Air Groups and Markings in Transition

According to the caption on this National Archives picture of a VC-4 F2H-4 Banshee refueling from a VC-5 AJ-2 Savage, it was taken on 28 January 1955. These aircraft were deployed with Air Group Eight aboard Lake Champlain between 28 September 1954 and 22 April 1955.

At the time, the standard Navy color scheme was an over-all sea blue; it was about to be changed to a light gull gray over white scheme to reduce visual detection at high altitudes. The Banshee sports an experimental natural metal approach authorized in 1952, which was being tested because it saved weight and the cost of paint and painting the aircraft. It proved to not be cost effective because of the increased corrosion control and remediation effort required.

The composition of the air group was also in transition. Up until the mid-1950s, the air groups were assigned two or three day-fighter squadrons and two or three day-attack squadrons. Each squadron was marked with the air group's assigned tail code, in this case "E". Upon deployment, the air group was augmented with detachments from big "composite" squadrons, which provided the aircraft and training for special missions like night attack, night fighter, heavy attack, nuclear weapons delivery, photo reconaissance, and airborne early warning. Each of these squadrons was assigned a two-letter tail code and up until now, retained them during the deployment. For example, the VC-5 Savage is marked the "NB" of VC-5, not the "E" of Air Group Eight. Air Group Eight had also deployed with AD-4Ws from VC-12 (NE), F2H-2Ps from VC-62 (PL), and HUPs from a helicopter utility squadron, HU-2 (UR). The VC-4 Banshees were assigned the air group for all-weather fighter missions and visual delivery of the Mk 8 nuclear bomb (the big pylon that mounted the bomb is visible just outboard of the engine inlet).

In this case, the VC-4 Banshee is now marked with the air group's tail code, E, although on the original print it's clear that "NA", the VC-4 tail code, is on the tip of the vertical fin. It's also marked with a 6xx series number, which is again an extension of standard air group markings, 1xx denoting the first fighter squadron, etc. This picture is therefore an example of the beginning of the fuller integration of the squadrons with the air group that was being accomplished. All-weather fighter and heavy attack squadrons were to become assigned to the air group rather than being detachments from a parent specialty squadron. (With the introduction of the A-6, all-weather attack also ceased to be a detachment.) All detachment aircraft from the remaining specialty squadrons like airborne early warning (VAW instead of VC after June 1956) and photographic reconnaissance (VFP after June 1956) were eventually to be marked with the air group tail code and three-digit numbers on the nose in accordance with a standard scheme for the duration of a deployment.

In mid 1957, the single-letter air group tail codes were changed to two letters. The first letter was either A for an east-coast air group or N for a west-coast air group. Note that the composite squadron tail codes like NB for VC-5 as on the AJ-2 above did not mean it was a west-coast air group...

A-12, The Gift That Keeps On Giving II

A gift to lawyers, in this case.

Back in June, I wrote: "I was surprised when writing the chapter on the A-12 Avenger II program in Strike from the Sea to discover that its termination was still in dispute. Given that it had occurred in January 1991, almost two decades before, that seemed unlikely until I discovered that it involved a $2.3 billion claim by the Navy against GD and Boeing (which now owns McDonnell Douglas, GD's original partner in the ill-fated program). That sum consisted of a demand for the repayment of $1.3 billion in progress payments and $1 billion (and apparently still counting) in interest. Avoidance of the payment of that kind of money justifies the efforts of legions of lawyers.

There were eventually two trials. The contractors won the first in 1995, which the government successfully appealed, and the government won the second in 2001, which the contractors successfully appealed. (A 2002 settlement floundered because the contractors and the government couldn't agree on the value of the "in-kind payments", i.e. goods and services as opposed to cash, to be made by the contractors.) According to today's Wall Street Journal, the U.S. Court of Appeals for the Federal Circuit has finally ruled on the 2007 Claims Court ruling against the contractors, upholding it.

It's probably finally over but I wouldn't bet on it."

And a good thing that I didn't, assuming I could find anyone who would bet against. Here's the latest, from a General Dynamics press release dated 24 November 2009:

The U.S. Court of Appeals for the Federal Circuit today denied a request for a rehearing of the Federal Circuit's prior decision sustaining the government's default termination of the A-12 aircraft contract to which General Dynamics and The Boeing Company were parties with the Navy. General Dynamics disagrees with this most recent decision and continues to believe that the government's default termination was not justified. The company also believes that the ruling provides significant grounds for appeal, and intends to petition the U.S. Supreme Court for review.

