by Tommy H. Thomason

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.

Inflight refueling capability was also added during the -2 production run and earlier airplanes retrofitted.

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 that shows the correct planform of the radome:
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

Monday, November 1, 2010

F9F-6 vs. F9F-8 Cougars

For completeness in documenting the development of the Panther/Cougar between the F9F-2 and the F9F-8 with either 1/72nd or 1/48th scale plastic kits, you need to convert kits to the earlier or later version. For the -2/5 Panther options and changes, see HERE.

The -8 Cougar is well represented in 1/72nd scale by the Hasegawa kit and in 1/48th by Collect Air resin kit and Fonderie Miniature and not as well by Revell, whose kit was actually 1/52nd. There isn't a -6 in either scale.

The changes from a -8 to a -6 are easy to summarize: shorten the fuselage by eight scale inches and the fuselage/wing fillet as shown (aft only; the forward section remains the same relative to the mid fuselage/wing) and reduce the chord of the wing:
Note that the speed brake has to move aft with the forward fuselage so a scale eight inches has to be removed from the fuselage behind it.

Some have noted that the length of the F9F-6 is given on the interweb as 40' 10" and the F9F-8, 42' 2". That would be a difference in total length of 16" inches, not 8. However, those dimensions appear to be apples and oranges. First, what you get for length depends on whether you measure along the waterline (i.e. the top view) versus along the ground. Depending on how much the airplane sits nose up and what the difference in height of the two points you're measuring between, you'll get different numbers for the length along the waterline versus along the ground. Second, it depends on what you measure to. For example, there is the tip of the Cougar nose, the tip of the barricade strap deflector that sticks out about three inches beyond the tip of the nose, and the tip of the inflight refueling probe mounted on the nose.

Measured along the waterline from the aft tip of the horizontal tail to the tip of the barricade deflector (the number provided in the Standard Aircraft Characteristics chart), the F9F-6 is 41' 0.75" long and the F9F-8 is 41' 8.875" long. (I'm not sure where the extra 1/8" goes, but I'm sure you're not concerned about it either.)

In the case of the Cougar, the horizontal stabilizer is higher than the tip of the nose, so when its length is measured along the ground, the distance is between an upper and lower corner of that angled "box", which is longer than its width for reasonable nose-up angles.

With respect to the dimensions cited from the web, the F9F-8 measurement along the ground to the tip of the barricade deflector is 42' 1.5625", which rounds to 42" 2". I'm not sure where the -6 measurement of 40' 10" comes from. It is likely to the tip of nose when measured along the waterline; that would make the distance between the tip of the nose and the tip of barricade deflector to be 2.75 inches, which is about right. It is almost certainly not the distance along the ground; in an early SAC, that is given as 40' 11" to the tip of nose, not the barrier guard, which would be even longer. In other words, the F9F-6 length of 40' 10" appears to be along the waterline and to the tip of the nose, whereas the F9F-8 length of 42' 2" is to the tip of the barricade deflector and along the ground. Apples and oranges.

In any event, I prefer to use station drawings from Grumman to compare the fuselages, and they confirm the eight-inch difference in length.

The wing change from the -6 to the -8 affected both the leading and trailing edges (the torque box including the flaperette and flap cove location was unchanged). The -6 leading edge slat was deleted and replaced with an extended and cambered leading edge outboard of the wing fence. The chord was also increased aft by enlarging the flap and extending the trailing edge outboard of the flap.

 The illustration above is from a Grumman report. As best I can tell from Grumman station drawings, this is a direct comparison of the -6 and -8 wings:

Note that the front of the flap extends farther forward (see the dashed line in the illustration above) on the lower surface than on the upper surface. You can also see the camber in the leading edge of the -8 wing out at the wingtip.

However, the wings in your kit may vary. For example, the Hasegawa 1/72 F9F-8 is an excellent kit, but the wings are not exactly the same as the Grumman drawings:

 The F9F-6 wing also folded upward until it was vertical, whereas the -8 wing only went up 80 degrees like the Panther's.

It helps to know that the F9F-6 was created by simply adding a swept wing and horizontal tail to an F9F-5 fuselage that had the fuselage/wing fillet extended forward. In the following illustration, the black lines are an F9F-5, the gray represents the F9F-6 additions, and the red lines depict the planform of the F9F-8. (The green lines show the location of the upper surface controls and flaps; note that on the lower surface of the wing, the front of the flap is located farther forward than it is on the upper surface.)
It is possible to convert a -8 kit to a -6. The tricky part is the aft portion of the fuselage/fillet, particularly when you note on the side view above that the difference extends well forward of the fuselage break for engine removal. The alternative is use a Panther kit for the fuselage and the aft portion of the wing/fuselage fillet. In 1/72nd that means either 1) converting a Hasegawa -2 to a -5 by lengthening the fuselage and modifying the vertical fin and rudder or 2) making do with the Matchbox/Revell -5 with its deep panel lines, thick canopy, and thin vertical fin. (In both cases, the lower rudder needs to be lengthened.) Joe Hegedus did an excellent job of the Matchbox option as documented in detail in the September 2009 issue of FineScale Modeler. He solved the vertical fin shortcoming (and provided the correct lower rudder) by retaining the empennage from the -8 Hasegawa kit. Note that he left the aft portion of the -8 wing alone to simplify the conversion.

In 1/48, Don Fogal accomplished the same thing by mashing together a Monogram F9F-5 and the old Revell F9F-8. Here is a picture of the gorgeous result:
 
The presence of the antenna fairing under the nose is correct for these markings. The F9F-6 was originally built without it but many were modified to have it.

There is a possibility that the 1/48th Trumpeter -2/3, which may be more readily available than the Monogram -5, really has the fuselage length of the -5. I've added an approximate way to check that in my Panther blog entry, HERE.

For much more detail on the Cougar, buy Steven Ginter's Naval Fighters Number Sixty-Six for drawings and illustrations and Number Sixty-Nine for pictures of Cougars in every Navy and Marine squadron. They are available HERE.