© Brooke Clarke 2018 - 2022

    Maximum Altitude
        Ultimate Weapon
    Fighter Performance
    Shooting Down
    Close Air Support
    Anti Submarine Warfare
        Link Trainers
    Electronic Warfare
Small UAVs
CPU-26A/P Air Navigation Computer, Dead Reckoning
RQ-4 Global Hawk


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.


Maximum Altitude

This is a consideration that applies to airplanes like the U-2 (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

This is related to Navigation - Gyroscope


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.

Dive bombing goes back as far as airplanes carrying bombs (Ref 5, Ref 6).  The bombsight looks forward and can easily be confused with a gun sight.

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.
YouTube: 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
YouTube: 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. - Aircraft,
Reflector Gunsights used by the US Navy,

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.

Ultimate Weapon

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.

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.


For Aircraft sight patents (gun, bomb, torpedo, Etc.) see: Mk 20 Mod 4 Gun-Bomb Sights: Patents

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 that pushes the bomb outside the prop circle.

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 displayed.
2386839 Bomb
                      displacing gear, George A Bronson, Douglas
                      Aircraft Co Inc, 1942-12-01

Photo from Pacific Aviation Museum -
Douglas SBD view of
                      bombs & bomb racks

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. 

                      Aerodynamic Retarder, Leo J Devlin, Edward H
                      Heinemann, Douglas Aircraft Co Inc, 1949-02-15
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
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

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, -

2949060 Article suspension arrangement for aircraft, Gantschnigg Gottfried Karl, Muehlberger Louis, Marsh White, Albert C Hake, Martin Co, 1960-08-16, - revolver bomb rack

AD Skyraider (later called A-1)
                      Airplane, Edward H. Heinmann & Leo J. Devlin,
                      Jan. 14, 1947

                      Airplane, Edward H. Heinmann & Leo J. Devlin,
                      Jan. 14, 1947

                      Airplane, Edward H. Heinmann & Leo J. Devlin,
                      Jan. 14, 1947
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.


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

Fighter Performance

Boyd (Ref 10) developed the Energy-Maneuverability theory (Wiki: E-M Theory) 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?

Shooting Down

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)


There are many gun sight technologies, see for example the US M-4 rifle list of options including Sights.

After learning about how the Navy used dive bombing after they discovered that horizontal bombing 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
Navy Mk. 18 Gyro Gun Sight - Uses a gyroscope to move the sight line to compensate for lead (Wiki).

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.
Lead Compensating
2407665 Aircraft fire control computer, Carl G Holschuh, Fram David, Sperry Gyroscope, App: 1940-08-01, Pub: 1946-09-17, -
Cited By (9)
Publication number  Priority date  Publication date  Assignee  Title
US2476300A *1941-11-22  1949-07-19  Sperry Corp  Sighting station for remote aircraft turret control
US2502506A *1945-03-27  1950-04-04  United Shoe Machinery Corp  Gun sight
US2520943A *1947-08-05  1950-09-05  Edwin H Ludeman  Computing sight - uses wingspan to figure range
US2550712A *1944-05-05  1951-05-01  Sperry Corp  Gun sight control
US2590954A *1944-08-23  1952-04-01  Gerber Alfred  Sighting device for weapons
US2660794A *1942-09-12  1953-12-01  Sperry Corp  Computing gun sight
US2978177A *1953-05-29  1961-04-04  Sperry Rand Corp  Device for predicting values of a fluctuating system at a predetermined future time
US3039194A *1957-03-05  1962-06-19  Mathema Corp Reg Trust  Control apparatus for anti-aircraft guns or the like
US3289534A *1963-05-22  1966-12-06  Ernst Leitz G M B H Wetzlar  Gun elevation control device

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.

Close Air Support

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  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:

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. 
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.


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 slower 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.

The term gunship (Wiki) has also been applied to helicopters, trucks (Wiki: Gun Truck, Technical) and boats (Wiki: Gun Boat, PBR, PCF/Swift). 

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)

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)

Trivia: Hanger One (Wiki) was the 1930s home for the USS Macon (ZRS-2) (Wiki) rigid airship and has very large hangers built for blimps.  This is where the Air Scouts met in the late 1950s.

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.

Simulators (Wiki)

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

Instrument Panel


Link C-2 Instrument Panel
Link C-2 &
                      C-4 Instructor's Desk


Link C-4 Trainer Link C-2 Instrument Panel Link C-2 &
                      C-4 Instructor's Desk Teaching "blind landing"

Link C-4 Trainer Link C-2 Instrument Panel Link C-2 &
                      C-4 Instructor's Desk

Link C-4 Trainer Link C-2 Instrument Panel Link C-2 &
                      C-4 Instructor's Desk
Yes Gears

Navy layout, Modified C-4
Yes Sim Yes Gears

British layout, Modified C-4
Yes Sim Yes Gears

color coded wiring,
strategic materials subs
Yes Sim Yes Gears
Link C-4 Trainer

more efficient ventilation
zipper inspection panels replaced with the sliding panels
Modern features
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 to the 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 -

                      Combination training device for student aviators
                      and entertainment apparatus, Jr Edwin A 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
2099857 Trainer
                      for aviators, Jr Edwin A Link, 1937-11-23
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.

