by Tommy H. Thomason

Wednesday, October 28, 2009

Grumman Panther

16 September 2011: Updated for new kits.

Another work in progress for which there was a lot of existing material. This one describes the differences between the -2 and -5 Panther, since there are -2s in 1/72 (the Matchbox -5 is not so good) and a -2 and -5 from different kit manufacturers in 1/48. Click Here for my thoughts on the 1/72 scale -2 kits.

There were three notable shape changes between the -2/3 and the -4/5: the fuselage was stretched by eight inches between the inlet fairing and the dive brakes; the vertical fin was revised (a bit differently than shown here); and the wing leading edge just outboard of the engine inlet was bulged forward with a small flow fence added (the fence was added after initial -5 production and retrofitted to -2/3s so it alone is not a distinguishing feature although the -2/3 fence is a slightly different shape). The -5 also had a small suck-in door behind the bigger one that was on the -2.

You have to do some rivet counting to see where the stretch is but it's there. Note also that the fiberglass reinforcement on the aft part of the canopy is wider on the -5, but this appears to have been retrofitted to the -2, so its absence denotes a -2 but its presence does not necessarily denote a -5.
 
The tail change is a bit subtler than shown on the illustration above. It was actually enlarged all around as depicted here and the -5 trailing edge was 2.75 inches farther aft.
Regrettably, the difference in the shape of the bottom of either fin isn't shown but the following illustration will make up for that. Note that there is also a difference in the gap between the -2 and -5 upper and lower rudders: the -5 gap was rectangular; the -2's was more triangular.
This is another view of the bottom of  the -2's fin:

Other -5 differences are the tail bumper (more on that below), larger stores pylons on the wing, and the configuration of a small "reverse flap" on the wing flap of -5 (See Yves Marino's comment below). On some -5s, the lower aft corner of the larger suck-in door is cut off to clear the engine inlet.


The cockpit was slightly different. The forward end of -2/3 side consoles was stepped up whereas the -4/5 consoles were flat.

Another detail that I hadn't noticed until just now (17 February 2014) is that the tail bumper is slightly different.  It looks like it was part of a fairing on the -2s (see http://www.primeportal.net/hangar/luc_colin3/f9f-2_panther_123652/index.php?Page=3) but not on the -5s (see http://www.primeportal.net/hangar/howard_mason/f9f-5_125295/index.php?Page=2)

Since I limit myself to 1/72nd scale, I don't know anything about 1/48th kits other than what I read on modeling websites. In this case, Pip Moss has measured the Trumpeter -2 and Monogram -5 fuselages and reports that the Trumpeter F9F-2/3 is 9.375 inches long along the waterline (37'6") and the Monogram F9F-5 is 9.625 inches long (38' 6"). That means that they are one scale foot different in length (a bit more than the actual 10.75 inches but the difference is approximately 1/32 inch, which is easily attributable to measurement accuracy), and both are a bit short but by less than 1/8 inch. On the other hand, Lewin Jones and others have measured the Hobbycraft (same mold as the Trumpeter kit) -2/3 and Monogram -5 and found them to be the same length, which means the Hobbycraft/Trumpeter fuselage is too long. Use the following illustrations to check for yourself.

One problem with the Hobbycraft/Trumpeter F9F-2/3 is the canopy.  See Michael Benolkin's review Here and Tom Cleaver's Here. Click Here for a description of an aftermarket substitute for the canopy and Here for a source for it.

F8U Crusader Variations

29 January 2017: Updated with a revised UHT (Universal Horizontal Tail) illustration

For the best single reference on F8U-1/2 configuration differences, buy Squadron Signal Publications Walk Around Number 38, F-8 Crusader by Ed Barthelmes. It includes details that I hadn't noticed or knew about, copiously illustrated in color.

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

This is another work-in-progress. I got a request for this particular one and since I had done some work on it, I've decided to post it and perfect it later. For a bigger picture, click on it.


 


F8U-1 Notes

The solid nose wheel was introduced with the F8U-2N (F-8D) and retrofitted to earlier production Crusaders as they came through overhaul, so there isn’t anything like a BuNo (other than 147037 and sub) or date certain that can be used. There are also examples of Es and possibly even NEs with the spoked nose wheel, but these are almost certainly shore-based airplanes taking advantage of built-up spares.

