by Tommy H. Thomason

Thursday, December 30, 2010

F8F Bearcat: -1 vs -2


The most obvious external differences between the Grumman F8F -2 Bearcat in the lead picture above and the F8F-1 were the 12" taller vertical fin and rudder and the 20mm cannon armament (the latter was also a feature of the F8F-1B, the B suffix indicating a change in armament) indicated by the longer barrels and the bumps on the upper surface of the wing.
The drawing above turns out to be incorrect. See http://tailspintopics.blogspot.com/2016/07/grumman-f8f-bearcat-vertical-tail.html

A not so obvious difference was the windscreen. See  http://tailspintopics.blogspot.com/2016/07/grumman-f8f-bearcat-windscreen.html

There was also a difference in the engine installation. Reportedly (see Davis Gandees comment below) only the first 23 "pre-production" F8F-1s had 5 exhaust stacks.

According to Gandees (and a subsequent comment by anonymous), the remaining F8F-1s had three exhaust stacks. The following sketch showing a fairing added to the trough to cover two lower stacks is is therefore incorrect.


The -1 shown here has the production exhaust trough with the lower side raised above the wing to smooth the flow over the wing and horizontal stabilizer.

 This is the -2 trough with three exhaust pipes.

Air that had passed through the oil coolers was dumped through two "shutter" controlled doors between the inner main landing gear doors. These are the doors on the F8F-1:
Picture by Craig/J361 on Hyperscale

These doors were a slightly different configuration on the F8F-2. They were longer, extending farther forward, and had a scalloped cutout on the inboard side.
Picture by Ron Cline

A fixed oil cooler vent was also added across the bottom of the aft end of the -2 cowl (Mark Hayward picture from the Prime Portal F8F Walkaround):


Mike West of Lone Star Models sells resin 1/48 F8F-1 and -2 cowls as well as other F8F improvements. Chris Bucholtz of Obscurco also offers a replacement F8F-2 cowl for the 1/48 Hobbycraft kit.

For much more detail on the F8F Bearcat and operational usage, see Steve Ginter's excellent monograph written with Grumman's Corky Meyer. It's also available from Sprue Brothers.

Friday, December 10, 2010

Blog Entry Changes

28 December 2010: Minor additions and corrections on the FJ-3 and FJ-4 Fury (October 2009)

13 December 2010: Minor corrections for the AD-5W seating in the Wide Body Skyraider (December 2009)

10 December 2010: Added matrix of configuration differences by BuNo and production Air Force F-111s to the F-111B entry (October 09)

23 November 2010: Added information, including additional cockpit illustrations, to early Phantom IIs (November 09)

1 October 2010: Modified the F-111B entry to provide more comments on the Revell kit and a picture of the ejection seat canopy modification (October 09)

20 September 2010: Added comparison of F-86 and XFJ-2 windscreen (October 09)

Sunday, December 5, 2010

Vigilante!

This is once again a work in progress, last updated on 6 December in the AM. I'm on the road so I don't have access to all my files. There may therefore be more errors and misstatements in the following than usual. Even then, it will pale beside the information available at Bob Jellison's website.

When the first pictures of the A3J-1 were published in Aviation Week, I thought it was the most beautiful airplane that I had ever seen.  It was intended to replace the carrier-based, long-range atomic bomb delivery capability then provided by the Douglas A3D Skywarrior, except it was supersonic with a unique weapon delivery system. As it happened, only 59 were built, including the two prototypes, since it was the victim of a budget battle won by the proponents of the submarine-launched Polaris missile.

The nuclear bomb was carried internally but not dropped. Instead it was propelled rearward, attached to empty fuel tanks, out the back of the airplane at about 30 knots (not at the same speed as the aircraft as is frequently reported). Development of satisfactory accuracy of the bombing system was not achieved by the time it was apparent that Polaris was the better alternative for the requirement.
Before the bomber version was cancelled, however, the range of the Vigilante was to be improved with the A3J-2. Additional fuel was added by increasing the height of the fuselage over the wing and adding two additional external stores pylons. The extra weight was accommodated with a bigger wing and flaps and the addition of boundary layer control to the leading edge flaps. The engine inlet was also modified. Note that in the -2 prototype, the bleed air piping for the leading edge slats ran forward in the armpit of the wing.
The Navy ordered 18 -2s but only two were completed as such. The next four were built to aerodynamically represent a reconnaissance version, the A3J-3P, and used for transition training in the replacement air group squadron. (The leading edge BLC piping was relocated to above the wing and integrated with the overwing fairing.) The last 12 became the first RA-5Cs, the redesignation of the A3J-3P in November 1962.

