by Tommy H. Thomason

Tuesday, December 31, 2013

Photo Gator

When the Navy needed to replace its existing fleet of light, carrier-based photo-reconnaissance airplanes, it traditionally modified an existing fighter. The F2H-2P and F9F-8P were followed by the F8U-1P.
The design modifications were developed while the F8U-1 fighter was in flight test. The major change was the reconfiguration of the forward fuselage for the installation of a set of cameras in lieu of the cannon and rocket armament. (The horizontal tail was reportedly reduced in size according to some but I can't find any evidence of that.) The prototype was a modification of the 32nd production F8U-1, BuNo 141363. John Glenn used the early production F8U-1P shown here to set a transcontinental speed record in July 1957.

In addition, Vought improved the area ruling of the airplane. There had been considerable concern before the first flight of the prototype F8U fighter when wind tunnel testing showed transonic drag to be higher than had been predicted. Vought hadn't paid much attention to the newly discovered area-rule concept up until then and hastily developed a set of modifications to refine the fuselage shape in accordance with it. One or two were actually incorporated prior to first flight, as a result of which it was discovered that the wind tunnel data was not correct and the F8U's long, slim fuselage was close enough to an ideal overall cross-section increase and decrease.

However, with area ruling in mind, Vought tweaked the F8U-1P fuselage cross section, bulging it both upward and outward between the cockpit and the wing, in part to provide a flat bottom to the fuselage (also see the profiles in the picture at the beginning of the post).

The upper forward fuselage faired into a larger overwing fairing.

The inflight refueling probe, which had been added to the fighter in a large blister aft of the cockpit as an afterthought, was now fully enclosed within the fuselage. A window was added to the underside of the nose cone for a viewfinder so the pilot could accurately position the airplane for photography. The pilot could switch between two lenses, one with a narrow angle for use with the forward-facing camera (station 1) and the other, a wide angle for use with the cameras at stations 2, 3, and 4 which took pictures downward and sideward.

The instrument panel was dominated by the viewfinder.

Like the F8U fighter originally, the first F8U-1Ps had Vought-furnished ejection seats. These were replaced by the Martin-Baker seat, probably during the very late 1950s or very early 1960s. See http://thanlont.blogspot.com/2011/02/transition-to-martin-baker-ejection.html

The F8U-1P's fuel capacity was increased by 224 gallons over that of the F8U-1 fighter by extending the main fuel cell downward into the volume provided by the elimination of the rocket pack and adding a small fuel cell forward of the main fuel cell. This provided a significant improvement in mission radius and endurance.

The F8U-1Ps were redesignated as RF-8As in September 1962. Seventy-three of the original 144 were rebuilt between 1965 and 1970 to add an uprated J57 and ventral fins; these were designated RF-8G and retained their original BuNos. (Five Marine Corps RF-8As reportedly got ventral fins early; high-speed directional stability was marginal without them.) At least some got the later wing with hardpoints for external stores and wiring changes for an ECM pod.

A subsequent upgrade in 1977 resulted in a change to the more powerful J57-P-420, which required the addition of the external cooling intakes on the upper aft fuselage; there was, however, no change in the designation.

Various ECM antennas were added to the vertical fin over time, including a large forward-facing one.

For a walk-around photos by Chris Ishmael of an RF-8G with the external AB-cooling intakes in a museum, see http://www.cybermodeler.com/aircraft/f-8/rf-8g_walk.shtml

For some illustrations from the flight manual, courtesy of the Marine Corps Aviation Reconnaissance Association, see http://www.mcara.us/F8U-1P_RF-8A_design.php

There are no kits of the F8U-1P/RF-8. In 1/72 scale, there are vacuform conversions from Falcon and Airmodel see http://www.helmo.gr/index.php?option=com_deeppockets&task=catContShow&cat=22&id=970&Itemid=35) and resin conversions from Ventura (see https://hangar47.com/RF-8_Crusader.html) and RVHP; only the RVHP kit includes decals and its accuracy is questionable. There is a review of the 1/72 Final Touch conversion parts and Tasman decals here: http://modelingmadness.com/review/viet/mansrf8.htm.

