RADAR where the beam had it's lower edge at the horizon because the useful slant range was shorter than the slant range to a plane that high. But there was no rule that required the beam to be that low. See also Ultimate Weapon below for the conditions at the start of W.W.II.
A magnetic compass is influenced by nearby ferrous metal as well as be nearby magnets. Both types of influence can be compensated but even after doing that there's still the problem of the Earth's magnetic field vector being more up and down than horizontal near the magnetic poles, i.e. near the poles a magnetic compass does not work reliably. So a number of approaches were used to determine bearing. Note there is a severe problem with a magnetic compass in a metal vehicle like a submarine, ship or armored tank or even an automobile.
Abrams Universal Sun Compass SC-1 - actually used in the desert in W.W.II for vehicles
AC_D500 Astro-Compass MkII - This is what amounts to a transit without a telescope for determining angles to the Sun or other heavenly body from an airplane
Aircraft Pilot's Standby Magnetic Compass - a backup to more complex systems that do fail now and then
KVHC100FG KVH C100 Flux Gate Compass module - mainly used on watercraft and on land, but the concept dates way back in aircraft
MC1 MC-1 Magnetic Compass Calibration Set similar to AN/ASM-344 - used for aircraft
MD1 Automatic Astro Compass Type MD-1 - a star tracker that works day and night to locate an airplane
In 1943 (Ref 1) radio aids to navigation were things like Radio Direction Finding working with known transmitter locations (like AM broadcast stations or NDBs (Wiki), to provide a bearing and beacons of the A/N type (Wiki). Dead Reckoning and Celestial Navigation were required skills. LORAN-A (Wiki) was developed during W.W.II and LORAN-C by 1958, but it was mainly used by ships then. By 1981 (Ref 3) VOR (Wiki), TACAN (Wiki), Omega (Wiki), autopilots (Wiki) were in common use. Note LORAN-C (LORAN-C, Wiki) was not common on aircraft yet.Modern aircraft use GPS to determine their position. Note that GPS by itself does not inherently have a bearing output. But because the aircraft is moving when in the air it can develop a bearing by calculating the difference in positions.
5001A Stanford Telecom 5001A Navstar Test Transmitter - made to test their GPS receiver ICs - an early simulator to test GPS receivers
AstechZ12 Ashtech Z-12 Reference Station GPS receiver - a GPS receiver used at reference stations on the ground that can output Differential corrections that make GPS receivers more accurate, mainly used for ships and surveying.
CSI LGBX Pro DGPS Receiver - A combined GPS and differential correction receiver mainly used for surveying
DAGR - Defense Advanced GPS Receiver - a current military GPS receiver
GPSpat GPS & Satellite Navigation Patents
HNV600 Rockwell Trooper GPS HNV-600 & HNV-960
HNBV-960 GPS receiver without front panel, but has antenna & backup battery
HNV-2000 Rockwell HNV-2000 PLGR II SPGR GPS Receiver
HP Z3805A Time & Frequency GPS Receiver - mainly for fixed location use for timing applications
Jackson Labs - LTE-Lite GPSDO Evaluation Kit - mainly for fixed location use for timing applications
KS-24361 (Lucent ) HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO System - mainly for fixed location use for timing applicationsin cell towers
Magellan GPS Commander - mainly for ships
Magnavox MX7221 GPS Receiver - guessing military or civilian use
NTgpsSTR2760 Northern Telecon GPS Satellite Sumulator STR2760 - a more modern GPS simulator than the ST 5001
PLGR PLGR GPS Family - the military GPS receiver prior to the DAGR
PSN-8 PSN-8 GPS receiver - a very early GPS receiver
PSN-9 GPS receiver - another very early GPS receiver
PSN-10 SLGR GPS receiver -another name for the Trimble Trimpack the first widley used military GPS receiver
PSN-11 PLGR GPS receiver
PSN-13 DAGR GPS receiver
Q5200 Quantic Q-5200/SM Timing GPS Receiver
ThunderBolt Trimble GPS Timing receiver
Trimpack Trimble Trimpack Family of GPS receivers
URN502 URN-502 Vehicle Mount GPS Receiver System - a very early GPS receiver (the largest one I have)
Z3805A Time & Frequency GPS Receiver - mainly for fixed location use for timing applications
The gyroscope is used in many different types of aircraft applications. Most of them are obvious, like the turn and bank indicator or for navigation functions, but the one that was part of the reason for making this web page was the Norden Bombsight. It turns out that it NEVER worked. The US Navy developed the Norden, but gave up on it and adopted dive bombing. The US Army took up the Norden, but it did not allow "precision bombing" and that tactic was abandoned and "carpet bombing" (Wiki) was the only one used.
When most people think of a bomber (Wiki) they think of the W.W. II B-17 (photos, Wiki), B-24 (Wiki) or the more modern B-52 (Wiki). Many movies about W.W.II show German Stukas aka: Junkers Ju 87 (Wiki) and American SBD Dauntless (Wiki) in actual dive bombing for some reason the difference between horizontal (Wiki) and dive bombing (Wiki) is misunderstood.
The Norden Bombsight (Wiki) has had a lot of publicity, but in fact it did not work. As far as I can tell horizontal bombing only works in carpet bombing mode, with atomic weapons, or maybe using Smart Bombs (Wiki). I think the jury is still out on the Smart Bombs. Note bomb sights for horizontal bombing look down whereas sights for dive bombing look forward and are often called "gun sights", for example the Mk 20 Mod 4 Gun-Bomb-Rocket Gun Sight.
5344105 Relative guidance using the global positioning system, Mark Youhanaie, Hughes Aircraft, 1994-09-06, - bomb relative to aircraft.
5451014 Self-initializing internal guidance system and method for a missile, James M. Dare, Jerome A. Farm, Barry C. Mears, McDonnell Douglas, 1995-09-19, - inertial nav, not GPS
5507452 Precision guidance system for aircraft launched bombs, Joseph R. Mayersak, Loral (Lockheed Martin), 1996-04-16, - JDAM - cited by 40 -
6237496 GPS guided munition, Anthony Steven Abbott, Northrop Grumman Systems Corp, App: 1997-02-26, Pub: 2001-05-29, - JDAM (Wiki) - cited by 48 -
I'm investigating the use of the A-1 Skyraider (Ref 7) in the dive bombing role. Note it's bombsight is above the instrument panel looking foreword, just like the 3x "rifle scope" bombsight on the Douglas SBD Dauntless (Wiki). The late model SBDs used the Mk 8 sight. But I don't remember ever seeing a movie showing the A-1 in the dive bombing role.
Saga of the SkyRaider - A-1 Spad 80510 - (3:25) "The Navy had been searching for a new dive bomber, attack aircraft to meet the changing tactical and operational requirements."
YouTube:VNAF A-1E Skyraider Air Strikes, Vietnam, 11/19/1964 (full) - (0:22 - Clearly dive bombing
Napalm Hell-The Opening Scene of Rescue Dawn (2006) in HD - For Napalm the A-1 seems to be using horizontal bombing were there is no bomb sight.
Mk 20 Mod 4 gun sight is the sight used on the A-1 Skyraider.Reflector Gunsights used by the US Navy
http://www.aircraft-gunsights.com/reflector-sights/- Aircraft Gunsights-archive.org, ,
The thing that may have put an end to dive bombing is the advent of Radar controlled Anti-Aircraft weapons (rockets & guns) (
Wiki: ZSU-23-4) in 1962. The 23mm rounds are too small for Proximity fuzes (China Lake Patents, Wiki) so a direct hit is needed. Prior to 1962/1963 dive bombing would work, but after that the planes could be easily shot down. Surface to Air Missiles (Wiki: SAM) were deployed in Vietnam starting about 1965.
In Toss Bombing (aka: Low Altitude Bombing (LAB, Wiki) the plane is pulling up at the point of bomb release. also see 1955 patent 2898809.
I have a book (Ref. -do not remember title-) where they devoted a chapter to the situation just prior to W.W.II and the fear that permeated pretty much every country about the ultimate weapon. Note the Atomic bomb (Wiki) was developed during W.W.II as was RADAR (Wiki). But the B-17 (Ukiah air show, Wiki) was in production prior to the start of W.W.II and could fly above 30,000 feet altitude where it was for all practical purposes undetectable. The Norden Bomb Sight (Wiki, Gyroscopes) was also in production even though it was more marketing hype than functional. So you can see that there's reason for the belief that the ultimate weapon, the high altitude bomber, would make W.W.II impossible. It could fly wherever it wants and drop bombs with precision. There would be no defense against it.
The phrase "The bomber will always get through" may have originated because at that time they were both impossible to detect (prior to radar) and impossible to shoot down (prior to proximity fuzes) from the ground. See Ref 55 and Ref 56: None of the bomber (or other) turrets worked. A fighter escort did work.A Fear For The Future by Stanley Baldwin (Wiki), 1932 - This is more a white paper, but I'm sure was the source for the book mentioned above.
Weird History Facts: Pre-Radar Listener Job: Old Forgotten Jobs of History – 1900’s -
The Sidewinder air-to-air missile (Wiki) was developed to shoot down high altitude bombers.
1675720 Searchlight, Chester B Mills, Sperry Gyroscope, 1928-07-03, - for naval use
Sperry Gyroscope searchlight patents
1850598 Searchlight control, Chester B Mills, Preston R Bassett, Sperry Gyroscope, 1932-03-22, -
2003661 Searchlight director, Preston R Bassett, Frank R House, Sperry Gyroscope, 1935-06-04, -
Note it uses audio horns to detect aircraft!