Here are pictures of the early spoked nose wheel hub:


The tendency of an F8U to land on the nose wheel, particularly after an in-flight engagement, may be why the Navy went to a solid hub nose wheel. One of the tenets of good design is that you don't make something relatively cheap and easily replaceable so strong that instead of it breaking in an overload situation to relieve the load, something else does that's expensive and/or very hard to replace or repair.

The early main landing gear wheel was also different.



According to my notes, the Sidewinders and refueling probe were added to 143701 (F8U-1 production #66) and subsequent. Note also that the spoilers for better lateral control weren't added until 143771 (#136) and sub.

Also the small inboard flap was incorporated on production #17 and sub, although this and probably the refueling probe/Sidewinder and wing spoiler installs were retrofitted to at least one of the early aircraft for test and evaluation purposes. (e.g. BuNo 1440446 had the inboard flap for the carrier trials on Forrestal in April 1956)

Vought Ejection Seat

Tom (Superheat) Weinel did some great work on describing and depicting the differences between the various F8U models and modification. This is one of his illustrations.


One unusual feature of the four-Sidewinder installation is that none of the missiles are mounted at the same angle in order to clear its partner on the Y-mount as well as the in-flight refueling probe on upper left side and the ram-air turbine on the lower right. Some kit manufacturer haven't gotten this right. Bill Gilman reports that Academy did with its 1/72 F8U but neglected to provide adequate instructions as to which pylon went where.
The F8U-2NE was to be armed with Bullpup but the requirement for the capability was cancelled before qualification was completed, which is why there aren't any pictures of it on deployed F-8s. (Early -2NEs, perhaps 149XXX, were delivered without the Bullpup fairing; it was retrofitted however, and used to house ECM avionics.) If you want to hang something menacing on the wing pylon, consider a WWII 2,000-lb bomb.

The F8U-1P/RF-8 wing, empennage, and fuselage from the main gear wells aft was basically the same that of as the F8U-1/F-8. The RF-8 was a little over three inches longer than the F-8s with the small radomes but only because of the pitot sticking out over the nose. The fuselage ahead of the wing and below the cockpit was modified to introduce more of an area rule effect and provide flat surfaces for the camera windows. As a result, the inflight refueling probe was now housed entirely within the fuselage and the fairing above the forward part of the wing was deeper and wider. The nose cone changed as well to incorporate the periscope window and the pitot.



 For more on the photo Gator, see http://tailspintopics.blogspot.com/2013/12/photo-gator.html

Wednesday, October 21, 2009

Proposed Super Furies

F2J

The designation was never officially made by the Navy, but two North American proposals (three if you count the "FJ-5") could have resulted in an F2J. The first was in the OS-130 competition. Like the winning Vought design, it featured a two-position variable incidence wing.











George Spangenberg wrote that it came in a close second and lost primarily because North American projected that the gross weight of its J57-powered proposal was almost 30,000 lbs, considerably more than the Vought proposal's with the same engine. Spangenberg correctly predicted that the Vought weight was optimistic, but would still be less than the North American design and therefore provide better performance.

Thanks to Doug Siegfried at Hook magazine for the artist's concept and to Tony Buttler for the three-view. (Note: the three-view is the J65-powered proposal; like Vought and most of the other offerers, North American submitted both J65 and J57-powered proposals.)

In November 1953, North American tried to end run the F8U program with a Super Fury proposal, which was a carrier-based derivative of the J57-powered F-100B (stretched fuselage, wing flaps, etc.) being proposed to the Air Force. The F-100B was a redesign of the J57-powered F-100A that incorporated the latest supersonic flight technology and almost doubled the internal fuel capacity. The inlet was now swept back and incorporated variable geometry, with a horizontal ramp on the upper side used to establish and control the shock wave associated with supersonic flight. Unlike the F-100A, the fuselage was to be area ruled for improved transonic performance and lower supersonic drag. It had also been lengthened by almost four feet to increase its fineness ratio and add more fuel. The wing was basically the same in shape and area, but it was thinner and designed to hold fuel. Flaps were added and boundary layer control incorporated for slower takeoff and landing speeds. The main landing gear now featured dual wheels.




For the Super Fury proposal, in addition to adding the requisite tail hook, wing folding, catapult hooks, etc., other changes were made to the F-100B design to further improve the prospect of carrier suitability. When the flaps were lowered, the folding portion of the wings was repositioned to provide 15 degrees of anhedral to improve lateral stability and aileron control at low speeds. The fuselage speed brake was intended to be deployed on approach and would retract automatically on touchdown. Another innovation was a retractable gun sight to improve over the nose visibility.