As far as I know, only the Falcon version is readily available. See  http://www.falconmodels.co.nz/kits.html

In 1/48, see Tom Weinel's post in Hyperscale HERE.

Last, but definitely not least, Fisher has released an excellent RF-8G conversion for the Trumpeter 1/32 kit. See http://fishermodels.indiemade.com/

Tuesday, November 26, 2013

AD (A-1) Skyraider Original vs Extraction Seat

The Navy contracted for the incorporation of the Stanley Aviation Corporation Yankee seat in at least two squadrons of its AD (A-1) single-seat Skyraiders. This was an extraction system as opposed to an ejection seat. In the event that the airplane needed to be jettisoned, the pilot was pulled out of his seat by a cable attached to a rocket as opposed to riding a seat that was propelled by a rocket (originally an explosive charge) out of the airplane. For more on the Stanley seat, see http://tailspintopics.blogspot.com/2011/10/yankee-tractor-rocket-escape-system.html.

The original AD seat and the one incorporating the extraction system were similar in appearance but very different in detail. The most obvious indication of the Stanley seat is the presence of a tube (the rocket) added to the right side of the existing canopy actuation mechanism that was usually concealed under a canvas cover (I'm not sure why but I suspected that it was prone to leaking).


The armor plate behind the pilot's headrest appears to have been unchanged but the head rest was now mounted to the seat structure, which included two U-shaped channels on each side of the seat.

An extraction initiation handle was located at the front side of the seat cushion.


The headrest of the original seat was narrower, with its forward surface bowed outward vertically, and mounted to the armor plate. The seat consisted of a back and a bucket. (Note that the canopy actuation mechanism is not shown in the following illustration and that there would almost always be cushions/parachute in the seat.)
There was, of course, no extraction handle.

This is the comparable illustration for the Yankee seat. (Note that the control column is not shown.)
The Air Force modified both its single-seat and wide-body Skyraiders with the extraction system.

Sunday, October 20, 2013

Lockheed P/F-80 Canopy Development

Why do I make a blog post concerning an Air Force fighter? Because the Lockheed P/F-80 was operated by the Navy, including an at-sea evaluation of the P-80A. The Navy also operated some F-80Cs as jet trainers. One subtle difference between the two models (and it must be pretty subtle because it seems to have been recognized only rarely and not by kit manufacturers) is the location of the windscreen and the length of the canopy.

I've covered the carrier-trials P-80A here: http://tailspintopics.blogspot.com/2011/11/lockheed-p-80a-carrier-trials.html ; much of the same material was covered in a Tailhook Topics Draft post here: http://tailhooktopics.blogspot.com/2012/02/lockheed-p-80-shooting-star.html.

Craig Kaston just provided me with photos that he took this weekend of the P-80A at the Planes of Fame Museum in Chino and the P-80C fuselage in the storage yard at the Yanks Air Museum. They provide a direct comparison of the location of the windscreens of the two canopies with respect to panel lines and access doors whose location did not change, e.g. the aft cockpit bulkhead and the instrument panel, when the canopy was redesigned for the installation of the ejection seat.
Note that the Planes of Fame P-80A has the later F-80C canopy resting on the top of the fuselage* (it probably wouldn't fit properly if it was closed because of the different mechanism used to slide it). The extra length of the F-80B/C sliding canopy (the location of the aft end of the canopy remained the same on both the A and the B/C, so the length increase required by the relocation of the windscreen was in the forward part of the sliding canopy) is also evident by the fact that the aft interior structure of this canopy would not rest against the cockpit headrest when the canopy was closed.

Craig also pointed out the difference in the boundary layer vent that I had not noticed.

*It is an example of the occasionally necessary and inobvious kludge by museums that sometimes leads to a blunder by model kit manufacturers.