For Aircraft sight patents (gun, bomb, torpedo, Etc.) see: Mk 20 Mod 4 Gun-Bomb Sights: Patents
Bombs are more aerodynamic than planes, so speed up as soon as they are released. Bombs mounted on the aircraft centerline would move forward and hit the propeller. This is an even bigger problem if the dive brakes (Wiki) are deployed to keep the plane from exceeding it's maximum speed. Propeller dive bombers need a way to keep a bomb from hitting the propeller. Either by having the bomb rack outside the prop circle or by a special mechanism (trapeze) that pushes the bomb outside the prop circle.
Wiki: Hardpoint - Pylon - Racks -
Wiki: Aircraft Armament Equipment -
Global Security: LAU-127, LAU-128, LAU-129 -
AIM-120 AMRAAM (Wiki) LAU-127
AIM-120 AMRAAM, AIM-9L/M, BOL Countermeasures Dispenser LAU-128 F-15
AIM-120 AMRAAM, AIM-9X, BOL Countermeasures Dispenser LAU-128A
BOL Countermeasures Dispenser
In the 2019 movie Midway (IMDB), there are a number of scenes where you can see the trapeze working on a dive bomber to move the centerline bomb outside the propeller circle. Also both the rifle telescopic type of sight as well as the 45 degree half-silvered type are displayed.
2344211 Bomb releasing rack, Roscoe I Markey, Pollak Mfg, App:1942-05-21, Pub: 1944-03-14, -
2362211 Electrical control system, Roscoe I Markey, Pollak Mfg, App: 1941-08-07, Pub: 1944-11-07, - bomb release
Photo from Pacific Aviation Museum -
2386839 Bomb displacing gear, George A Bronson, Douglas Aircraft Co Inc, 1942-12-01 - probably for the SBD (Slow But Deadly)
"This invention relates to a bomb displacing gear for use on an airplane in conjunction with a bomb rack or other bomb carrier which is constructed to release the bomb at the will of the air craft operator, and particularly to a bomb displacing gear for use on dive bombing airplanes. The bomb rack is usually placed in a bomb bay formed in the under surface of the fuselage, both to keep the plane aerodynamically clean, and to bring the weight of the bombs nearer the level of the center of gravity of the plane.
In dive bombing, the diving angle is preferably between 70 and 90 degrees to reduce to a minimum the gravity deviation of the bomb trajectories from the direction of the dive and the consequent need for allowing for this deviation in sighting the airplane for the dive. The bombs released at the end of the dive, being aerodynamically cleaner than the airplane, tend to fall more rapidly than the plane. In high angle dives the bomb trajectory after release is nearly parallel to the fight path of the airplane.
If the trajectory begins at the undersurface of the airplane, there is danger of the bombs falling into the propeller blades and breaking them or being exploded. Accordingly, devices have been employed to move the bomb upon its release from the bomb rack to a position sufficiently displaced outwardly from the fuselage that the bomb trajectory will clear the path of the propeller even in 90 dives."
Note trapeze on bomb at centerline needed to clear prop.
The wing mounted bombs do not need the trapeze since they will clear prop.
The bombsight was a 3X telescope on plane centerline at pilots eye level. The pilot needed to put his eye on the eyecup so that the cross-hair was correctly on target (no parallax (Wiki). The later model bombsight was a reflex type (NC-3 , Wiki) where the cross-hair stays on the target as the pilots head moves side to side.
2461967 Aerodynamic Retarder, Leo J Devlin, Edward H Heinemann, Douglas Aircraft Co Inc, 1949-02-15 - "...actuated preparatory to initiating or terminating a. dive..." Dive Brakes (the modern term is "air brakes" since dive bombing is no longer in fashion).
2466980 Missile ejector for aircraft, George A Bronson, Douglas Aircraft Co Inc,, 1949-04-12 - bomb rack for dive bomber
a cannon shoots the bomb away from the plane so it will clear propeller circle
Skyraider & Atomic Bomb (Wiki:Mk 4 1949 - 1953?) ?
or maybe just an improvement for iron bombs
2491400 Bomb release rack, Thumim Carl, ITE Circuit Breaker Co, App: 1945-02-14, Pub: 1949-12-13, -
2534744 Bomb shackle, Jr George W Wardwell, 1950-12-19, -
2609729 Bombing instrument for aircraft, Wilkenson Erik Alvar, Faxen Per Torsten, 1952-09-09 - improved dive bombing improved dive bombing
2634656 Rotary bomb bay door with bomb releasing means, Albert T Woollens, Buchal Werner, Glenn L Martin Co, 1953-04-14, -
2756091 Military stores rack, Frank J Komerska, Ainsworth Manufacturing Corp, 1956-07-24, -
2949060 Article suspension arrangement for aircraft, Gantschnigg Gottfried Karl, Muehlberger Louis, Marsh White, Albert C Hake, Martin Co, 1960-08-16, - revolver bomb rack
2971792 Store retaining device, John C Steinmetz, North American Aviation, 1961-02-14, -
AD Skyraider (later called A-1)
D146221 Airplane, Edward H. Heinmann & Leo J. Devlin, Jan. 14, 1947
General-purpose bomb (Wiki) - includes variations. The Mk 82 Snake Eye has retarding petals to prevent the bomb fragments hitting the aircraft that dropped it. A ballute (Wiki) serves the same purpose. Did not find a patent for the 1948 ballute cited on the Wiki page.
4005655 Inflatable stabilizer/retarder, Nick Kleinschmidt, James V. Netzer, Navy, 1977-02-01, - ballute or fins.
Parachute Mine (Wiki)
Blockbuster bomb (Wiki)
Bunker Buster (Wiki)
6698357 Hydrocarbon warhead and method, John W. Jones, Lockheed Martin Corp, App: 2001-04-05, Desert Storm, Pub: 2004-03-02, - hardened and deeply buried target or HDBTFirebombing (Wiki)
Incendiary device (Wiki), Napalm (Wiki) , Firebombing (Wiki)
2445311 Incendiary bomb mixture, Henry H Cooke, John B Holtzclaw, App: 1942-03-28, SECRET, Pub: 1948-07-20, -General-purpose bomb (Wiki)
2501766 Incendiary grenade, Louis F Fieser, George C Harris, Emanuel B Hershberg, Morgana Morley, Frederick C Novello, Stearns T Putnam, US Secretary of War, App: 1944-02-21, SECRET, Pub: 1950-03-28, - 1/2 pint glass jar, a steel ball is released when the arming ring is pulled, allowing it to break a glass ampule upon impact.
Daisy Cutter (Wiki: BLU-82)
2586801 Incendiary bomb, Robin B Epler, David L Woodberry, US Secretary of War,App: 1942-08-27, Secret, Pub: 1952-02-26, -
4132170 Fuel-air type bomb, Periam B. Hardy, Lewis L. Gay, Edward L. Husler, Beechcraft Corp, App: 1971-02-12, Vietnam, Pub: 1979-01-02, -
Free-fall, gravity, dumb or Iron bomb (Wiki: Unguided bomb)
Carpet bombing (Wiki)
Guided bomb (Wiki) - Guidance: Command, Heat seeking, Laser Designated (laser-guided bomb), GPS (DCI Statement on the Belgrade Chinese Embassy Bombing, House Permanent Select Committee on Intelligence Open Hearing, 22 July 1999)
The ability of aircraft to launch torpedoes has been an important capability of aircraft. In particular it required special developments in order to work in specific cases, such as at the shallow water of Pearl Harbor (Wiki).
1032394 Method of and apparatus for delivering submarine torpedoes from airships, Bradley A Fiske, (not assigned), July 16, 1912 89/1.54; 89/1.51; 114/239; 114/20.1 - a strap holds torpedo under airplane and when level is pulled it drops torpedo into water and at the same time starts torpedo motor.
2467831 Sighting mechanism, Frithiof V Johnson, GE, App: 1942-09-26, TOP SECRET: Pub:1949-04-19, - gyro based - cited by 18 patents - for machine guns
3002680 Graphical Vectoring Computer, Stephen J O'neil, Leo D Upham, USAF, Oct 3, 1961 - air to air combat: computes bearing to intercept -referenced from other patents.
3010648 Method and apparatus for controlling release of objects from aircraft, Kurt A Erfurth, Friedrich G Wazelt, USAF, Nov 28, 1961 - Cargo, paratroops - graphical triangle solver
4145952 Aircraft gun sight system and method for high angle-off attacks, Gene Tye, Lockheed Martin, 1979-03-27, -
NAVPERS 10826 See Ref 17 below
NAVORD OD 9239
Boyd (Ref 10, Ref 40, Ref 44) developed the Energy-Maneuverability theory (Wiki: E-M Theory, Fighter Mafia) where a chart can be used to compare two aircraft to see how they compare in a dog fight at various altitudes and speeds. It will show which plane has the advantage given pilots that can get everything out of each plane.
page 148: Specific Energy = Velocity times [Thrust minus Drag] over Weight. These values change with altitude, so there's a plot for a given plane. When two of these plots are overlaid the plane with the higher specific energy has an advantage in a dog fight at that altitude. Note lowering the weight has a huge effect.