 


North American chose to propose armament of three T-160 20 mm cannons. Dual rotating rocket launchers contained 44 two-inch folding fin rockets could be substituted for the guns. One feature from the F-100B design was an alternative forward fuselage that incorporated a radome housing a small search radar in place of the APG-30 ranging radar.

Although it had the same engine and equipment, the Super Fury was heavier than Crusader so it would also have cost somewhat more. Although shorter, only 22 could be spotted in the requisite deck space compared to 25 F8Us . The Super Fury proposal was also deficient in military power ceiling. However, it was projected to be slightly better than just supersonic on military power, faster than required on combat power, have considerably more range on internal fuel and external fuel, and otherwise meet or exceed the requirements.

The proposal’s most compelling feature was that a prototype of sorts was flying and first Super Fury production delivery was expected in early 1956 on that basis. As it turned out, the Air Force decided not to proceed with the F-100B (although it did seque into the F-107) and the Vought F8U Crusader was a success.

FJ-5

Both Grumman and North American had previously gotten contracts from the Navy for new day fighters - the original F9F-8 (then F9F-9, then F11F-1) and FJ-4 respectively - using the funds provided to the F9F-6/7 and FJ-3 production contracts for product improvements. Both were powered by the Wright J65, the same as the FJ-3 and A4D. In accordance with the vision of the then Fighter Class Desk officer, the FJ-4 did not have an afterburner and was optimized for low cost of acquisition and operation. It was, however, to be a great dog fighter, with excellent maneuverability at altitude and near-sonic speed and did in fact achieve those goals. Grumman managed to get an afterburner on the F11F but it was a new Wright design and disappointed in thrust and therefore supersonic performance.

Against all comers, Vought had won the competitive day fighter contract in accordance with a new specification that required an afterburner. Both J65 and J57-powered designs were proposed, with the Navy selecting the higher performance J57 design. At this point, Grumman and to an even greater degree, North American, were in a disadvantageous position if the J57 turned out to be as good as expected and the Crusader met Vought's performance projections.

Both Grumman and North American then turned to the new General Electric J79 engine which was not available for the competitors to consider for the 1952 day fighter proposals in futile attempts to provide an attractive alternative to the F8U. Grumman apparently got to the Navy first and/or best, since BuAer began planning to buy a J79-powered F11F Super Tiger as the F12F. (One more time, the F12F was not the Grumman Design 118.) Unfortunately for Grumman, the XF8U went supersonic on its first flight in March 1955 and the F12F plan was dropped. However, BuAer did contract with Grumman for two J79-powered F11F-1Fs because they wanted to get some flight experience on the J79 before the F4H flew with it. Grumman was still hopeful that Vought would stumble with the F8U and/or the F11F-1F would be good enough to reinstate a Navy production program and/or be of interest to foreign buyers. North American's proposal didn't even get that far. Vought, of course, didn't stumble. The F8U was even faster than they guaranteed.



Strictly speaking, the "FJ-5" wasn't a navalized F-107, which was powered by the bigger J75. The  FJ-5 had a gross weight of about 20,000 pounds and the F-107, 40,000 pounds. The two roughly compared like the Crusader I and the Crusader III. The FJ-5 had a bigger wing relative to its weight since it had to takeoff and land from aircraft carriers while the F-107, like the F-105, was to be flown from mile+ long runways. The designation doesn't appear to have been officially applied.

Much more on the FJ-5 is available here.




To summarize the North American Super Fury proposals from a schedule standpoint:

Tuesday, October 20, 2009

FJ Furies

28 October 2016: For some more notes on the FJ-4/4B, see http://tailspintopics.blogspot.com/2016/10/north-american-fj-44b-fury-notes.html

Summary

This will be a work in progress for some time as I add information to it. For starters, North American produced several different Furies for the Navy:

FJ-1: Straight wing early jet

XFJ-2: Minimal modification of the USAF F-86E/F Sabre to expedite evaluation and qualification of a carrier-based derivative.

FJ-2: Production swept-wing design based on the F-86 and powered by its J47 engine.

FJ-3: FJ-2 redesigned for the more powerful Wright J65 engine.

FJ-4: Complete redesign of the FJ-3 airframe for longer range, better endurance, and better altitude performance and maneuverability but retaining the Wright J65 engine.