Monday, October 7, 2013

Things Under Wings - Drop Tanks Update

For a primer on Douglas drop tanks, see http://tailspintopics.blogspot.com/2011/07/douglas-low-drag-external-fuel-tanks.html

Now take a close look at this picture:

Normally, both the A4D and the AD would have 300-gallon drop tanks under the wings. In this case, however, the A4D is carrying 150-gallon tanks and the AD, which is in the standard tanker configuration, 400-gallon tanks.

For more on the AD tanker configuration, see http://thanlont.blogspot.com/2013/10/texaco.html

Tuesday, October 1, 2013

A3D Skywarrior External Pylons

Rick Morgan provided the following with respect to the A3D-2T Skywarrior external pylons discussed here: http://tailspintopics.blogspot.com/2013/09/ta-3b-skywarrior.html. (Rick also provided pictures of TA-3Bs with the pylon and practice bomb dispenser that I've added to that post.)

Concerning pylons on A3Ds, as I understand it all of the Versions had hardpoints to attach them.  This is a photo of a VQ-2 EA-3B in the Med refueling from a VA-216 A-4B off Saratoga in 1967 with what I believe is an ALQ-31 pod installed.

An old VQ friend tells me that they actually flew fighter training missions during this period with the equipment due to the lack of other EW assets in 6th fleet, most of the other aircraft being in Vietnam.  This is the only time I’ve found so far where EA-3Bs were actually used for active jamming. (Contrary to a lot of published references, I have yet to find a VQ operator who used the EA-3B for jamming in Vietnam- the stories undoubtedly confuse the EAs for EKAs).

The ERA-3Bs  at VAQ-33/34 carried ALQ-76 pods on their pylons, of course.

For a brief description and a picture of the ERA-3B (and an explanation of A-3 Bombers versus Versions), see http://tailspintopics.blogspot.com/2010/09/mighty-skywarrior.html

Friday, September 27, 2013

TA-3B Skywarrior

The trainer designation for the TA-3B is a little confusing since it was a bombardier trainer, not a pilot trainer. Although you can find otherwise, I'm pretty sure that no Skywarrior ever had dual controls.

This was the TA-3B:

It was a Version as opposed to a Bomber. For an explanation of that and a bit more background on the TA-3B, see: http://tailspintopics.blogspot.com/2010/09/mighty-skywarrior.html

There were some notable external differences between the TA-3B and the other Versions.


The third crew position on the flight deck faced forward.

The canopy configuration was unique.
The bombardier crew position was relocated to the cabin, so the periscope fairing was located farther aft. It had windows on both sides of the cabin instead of only on the right like the EA-3B.

The 20 mm turret was just a sheet metal fairing with a window on its lower side for a camera to score bombing accuracy.

Since it did not have a bomb bay, wing pylons were added to carry practice-bomb dispensers. These pylons were subsequently used on A3Ds modified for missile launch and other test requirements and the aggressor ECM jamming trainer requirement (ERA-3B). (Note that the wing shown is the original one; all the TA-3Bs had the CLE wing: see link above.)


 Rick Morgan provided pictures of a VAH-123 TA-3B with the practice-bomb dispensers on the pylons:


Wednesday, September 18, 2013

The Bigger Banjo

Kitty Hawk has announced a 1/48th scale kit of the F2H-3/4, which is a welcome addition to the modeling catalog, at least for Naval aviation enthusiasts. The three-view that they've published, however, appears to have some small errors and I'm trying to contact them to offer assistance. On line comments on the kit have also revealed a lack of knowledge about the F2H derivatives. If your Banshee background is a little weak or you want to know more about the airplane, see http://tailspintopics.blogspot.com/2009/12/f2h-banshee-modeling-notes.html

I thought I had posted this old Tailhook Topics article about converting one of the -2 kits (and the Hawk/Testor's kit was actually based on a XF2H-1 flight test article) but apparently not:
Note for example the difference in the size of the horizontal tail between my drawing, which was based on a  pretty good McDonnell lines drawing, and the Kitty Hawk illustration that you can find on modeling sites.