Boeing's release was a bit longer:

J. Michael Luttig, Boeing executive vice president and general counsel, today said that the company intends to appeal to the Supreme Court after the U.S. Court of Appeals for the Federal Circuit refused to rehear the company’s appeal in the long-running A-12 case. "We are disappointed in today's decision. The Court of Appeals' decision is clearly wrong as a matter of law and it has broad implications for all forms of government contracting nationwide. As a consequence, I have directed that an immediate appeal be taken to the Supreme Court of the United States," Luttig said. At issue in this litigation, which has been pending over a decade, is the manner in which the Defense Department terminated the A-12 military aircraft program and whether the government owed Boeing (then McDonnell Douglas) and General Dynamics Corporation money for work in progress when the contract was terminated, as well as certain other expenses. The trial court originally ruled in favor of the contractors, but various appeals over the years have delayed a final decision.

As Yogi said, it ain't over 'til it's over.

The Hell It Won't Fit

In the early 1950s, atomic bombs were reduced to a weight that could be managed by tactical aircraft. The lighter of the two options, the Mk 7, was the implosion device but the mechanism was bulky. It could just barely fit under an AD Skyraider with the one of the three tail fins retracted. However, the admirals wanted to also deliver it by jet, with the best candidate at the time being the F2H Banshee. As can be seen from this drawing, there was negative ground clearance under normal circumstances.

I've read that when the F2H-2B was jacked up to load the Mk 7, metal sleeves were put over the main landing gear pistons to keep the struts fully extended and provide a few inches of ground clearance for taxi and takeoff. This fell off at lift off, restoring normal function to the landing gear struts. That may be but on the F2H-3/4 at least, strut extension was accomplished by a system that added additional hydraulic fluid to the main landing gear shock strut to get a few inches of ground clearance for launch with this huge store. A portion of this fluid was automatically bled from the strut on gear retraction to provide the capability to land with the store, presumably not aboard a carrier.  The pilot was provided with a switch to bleed off the remainder for normal strut operation.

This F2H-3 picture shows the extended main landing gear struts. (The weapon is a BOAR, which was a Mk 7 modified with a rocket for greater separation from the explosion, primarily for the benefit of the AD Skyraider community, whose survival after delivering an atomic bomb was otherwise iffy at best.)

 For a bit more on nuclear Banshees, go here

It Seemed Like a Good Idea at the Time V

The Vought F7U-1 was one of the more gimmicky designs ever to fly. Some of the wonderfulness came directly from it being "tail-less", which sounds like a simplification but introduced complications from a carrier landing standpoint. An airplane with no horizontal tail can't have trailing edge flaps, since there's no way to counteract the nose down pitching moment that flap extension causes. No flaps means a high approach speed, which was unacceptable for a carrier-basing, unless the airplane has lots of wing area and/or approaches at a high angle of attack. In order to minimize the former, Vought relied more on the latter. The high nose attitude resulted in a long nose gear. To reduce the rearward loading on the nose gear strut attachment when the nose wheel touched down, the wheel was spun up to speed before landing by compressed air from the engine impinging on a set of vanes on the nose wheel hub. The main gear could be set in either of two positions, forward for takeoff and aft for landing. And the tail hook was attached to the top of the fuselage, so the nose would not pitch down when the hook engaged a cross-deck pendant. This resulted in the hook being stowed on the top of the aft fuselage instead of the bottom, which meant that it was longer than usual. That led to a three-segment hook that folded back on itself for stowage.

It's difficult to see in either the illustration or the photo, but the most forward segment of the hook  was a V-frame. It was covered by a pair of triangular doors. When the hook was extended, it was retained in its stowed position by a latch until the hook engaged a cross-deck pendant and then was released to pivot in line with the two hook segments aft of it.

As if that weren't complicated enough, the hook throat included another Vought innovation, a "trigger" that forcibly ejected the cross-deck pendant after the aircraft was stopped to insure that the hook released the pendant. If it didn't, a sailor had to run out and knock it loose so the airplane could taxi out of the landing area.