Boyd says that the Air Force seems to think heavy bombers that can deliver atomic weapons are their main mission and fighters have been neglected. I'd say that close air support and dive bombers have also been put way down on the priority list and need to be reconsidered.
The F-5 (Wiki) might be considered a light weight fighter?
It turns out the Flak (Wiki) in W.W.II while demoralizing to aircrew members was not effective in shooting down aircraft. This is because it was virtually impossible to set the time fuze and aim the gun so that the round exploded anywhere near the target aircraft. The National Defense Research Committee (Wiki NDRC) had as one of it's projects the development of the proximity fuze (Ref 4, developed partially at China Lake) which was used not only to shoot down aircraft but also to attack ground troops.
The Sidewinder missile (Wiki) was developed at China Lake and makes use of thermal IR for terminal homing. Note that the sidewinder was NOT intended for air to air combat (Wiki: Dogfight), but rather to shoot down high altitude bombers (See: Ultimate Weapon).
Surface to Air Missiles (Wiki: SAM) really began when the SA-2 (Wiki) became operational and one of its first targets was the Powers U-2 shot down on May 1, 1960 (Wiki). Each Surface to Air system that uses RADAR has a threat envelope in terms of diameter and altitude that's shaped like an upside down water drop. Some are tall and skinny, some are short and fat. If an aircraft avoids flying through the threat envelope he can not be shot down by that weapon. Even inside the threat envelope and aircraft can evade the threat if the pilot knows the type of system and that he is being painted early enough, i.e the function of the Radar Warning Receiver (see EW below).
At a meeting of the Air Scouts in the late 1950s at Moffett Field while up close to an F-8 Crusader Jet (Wiki) we learned that the guns had been upgraded from .50 caliber to 20mm. The reason was that the planes almost shot themselves down. This happened when firing the guns at a barge being towed a safe distance behind a ship. The problem was that after firing the guns the F-8 could speed up in a dive and get in front of the bullets which then hit the F-8 from behind when it slowed. Note for landing and takeoff the wing leading edge is raised up rather than use flaps. (photo on Wiki page showing wing in up position)
While the RPG-7 was designed to be an anti-tank weapon it does have a self destruct timer that goes off at about 900 meters. So it can be used to shoot down aircraft if they are at that range. This was the case in "Black Hawk Down" (Wiki: film, Mogadishu).
After learning about how the Navy used dive bombing after they discovered that horizontal bombing (see: Gyroscopes Norden) did not work, I looked for dive bombing sights, but could not find any. It turns out most people call them "gun sights" even though one of their functions is dive bombing. For example:Mk 20 Mod 4 Gun, Bomb, Rocket Sight - sight line fixed to aircraft and also used for torpedoes
Navy Mk. 18 Gyro Gun Sight - Uses a gyroscope to move the sight line to compensate for lead (Wiki). I think this is also part of how the NLAW works to hit moving armored tanks.
2182722 Gun turret for aircraft, Gavardie Pierre, Henry Edmon De, App: June 18, 1937, Pub: Dec 5, 1939, - ball turret, manually operated
2233918 Airplane machine gun mount, Howard M Fey, App: 1937-12-29, Pub: 1941-03-04, 89/37.17; 89/37.08; 89/41.15; 89/41.18 - "Ball Turret" (Wiki)
2236312 Gun mount, more especially for use in aircraft, Funk Alfred, Messerschmitt, App: 1937-04-30, Pub:1941-03-25, 89/37.16; 89/37.12 - manual ball mount
2429467 Fire Control Means for Aircraft Gun Mounts, Morris F. Ketay, Bendix Aviation Corp, Filed: Dec 14, 1939, Pub: Oct 27, 1947, 89/37.17; 89/41.01; 89/41.02; 89/203 - probably for the B-17. Includes motors to move turret in azimuth and elevation as well as some compensation of gun sight for altitude and air speed of the B-17. Does not appear to include any gyroscopes.
2434653 Power-operated aircraft gun turret, Carl G Holschuh, Lester C Warner, Sperry Gyroscope, App: 1941-10-24, Pub: 1948-01-20, 89/37.17; 74/437; 89/41.18; 74/393; 89/41.01; 89/41.15; 89/41.12 -
2454806 Means for mounting machine guns in airplanes, Paul H Kemmer, Carl E Reichert, Jr Charles S Butt, Pub:1948-11-30, - Remote control of quad 50 guns, no gunner.
2407665 Aircraft fire control computer, Carl G Holschuh, Fram David, Sperry Gyroscope, App: 1940-08-01, Pub: 1946-09-17, -
Cited By (9)
2410831 Scanning device, Leon A Maybarduk, Walter W Mieher, Stephen J Zand, Gifford E White, Sperry Gyroscope, App: 1942-04-10, Pub: 1946-11-12, 342/74; 74/1R; 74/22R; 89/41.07; 342/425; 343/760; 343/759; 343/765 - scanner for an aircraft nose or pod mounted radar.
2473050 Emergency radio signal for airplanes, Charles J Camp, 1949-06-14, -
2552969 Telltale radio signal device, James P Holman, 1951-05-15, -
2628307 Emergency signaling apparatus, Jack M Lloyd, Wiley M Williamson, 1953-02-10, -
CAS (Wiki: action against hostile targets that are in close proximity to friendly forces and which requires detailed integration of each air mission with fire and movement of these forces...). In the Vietnam era the Douglas A-1 Skyraider (Ref 7, Wiki) had an excellent reputation because of its long loiter time. Carrier based jets had a very short loiter time because of high fuel consumption.
The A-10 Warthog (Wiki) is the replacement for the A-1 Skyraider (Wiki) The A-10 is turbofan (Wiki) powered and its main gun is the GAU-8 30mm cannon (Wiki) which has been shown to be very effective against tanks. But I think improperly positioned firing forward instead of off the left wing like in Gunships (Ref 2). The gun sight used on the AC-47 Spooky (Wiki) gunship is the Mk 20 Mod 4, the same as the sight on the A-1 Skyraider.
In order to call in air strikes a team consisting of an Army and an Air Force would man a radio such as the GRC-206 (GRC-206, MT-6250) that would be mounted on a Jeep or later HMMWV. Note the generator for the Jeep mounted system (MEP-25) burned gasoline like the Jeep, but the generator was changed to a Diesel burning model with the introduction of the HMMWV so they would use the same fuel. The radio controls are duplicated so the each soldier has his own controls.
YouTube: Mar 5, 2022:
Finally: US Tests the NEW Super A-10 Warthog After Getting An Upgrade, 10:30 - various suites and what they do
YouTube:Meet America’s New Attack Aircraft; The Sky Warden, 5:46 - AT-802U Sky Warden (Wiki). Air Tractors have flown over my house in the role of fighting wildfires.
How Is An Airplane Built? Air Tractor Factory Tour, 23:10 - Brochure: The model number corresponds to the spray tank capacity in gallons, i.e. the AT-802 has an 800 Gallon tank. The new 1002 has a 1,000 Gallon tank.
But these Air Tractor AT-802s will be fitted with weapons and avionics by L-3 for military use.
L3 Harris and Air Tractor Sky Warden team Selected for USSOCOM Armed Overwatch Contract -
U-28A Draco is the military designation for the Pilatus PC-12 (Wiki). These flew over my house and were at 16,000' doing IR fire mapping during the August Complex fires.
YouTube: The Tricked-Out Cropduster the US Military Can’t Get Enough Of (The AT-802 Skywarden), 15:29 -
One of the earliest proponents of the pylon turn (Wiki) gunship (Wiki) was Gilmour Craig MacDonald (Ref 2) who proposed it as a way of attacking surfaced submarines in W.W.II. Note that a standard aircraft turn (Wiki) is measured in minutes with 2 minutes being a standard rate turn. Planes flying faster than 250 kn might make a 4 minute turn and very slow planes may make a 1 minute turn. Note this is related to wing loading (see above) Even W.W.II subs can dive in less than 2 minutes, so after the first strafing run when the plane completes its turn the sub will be gone. This is why in W.W. II sub movies they are practicing to shorten the time to dive and the captain is using a stopwatch to measure that time.2 Minute Turn Table
This same idea applies to aircraft engaging targets on the ground. The AC-47 Spooky (Wiki) was the first real application of the idea. It's based on the C-47 (Wiki) aka DC-3 (Wiki) cargo plane. It used the Mk 20 Mod 4 Gun-Bomb-Rocket Sight which can be adjusted for these different functions. But instead of looking forward the sight in mounted to look to the left. That's because the plane is making a pylon turn (Wiki) where the left wing is pointing to a fixed point on the ground.
I think the A-10 would have been better if the gun was installed in the wing instead of firing forward. From the Wiki Pylon Turn web page "...the gunfire was accurate enough to be used even in close proximity to friendly troops,..."
Since gunships carry multiple Gatling (Wiki: Mini, Gatling) guns they are typically are made from cargo planes that can carry the weight of all the ammunition. A fighter aircraft would not be suitable.
Note an airplane at 3,000 feet (1,000 yards) is out of range for small arms of the ground shooting up. It takes a trained sniper to hit a fixed target at 1,000 yards (see: ballistics) let alone a fast moving aircraft. BUT . . . it's easy for a MANPADS (Wiki) to bring down a plane that's within about 4 miles.