More later...

Wednesday, September 4, 2013

Vought XF4U-1 Corsair

I've been collecting material on the XF4U-1 for many years. I've never been satisfied by the three-view drawings that became available or the ones I did. Recently, Bill Spidle came to the rescue once again with Vought factory drawings that satisfied my concerns and proved, as I expected, that the relationship of the wings and empennage did not change between the prototype and the production Corsairs. I was surprised to discover that the XF4U-1 turtleback was notably lower than the production airplanes. However, it now seems logical that when the cockpit was moved aft, Vought raised it a few inches in order to reduce the impact on the all-important visibility past the nose necessary for carrier landings. As subsequent incidents would demonstrate, it wasn't enough.
Warren Eberspacher created a set of drawings in the early 1970s that appeared in issues of Air Classics and the American Aviation Historical Society Journal. For some reason, he shortened the distance between the wing and the empennage along with making other detail errors. The Lloyd Jones drawings in Bert Kinzey's D&S Volume 55 contain the same fuselage length error. Japanese illustrators Hidel Maki and Riku Watanabe got the length right but not the subtle change in fuselage depth aft of the cockpit.

Another wrinkle is that the modifications were made to the prototype over time. For example, after the July 1940 crash, the engine was moved about 4.5 inches forward, which can be discerned from close examinations of before and after pictures, and the exhaust stack fairing was modified. I show the later cowling in the side view above.
Except for the exhaust stacks and the gun ports, the cowling looks pretty much identical to the earliest production Corsair with the 360-degree cowl flaps.

David Weeks reminded me about the propeller change that probably occurred during the post crash rebuild:


I was aware of the difference in ailerons between the prototype and production Corsairs, but the rudder and elevators were also different, at least initially: the rudder's aerodynamic balance did not extend as far forward and the elevator was broader in chord. I don't know exactly when these were modified, but it appears that the rudder change was accomplished before the elevator change. In this picture, the XF4U has the production rudder but the elevator has not yet been changed.

In this picture, taken after the elevator change, you can still see the fairings on the tail cone for the larger elevator.
Note the tube extending out of the fuselage for the spin chute installation. The XF4U had a stinger-type tail hook that was installed initially and also for shore-based testing but in most pictures, the spin-chute tube is present.

Another notable difference between the XF4U-1 and the production Corsairs was the shape of the cooler inlet in the leading edge of the wing.
Note the angled panel line outboard of the inlet on the production Corsair.

Whereas the oil cooler was partially hidden by the production inlet, it was not in the prototype's:

I also added various details to the top view and a scrap bottom view of the left wing from pictures.
I'm pretty sure that the size and location of the downward vision window is correct. For a description of the anti-aircraft bomb concept, see http://thanlont.blogspot.com/2008/06/antiaircraft-bombs.html. The water sensor on the bottom of the wing automatically deployed the flotation bags.

The prototype had a more complex flap system than the production airplanes, with a small span-wise fore flap above the leading edge of the main flap. This created a double slot arrangement that was not carried forward to production.
National Archives via Joe Hegedus

Note the 360-degree cowl flaps. The picture was taken pre-crash, so the airplane has the short cowling, smaller aero balance on the rudder, big elevator, and propeller with the tapered tip. It is also one of the few pictures taken when the tailhook was installed.

David Weeks wrote and illustrated an article about his excellent conversion of a Tamiya's 1/48 F4U-1 "birdcage" into an XF4U-1 in the January/February 2011 issue of the IPMS/USA Journal (also see http://www.hyperscale.com/2009/features/xf4u148dw_1.htm). Although he used the Jones' drawing, the fuselage length error is not at all evident.  The October 2004 issue of FineScale Modeler has an illustrated description of Paul Boyer's equally excellent conversion of Hasegawa's 1/72 F4U-1 "birdcage".