                      Aviation trainer, Jr Edwin A Link, app:1934-07-26,
                      Pub: 1938-05-31
                      Aviation trainer, Jr Edwin A Link, app:1934-07-26,
                      Pub: 1938-05-31 2119083 Aviation trainer, Jr Edwin A Link, app:1934-07-26, Pub: 1938-05-31, 434/244; 340/979; 340/952; 381/86 -

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.

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
                      Trainer for Radio Range A-N Navigation
                      Recorder, Jr Edwin A Link, 1939-11-14
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

Llink Celestial
                      Navigation Trainer Collimator
                      Collimator, Lowkrantz Gunne, Link Aviation
                      Devices, 1943-02-02
2310031 Collimator, Lowkrantz Gunne, Link Aviation Devices, 1943-02-02, -
Makes a star image at infinity.  See Wiki, Optics\Collimator
testing sextants

                      Recording navigation instrument, Lowkrantz Gunne,
                      Jr Edwin A Link, Link Aviation Devices,1944-05-23,
                      - sextant
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."

Antenna-Minature Radio Range
                              (Automatic) Type M-1
Antenna-Minature Radio Range
                              (Automatic) Type M-1

                      Automatic miniature radio range equipment, Grant C
                      Melvin, Stanley B White, 1944-06-27
2352216 Automatic miniature radio range equipment, Grant C Melvin, Stanley B White, 1944-06-27, -

Sparks-Withington Co.
Works with patent 2463583.

                      Aviation trainer, Edwin A Link, Karl A Kail, Link
                      Aviation Devices, 1944-09-12
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

                      Navigation instrument, Jr Edwin A Link, Harold A
                      Marsh, Link Aviation Devices, 1944-10-03
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.

                      Celestial navigation trainer, Edwin A Link, (not
                      assigned), 1944-12-05
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

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)

                      Training device, Harold A Marsh, Link
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
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.

                      Training device, Jr Edwin A Link, App: 1939-01-14,
                      SECRET, Pub: 1948-05-25 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
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,
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
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
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,
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
















669581 Device
                      for causing flow of fluid, Spencer Turbine Co,
1669581 Device for causing flow of fluid, Spencer Turbine Co, 1928-05-15
3" H2O static, 1/4 HP, 225 CFM, 115 VAC
                      Turbine Co

1708907 Check valve

1958023 Pressure regulator, Spencer Turbine Co, 1934-05-08 - bellows & throttle valve

Electronic Warfare

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.

The belief what that Russian RADAR had a known range and if you assumed that they set the vertical 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.

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 the soviets pointed their RADAR sets up a little and so they could easily see the U-2 (Wiki) so a number of programs were started to make the U-2 less visible to RADAR.  That also let 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. 

Also see Gunships above for why in W.W. II movies they are doing exercises to shorten the time to dive.

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.
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.

Small UAVs

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)

Developed by Prox Dynamics (patents) in Norway, now (2022) part of PRS, VRS.
YouTube: What can a Black Hornet drone do?


 (patents) hakes many models of quad copters.  They are very stable, I'd call them a tripod in the sky.

AeroVironment (Wiki)

Prior to 1989 the company patented scientific instruments aimed at measuring properties of air. Paul MacCready (Wiki) patented some human and solar/electric/hydrogen aircraft.

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.


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.

CPU-26A/P Air Navigation Computer, Dead Reckoning

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.

                      Air Navigation Computer, Dead Reckoning
Fig 2 Drive wheel and slide
                      Air Navigation Computer, Dead Reckoning
Fig 1 Carry case with drift instructions.
                      Air Navigation Computer, Dead Reckoning
3112875 Computer slide construction, Ben Van Caro, Burton L Fredriksen, Felsenthal Inst, 1963-12-03, -
                      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

YouTube: 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 doing celestial navigation.

RQ-4 Global Hawk

Wiki -


China Lake Patents - Sidewinder, Proximity Fuze & Others
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
Gyroscopes - Norden Bomb Sight
MD1 Star Tracker Navigation System
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
Ruger SP101 Laser Sight
Sonobuoys - Underwater Locator Beacons & Roswell Connection - CRT-1B
StormScope - lightening mapper
Torpedoes - "Range" problems with torpedoes, battleship guns, depth charges, horizontal bombing
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: The fighter pilot who changed the art of war, Robert Coram, 2002 -
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 Robert L. Shaw
Ref 22
Threat Warning for Tactical Aircraft: A Technical History of the Evolution from Analog to Digital Systems - Bjorn M. Fjallstam
Ref 23
The Cold War and American Science: The Military-Industrial-Academic Complex at MIT and Stanford - Stuart W. Leslie
Ref 24
Red SAM: The SA-2 Guideline Anti-Aircraft Missile (New Vanguard) - Steven Zaloga
Ref 25
National Intelligence Estimate, Number 11-3-17 Soviet Strategic Air and Missile Defenses 9 Nov 1967
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 -


AIRCRAFT GUNSIGHTS - as of 2021 link is broken.  Too bad since it was a very comprehensive site. (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." - 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