Anti Submarine Warfare (Wiki)
While the destroyer (Wiki) was designed to hunt and kill submarines, (they were called originally "submarine destroyers" and that name got shortened to destroyer) it's not that good at it. A much better option is to use aircraft for this purpose. When I lived in Mountain View, California the local Moffet Field Naval Air Station (Wiki) was used for training pilots and as a base for the P-3 Orion Sub hunters (Wiki). They make use of radar, sonobuoys and MAD (Wiki) to detect subs and also have weapons that can destroy them. (Ref-12)
The most powerful anti submarine strategy in W.W.II was the use of aircraft. Even when planes were not armed submarines were afraid of them. Destroyers were not very effective in protecting convoys in the Atlantic but when merchant ships were converted to be short aircraft carriers (Wiki) the level of protection went way up.
In the late 1950s the Air Scouts met at Moffett Field and one of the sessions involved time in a flight simulator. It was maybe 6 to 8 feet wide and maybe 20 to 30 feet long. Fixed to the ground and no pilot's outside visual simulation, that's to say pure instrument flying. In addition to the cockpit with opaque canopy there was an instructor position that had a duplicate set of instruments and in addition a plotting board. The instructor had inputs and could "make things happen". The interesting thing was the cockpit was illuminated by UV light and the instrument markings glowed. This allowed the pilot to maintain his night vision when flying at night. If white instrument lights were used that would not be the case.
Around the time of the Link Trainer there were other training devices some of which included a flying craft powered from a boat or truck.
Red Bird Flight Simulators - advanced versions of the Link Trainer
There were various versions of the "Link Trainer". I had the cockpit part like in the patent drawings below. It was made of wood and painted yellow. Inside there were 1/8" wire rope connected to the stick and working through pulleys could move the body relative to the mount. No motors or electronics. Maybe a home made item rather than surplus?
Version details from AAF T.O. No. 08-25-1
Teaching "blind landing"
Navy layout, Modified C-4
Yes Sim Yes Gears E-2
British layout, Modified C-4
Yes Sim Yes Gears S-W
color coded wiring,
strategic materials subs
Yes Sim Yes Gears Late
more efficient ventilation
zipper inspection panels replaced with the sliding panels
Yes Sim Yes Gears
The first patent (1825462) was for an entertainment apparatus. The movements it made were directly related to the control stick position. Note that this does not provide the same feeling as flying in a real airplane. For example when you are flying in a real airplane and it makes a turn the plane banks during the turn in such a way that a glass of water will not show any movement.
The other first generation patent (2099857) is about simulating the instruments. This was based on projecting an optical image on a ground glass, which would have required a canopy to dim or eliminate room light.
During this time the patents were in the name of Edwin A. Link and not assigned. Trainers were developed for various aspects of aviation that could make use of the entertainment apparatus, such as A-N Radio Range navigation (2119083, 2352216) and instrument flying where a plot on a map could be made (2179663).
After W.W.II started for the U.S. Link Aviation Devices company was formed and worked on aerial sextant based navigation. (also see: Astro-Compass MkII, Kollsman Aircraft Periscopic Sextant, A-10 Aircraft Sextant) They made the Link A-12 sextant while designed for aircraft use could also be used on ships. Along with the sextant Link also made trainers for sextant use, but for ships and aircraft. Part of that effort was the collimator (2310031).
In 1947 the Link Aviation started as the assignee for patents.
Link (Wiki: Flight Simulator, Edwin Link, Link Trainer, Link Piano and Organ Company) had a factory in Sunnyvale that was later a location of Fry's Electronics. Some key parts of a flight simulator are the instruments, outside visuals and physical movement (Ref 8).Way Back Machine: The Link Flight Trainer: A Historic Mechanical Engineering Landmark ASME International, June 10, 2000 -
War Bird Information Exchange - Link Trainer and Other World War II Simulator Information -
YouTube: A working flight simulator, no computers necessary, 5:53 - Patent number plate at: 2:45
The following numbers are a guess since the image is very fuzzy.
1825462 Combination training device for student aviators and entertainment apparatus
2099857 Trainer for aviators
2119087 Aviation trainer
2178637 Means and method of instrument indication in airplanes and the like
Link Patents (Trainer, Sextant, Sextant Simulator, &Etc)
1732597 Amusement apparatus, Henry B Faber, Frederick W Payne, 1929-10-22, - 2 years prior to Link 1825462
Simulates a sight seeing flight with maybe a dozen passengers.
Wind in your face and occasionally sea water and/or clouds
Scenic scrolls left and right.
pitch and yaw movement using hydraulics
the pilot has control over the various functions.
This may have been an inspiration for Link.
1825462 Combination training device for student aviators and entertainment apparatus, Jr Edwin A Link, 1931-09-29, -
Electric motor (46) drives suction pump (47) for bellows
Electric motor (97) drives valve disk (99) causing plane to tilt so that the pilot will then need to use the stick to bring it back to level.
This version does not seem to have any Azimuth change.
1982960 Illuminated aerial display, Jr Edwin A Link, 1934-12-04, -
a three character, 12-segment alphanumeric scrolling display for a biplane.
2099857 Trainer for aviators, Jr Edwin A Link, 1937-11-23, -
Improvement on 1825462 with working instruments
many drawings of different aspects.
Uses air technology from pipe organs (Wiki, Zephyr Organ Blowers, eBay "pipe organ blower") typically supply 3" to 6" of water pressure.
double acting air motor (2, Wiki) via belt (30) causes plane to move in Azimuth.
2119083 Aviation trainer, Jr Edwin A Link, app:1934-07-26, Pub: 1938-05-31, 434/244; 340/979; 340/952; 381/86 -
Wiki: Low-frequency radio range, aka A-N Beacon
The small plane/cockpit (1) is turned by a motor (Fig 4: 12) depending on pilot inputs. The panel indicator (4a) and Headphones (41) are driven by a 1 kHz tone that simulates what would be heard when flying near the A-N beacon. Note if the plane is out of any of the 4 beams nothing will be heard, like at the starting position (X in Fig 2). The student learns how to fly over the beam and then to fly on the beam toward the beacon so that he flies directly over the beacon.
This simulator is devoted to A-N Range training (Wiki). Once a plane gets off the beam it takes some skill to get back on a beam and know which beam it is. Hence a big need for training.
See BIF Ref 48: Radio Navigation Aids
2178637 Means and method of instrument indication in airplanes and the like, Jr Edwin A Link, 1939-11-07, - projecting instruments onto a ground glass screen
Note book showing A-N beacon & the Recorder in action showing A-N on map. Photo from Wiki Flight Simulator
2179663 Recorder, Jr Edwin A Link, 1939-11-14, -
Today we would say it performed a map plotter function. Looks functionally identical the 1960s MIT Turtle Robot (Wiki) used by Seymour Papert (Wiki) associated with the Logo Language (Wiki).
The pen (which could be moved up/down) was half way between the two large wheels. The large wheels were exactly the same diameter so that when they were driven at the same rate in opposite directions the turtle would pivot about the point of the pen. When the two large wheels were driven at the same rate and direction the turtle would go in a straight line.
2244464 Signal controlling means, Jr Edwin A Link, 1941-06-03, -
for a Left-Center-Right Turn and Bank indicator.
D132977 Design for a case for an octant or the like, Harold A. Marsh, Link Aviation Devices, 1941-07-07, Link A-12 Sextant
2310031 Collimator, Lowkrantz Gunne, Link Aviation Devices, 1943-02-02, -
Makes a star image at infinity. See Wiki, Optics\Collimator
2349506 Recording navigation instrument, Lowkrantz Gunne, Jr Edwin A Link, Link Aviation Devices,1944-05-23, -t
Also See patents 2359484, D132977
Link A-12 Sextant (Smithsonian: "The Link A-12 Sextant represented a new generation of “averaging” sextants."
2352216 Automatic miniature radio range equipment, Grant C Melvin, Stanley B White, 1944-06-27, -
Works with patent 2463583.
2358016 Aviation trainer, Edwin A Link, Karl A Kail, Link Aviation Devices, 1944-09-12, -
Bellows (18, 19) rock trainer.
2358018 Aviation trainer, Lowkrantz Gunne, Link Aviation Devices, 1944-09-12, - improves altimeter & rate of climb; prevents damage to these instruments in some cases
2359484 Navigation instrument, Jr Edwin A Link, Harold A Marsh, Link Aviation Devices, 1944-10-03, -
Much more reliable and user friendly than prior art aircraft sextants.
Sextant (see: Navigation)
Also See patent 2349506,
Link A-12 Sextant
2359866 Variable speed drive apparatus, Lowkrantz Gunne, Link Aviation Devices, 1944-10-10, - for trainer course plotter - introduced for the C-3. Prior course plotters required disassembly to change gears.
2364539 Celestial navigation trainer, Edwin A Link, (not assigned), 1944-12-05, -
For training aircraft navigators in celestial nav.
Makes use of a number of the 2310031 collimators (300) for the navigation stars that will be sighted by the aircraft sextant. The other stars are just point light sources on the hemisphere and not used for sextant sighting.
2360882 Leveling device for aviation trainers, Harold A Marsh, Link Aviation Devices,1944-10-24, - to get in and out
2385291 Training device, Edwin A Link, 1945-09-18, - projects image of ground that moves in response to the trainer controls.
2391245 Ball bearing, Karl A Kail, Link Aviation Devices, 1945-12-18, -
When the trainer is mounted on a counter weighted arm so a large strong bearing is needed.