These two pictures illustrate the difference in wing planform between the A3J-1 and the RA-5C.
If you look closely at the pictures (click on them first) you'll see two different positions of the unusual A3J/RA-5 lateral control system, one to roll left and the other to roll right. There were two sets of spoiler/slot/deflector controls on each wing, one to raise it and the other to lower it. The spoilers were hinged at the leading edge and the deflectors at the trailing edge to direct air flow through the slot.
All four sets were opened simultaneously to function as a speed brake.

The RA-5C was probably the best, certainly the most capable, reconnaissance airplane the Navy ever operated from carriers. It has never been replaced with anything comparable. It was fast, with good range/endurance, and big enough to carry an internal equipment pallet and a belly pod that could be fitted with cameras, side-looking radar, and electronic signal detectors. It retained the weapon delivery capability using the stores pylons but it is unlikely that it was ever used as an attack airplane, considering the RA-5C's value as a reconnaissance platform and that relatively few were assigned to each carrier air wing.

Counting the 12 A3J-2s that were completed as RA-5Cs, 91 RA-5Cs were built for a total of 156 aircraft:
2   XA3J-1s                     BuNos 145157/8
57 A3J-1s (A-5As)          BuNos 146694/708, 147850/863, 148924/933, 149276/299
2   A3J-2 prototypes        BuNos 149300/1
4   YRA-5C (YA3J-3P)  BuNos 149302/5
12 RA-5C (A3J-3P)        BuNos 149306/17
43 RA-5C (J79-GE-8)     BuNos 150823/842, 151615/634, 151726/151728
36 RA-5C (J79-GE-10)   BuNos 156608/653

The nomenclature above is not precise in all cases since it is intended to differentiate between the various contracts, initial intentions, etc. Note that -3 is not a typo.

The 91 RA-5Cs built were augmented by conversions of earlier production. Not all sources agree, but Joe Baugher's website provides a list of conversions by BuNo. According to his tally, there were 43 A-5As converted including one of the A3J-1 prototypes. In addition, the first six of the original order of 18 A3J-2s were rebuilt to the RA-5C configuration, for a total fleet of 140. Some sources state 134, with the difference likely being the omission of the two A3J-2 prototypes and the four YA3J-3Ps. Of course, due to attrition (almost half of the A-5s built were destroyed in accidents and combat), the fleet never totaled 140 aircraft at any time. In fact, the production line was restarted, a very rare event, to build the last block of aircraft in order to bring the numbers back up to a satisfactory level.

The last new-build RA-5Cs were slightly different in addition to being powered by the J79-GE-10, which had a notably different afterburner nozzle.

Also see http://tailspintopics.blogspot.com/2012/12/j79-exhaust-nozzles.html

The engine inlet of the last new-build aircraft had a different outboard shape, being straight instead of curved, and a small leading-edge extension was added along the side of the nacelle.

Early RA-5C inlet:

Late RA-5C inlet and leading edge extension:

There were, of course, detail changes over time to the ECM antennas, tail cone, etc. It also appears that some of the conversions from A-5As (and a couple of early build RA-5Cs) were to the later build inlet configuration with the leading-edge extension like BuNo 146702 shown here. Note that the RA-5C vertical fin tip slopes downward from front to back due to the addition of an IFF antenna.
From photographs, Craig Kaston has identified the following BuNos as receiving the late-build configuration: 146702, 149276, 149287, 149299, 149301, 150831, and 151630. Note that the last two were originally delivered as RA-5Cs in the early configuration.

Trumpeter has produced both 1/72nd and 1/48th kits of the RA-5C. It is reportedly a mix of features of the early and late configurations, but the major knock on the kit is the shape of the forward fuselage and vertical fin. For comparison, here are Rockwell drawings. (The first one shows the tip of the vertical fin as being roughly straight across, which is incorrect for almost all, if not all, of the RA-5Cs.)


As usual, Steve Ginter offers one of the best monographs on the subject, North American A-5A/RA-5C Vigilante Naval Fighters Number 64. It is also generally available from Sprue Brothers, along with lots of other Vigilante kits and stuff.

   To be continued...

Sunday, November 14, 2010

F3H Demon

The McDonnell F3H Demon is another of the airplanes that doesn't get the respect that it deserves from the aviation enthusiast equivalent of the mean girls in high school. It provided carrier-based all-weather defense against Soviet bombers for several years, proving far more useful than the flashier and less disparaged fighter that it was initially a backup for. The much-praised McDonnell F-4 (F4H) Phantom owes more than a little to the experience, good and bad, by McDonnell and the Navy with its older brother.

