By Tommy H. Thomason

Monday, September 22, 2008

Development of the Davis Barrier
















The Davis barrier was created by the Naval Aircraft Factory to replace the conventional barrier that was satisfactory for stopping single-engine propeller-driven airplanes that didn't pick up an arresting cable with the tail hook but not for twin-engine ones like the F7F Tigercat. The problem was that unlike the single-engine situation, where the propeller hit the barrier cable at a very shallow angle and wouldn't cut it, the nose gear of a twin-engine airplane would pull the cable out and forward, so when the propellers got to it, the cable might be at enough of an angle for it to be cut.

This wasn't exactly the situation here, but demonstrated the problem. In this test, the Davis barrier used a one-inch steel cable to actuate the retarding cable that was to snag the main landing gear. Fortunately the PBJ (U.S. Army Air Forces B-25) was unoccupied for the test, because a prop cut the actuating cable and flailed the cockpit with it. This resulted in the actuating cable becoming a canvas strap.

Friday, September 19, 2008

What's That?

It turns out to be an extendable radome housing an H2X radar. The TBM was a control plane for a TDN/TDR drone equipped with a transponder and a TV camera. In 1943. The controller in the TBM could guide the drone to the target using the radar and then dive it into the target using the TV image. Neither the drone nor the target needed to be within eyesight of the control plane.

Although it worked, the Navy fighting the war in the Pacific would have nothing to do with it. At the insistence of the Navy in Washington, the Special Unit involved was finally allowed a 30-day trial in late 1944 against Japanese targets on and near Bougainville and Rabaul that arguably demonstrated the effectiveness of the concept. It was then summarily withdrawn and disbanded. (It's not clear whether the beyond-visual range capability was utilized.)

For a good summary of the TDR (the very similar TDN wasn't used in combat), see http://evanflys.com/tdr-1

The photo is National Archives 80-G-387191.

Tuesday, September 16, 2008

Is This The Grumman F12F?

In a word, No. The F12F designation was assigned to a derivative of the F11F Tiger that was to be powered by the new General Electric J79 engine. The program was canceled in January 1956. (It's not clear if the contract was ever issued but two Bureau Numbers were assigned to the F12F.) The effort to evaluate the F11F with the J79 continued, however. The first of two F11F-1Fs flew in May 1956.

Pictured is the Grumman Design 118 proposed to the Navy in late 1955. It and a subsequent J75-powered proposal were rejected in mid-1956 in favor of the Vought XF8U-3. It is unlikely that the Navy ever considered it seriously enough to assign it a designation since the McDonnell F4H was already on contract.

Saturday, September 6, 2008

Bell XFL-1

I have this weakness for unappreciated "failures" (see Bell HSL and Grumman/GD F-111B below). My latest attempt to provide a nuanced and balanced account of a little known or notorious aircraft program is the one-off Bell XFL-1, a navalized version of the much more successful but frequently maligned P-39 Airacobra.

Order here: Ginter Books

Next, I plan to write a monograph on the XF8U-3, which actually enjoys a great reputation, possibly because it was canceled after initial envelope expansion and before its development was complete and operational evaluation had been accomplished.