2396857 Training device, Raymond E Kittredge, Link Aviation Devices, 1946-03-19, -
for flying plane using RADAR.
lots of servo motors and bellows.
2417554 Locking device for aviation trainers, William D Jones, Link Aviation Devices, 1947-03-18, - simpler locking than prior art patents: 2360346 & 2360882 (see above)
2420048 Training device, Harold A Marsh, Link Aviation,1947-05-06, -
improved over patent 2364539 celestial navigation trainer
2435502 Radio signaling means for aviation trainers, Gregor L Lang, Link Aviation, App: 1942-04-29, W>W.II, Pub: 1948-02-03, cites 14 patents.
Plotter (12) shows path on map, DF Loop (69) on trainer roof is functional.
For A-N radio range and bearing on beacon stations and blind landing 75 Mhz marker beacon and RDF.
Also see Radio Direction Findings (RDF), ARN-89.
2442297 Training device, Jr Edwin A Link, App: 1939-01-14, SECRET, Pub: 1948-05-25, - Star projector for Celestial Navigation (Wiki) - See Navigation\Celestial Nav Trainer.
2443076 Simulated directional gyro for aviation trainers, Lowkrantz Gunne, Link Aviation, 1948-06-08, - couples to the trainer stand
2450239 Aviation trainer, Karl A Kail, Link Aviation, 1948-09-28, -
Tachometer & manifold pressure simulation
2450261 Training equipment for aviators, Russell L West, Link Aviation, 1948-09-28, -
Simulates problems related to multi-engine balance
Bellows and linkages
2463583 Radio beacon keying circuit, Stanley B White, App: 1944-12-15, W.W.II, Pub: 1949-03-08, -
Works with patent 2352216 (20) transmitting antenna array for A-N radio range navigation trainer.
2475366 Natural horizon simulating device for training purposes, Jr William W Wood, Lowkrantz Gunne, Link Aviation, 1949-07-05, - for celestial navigation simulator
The Horizon simulator is just in front of the sextant operator, the hemispherical dome is the star field for the sextant.
The inset image is of a ship but this would also apply to aircraft.
2467899 Adjustable indicating structure on a measuring apparatus, Lowkrantz Gunne, Link Aviation Devices, 1949-04-19, - for reading a sextant
2471439 Device for simulating runway localizer (Wiki) and glide path beams for "blind landing" training purposes, Grant C Melvin, Peter C Jones, Stanley B White, App: 1945-11-14, W.W.II, Pub: 1949-05-31
2485301 Wind drift instrument, Lowkrantz Gunne, Karl A Kail, Link Aviation, 1949-10-18, -
for use with trainer.
2485331 Apparatus for training aircraft personnel in radio navigation, Ahlert P Stuhrman, Charles W Mckee, Link Aviation, 1949-10-18, -
Improvement on prior Link patent 2119083.
Also See Radio Direction Finding
2548888 Radio range training device, Peter C Jones, 1951-04-17, -
Lower cost, for use with Link Trainer.
Air Motor Patents, Rotary Vane
1594132 Rotary machine, Alfred C Stewart, 1926-07-27, -
Vane type air motors are used on air powered impact wrenches, see YouTube Torque Test Channel.
1668532 Rotary machine, Alfred C. Stewart, 1928-05-01, -
2324903 Elastic fluid compressor or motor, Beckman Richard, 1943-07-20, -
Air Turbine Patents
1061205 Apparatus for propelling fluids, Ira H Spencer, Spencer Turbine Cleaner Co, 1913-05-06 - air turbine
1669581 Device for causing flow of fluid, Spencer Turbine Co, 1928-05-15
3" H2O static, 1/4 HP, 225 CFM, 115 VAC
1708907 Check valve
1958023 Pressure regulator, Spencer Turbine Co, 1934-05-08 - bellows & throttle valve
I wrote about the Link Collimator for the Optics web page but then moved it to this page. But in Feb 2023 I was luck to get an example of the Link Collimator so added this paragraph for it.
In order to train navigators in the use of the averaging sextant (e.g.: A-10, Periscopic, Wiki) which is more accurate than the old single reading type sextants. These were developed for aircraft, but also used on ships. Link invented a complete training system that could be integrated with their aircraft trainers. The trainer uses a dome structure, similar to a Planetarium (Wiki), except the stars can not be projected on a screen because the angle between the horizon and the star would depend a lot on the position of the observer. To get around this the navigation stars are formed using a collimator (Optics:collimator, Wiki) so that the star image appears to be at infinity.
I expect properly aligned binoculars will show a single point of light when looking into the collimator.
In the center of the objective lens is a small projection with a mirror at 45 degrees to the main axis. Off to the side is a small lamp. This lamp, when reflected by the small mirror, sends a beam of light along the centerline of the collimator objective lens.
By inserting a standard (Focal Length: TBD) 1-1/4" astronomical eyepiece lens into the space normally used by the star image source the spot of light from the alignment lamp might be adjusted using the mounting screws so that it's centered. Note that when installed at one focal length behind the objective a 1-1/4" eyepiece will be focused at infinity, so it can not be use to observe the sextant position about ten feet from the objective. So it's questionable how the eyepiece would be used.
Next the three alignment bolts are used to align the main collimator. Is that done with the alignment lamp or the star image?
If you know anything about the small projecting 45 degree mirror please let me know.
Part No 24800 ?
Serial No. 80761
O.A. Length: 14-1/2"
Weight: 10 lbs
Objective dia: 4-1/2"
Illuminator O.D.: 1-1/4"
Mirror dia. (guess) 3"
Star image: G-E, Mazda 51; 6 - 9 Volts
Alignment: 6V @ 200mA
My Link Collimator.
Fig 1 ObjectiveSmall projecting mirror protection cover in place
Fig 2 Mirror Protection cover removed
Fig 3 Bottom Labels
Fig 4 Broken Star Image Lamp
(filament is good, base crushed)
Fig 5 WARNING Easy To Break Parts
Fig 6 Star reticule in 1-1/4" dia housing
New GE 31 lamp installed, old broken lamp shown
Fig 7 (wait till dark) Artificial Star Image
Camera focused at infinity.
Camera on Monfrotto 55 tripod.
Fig 8 Next day, still on tripod, changed to auto focus otherwise the image would be totally out of focus
Fig 9 Try with Binoculars
Below photos courtesy of Jerry Jackson
Note that neither the Jerry Jackson nor the 2310031 patent has the alignment mirror and lamp.
2310031 Collimator, Lowkrantz Gunne, Link Aviation Devices, 1943-02-02, - testing sextants 2364539 Celestial navigation trainer, Edwin A Link, (not assigned), 1944-12-05, -
For training aircraft navigators in celestial nav.
Makes use of a number of the 2310031 collimators (300) for the navigation stars that will be sighted by the aircraft sextant.
There are more patents in the Link Trainers section of this web page.
Link D-2 Celestial Trainer"
These were also called A-N Radio Beacons (Wiki, Ref 49, Ref 50) These are different from the Non-directional Radio Beacons (Wiki: NDB) which are omnidirectional. One of the main things the Link Trainer did was train pilots in how to fly A-N Radio Beacons.
Transmitter & Antenna
The transmitters operated in the Low Frequency range between 190 and 535 kHz, i.e. just below the Medium Frequency AM broadcast band.
The A-N beacon transmitters used crossed loop antennas and later an Adcock (Wiki) type antenna to form directional beams.
Rotating Beacon Light on Tower
1700226 Unattended beacon, Frank R House, Sperry Gyroscope, 1929-01-29, - automatic changeover when active lamp fails.
1753144A Unattended beacon, Preston R Bassett, Sperry Gyroscope, App: 1923-06-20, Pub:1930-04-01, - rotating horizontal beam with mirrors to make vertical beam.
1864436 Landing field light, Frank R House, Sperry Gyroscope, 1932-06-21, -
If arc light (64, 65') fails then incandescent lamp (29) is made active.
A pair of Westinghouse 2kW lightening plants (AC generators) were used with many automatic fail safe measures.
1422027 Automatic electric generating unit, William W Bucher, Kohler, 1922-07-04, -
1448190 Automatic electric-lighting unit, William W Bucher, Kohler, 1923-03-13, -
1481919 Electric power system, Thomas J Mcgill, Westinghouse, 1924-01-29, - farm lighting plant
When heavy loads are needed the engine (1) drives AC generator (2).
At night or when the load is light 32V electric motor (9) is powered from battery (22).
In order to start engine (1) the clutch (4) is closed and motor (9) turns over engine (10.
PS I had an Allis Chalmers B12 garden tractor with a DC generator to charge the battery.
But for starting the generator was powered from the battery and acted as a starter motor.
1590478 Electrical system, Nyman Alexander, Edward B Newill, Westinghouse Electric and Manufacturing Co, 1926-06-29, - Farm Lighting System
Automatic starting (6) of engine (2) which powers the AC generator (1) when load applied.
With a number of self protection functions.