The Bureau of Aeronautics initiated the F3H program as a backup to the Douglas F4D Skyray. They were intended to be all-weather interceptors launched in response to the warning of an incoming bomber raid, climbing rapidly to altitude and destroying the threat with a salvo of unguided 2.75-inch diameter folding fin rockets aimed solely by radar. Both were to be powered by the new Westinghouse J40 engine.

Unlike the F4D, which carried the rockets in pods under the wings, the original F3H incorporated a 24 rocket-filled tray that deployed out of the belly. It was also a sleek, gorgeously sculpted design that looked like it was going Mach 1 even when it standing still.

In 1950, however, before the XF3H even flew, the Navy decided to make the Demon a backup as well for the two general-purpose fighters that it had on contract, the Grumman F10F Jaguar and the Vought F7U-3 Cutlass. This required an increase in fuel capacity and a change in armament capability, but Westinghouse was developing an uprated J40 which would allow the increase in gross weight, and with minimal armament and fuel load, provide the rate of climb necessary for the interceptor mission. The fuselage was deepened slightly, the nose canted down by five degrees for better visibility on approach, the inlets enlarged by 26 square inches, and the aft fuselage extended rearward about 18 inches, in part to compensate for the addition of four 20 mm cannon and their ammunition in the forward fuselage below the pilot in lieu of the internal rocket storage. The radome shape was changed to improve transmissivity.

The wing area was increased slightly by extending the leading edge forward, increasing the slat chord by nine inches. However, the basic structure of the wing was also redesigned to increase its stiffness and incorporate a new wing fold break required by the change to inboard ailerons that had been developed on the XF3H for better roll control at low speeds. The horizontal stabilizer area was increased as well and changed from a stabilizer/elevator design to a stabilator.
The F3H-1 also had a one piece windscreen, among other detail changes.

For some more detail on the differences between the -1 and -2, see http://tailhooktopics.blogspot.com/2014/06/converting-f3h-2-to-f3h-1n.html

Unfortunately, the original J40 disappointed from just about every standpoint imaginable and the Navy was forced to replace it in both the F4D and F3H as well as the Douglas A3D Skywarrior. Douglas got the Pratt & Whitney J57; McDonnell was forced to make do with the Allison J71, an inferior engine compared to the J57. As part of the redesign, the F3H-2 incorporated a wing of greater area that also had a cambered leading edge.
The first production -2s retained the one-piece windscreen and auxiliary air inlet doors of the -1 but the windscreen was changed to a more conventional three-piece one after what may have been a fatal bird strike on the original design and the auxiliary air inlet was deleted as not required. By happenstance, the -1 was produced when Navy fighters were painted overall gloss sea blue and the -2, when the basic scheme had changed to gull gray and white.

 (Photo from Mark Nankivil)

The first -2s were the -2N and -2M. The former was equipped with a Hughes APG-51A radar and armed with four 20 mm cannon and Sidewinders. The latter was armed with the cannons and the Sparrow I missile, which required the substitution of the Sperry APQ-51A radar. The ultimate configuration was the -2, which had an APG-51B radar to control Sparrow III missiles.

Many if not most of the -2Ns were updated to the -2 configuration in overhaul. The first production -2 was BuNo 143403. My understanding is that none of the -2Ms became -2s and were soon relegated to shore-based squadrons for initial checkout in the F3H or put into storage before being stricken.

For more on the variants and missiles, see http://tailhooktopics.blogspot.com/2011/05/f3h-sidewinder-and-sparrow.html
Drawings of the different Sparrows can be found here: http://tailspintopics.blogspot.com/2013/08/things-under-wings-sparrow-missiles.html

Spoilers were subsequently scabbed onto the wing to improve roll control.
(Don Hinton Photo)

Martin Baker seats replaced the McDonnell seats late in -2 production (BuNo 146709-146740) and were retrofitted to earlier aircraft when they went through overhaul. The first ejections using a Martin-Baker seat from the F3H reportedly occurred in March 1958 with the last in a McDonnell seat in November 1960.

The "beaver tail" was also shortened on BuNo 143403 and subsequent. I don't know if this change was retrofitted.



The two upper 20mm cannon were removed from some aircraft in service to reduce weight.

For more on the XF3H and subsequent Demon proposals, see American Aerospace Archive 4, HERE. My book, Naval Air Superiority, contains a chapter devoted to the F3H; purchase information is provided in the sidebar, right. Steve Ginter's F3H monograph is available from Sprue Brothers.

Not counting the Airmodel vacuform "kit", which is neither complete nor accurate, there have been two 1/72 scale F3H kits, Rareplanes and Emhar, both of the -2. The Rareplanes is a fairly complete and accurate vacuform kit, lacking only decals. I built this one several years ago.
A detailed review of the Emhar model is provided HERE.

