Lockheed P-80A Carrier Trials Mea Culpa

Well this is embarrassing. Once upon a time, I wrote about the Lockheed P-80A carrier trial aboard FDR with this illustration.

I posted the page here along with additional information and photographs: http://tailspintopics.blogspot.com/2011/11/lockheed-p-80a-carrier-trials.html

Yesterday, while providing information to a friend who was writing a book on Landing Signal Officers, I had the opportunity to review the picture I used to establish the presence of the barrier guard in front of the windscreen:

There appears to be a mast in front of the windscreen.

This is another from the same event:

It's a crop from a fairly high resolution scan of an 8x10 picture. There is clearly no mast on the airplane and I suspect that there never was.  What looks like a mast on the first picture is likely something on the superstructure of the island. It is also much taller than it needs to be for the purpose and there doesn't appear to be any supporting structure, particularly desirable for such a tall, thin guard.

Not proof, but it is not present in any of the other pictures taken of this airplane during shore-based testing.

I had concluded that it was a barrier guard (or strictly speaking, a Davis barrier* activator) necessary in the event of a collapsed nose gear) because I was expecting to see one. A scabbed-on guard had been added to the McDonnell FH-1 for its carrier trials accomplished three months earlier and was standard equipment on Navy carrier-based jets until the advent of the angled deck.

My guess is that the P-80 trials were accomplished without a barrier activator by the simple expedient of keeping the deck clear, sort of an early version of the angled deck. But, see Gerald Asher's comment below.

*For a gouge on the difference between the standard barrier, the Davis barrier, and the barricade, see http://thanlont.blogspot.com/2010/10/barriers-and-barricades-one-more-time.html

Grumman F9F Nose Cone Variations

Roy Stafford called my attention to an F9F nose cone change that I hadn't noticed. As often happens, the subsequent research generated enough illustrations for a post.

The original F9F Panther nose cone had a small inlet on each side.

Early during the Korean War, there were incidents of F9F nose cones blowing off following strafing runs. It was unexpected, since the Navy had experienced nothing untoward when evaluating the Panther's 20mm guns. And Grumman didn't either when the Navy asked it to evaluate the problem, right up until the last flight of the planned test program. On that one, Corky Meyer serendipitously got the residual gun-gas conditions just right and blew his nose off, rather far away from Grumman and out over the water, as it happened.

The result was the addition of a vent in the aft end of the nose cone.

The modification was rushed out to the fleet, which accounts for the zinc-chromate primed hood over the new vent in the photo of an F9F-2 above.

This configuration was carried forward to the F9F-5.

Note that the Panther in the above picture is fitted with the barricade deflector in front of the two inboard 20mm cannons.

This is neither an antenna or a handle used to pull the nose cone open as some have speculated. It was added in conjunction with the addition of the barricade forward of the existing barriers on carriers during the Korean War. It kept the inboard barrels from being snagged by the barricade straps during an engagement, which would likely have resulted in the airplane being slewed into the island or the catwalk. (For more on the barricade versus the barrier, see http://thanlont.blogspot.com/2010/10/barriers-and-barricades-one-more-time.html)

The Cougars had a different gun-gas vent. The small inlet and hooded vent were replaced by two open vents, one above the other. (The fairing on the underside of the nose covers an antenna introduced on the F9F-8 and retrofitted to some F9Fs).

The final change was the addition of an in-flight refueling probe.

Douglas A3D-2 (A-3B) Skywarrior Canopy

Celestial navigation is the means of determining one's position on the surface of the earth solely by reference to the position of the sun, moon, planets, or stars. Even into the jet age, it was used by navigators to at least verify a position established by other means. On an airplane, it required a viewing port at which a sextant could be employed to measure the height above the horizon of a selected celestial body.

Kollsman developed the periscope sextant in the late 1940s for high-speed, pressurized airplanes. It featured a small port and sextant mount in the top of the fuselage. When sights were to be taken, the periscope sextant was inserted into the mount. The tip stuck out about an inch above the skin on the airplane.

The port was located in the right-rear clear panel of the canopy.

The crewman using the sextant (see HERE) would sit on the seat at the right rear of the cockpit.

Note that the illustration shows the mount but not the sextant, which was normally stored when not in use.