1910427 Method of adjusting radio beacon courses, Diamond Harry, Diamond Harry, US Govt, 1933-05-23, - to improvements in the performance of the double-modulation equisignal type directive radiobeacon - phasing network to tweak beam direction
1913918 Triple-modulation directive radio beacon system, Diamond Harry, Frank G Kear, US Govt,1933-06-13, - 30 degree steps
1923920 Course shift-indicator for the double-modulation type radiobeacons, Diamond Harry, Francis W Dunmore, US Govt, 1933-08-22, -
1961206 Twelve-course, aural type, triple modulation directive radiobeacon, Diamond Harry, US Govt, 1934-06-05, - lobe switching & 850, 1150, 1450 Hz tones
1989086 Radio warning signal, Diamond Harry, Francis W Dunmore, US Govt,1935-01-29, - NDB - not sure how it's an anti-collusion system
1992197 Method and apparatus for a multiple course radiobeacon, Diamond Harry, US Sec of Com, 1935-02-26, - 6 lobes
2110761 Automatic volume control for radio receiving apparatus, Diamond Harry, Francis W Dunmore, US Govt, 1938-03-08, - beacon mod @ 65 & 86-2/3 Hz
2120241 Radio guidance of aircraft, Diamond Harry, Francis W Dunmore, US Govt,1938-06-14, - landing beam
2121024 Radio transmitting and receiving system, Diamond Harry, US Sec of Com, 1938-06-21, - beacon system,
2172365 Directive antenna system, Diamond Harry, US Sec of Com,1939-09-12, - better night operation of beacon
2179499 Method of blind landing of aircraft, Diamond Harry, US Govt, 1939-11-14, -
1. radiobeacon off end of runway
2. provision to circle airport - beacon at center of airport
3. lateral and longitudinal guidance - narrow beam
4. vertical guidance -
These were first installed in pods that could be merged with the aircraft or attached to a bomb rack. In either case there was a need to make the unit small in diameter and compact. The AN/APS-20 (Wiki) was an early airborne radar. The early versions operated in S-band (8' dia. radome) and the APS-20E operated in X-band. There were many variants of the APS-20 in service starting in 1945 and lasting for a few decades.
2407305 Scanning device, Langstroth Hall, Fred C Wallace, Sperry Gyroscope, App: 1942-04-10, W.W>II, Pub: 1946-09-10, - conical scan after locking on target
2505424 Radar scanner antenna feed, Tomlinson I Moseley,App: 1946-08-27, W.W. II, Pub: 1950-04-25, - waveguide feed horn
2543188 Radar scanner apparatus, Tomlinson I Moseley, App: 1947-04-15, W.W. II, Pub: 1951-02-27, -
2544433 Radar scanner unit, Tomlinson I Moseley, App: 1946-05-27, W.W. II, Pub: 11951-03-06, -
To counter aircraft ground troops can use RADAR directed guns and missiles. The aircraft can defeat this by using Radar Warning Receivers which let the pilot know the rough bearing to the threat, what kind of threat it is and if a missile has been launched. In some cases radar suppression flights (Ref 11) might launch an Air to Ground Missile (Wiki: AGM) which can home on the RADAR signal such as the Shrike (Wiki) or HARM (Wiki).
Another aspect of EW is jamming (Wiki). During W.W. II communication jammers (Hexjam) were developed, but typically were not used since it was more valuable to listen in to learn what the enemy was up to. This included breaking their secret codes and ciphers. I have a number of pieces of military voice security equipment (CryptoM) and key loading equipment (CryptoM).
While learning about the U-2 (Wiki) I bought a used copy of the book "Spyplane: The U-2 History Declassified", Norman Polmar, 2001. It turns out the prior owner was Ed Lovick (Amazon, YouTube) who had added newspaper clippings and post-it notes related to stealth. Ed holds 5 patents. also see Ref 53 & Ref 54.
The belief what that Russian RADAR had a known range and if you assumed that they set the vertical antenna angle such that the bottom of the beam was near the surface of the Earth then the top of the beam at the maximum range would be, AFAICR, about 50,000 feet. So if a plane was flying that high it would not show up on their RADAR. This was the basis of the U-2. It turns out that the Russians did not do that, and instead aimed their antennas up and were tracking all the U-2 flights. But they could not shoot them down so kept that a secret. (Aerial Photography Ref 7).
Surface to air weapons that are RADAR guided have a kill envelope, plotted with elevation on the Y-axis and distance from the RADAR on the x-axis. If an aircraft avoids flying in these upside down tear drop shapes then it's unlikely they will be shot down by that system. At the time the U-2 was flying above the kill envelope of the then current Soviet anti-aircraft systems.
It turns out that because the soviets pointed their RADAR antennas up a little and they could easily see Power's U-2 (Wiki) so a number of programs were started to make the U-2 less visible to RADAR. That also led to the A-12 (Wiki) and SR-71 (Wiki) which had very low radar cross sections (Wiki).
Prior to RADAR being so common work was done to make planes harder to see as they approached German submarines during W.W.II. Since the plane appeared as a black shape against a light background the answer was to install lights (Wiki: Yehudi lights) that had their brightness automatically adjusted to match the sky brightness. This allowed a plane to get within 30 seconds of flying time before being spotted. This allowed attacking the sub before it had time to submerge.
There was a Navy program to light ships to make them harder to see (YouTube: Not What You Think: Why Military Ships are Gray and Icebreakers Red? @12:09 - Counter Illumination.
Also see Gunships above for why in W.W. II movies they are doing exercises to shorten the time to dive.
3096494 Microwave amplitude modulator, Jacobs Harold, Frank A Brand, James D Meindl, Michael A Benanti, Army, 1963-07-02, -
3568194 System for degrading radar return signals, Robert G Wilson, Gordon L Burton, Edward N Skomal, US Air Force, App: 1967-10-11, Vietnam, Pub: 1971-03-02, - active method makes target appear as in incoherent object.
4019699 Aircraft of low observability, Robert W. Wintersdorff, George R. Cota, Teledyne, 1977-04-26, - a flying wing, B-2? canted tail fins a la SR-71.
4066226 Airfoil, reduced profile, "Y" flow, hybrid, Kenneth Edmund Fischer, 1978-01-03, - nothing to do with stealth.
4117485 Radar target cross section control method and means, Benjamin B. Gorr, Richard B. Mack, US Air Force, 1978-09-26, - "... reduction or enhancement..."
4301456 Electromagnetic wave attenuating surface, Edward Lovick, Jr., Lockheed, 1981-11-17, - uses a Teflon - Aluminum foil sandwich to provide isolation between a Tx and Rx antenna on an aircraft.
5488372 Electronic avoidance configurations, Kenneth E. Fischer, Priority: 1976-04-09, TOP SECRET, Pub: 1996-01-30, - not just mirrors, but focusing mirrors to minimize the signal strength at the illuminating source location.
UAV Classification types (Wiki)
20 - 55
55 - 1320
Hermes 450, Bat,
V-247, MQ-8, TB2,
MQ-9, RQ-4, MQ4C, X-47,
By Size/weight: Micro air vehicle (Wiki), Miniature UAV (Wiki). Modern model RC aircraft have navigation and flight control systems (Wiki) that are very sophisticated, small and light weight.
The Gyrodyne QH-50 DASH Drone Helicopter is a full size UAV. In the movie DUNE (Wiki, IMDb) in the future on another planet they use Ornithopters (Wiki). See the AeroVironment Nano Hummingbird (Wiki) which is an R&D item, not fielded as far as I know.
Black Hornet Nano (Wiki)
5035382 Rapid assembly aircraft for ground surveillance, Peter B. S. Lissaman, W. Ray Morgan, Martyn B. Cowley, Charles J. Sink, William D. Watson, Aerovironment, App: 1989-04-17, Pub: 1991-07-30, 244/190; 244/79; 446/34; 348/144; 244/3.12; 244/120 - maybe the RQ-11 Raven?
5100357 Toy aircraft and method of flight control thereof, Tyler MacCready, Martyn B. Cowley, Taras Kiceniuk, Jr.Parker MacCready, Walter R. Morgan, Matthew R. Kruse, Aerovironment, App: 1990-05-10, Pub: 1992-03-31, 446/61; 446/35; 446/68 - seems like a lot of manpower just for a toy.
There are various aspects of this.
1. Ways to detect and locate the UAV: RADAR, Passive RF, EO/IR, sound
2. How to stop the UAV: Jamming, conventional weapons (explosives, lasers) (not suitable around civilians), Kinetic weapons (Wiki) (also may not be suitable around civilians), Nets & party spray string (DARPA).
leidos Counter Drone Technologies - High Power Microwave - this might be more than jamming, i.e. the idea might be to destroy the electronics just behind any antenna.
KVSG-6 Drone Jammer - 2.4 - 2.5 GHz WiFi, GPS L1 & L2, 860-920 MHz ISM, $33-434 ISM, 5.8 GHz ISM
20200130835 Detachable projectile module system for operation with a flying vehicle, Devin Donald LeBaron, David Earl James, Kendall James FOWKES, Jon Erik Knabenschuh, Eric James FOWKES, Justin Craig HUNTINGTON, Fortem Technologies, 2020-06-30, -
11255643 System for countering an unmanned aerial vehicle (UAV), Wen Jun Edwin Ang, Yong Peng TAN, Juan Kiat Quek, Ce Yu POO, Yuen Hoong Benedict Woo, Cheng Hok AW, Advanced Material Engineering, 2022-02-22, - makes use of a special 40mm round
- cites and described prior art -YouTube: Australian 'drone killer' system Slinger heading for Ukraine | 7.30, 6:37 - (Wiki: Slinger, M230 Auto Cannon) which uses 30x113 ammo (Wiki).