During shore-based trials at Pax, the rectangular fairing over the aft hook segment came off during three arrestments, so it was reattached to the V-frame and hinged to the side to allow the hook to extend. The pendant ejector was deleted "in an effort to simplify the arresting hook assembly." The whole experience was summarized with the statement: "The arresting hook assembly is complicated, and its practicability for service use is doubtful."

The F7U-3 had a conventional V-frame hook attached to bottom of the aft fuselage.

The Knee Bone Connected to the Thigh Bone

There was relatively little innovation in the basic tail hook design. Whether it was a V-frame or a single "stinger" appears to have been based on whether the aircraft structure had a single keel or two heavy stringers on the bottom of the aft fuselage because the tail hook attach point had to tie in to a main structural load path.

For example, the FR-1 Fireball, which was an early attempt to take the jet engine to sea by combining a piston engine in the nose with a jet engine in the tail, provided for removal of the jet engine by making the aft fuselage a separate bolted on structure. To avoid loading that joint and inexperienced with the dynamics of an arrested landing, Ryan engineers attached the tail hook to the aft end of the forward section of the fuselage. When the hook snagged a cross-deck pendant, the result was a nose-down pitching moment. This was really hard on the nose gear and there were failures.

Douglas, somewhat more savvy about carrier operations, initially chose to integrate the tail bumper and the tail hook on the F4D, as shown here on the mock up with the hook in the "stinger" position for taxi over the remaining wires and barriers.

At least one of the two XF4Ds were built with this design, but by the time the XF4D went to sea for initial carrier trials, this arrangement had been replaced with a more conventional V-frame hook that was attached directly to the airframe.

It Hurts When I Do That

Because of the relationship of the tail hook and the center of gravity, many (Tom Weinel,  F8U pilot and subject matter expert, says this was actually the norm) arrestments resulted in the airplane briefly wheel-barrowing. As you might imagine, the initial impact could be hard on the nose wheel, which sometimes broke. There wasn't much to be done with the geometry and other changes to the hook installation didn't have much effect, so a stronger nose wheel and shock strut with more stroke was retrofitted.

It could have been much worse. The F8U program began while the Navy was still operating jet airplanes from straight-deck carriers. The proposal shows a retractable Davis-barrier pickup on the belly, which was necessary due to the distance between the nose wheel and the main gear and the likelihood, due to the low ground clearance, that the barrier cable might bounce off the belly and drop back down on the deck. It kept the barrier cable up until the main gear could snag it. The landing crash rate of the F8U was tolerable on an angled-deck carrier; on an axial deck, the F8U might well have suffered the same fate as its sibling, the F7U: a terrible reputation and a quick exit from the inventory.

When Rube Goldberg Isn't Enough

Jets weren't compatible with the barrier cable system used on axial deck carriers to protect the people and planes forward of the landing area if the tail hook of the arriving airplane didn't pick up any of the arresting wires. A Rube Goldberg creation, the Davis barrier, provided the same function by having the cables lie flat on the deck and adding an actuation strap where they were located for propeller-driven aircraft. When the jet's nose gear hit the actuation strap, vertical straps tied to both the actuation strap and the cable would jerk the cable off the deck where it would snag the main gear. A barrier guard was added in front of the wind shield to snag the strap in the event of a nose landing gear collapse. Unfortunately, this arrangement only worked at a specific range of speeds. If the airplane was going a bit fast when it hit the actuation strap, the main gear would pass by before the cable had come up far enough to engage it; this resulted in the addition of the big barricade beyond the barriers, still used on angled deck carriers to land an airplane when the arrested landing isn't possible for some reason. If the airplane was a bit slow, the cable would come up off the deck and fall back down before the main gear arrived. Although the barricade would stop the airplane in this case as well, it was an event to be avoided since disentangling the airplane and resetting the barricade were time consuming. Instead, a barrier cable pickup was to be added to some airplanes between the nose gear and main landing gear. It would insure that the cable would stay up off the deck and do its job in a low speed barrier engagement. Only a few new aircraft were equipped with a barrier cable pickup, like the XFJ-2 shown above, before the introduction of the angled deck eliminated the barrier requirement.