There are also four kits, again of the -2 variants, in 1/48. Phil Brandt built and reviewed the Golden Wings vacuform in his inimitable style HERE. The Grand Phoenix injection-molded kit is reviewed HERE and HERE. The AZmodel kit (reportedly recycled Grand Phoenix molds with difference ordnance and marking options) is reviewed HERE. The Hobbyboss kit is reviewed HERE and HERE.
In the latter review by Gary Meinert, it is noted that:  "This kit (No.80365) is incorrectly labeled the F3H-2M. In fact, it is the F3H-2 with the short tail cone or "beaver tail". ( In 1962, the F3H-2 was re-designated F-3B). The initial Hobby Boss release from last year (kit No. 80364) has the long beaver tail and is therefore an F3H-2N or 2M." Terry Hill provided Hobby Boss build notes HERE

Furball has just released a set of 1/48 decals for various colorful F3H-2s and 2Ms. For a summary description and review, click HERE.

Friday, November 5, 2010

F11F Tiger

Grumman only built 201 F11F Tigers, the jet-powered equivalent of its F8F Bearcat: a day-fighter tailored for low cost, maneuverability, and minimum size at the expense of maximum performance. It was in accordance with the vision of the BuAer Fighter Class Desk officer who authorized its development using F9F production contract funds, which was a standard practice at the time although generally not for this degree of change. Unfortunately, after he left BuAer for his next assignment, the new Class Desk modified the procurement requirements for the competitive day fighter to emphasize performance instead. The result was the F8U Crusader, which outclassed the F11F with its original engine in just about every respect.

For other information on the F11F, see http://tailspintopics.blogspot.com/2014/10/f11f-tiger.html

The first 42 Tigers, BuNos 138604-138645, had the so-called short noses (BuNo 138603 was a static test article); the last 157, BuNos 141728-141884, had long noses. In between were two F11F-1Fs, BuNos 138646-7, which were powered by the General Electric J79 and demonstrated what the Tiger was capable of with a first-class engine.

The first three F11Fs, then designated F9F-9s in accordance with their origination as a product improvement of the Cougar using its production funds, had really short noses.
For production, the nose was lengthened and incorporated an in-flight refueling probe at its tip. The short-nosed Tigers also had only two stores pylons. The ranging radar was located behind a dielectric panel on the nose halfway between the windscreen and the tip. The gun camera was collocated behind a clear panel on the upper right side of the nose just aft of the tip.

Wright had problems with development of an afterburner for the J65 with serious consequences for Grumman’s test program and the F11F’s performance. The solution was the J79. The Navy agreed to let Grumman substitute it for the J65 in the last two Tigers of the first production lot, if for no other reason than to get early flight experience with the new engine. (General Electric also put a J79 in one of the two F4D prototypes as part of their development program.) However, in mid-1955 there was a plan to buy a J79-powered variant of the F11F, designated the F12F, and BuNos 143401 and 143402 were issued for prototypes. The contract was canceled on 4 January 1956. The two F11F-1Fs were now referred to as "aerodynamic and powerplant flight test vehicles serving as prototypes for potential production F11F-2 aircraft."

The Navy intended to equip the second lot of F11Fs with a visual-assist radar for an all-weather capability employing Sparrow IIs, so the nose and instrument panel were modified accordingly. The in-flight refueling capability was changed to a probe that retracted into the right upper side of the nose and the gun camera was moved to the base of the windshield. However, the Sparrow II program wasn't fairing any better than the F11F so for production, the APG-30 ranging radar was retained but relocated to the nose. As a result of F11F-1F flight test, a leading edge extension was added to the inboard leading edge of the wing along with two more stores pylons.

Martin-Baker seats were bought for the F11Fs but they were not installed, except for two airplanes pulled out of Davis Monthan storage in 1974 for a flight test evaluation of the Rohr in-flight reverser. One was modified with the reverser and the other provided the unmodified baseline.

As usual, the best single references are from Steve Ginter. The F11F-1 is covered in Naval Fighters Number Forty and the F11F-1F in Number Forty-Four.

Hasegawa produced an excellent 1/72 kit of the long-nose F11F. It was subsequently reissued with a resin part for a conversion to the short-nose configuration, but unfortunately the transition to the shorter nose begins too far forward, which means it doesn’t look quite right. Some might question whether the stowed depiction of the arresting hook, upside down and backwards, is correct but it is. On prior Grumman fighters, the tail hook slid aft in a tunnel and hung down from the very aft end of the fuselage. The F11F installation was simpler and lighter.

