by Tommy H. Thomason

Saturday, February 13, 2016

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:

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

Thursday, February 11, 2016

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

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.

Friday, February 5, 2016

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: