By Tommy H. Thomason

Monday, November 17, 2008

Launching Athwartships





















In 1928, catapults on the flight deck were considered obstructions by some but hangar deck catapults were of interest. Aircraft could be launched during recoveries and more aircraft could be launched during a shorter period of time. In order to maintain maximum freeboard at the bow and keep water out of the hangar deck, the launch had to be made sideways. or athwartships. One such catapult was installed on Yorktown. To provide enough length for the launch, the airplane was positioned on a outrigger on one side of the ship. like the early production Hellcat shown above, and then catapulted through the hangar deck and out the other side of the ship as shown here.

















This concept and the installation of arresting gear forward for landings from the bow aft as well as from the stern forward were operationally evaluated and then removed as not being as worthwhile in practice as they had seemed in theory...

Monday, November 10, 2008

Most Accurate Aviation Movie Ever?

Faint praise perhaps, but The Bridges at Toko-Ri has to be in the top three. It was based on a slim novel by James Michener, who was embedded on aircraft carriers in action early in the Korean War.

The only major license taken in the book and repeated in the movie was the use of glamorous jets (Banshees in the book and Panthers in the movie) to drop the bridges. They and their puny bomb/rocket loads would have been used for anti-aircraft defense suppression instead, with Skyraiders doing the heavy lifting. Oh, and the F9F-5P shown here is an F9F-5 with a camera window painted on it - the real F9F-5P nose was 12 inches longer and didn't have four 20mm cannon sticking out the front of it.

Another is a very minor marking error on the actual F9F Panther used in the final scenes. The aircraft number is 209 but the number on the vertical fin is 4. It should be 9. (I checked the airborne footage before the crash landing; it doesn't appear that any number is on the fin of the aircraft being filmed.)


However, in this scene of CAG's crash in 21PP, they've taken the trouble to include Davis barrier straps being dragged as shown in the real barrier engagement of 109D shown above in black and white. In exterior closeups of the cockpits during the landing approach, the barrier engagement post in front of the canopy is extended. Compare it to the following picture, which is of an actual incident (the pilot caught one of the last wires and the barrier operator chose not to lower it).

















It would appear that all of the scenes with airplanes were shot specifically for the movie, with no stock footage of the GB crash or other foolishness. It isn't immediately obvious that the scenes done with models weren't the real thing and they were good enough to win the 1955 Academy Award for Best Special Effects - no CGI back then. And I'm sure that most fighter pilots' wives look like Grace Kelly.

If you haven't seen it or seen it in a while and have any interest in carrier-based Naval aviation history, I suggest that you go buy the DVD from Amazon. Only $10. For men of a certain age, like me, it's also a great movie.

Monday, November 3, 2008

Real Men Don't Need Catapults

That is, if they are flying a fighter with a low wing-loading and a high thrust to weight like the F4D Skyray and they want to go back to home plate...

From the January 1958 issue of Naval Aviation News. The incident occurred in October 1957 during Operation Strikeback in the North Atlantic, with the takeoff on 13 October.

Friday, October 31, 2008

General Purpose F8U

Most of the Navy's jet fighters through the 1950s to a greater or lesser degree were general purpose, in that they could also drop bombs and fire rockets. The F8U was an exception for a few years. It was originally equipped with an integral rocket pack, but this may have been primarily intended as an air-to-air weapon. In any event, it was deleted after the F8U-2 (F-8C).

The F8U-2NE (F-8E) was to have a full air-to-ground mission capability including the ability to fire Bullpup A and B, as shown in this iconic display, as well as Shrike and Walleye. These and conventional bombs up to 2,000 lbs were to be carried on a stores pylon added on each wing. A hump was added over the wing to house the Bullpup avionics.

In September 1963, OpNav deleted the requirement for Bullpup, Shrike, and Walleye qualification from the F-8E "because of cost and mission reassignment," but retained the Zuni and 2,000-lb bomb delivery capability. It does not appear that the Bullpup qualification was ever reinstated. The hump was eventually used for defensive ECM avionics.

For more on F8U Crusader armament changes, see http://thanlont.blogspot.com/2013/03/a-brief-history-of-f8u-crusader-armament.html

Monday, October 20, 2008

1950s Navy Day Fighter Specification

In the early 1950s, BuAer was not of one mind with respect to the specification for a carrier-based day fighter. The class desk officer (equivalent to a program manager), an experienced fighter pilot, thought the best airplane for the mission was simple, light, and maneuverable. Supersonic speed, and therefore an afterburner, was not only unnecessary, but undesirable. He placed a contract with North American for the FJ-4, a substantial modification of the FJ-3 Fury, which was in turn a variation of the Air Force's F-86 Sabre Jet. This would provide the earliest availability of his vision of the optimum day fighter. At roughly the same time, a competition was initiated for a new day fighter, with supersonic speed explicitly not required, among other stipulations to reduce unit cost and complexity. As luck would have it, his tour of duty at BuAer ended shortly after the request for proposal was issued and he left for his next assignment. The RFP was immediately amended in accordance with different views on what was needed in the new fighter. The result was the 1,000 mph F8U Crusader. Both are shown here on Forrestal in 1956 during carrier qualifications. All the FJ-4s produced were assigned to the Marine Corps. A subsequent derivative, the FJ-4B, was procured as an attack airplane to provide a backup to the A4D Skyhawk.

Friday, October 10, 2008

400 MPH! (?)


"On 1 October 1940, the XF4U-1 made a flight from Stratford to Hartford with an average ground speed of 405 mph, the first U.S. fighter to fly faster than 400 mph."

If that was the actual wording of the Vought press release, that's not too misleading. It doesn't claim a world record (it wasn't). It implies that the course was not flown in both directions, a record requirement that would eliminate a beneficial tail wind component*. Moreover, it specifically states that it was a ground speed, not an air speed, which is what really counts in an apples-to-apples comparison of airplane performance. It doesn't describe how, much less how accurately, the beginning and end points of the speed run were determined from an altitude of over 20,000 feet. (At the time, speed records had to be set at a very low altitude. However, top speed for propeller-driven airplanes was attained at altitude. Click Here for examples.) It also doesn't state the engine rating or horsepower used. The distance, about 50 miles, does limit the amount of altitude that could be exchanged for speed and reduces the impact of an error in determining the beginning and end points.


The Navy's Service Acceptance Trials report provides a more accurate measurement of the XF4U's performance: 371 mph at rated power with the specified useful load. (Click the picture for a readable version.) The Navy did wind it up to 402 mph, but with the "radio mast and antenna not installed, the gun holes and handholds faired." There's no mention of what rpm and manifold pressure were used to attain that speed.

To be fair, the XF4U was powered by the X model of the Pratt & Whitney R-2800 engine. Later production models of the Corsair with more developed and powerful R-2800 engines were capable of exceeding 400 mph in level flight at altitudes above 20,000 feet.

Ron Lewis also notes that the Lockheed P-38 Lightning was the first fighter to exceed 400 mph in level flight, making the XF4U the first single-engine fighter to do so. In a quick interweb search, I didn't find a Lockheed or Army Air Forces claim that the sole XP-38—which first flew on 27 January 1939 and crashed about two weeks later at the end of an attempt to set a transcontinental speed record—reached 400 mph in its brief flight test career. It was reportedly capable of that (click HERE). The first YP-38 flew on 17 September 1940, about two weeks before the XF4U's "400 mph" flight, a second chance for the Lightning to have beaten the XF4U to that milestone. Again, I didn't find a report of a claim to that effect. Therefore, although the P-38 was appears to be the first U.S. fighter capable of 400 mph in level flight, Vought might have been correct with respect to the XF4U being the first to actually do it.

* At the same altitude both ways. There was a helicopter speed record set by taking advantage of a tail wind in both directions, but that's a story for another time...

Wednesday, October 1, 2008

Davis Barrier Redux

Blogdog asked about the difference between the Davis barrier and the barricade because he was aware that both involved straps. A detailed explanation is provided in my book, U.S.Naval Air Superiority, but the brief answer is that the Davis barrier was a modification of the existing barrier specifically to stop jet and twin-engine airplanes; the barricade was a subsequent addition to handle situations where the Davis barriers weren't effective. The upper photo is a fit check of an AJ-2 Savage and the barricade. The lower photo is of a fit check of an early version of the Davis barrier. The top strap is the "actuator" and is located where the steel cable was for stopping single-engine propeller-driven airplanes that didn't hook a wire. The steel cable is now lying on the deck. If the jet or twin-engine airplane arrived at the Davis barrier untrapped, the nose gear would snag the top strap. The vertical straps would then pull the cable up as the airplane continued forward, hopefully in time to engage the main landing gear struts and drag the airplane to a stop. A barrier actuator (a simple post, often extended by a spring when the tailhook was lowered) was provided in front of the windscreen to activate the barrier if the nose gear had collapsed.

There was a shortcoming. If the airplane was going too slowly when it hit the Davis barrier, the cable would fall back down before it caught the main landing gear. If the airplane was going too fast, the cable would not get up high enough, fast enough, and the airplane would roll right over it, unstopped. As it turned out, the combination of the Davis barrier and the barricade also proved to be what was needed to safely operate jet airplanes on axial decks, in terms of almost always keeping a crash from involving the people and planes forward of the barricade.

For other posts I've made on the Davis barrier and the barricade, see:

http://thanlont.blogspot.com/2010/12/davis-barrier-one-more-time.html

http://thanlont.blogspot.com/2010/10/barriers-and-barricades-one-more-time.html

http://thanlont.blogspot.com/2008/09/development-of-davis-barrier.html

http://thanlont.blogspot.com/2009/09/when-rube-goldberg-isnt-enough.html

http://thanlont.blogspot.com/2008/11/most-accurate-aviation-movie-ever.html