There is pretty complete coverage of the XF4U-1 cockpit in the comprehensive guide to the Corsair by Rafe Morrissey and Joe Hegedus (see http://www.sampublications.com/books/modellers-datafile/f4u-corsair/prod_21.html or http://www.squadron.com/The-Vought-F4U-Corsair-SC-SAM-Publications-p/sa5912.htm). For some reason, the left console wasn't included, so here it is:

More later,

Sunday, August 25, 2013

Things Under Wings - Sparrow Missiles

This is another one of those works in progress that I'll have to update and correct. But in the meantime, one or two people are looking for pretty good dimensioned drawings of the Sparrow I.

The Sparrow "family" of missiles began with the Navy's desire to use guided missiles for air defense of its carriers. The first Sparrow was a so-called beam rider. The pilot aimed the plane's radar at a target and launched the missile, which was equipped with rearward facing antennas that detected the radar beam. The missile control system used that input to continually correct the Sparrow's direction of flight so as to stay more or less in the center of the beam and arrive close enough to the designated target for its proximity fusing to detonate its warhead (sort of a misnomer since it was actually located in the middle of the missile).

Various lengths for the Sparrow I can be found on the interweb but I'm relying on Craig Kaston's detailed measurement of the one at the Pt. Mugu museum for the above drawing. Note the sharply pointed nose for high speed flight, possible because the antennas were facing aft, not forward.

Craig also provided pictures of the forward fins, which provided the flight control, and the antenna fairings between the aft fins, which were fixed.


The Sparrow I failed to meet expectations. It was more or less operationally employed on the F3D-2M (the Skyknight was also used for much of its development as well), the F7U-3M Cutlass, and the F3H-2M Demon, but for only a year or two in each case.

VX-4 F3D-2M, Project Steam:

VX-4 F7U-3M shipboard evaluation:
 Note the flare installation at the aft end of the missile.
I'm not sure what this was for. It may have been to provide visual tracking after the rocket motor burnout to get the missile back under control if it had not captured the beam after being launched.

Some comments on the F7U-3M can be found here: http://tailspintopics.blogspot.com/2012/12/cockpit-confusion.html

A VF-112 F3H-2M with a Sparrow I:

It appears that the operational Sparrow Is were painted black, although the pylon adapters appear to be painted sea blue, the aircraft color scheme that preceded the gray/white one.

Putting a radar in the nose of the Sparrow eliminated all the shortcomings of beam-riding and promised a near sure-kill after launch within its envelope and without any further involvement by the pilot of the interceptor. This was the Sparrow II:
Note that both the aft fins and forward wings have shapes different from the Sparrow I's. The forward wings have also been moved forward, either because of a cg change or to provide more control power for maneuverability. Douglas was promoting the Sparrow II for its F4D and F5D fighters and it was flight tested on the F4D.

The Navy continued to fund Sparrow II development for a while after the cancellation of the F5D. Then the Canadians briefly carried it forward as a weapon for the Avro Arrow program. In the end, incorporating a radar in the Sparrow proved to be a concept ahead of its time, one not fully realized until the Phoenix missile became operational.

The practical solution proved to be semi-active radar homing. This put a radar receiver in the nose of the missile that provided guidance based on the reflection from the target of the radar transmission from the fighter that launched it. This was the Sparrow III, as depicted in its July 1960 Standard Aircraft Characteristics chart (there were many detail changes over time):
The wings and fins were basically the same as those on the Sparrow II although the forward wings had been moved aft to roughly the same location as the Sparrow I's. It was first deployed on the F3H-2 (no suffix and equipped with a different radar than the F3H-2M; for more on the F3H, see http://tailspintopics.blogspot.com/2010/11/f3h-demon.html).

The Sparrow I and III used slightly different launchers. See http://tailhooktopics.blogspot.com/2011/05/f3h-sidewinder-and-sparrow.html

The combination of the Demon and Sparrow finally provided the fleet with an effective air-to-air missile defense against jet bombers. The F3H-2 was soon replaced by the F4H Phantom II,which was specifically designed to be a Sparrow-armed fighter.