The last 21 A3D (A-3B) bombers were delivered with a built-in sextant station located over the rearward facing seat (the periscope bubble is protected with a red cover).

These also had the DECM tail in lieu of the 20 mm turret.

Note that the fourth-man seat was relocated at some point.

 I'm not sure that these airplanes also had the right-hand sextant position (at least one did), but for sure it was retained as a backup, at least initially, on most bombers that were retrofitted with the left-hand sextant installation.

Note that there are photographs of A-3Bs with the left-hand canopy sextant installation and the 20mm turret, so it wasn't a retrofit associated with the DECM tail.

At some point, the fourth crew seat was relocated to be over the entry/escape hatch.

I had thought that later KA-3Bs lost the right-hand sextant port but there are several examples with as well as without.  The same is true for the EKA-3Bs since there was at least one with both:

As it happens, this is BuNo 147658 from the block of bombers delivered with the built-in sextant at the rearward-facing seat, which suggests that that the right-hand port was not deleted at the time.

What looks like a Venetian blind in the right-rear clear panel of some A3D-2 (A-3B) bomber/tankers is actually the sense antenna for the AN/ARN-59 DF system. There was a similar but much less prominent antenna in this location for the AN/ARR-15 MHF radio receiver in very early A3Ds. As to its exact configuration...

My overall post on the A3D Skywarrior, Bomber and Versions, is here: http://tailspintopics.blogspot.com/2010/09/mighty-skywarrior.html

Grumman A-6B Iron Hand

29 January 2016: Still refining and correcting...

Thanks to Mick Roth and Rick Morgan, who generously provided most of the information and many of the illustrations for this post and then patiently answered my questions. However, this is still a work in progress and subject to their review (and comments from others for that matter).

The escalating air battle during the Vietnam War resulting in the introduction of the big SA-2 Guideline surface-to-air missile (SAM) by the North Vietnamese.

Various counters to it were successively employed by the Air Force and the Navy including electronic warning, evasive maneuvers, jamming, and anti-radiation missiles (ARM). The latter was the most satisfying, because—if successful—it resulted in the destruction of the SAM-site radar. However, the original ARM (the Shrike, which was based on the Sparrow air-to-air missile) had less range than the SAM, making an attack on a SAM site too much of a fair fight.

The solution was the repurposing of the U.S. Navy's big ship-based SAM, the RIM-66/SM-1 Standard Missile, from anti-aircraft to anti SAM-site radar.

Since it was a bit big (pushing 1,400 lbs) for the little A4D Skyhawk then being used for the Iron Hand missions, the resulting AGM-78 Standard ARM missile was to be carried by modified Grumman Intruders, designated A-6B. As the mission equipment, tactics, and missile evolved to be more effective, the A-6Bs were continuously updated. From a modelers standpoint, there were four different configurations (see http://rickmorganbooks.com/a-6b-standard-arm.html for a more detailed and less informal description of airplane and missile).

Mod 0 Early: As shown on the following picture of a test-bed NA-6A, the main external configuration feature was the addition of APS-107A/B* elongated-diamond homing antennas on each side of the upper part of the radome and the lower side of each engine nacelle along with wing and stabilizer tip antennas. Several other small antennas are also circled. The BDA (Bomb Damage Assessment) aft antenna and right side ER-142 DF antenna wouldn't be visible in this picture; the forward BDA antenna and the left side ER-142 antenna could be hidden behind the crew ladder.  Note the LAU-77A/A adapter on the outboard pylon (it is missing the DECM boom that would be on the A-6Bs) that was used to configure it to carry the Standard ARM missile

* The APS-107B was part of the Mod 0 Update. It allowed the employment of the AGM-78B/C/D missiles in addition to the AGM-78A. There was no external change from a modelers standpoint

The APS-107A/B homing antenna:

Forward fuselage antennas:

 There was also an aft BDA stub antenna under the aft fuselage.

Forward facing wingtip antenna:

Mick Roth

Rearward facing stabilator-tip antenna.

The combination of the wing and stabilizer-tip antennas provided 360-degree warning coverage.

Mod 0 Late: The major change was the replacement of the APS-107B with the ALR-55 and the ER-142 with the ALR-57, which was identified as the Mod O/1 Update.