FJ-4B: FJ-4 modified for the jet attack mission.

Other "Fury" proposals: There were also at least three serious proposals for follow-on programs: A variable-incidence, two-position wing for the OS-130 proposal that Vought won with what became the F8U-1 Crusader; a carrier-based variant of the F-100B, which had been proposed to the USAF but was not produced; and a down-sized version of the USAF F-107 that was powered by the General Electric J79 instead of the big Pratt & Whitney J57. For more, click here

FJ-1

Only a handful of FJ-1s were built as part of the Navy's transition from propeller-driven fighters to jet-propelled fighters. It was carrier-qualified and operated by one squadron, but never deployed, reportedly due to the very short time between engine overhauls, which would have imposed an unacceptable maintenance burden at sea.

XFJ-2 

The two XFJ-2s had all of the carrier-basing modifications except for the folding wings and did not have any armament. They retained the F-86 inlet lines and canopy except for the windscreen, which was modified to increase the field of view forward to the side of the nose. The slatted wing of the early F-86F was used rather than the "6-3" wing of the later F-86F for better low-speed handling qualities.The single XFJ-2B was an F-86 modified with the XFJ-2 windscreen and the Navy's four 20mm cannon armament in place of the F-86E's six .50-calibre machine guns.


XFJ-2 (NA-179) BuNos 133754 and 755: Based on the F-86E but with the J47-GE-27 engine (F-86F) in lieu of J47-GE-13 (F-86E). Slatted, non-folding wing with 37’ 1’ span (ailerons extend to the wingtip). Forward and downward visibility improved by modifying the windscreen. Seat and canopy strengthened to withstand a deceleration of 40 Gs. The structure was strengthened to meet the design requirements for H-8 catapult launch and Mk 7 short-run-out arrested landing. FJ-2 landing gear, fixed catapult hook, retractable holdback and tail bumper, manually-retractable barrier guard and barrier pickup, and FJ-2-type arresting hook installed. Provisions for 200-gallon drop tanks. Cockpit rudder lock omitted and external gust lock provided. No provisions for guns, fire control or other armament equipment. The major differences from the FJ-2 were the lack of wing folding and the F-86 intake and canopy, except for the windscreen.


 

XFJ-2 main landing gear:


XFJ-2B (NA-185) BuNo 133756: Essentially an F-86E-10 with the Navy's 20mm cannon armament and the XFJ-2 windscreen. "B" was the Navy's suffix for an armament change, which may seem odd because that installation was to be the Navy's FJ-2 armament. However, the two XFJ-2s did not have any armament at all, hence the distinction.

Note the windscreen change from the F-86:


F-86F

XFJ-2












FJ-2

In addition to the carrier-basing changes introduced on the XFJ-2, the sliding canopy interface with the fuselage was redesigned, apparently to allow the pilot to sit higher while the canopy was opening or closing. The windscreen was also modified again to further increase the forward visibility. The intake was enlarged for more thrust at low speeds. The wheel track was reported increased by eight inches over the F-86, probably to provide more oleo travel for higher sink rate landings. The horizontal tail dihedral was deleted. It reportedly also had more area to provide for the longitudinal control power required when the flap travel was increased for stall speed reduction compared to the F-86.

The FJ-2s were all relegated to the USMC as being somewhat underpowered for carrier operations, although they were fully carrier capable as well as qualified. Almost all were in the experimental natural-metal scheme (see http://thanlont.blogspot.com/2009/12/it-seemed-like-good-idea-at-time-vii.html).
VMF-235 operated a few aircraft—21, 22 and 23WU—from Hancock during Project Steam in July 1954 and VMF-122 deployed aboard Coral Sea as part of CVG-17 (3XXLC) from March to September 1955.

FJ-3

Carrier-basing changes added about 1,000 lbs to the weight of the FJ-2 compared to the F-86 it was derived from. To restore performance, the more powerful J65 was substituted for the J47. To provide more air for the increased mass flow of the new engine, the intake was deepened yet again.

The only other notable external difference from the FJ-2 was the substitution of a scoop in place of the small flush NACA intake on each side of the upper aft fuselage.


In order to improve low speed handling qualities and provide more internal fuel, the FJ-3 was redesigned during production to have a fixed cambered wing leading edge replacing the slats that were on the FJ-2 and early FJ-3; this was retrofitted on the FJ-3. On BuNo 136118 and subsequent, provisions were added for two pylons on each wing inboard of the existing ones for external tanks, for a total of six. The FJ-3s were also retrofitted for inflight refueling with the installation of a fixed probe extending from the left wing.