Another minor problem with the Hasegawa kit is the main landing gear installation.The top of the main gear strut has to be positioned slightly away from the interior of the wheel well (I put a small wedge of plastic on the interior of the strut just under the locating pin) or it cannot be positioned at the correct angle due to interference with the lower edge of wheel well. The attachment pegs on part C12 also have to be modified as well so it can be properly positioned.

Tuesday, November 2, 2010

Trader and Tracer

Kinetic has announced the release of a 1/48th S-2E, with the possibility of a WF-2 (E-1B) and a TF-1 (C-1) to follow. Hopefully, they will not rely on the drawings that have been used for 1/72 conversions. The following are based on Grumman drawings.

The TF-1 had a deeper fuselage than the S2F-1 but shared its wing and vertical fin/rudder. It had the same horizontal tail as the S2F-2 and -3. One result of using the S2F wing is that there is no deice boot where the searchlight was located on the ASW aircraft.



The aft end of the nacelle was terminated with a fairing. At least the left nacelle had a large door in this location for a compartment housing a life raft.

Note in the side view above and the following picture that the cockpit side window did not extend as high as the S2F's (my guess is that the overhead hatch had been increased in size) and there was no "crease" extending aft of the bottom of the window, indicative of the slightly wider fuselage. This picture also shows the gap in the deicing boot on the right wing. The large escape hatch on the forward end of the cabin was only on the right side of the fuselage.


Unfortunately, I don't have factory drawings with cross-sections that I trust. The following is my best guess based on what I have including pictures. The gray area is the cross-section provided on the Grumman WF-1 drawing for modelers. Note that the C-1 and E-1 fuselages do not have the longitudinal crease below the cockpit side window like the S2F and the upper side of the window is lower than it is on the S2F. The overhead hatch looks different as well and clearly extends more aft. These differences (except for the length of the overhead hatch) appear to result from the C-1 and E-1 fuselages having an oval cross-section immediately aft of the cockpit.


The WF-2 (E-1B) fuselage was based on the TF's but was stretched 18 inches between the wing and the cockpit. Mike Hazlewood (http://www.vagabonddecals.com/) went to the trouble of overlaying the C-1 illustration above (created by me with whiteout modifications to someone else's drawing for an IPMS Update column many years ago) and the E-1 drawing below (created by me from Grumman-provided material using Illustrator) to illustrate that. Note that the tailhook installations don't overlay, which I think they should, and there are other slight discrepancies(click HERE for my diatribe on making accurate drawings), but it does show the stretch and the difference in the pilot's side windows.

 The wing was redesigned to accommodate a new fold mechanism necessitated by the radome above the fuselage.

The chord was increased slightly between the wing root and engine nacelle, as was the span, by 3' 8 3/4".
The dihedral was also increased outboard of the wing fold joint.



The requirement to redesign the wing in such detail also resulted in the deletion of the gap in the deice blanket coverage on the right wing.

Another oddity resulting from the wing fold was a change to the wheeled tail bumper that allowed it to function as a tail wheel and free swivel, since the Tracker was a tail sitter with the wings folded.


The major blunder in all the 1/72nd conversions and kits that I've seen is the planform of the radome. (The added depth of the fuselage is not fully realized as well.) I had read that the Mach 2 fuselage does not have the 18" plug in the forward fuselage but Jackman over on Aircraft Resource Center has begun to build one—see HERE—and determined that the overall length, at least, is correct.) This is a build of the RVHP kit, which also clearly has the wrong radome planform: HERE For my notes on a partially built Falcon conversion, see http://tailhooktopics.blogspot.com/2013/08/half-baked-172nd-grumman-wf-2e-1b.html. However, as Walt Fink's build demonstrates, it can result in a very nice model:

This is a pretty good drawing from Grumman documents:
Note that the E-1B has the large carburetor air scoops on the top of the nacelle and CSD cooling air inlet/exhaust (on the lower right hand side of the engine nacelle ahead of the gear door on both the right and left nacelle) as the S-2D/E/G and a similar fuel dump pipe needed to get the gross weight down quickly in the event of an engine failure shortly after takeoff.


Don't be confused by pictures of the WF aerodynamic prototype created from a TF (C-1). It did not include all the physical changes, for example the WF wing and the plug in the forward fuselage. After Grumman test, the radome was removed and it was operated as a transport.

Someone asked me what the WF-2 (E-1B) cabin looked like. All I have at the moment is this diagram from the mockup review.

There's more on the WF-2 (E-1B), including the identity of the WF-1, here: http://thanlont.blogspot.com/2011/10/designation-story.html