US Navy photo via Tony Thornborough annotated by Mick Roth

The system changes did not affect the external antenna configuration or location with the exception of the Mod O and O Update diamond antennas when the APS-107 system was replaced. These might have been left in place, removed and covered by a blanking plate, or in at least one instance, the engine nacelle antennas were left in place and a radome without antennas installed.

Here the antennas have been removed and covered with a blanking plate.

The most obvious difference between the Mod 0 cockpit and that of an A-6A bomber's was the addition of a row of threat warning lights at the top of the instrument panel, a radar warning instrument for both the pilot and the bombardier/navigator, and the replacement of the B/N's attack-radar control stick (that radar had been removed) with a missile control panel.

Mod 1: This version featured a radome festooned with small antennas and a rudder modified with even more that covered the aft quadrant:

Bruce Trombecky via Mick Roth

The bottom of the rudder was modified to add a bulge that terminated in a faceted antenna mount/fairing; the position light was raised up over it.

The Mod 1 had a different wingtip antenna mount/fairing with an aft antenna added to provide 360-degree coverage without the need for an antenna on the stabilator tip.

 Mick Roth

 

 Photos from Squadron/Signal A-6 Walk Around, Mick Roth captions

The B/N center console reverted back to one more similar to the standard A-6 bomber's, However, the hand controller (slew stick) was only used for Standard ARM and APS-118 functions since the APQ-112 attack radar had been removed from Mod 0 and Mod 1 A-6Bs.

 There were only five Mod 1 A-6Bs: 149955, 151591, 151820, and 152616/7

PAT/ARM: These final versions of the A-6B were only distinguishable from the basic A-6A by the BDA (Battle Damage Assessment) antennas that were retained. They also got back their all-weather attack radar capability. Only three were so modified: 155628/29/30

Masumi Wada as annotated by Mick Roth

 The AGM-78:

National Museum of the United States Air Force

At some point after 1971, the A-6B ejection seats would have been changed from the GRU-5 to the GRU-7:

The major difference is the parachute housing, which changed from a metal "sugar scoop" to a plastic container.

Obscuro provides a 1/72 conversion for the A-6B Mod 1. See HERE. Unfortunately, it does not include the rudder modification but that's no hill for a stepper. Note that the pedestal provided was for the Mod 0 cockpit, not the Mod 1

Darren Roberts (Steel Beach Accessories) is planning to offer 1/48 and 1/32 A-6B conversions.

AGM-78 missiles are available from Eduard in 1/72 and 1/48. They are also reportedly included in the Hasegawa 1/48th Weapon Set and F-4G Wild Weasel kit. A 1/32 AGM-78 is available from AMS Resins but you have to contact Harold directly.

Photo Panthers: F9F-2P vs. F9F-5P

To start with, the F9F-2 and F9F-5 were similar but different in detail. The -5 had an eight-inch plug in the forward fuselage ahead of the engine inlet, a somewhat larger vertical tail, and other more subtle changes. See http://tailspintopics.blogspot.com/2009/10/grumman-panther.html

However, although the -2P and -5P have very different noses, most published pictures and illustrations that are identified as being of -2Ps are actually -5Ps.

The -2P was a depot-level kludge to convert a fighter for the photo-reconnaissance mission. (The F2H-2P was a few months away from operational use and a jet photo-reconnaissance capability was needed in Korea.) The existing nose cone was modified by blocking off the gun ports and adding a flush clear panel in its upper left side. The armament was removed and replaced with a platform for an oblique camera. The nose cone slid forward for access to this camera.

The gun sight was removed and replaced with a camera control panel.

On at least some F9F-2Ps, a camera window was also added on the underside of the nose cone for a downward facing camera,

The nose cone had to be removed for access to this camera.

The F9F-5P, on the other hand, was a bespoke photo-reconnaissance jet procured from Grumman. It had a 12-inch longer nose. Only the front part slid forward. The aft section was accessed by a sideward-hinged door.

The F9F-5P had a flat-panel windows on each side of the nose and two downward-facing windows under the nose. There were various combinations of cameras that could be installed.

The pilot was provided with a large viewfinder in lieu of the gun sight to be able to accurately position the airplane for pictures of the terrain and objects of interest directly below it. There was a small clear panel for the periscope aft of the downward facing windows. There was also one just forward of them in the sliding section for a small movie camera.