2372383 Projectile, Martin L Lee, 1945-03-27, - probably a 5" gun round that deploys a metal net - not suitable around civilians
9175934 Auto-injector countermeasure for unmanned aerial vehicles, James C Kilian, Lockheed Martin, 2015-11-03, - stings like a bee injecting an electrically conductive fluid
10399674 Systems and methods countering an unmanned air vehicle, Wayne Goodrich, Insitu Inc, 2019-09-03, -Fig 6 wild animal net gun - looks like the DARPA unit (not string)
7546794 Adjustable multi-caliber, multi-feed ammunition container, J. Stephen SarlesDaniel R. LandwehrLeslie E. Erickson, EOS Defense Systems, 2009-06-16, - box can hold: 200 rounds of .50 cal, 96 rounds of 40mm or 400 rounds of 5.56/7.62.
7802391 Rounds counter remotely located from gun, James P. Quinn, Jason L. Seelye, Mark Prichard, James T. Dillon, EOS Defense Systems, 2010-09-28, - by placing the rounds counter on the azimuth table it works for different model guns.
7921761 Dual elecation weapon station and method of use, James P. Quinn, EOS Defense Systems, 2011-04-12, - Slinger (What does elecation mean? Let me know) - cites 46 prior art patents, cited by 98 patents. gimbaled weapon system (GWS)
7946213 Dual elevation weapon station and method of use, James P. Quinn, EOS Defense Systems, 2011-05-24, -
Flakpanzer Gepard (Wiki) - works well against the Shahed-136.
When I was in high school (1957) radial engines (Wiki) were the standard aircraft engine. I think it was Palo Alto high school had what may have been a Wright R-1820 (Wiki) on a stand with wheels to train students. Pratt & Whitney also made radials like the R-1340 (Wiki).
I was reminded of this by a YouTube: Sikorsky S58 Starts the engine like an OLD car, 2:11 -
S-58/H-34 (Wiki) R-1820-84 Cyclone. The sound is great.
N867 registration -
The AI shield Vbat-128 was introduced in 2021, see Jane's: Navy League 2021: Martin UAV officially unveils V-Bat 128 UAV.
At the nose is a trillium HD80 gimbal, (the videos are impressive, but should be compared to the DJI). These come in four flavors
Most of the aircraft photos I've taken are of things flying over my house or at the local airport. Taken by steeping out the front door and looking up.
See: Ukiah Airport and scrolling down.
Before the advent Electronic Aids to Navigation pilots used dead reckoning (Wiki) to know where they were and how to get where they wanted to go. In the days of sailing ships all educated men knew spherical trigonometry (Wiki) by heart because that was at the heart of navigation on a sailing ship. Spherical trigonometry is no longer taught in schools. Dead reckoning is still taught to pilots and aircraft navigators, but I suspect it's of a second or third order importance where GPS is the current gold standard.
This is a combination of the Computer Mk 8B, Stock No. 1152-000-000, Mfrs Part No. FNA-314A and a graphical drift calculator all in one instrument.
The E6-B Flight Computer
Fig 1 The Mk 8B has the large arrow set to 60 Miles at 1 hour.
But the wheel moved so needs adjustment.
Fig 2 Drive wheel and slide
Fig 1 Carry case with drift instructions.
3112875 Computer slide construction, Ben Van Caro, Burton L Fredriksen, Felsenthal Inst, 1963-12-03, -
aimed at one handed operation & low cost of manufacture
3131858 Computer, Louis A Warner, 1964-05-05, -
3231188 Computer, Louis A Warner, 1966-01-25, -
3361346 Computing device, Louis A Warner, 1968-01-02
How to Use the Manual E6B Flight Computer, 9:08 -
Aircraft-to-Carrier Homing.pdf - starting at page 4 info on the E-6B Whiz Wheel.
Scott Manley: I Passed A 21st Century Aviation Exam With an 80 Year Old 'US Army Air Forces' Computer, 13:40 -
2478981 Navigation apparatus, Jr Waldo Emerson Randall, 1949-08-16, - a circular slide-rule type device for doingcelestial navigation.
RQ-4 Global Hawk, 13:00, -
3703998 Drone aircraft with telescopic fuselage, Peter F Girard, Teledyne Ryan Aeronautical, 1972-11-28, - an early version designed to be carried by a bomber (B-52?)
14 March 2023 added this paragraph because Russia shot down one of these over the Black Sea (near Ukraine) (Wiki: USAF)
Added this paragraph after watching the YouTube: The Most Secret US Helicopter?, 11:00 -
Started out with Piasecki Helicopter (Wiki) 1940 - 1956. Frank Piasecki opened Piasecki Aircraft in 1959 (home page, History Poster).
Piasecki Helicopter sold to Boeing Vertol (Wiki) in 1960 (without Frank).
2507993 Tandem rotor helicopter, Frank N. Plasecki, Plasecki Helicopter Corp, App: 1946-12-16, W.W.II, Pub: 1950-05-16, - HRP Rescuer (Wiki)
By USN - U.S. Navy Naval Aviation News April 1947 , Public Domain, https://commons.wikimedia.org/w/index.php?curid=5000878
D146984 Helicopter, Frank N. Plasecki, Plasecki Helicopter Corp, 1947-06-24, -
D153316 Helicopter, Frank N. Plasecki, Plasecki Helicopter Corp,1949-04-05, - H-16 Transport (Wiki)
YH-16 with Roll in - Roll out cargo compartment.
Wiki File: Piasecki YH-16 helicopter in flight.jpg
2552864 Tandem rotor helicopter, Frank N. Plasecki, Plasecki Helicopter Corp,1951-05-15, -
In Fig 1 there is a propeller (20) to cool the piston engine (16). PH-26
In Fig 2 the piston engine (40) does not show cooling, maybe because turboshaft engine
D187895 Rotary wing aircraft, Leon L. Douglas, Vertol Aircraft Corporation, 1960-05-10, - CH-46 (Wiki)
D188146 Rotary wing aircraft, Leon L. Douglas, Vertol Aircraft Corporation,1960-06-07, - CH-47 (Wiki)
40 mm -
Aerial Photography - DJI Mavic mini 2
Barometers & Altimeters
Black Box -
China Lake Patents - Sidewinder, Proximity Fuze & Others
Drop Zone Assembly Aid System -
Electro-Optical Gadgets - Grimes AN-3038-2A aka C-5A UV Cockpit Light - MODEL 9379640 Cockpit light -
FN FAL - Types of Sights -
Gibson Girl AN/CRT-3B life boat survival beacon transmitter
GRC-206 Program Pacer Speak & MT-6250 - Forward Air Controller
Gyrodyne QH-50 DASH Drone Helicopter -
Gyroscopes - Norden Bomb Sight
MD1 Star Tracker Navigation System
MIL-S-5807A Sextant, Aircraft, Periscopic
Mk 20 Mod 4 Gun-Bomb Sight
Navy Mk. 18 Gun Sight
Outdoor Intrusion Alarms - Vietnam era
Radar Warning Receivers - AM-6536 - AN/ALR-54 LAMPS
Radio Direction Finding -
Radiosonde - Area I Altius-600 Drone & ADM-160 MALD (Wiki)
RPG-7 Rocket Propelled Grenade Launcher
RWR - RADAR Guided & Laser Guided
Ruger SP101 Laser Sight
SDU-5 distress strobe beacon & Battery Adapter.
Sonobuoys - Underwater Locator Beacons & Roswell Connection - CRT-1B
StormScope - lightening mapper
Torpedoes - "Range" problems with torpedoes, battleship guns, depth charges, horizontal bombing
Ukiah - Helicopter photos from my house - and scroll down, Kaman K-Max,
Ultra Violet light -
Aircraft Cockpit UV Instrument Lights -
Wallace & Tiernan FA 181 Altimeter, Barometers & Altimeters, Aneroid (aircraft instruments)
There are many more aircraft books that are specific to Sonobuoys.
Ref 01 Air Navigation, Weems, 1943 -
Ref 02 The United States Air Force in Southeast Asia: Development and Employment of Fixed-Wing Gunships 1962-1972, Jack S. Ballard, 1972 -
Ref 03 Aviation Electronics, Keith W. Bose, 1977 -
Ref 04 The Deadly Fuze: Secret Weapon of World War II, Ralph B. Baldwin, 1980 -
Ref 05 The History of Dive Bombing, Peter C. Smith, 1981 -
Ref 06 Dive Bomber!, Peter C. Smith, 1982 -
Ref 07 Skyraider: The Douglas A-1 "Flyhing Dump Truck", Rosario Rausa, 1982 -
Ref 08 Flying without Wings: A flight simulation manual, Paul Garrison, 1985 -
Ref 09 Spyplane: The U-2 History Declassified, Norman Polmar, 2001 - (prior book owner Ed Lovick who wrote RADAR Man, father of Stealth) -
Ref 10 Boyd (Wiki): The fighter pilot who changed the art of war, Robert Coram, 2002 - Fighter Mafia (Wiki), Energy–maneuverability theory (Wiki),
Ref 11 First in, Last Out: Stories by the Wild Weasels, edited by Colonel Edward T. Rock, USAF, 2005 -
Ref 12 The Ears of the Air ASW: A History of U.S. Navy Sonobuoys, Holler, Horbach & McEachern, 2008 -
Ref 13 Radar Man: A Personal History of Stealth, Ed Lovick, 2010 - his time at Lockheed skunk works
Ref 14 Aircraft Versus Submarine 2004 -
Ref 15 Ed Heinemann 1980 -
Ref 16 By Sea, Air, and Land 1992
Ref 17 Naval Airborne Ordnance NAVPERS 10826-A 1958 (1961)
Ref 18 United States Naval Aviation, 1910-1995, 1997
Ref 19 Navy Attack: Spads, Scooters & Whales 1990 - excellent photos
Ref 20 America's Pursuit of Precision Bombing, 1910-1945 - 1995 - about how horizontal bombing never worked
Ref 21 Fighter Combat: Tactics and Maneuvering Hardcover – November 14, 1985 by Ref 26 Patterns and Predictability: The Soviet Evaluation of Operation Linebacker II by Dana Drenkowski & Lester W. Grau -
Ref 27 The Hunter Killers: The Extraordinary Story of the First Wild Weasels, the Band of Maverick Aviators who Flew the Most Dangerous Missions of the Vietnam War, Dan Hampton,2015
Ref 28 War in the Forth Dimension; US Electronic Warfare, from the Vietnam War to the Present, Dr. Alfred Price, 2001 -
Ref 29 National Electronics Museum - Library & Archives -
Ref 30 The Radio Manual, Sterling (History of the Original W3DF), 1943, - includes radio aids to navigation
Ref 31 T.O. No. 08-15-1, Army Air Forces Radio Facility Charts, Jan 1946, - data on A-N radio stations in the U.S.