Steve Ginter finally published his long awaited monograph on the FJ-3 to complement the ones on the FJ-1, -2, and -4.  Order it here: http://www.ginterbooks.com/NAVAL/NF88.htm. Being able to review that many pictures of FJ-3s in one place pretty much satisfied two questions that I had: 1) the blue airplanes (not counting the colorful FJ-3Ds) invariably had the slatted wing; the gray/white airplanes invariably had the hard wing with the cambered leading edge, and 2) the barrier pickup was removed from the FJ-3 but there is one picture of a gray/white airplane with it extended, so it wasn't removed as early as I suspected.

FJ-3M

An FJ-3 with provisions for Sidewinder missiles. These were invariably gray/white with the hard wing.
 

FJ-4
The significant performance improvement of the FJ-4 over the FJ-3, since they were powered by the same engine, was the redesign of the wing.


Unfortunately for North American, the BuAer fighter class desk proponent of small, simple, maneuverable fighters without afterburners left for his next assignment just after the OS-130 day fighter request for proposals was issued. The day-fighter requirement quickly shifted back to supersonic fighters and resulted in the F8U Crusader. Like the FJ-2, the FJ-4 was carrier qualified but relegated to the USMC.


FJ-4B
 The Navy contracted with North American for an attack variant of the FJ-4 to provide a backup to the A4D then under development. The FJ-4B had additional wing pylon stations, an additional pair of speed brakes for better control of speed in a high-angle attack, and small spoilers for better roll control with an asymmetric load, a Mk 7 atomic bomb under the left wing.

For maximum range, the bomb-laden FJ-4B would also carry a 150-gallon external tank on each outboard wing pylon and a 200-gallon tank on right main pylon.


When armed with Bullpup missiles, a missile-control pod was carried under the right inboard pylon.
Note the asymmetric loading with two different types of fuel tanks.

North American also developed a unique buddy refueling system that was used to maximize the strike airplane's radius of action.

The A4D proved adequate to the task and cheaper to buy and operate. The FJ-4B therefore served only in west coast attack squadrons and was eventually replaced with A4Ds.

One change that is not reflected on the otherwise excellent North American FJ-4 drawing is the span of the horizontal tail. This was subsequently* reduced to 157" by cutting off about 18 inches of the tail on each side. On the SAC drawing, the tail is correctly dimensioned but the drawing of the tail still has a bit too much span. Since model kit manufacturers most likely used the North American drawing, a check of that dimension is advised.

Early Flight Test                                                      Production

There are several kits of the Furies in both 1/72 and 1/48 scale but in 1/72 scale only the FJ-4 is represented by a complete and reasonably accurate injection-molded kit. This attractive model from that Emhar kit was built and photographed by Gordon L. Hewstone:


For useful notes on and photos of another Emhar build, see: http://www.britmodeller.com/forums/index.php?/topic/235015791-emhar-fj-4-fury-172/

The old 1/48 injection molded FJ-2/3 kit from Esci has an obviously inaccurate canopy and nose, among other shortcomings.

There are FJ-3 resin kits available in 1/72 from RVHP (which is out of production) and 1/48 from Collect-Aire.

It is, however, not very difficult to modify an F-86 kit into an XFJ-2.

*Craig Kaston reminded me of the reason why, as reported in an article by Peter Garrison in the March 2001 issue of Air&Space magazine:

"William R. Laidlaw, former chief of the Structural Dynamics Section at North American Aviation, describes in The Revolution in Structural Dynamics a similar approach to controlling stabilizer flutter in the 1950s. During a test flight, an FJ-4 Fury, a carrier-based derivative of the F-86 Sabre Jet, lost more than half of both horizontal stabilizers to a flutter incident (the pilot managed to land safely). Engineers mounted a Fury tail assembly on a rocket sled at the Navy's test facility at China Lake, California, and the flutter was duplicated. North American engineers considered various modifications to solve the problem, but finally settled on the crudest one: They sawed 12 inches off each end of the tail. A few months later, however, an FJ-4 shed its tail during a pullout from a high-speed dive, killing the pilot. The experts went back to work. They then discovered that putting a heavy load on the tail reduced its flutter margins. Another amputation, this time of a mere six inches, solved the problem for good."