Ref 32 Flight Briefing for Pilots Vol 3, Radio Aids to Air Navigation, Birch & Bramson, 1978, ISBN: 0-87165-008-8, - VHF DF, ADF, VOR, DME, ILS, NDB
Ref 33. Instrument Refresher Course Precourse Workbook (DTIC: a156708.pdf), Major David R. Vandenburg, 1985 - chapter on the CPU-26A/P
Ref 34. Hell Divers: US Navy Dive-Bombers at War, John F. Forsyth, 1991 - personal experiences of W.W. II flying Hell divers (Wiki), F6F Hellcats (Wiki) on the Intrepid (Wiki).
Ref 35. U.S. Navy Dive and Torpedo Bombers of WWII, Barrett Tillman & Robert L. Lawson, 2001 -
Ref 36. YouTube:
Why are Modern Fighter Jets Slower than 1960s?, 9:10 - Combat range & combat turningWhy the "Sound Barrier" Had to be Broken, 18:31 -
Ref 38. John Paul Stapp: The Fastest Man On Earth, 8:48 - Origin of Murphy's Law
Ref 39. The Navigator (801 pages) Vol 7 No.3 pg 35 "D-2 Celestial Trainer" Capt. John C. Allison - 1 page blurb
Link D-2 Celestial Trainer"
Ref 40. The Pentagon Wars: Reformers Challenge the Old Guard by Colonel James G. Burton, 2014 - Book has a lot of information about aircraft and Boyd (Ref 10). Got this book after seeing the movie by the same name (IMDB, Wiki, YouTube). There's an appendix with a reading list compiled by Boyd. Pierre Sprey (Wiki), also mentioned (I think in this book) is the concept of OODA (Wiki).
Ref 41. Like Charlie Wilson's War (IMDB, Wiki) this more a documentary than movie. Based on the book Charlie Wilson's War: The Extraordinary Story of the Largest Covert Operation in History (Wiki, Video). Operation Cyclone (Wiki) 1979 - 1992 CIA in Afghanistan.
Ref 42. Also see:Ghost Wars: The Secret History of the CIA, Afghanistan, and Bin Laden, from the Soviet Invasion to September 10, 2001 (the day before 9/11), pub 2004 (Wiki) -
Ref 43. The Warthog and the Close Air Support Debate, Douglas N. Campbell, 2003 -
Ref 44. Why the F-16 Was Designed to be UNSTABLE, 14:04 - The Fighter Mafia (Wiki) did not like loosing dog fights in Vietnam.
Ref 45. The Warthog and the Close Air Support Debate, Douglas N. Campbell, 302 pgs - The jurisdiction of the Army is limited to aircraft below a weight limit, so they developed the AH-56 Cheyenne (Wiki) for Close Air Support. The Army also has the AH-1 Cobra (Wiki). Notice that there is not an attack verion of the UH-60 Blackhawk (Wiki). The Air Force developed the A-10 Thunderbolt (Wiki) but did it kicking and screaming since it's not what most of the Air Force does.
Ref 46. Johnson-McConnell agreement of 1966 (Wiki) - replaced the Pace-Finletter MOU 1952 (Wiki) limit on Army fixed wing aircraft of 5,000 pounds with a functional division that gave the Army helicopters and the AF fixed wing aircraft. Also see: Key West Agreement 1948 (Wiki) that defines the jurisdiction of the Army, Air Force and Navy.
Why the US Air Force Installed a Howitzer on a Cargo Plane, 11:35 - @2:23Mk 20 Mod 4 Gun-Bomb Sight in AC-47,
Ref 48. Bombardiers Information File (BIF), 251 pgs (pdf), - E-6B, Pitot-Static System, Gyro-Stabalized Flux Gate Compass, Astro-Compass, Radio Navigation Aids, M-Series Bombsight..., Life Raft Kits and Discipline, One Man Life Raft, Signal Devices (M2, AN-M8), C-1 Life Vest, Vest Type Emergency Kit
Ref 49. America's Abandoned Airways - Strange Arrows in the Ground, 46:50 - Tower with rotating light (w/automatic lamp changer), dual Westinghouse 2kW lightening plants, building with with beacon and route numbers on roof, 12' long x 11' wide arrow head
Ref 50. Arrows Across America - 62 LA-A Grants-Milan Airport: museum
Ref 51. Conduct of the Persian Gulf War: Appendix T: Performance of Selected Weapon Systems, 1992 (a249391.pdf)
Links in table to Wiki. But the paper has observations (problems) related to each system
Ref 52. How a Tiny Hole Caused Dozens of Air Disasters, 12:57 -
F-16 Fighting Falcon AAV
F-111 Aardvark Bradley, Ref 40
Mine Countermeasures ship
F-117 Nighthawk LMCOBS
Naval Gunfire Support
F/A-18A/C Hornet LAV
AIM-9 Sidewinder AAM
F/A-18D Hornet M1A1 Abrams
AIM-7 Sparrow AAM
CH-46 Sea Knight
E-8 JSTARS M270 MLRS & MGM-140 ATACMS
KC-135 Stratoanker MIM-104 Patriot SAM
E-2C Hawkeye EWS
E-3 Sentry AWACS
MH-53E Sea Stallion TWV (Medium)
RQ-2 Pioneer UAV TWV (HMMWV & CUCK),
MV, HMMWV, CUCV
F-4G Wild Weasel, RWR
S-3B Viking Trailblazer
SH-3H Sea King Trojan Spirit
Ref 53. The secret origins of America's STEALTH Black Hawks, 24:22 -Stealth Helicopter (Wiki, Mil History) RAH-66 (Wiki),
Ref 54. Structural Concepts and Aerodynamic Analysis for Low Radar Cross Section (LRCS) Fuselage Configurations, David W. Lowry et al, Sikorsky, July 1978, 140 pages, (ADA058906.pdf) - vertical drag slows climb ability, horizontal lower drag increases top speed; substantial reduction in static stability;
Ref 55. Aircraft Turrets And Defense Tactics | Interesting Historical Facts You Might Not Know | Ep. 1, 56:40 - Sperry ball turret (B17E) was the only effective turret of W.W.II.
Ref 56. Aircraft Turrets And Defense Tactics | Interesting Historical Facts You Might Not Know | Ep. 2, 45:41 - "At the start of W.W. II the AAF believed that the bomber will always get through"
Ref 57. Scientific American, Aug 2021: The Physics and Hype of Hypersonic Weapons, -
Ref 58. The Link Trainer: the Insanely Sophisticated Steampunk Simulator, 28:39 - the origin story seems off. I think the first patent was for an amusement device, nothing serious.
Ref 59. The Steampunk Flight Simulator That Helped Win World War II, 15:00 - Link's father's business related to air powered organs is in the entertainment business area.
AIRCRAFT GUNSIGHTS - as of 2021 link is broken. Too bad since it was a very comprehensive site. Archive.org (10 Aug 2020)
Glenn’s Computer Museum - with some mechanical computation element - Old Bombsights, Gun Sights & Navigation Computers -
National Air and Space Museum - A-1C Gun-Bomb-Rocket (GBR) Sight -
A-1 Skyraider Combat Journal - Byron E. Hukee
The Official Website of the A-1 Skyraider Association
The Able Dogs -
The Pacific War Online Encyclopedia - Dive Bombers - "The best naval dive bombers in the Pacific War could maintain a dive angle of perhaps 70 degrees. A dive this steep could easily build up enough velocity for the aircraft to become impossible to control: As the speed of the air flow across some control surfaces approached the speed of sound, the control surfaces became useless. To avoid this difficulty, and to ensure that the aircraft could pull out after dropping its weapon from an altitude low enough for accurate bombing, dive bombers were generally equipped with some form of dive brake."
ibiblio.org - USN - General References - Aircraft Armament - Mk 14 Gun Sight (requires clean dry compressed air for the gyros) -
PRC68, Alphanumeric Index of Web pages, Contact, Products for Sale
Page Created 27 Aug 2018