by Tommy H. Thomason

Thursday, May 26, 2011

Early Phantom IIs Redux

In the process of developing a reference package for a resin kit manufacturer who is interested in producing a conversion to the early F4H Phantoms, I annotated some pictures to illustrate the differences. For the original post, click HERE. (I also revised the configuration matrix posted there based on Rex's comments. The only error corrected was the number of bombs on the #11's demo, 22 instead of 24.)

Here is a summary of the major external differences that make up the combinations and permutations:

Noses
1) 24", no IR sensor
2) 24" with IR sensor
3) 32" with IR sensor

Engine inlets
1) Hooded on top
2) Hooded modified to eliminate the hood (see second Sageburner)
3) Not hooded

Ramps
1) No holes in aft ramp (XF4H only?)
2) No boundary layer discharge chutes
3) Boundary layer discharge chutes at top and bottom of ramp
4) Boundary layer discharge chute at bottom only

Fuselage
1) Flush NACA-type inlet on lower forward fuselage
2) Scoop inlet on lower forward fuselage

Wing
1) First five aircraft: No inboard leading edge flap; there were two RATs, one in the inboard leading edge of each wing
2) The rest of the F-4As and F-4Bs had an inboard leading edge flap and a RAT incorporated in the left mid fuselage.

Tailhook Fairing
There was a fairing behind the tailhook on the first several aircraft. It was removed early in development on the first F4H and not incorporated in production.

Stabilator
The original stabilator had a symmetrical leading edge. Probably as part of the redesign of the wing to provide increased lift for aircraft 6 and subsequent, a cambered leading edge was added. Interim stabilators have a zig-zag pattern at about 20% chord where they were modified. Production stabilators incorporated the cambered leading edge in the basic structure.

F4H-1 First Flight


F4H-1 First Flight Top View

F4H-1 In Development

F4H-1 No 4, 4 December 1959

Tailhook and Tailhook Fairing

I've modified this drawing since I first posted it yesterday to improve the shape of the tailhook and the fuselage aft of the hook as well as make some changes to the leading edge of the fin. Note that while the basic shape is based on MacAir drawings, they don't agree to within a line width and the details were added by reference to photographs. Slavish adherence to this drawing by a modeler would be inappropriate.

This is the best picture I can find of the original tailhook fairing, here in the May 1958 on the first F4H



However, although it was removed on the first F4H by December 1958 as shown here, it was still present on #6 during its first at-sea carrier trials.

This is the early tailhook. Note the flat bottom just aft of the afterburner nozzles.

This is the production tailhook, in this case on an F-4K.


F4H Carrier Qualification

F4H Carrier Trials Rudder

The bottom of the rudder was cut out, apparently to insure no interference with the stabilator when the rudder was fully deflected and the stabilator was full trailing edge up. This was not carried forward to production.

Tuesday, May 17, 2011

1/72nd F9F-2 Panther

For many years, the Grumman F9F-2 Panther was very well represented in 1/72nd scale by the Hasegawa kit. I noted a few minor external flaws in a review that I did for an IPMS Update once upon a time:
  • Overly long gun barrels
  • Nose gear - too great an angle between the nose gear strut and shimmy damper; strut needed to be more vertical relative to the fuselage
  • Tail bumper should be extended with the gear down
The cockpit area needed the most modification for an accurate model. The glare shield needed to be deleted. The original kit decal for instrument panel did not match the plastic part - it was close if the instrument panel was widened a bit at the top. The gunsight was very nice but a bit oversize and needed to cantilever back into the cockpit. The back and headrest of the ejection seat needed to be cut down. Finally, the internal structure of the canopy was misrepresented. First, it had to be cut down so it was parallel to the canopy rails. Second, it moved with the canopy, so if the model was to be displayed with the canopy open, it needed to be cut off the fuselage and added to the canopy along with the canopy actuator. If you went that far, then you might as well close out the back of the cockpit with correctly shaped armor plate.

Now Hobbyboss has produced an all-new 1/72 F9F-2 kit and after a quick look, I am impressed. There's quite a bit more detail, particularly in the cockpit, than in the Hasegawa kit. The length and wing span are spot on.  It comes very, very close to capturing the odd shape of the underside of the F9F-2 vertical fin, among other nuances that indicate close attention to replicating the real article.

There are a few small nits. In my opinion, the top of the vertical fin could be a bit wider and more rounded; the wing trailing edge shouldn't go straight out to the tip tank but curve forward slightly at the outboard end; and the gun gas vents in the nose (which were a field retrofit and not on Panthers early on in the Korean War), the tip tank lights, and the trim tab actuator fairing on the underside of the left wing should not be as prominent.

Trim tab actuator fairing and tip tank light:

Gun-gas vent (note that the nose wheel is swiveled 180 degrees):
For more on the gun-gas vent change, see http://tailspintopics.blogspot.com/2016/02/grumman-f9f-nose-cone-variations.html

The suck-in door on the top of the fuselage ahead of the aft fuselage join should be straight across the bottom: the mid-length change in direction was a -5 requirement due to its longer engine. Another F9F-5 feature that shouldn't be there is the little vent on the transition of the fuselage to the vertical fin as well as the misrepresentation of the small suck-in door just ahead of it that again, was only on the F9F-5.

Note in the picture above that there are no doors or vents aft of the large rectangular fuselage door that is sucked in (it is spring-loaded to be flush when the engine is not running). If you look closely you'll see the curve in the trailing edge of the wing as it nears the tip tank and that there is no gun gas vent in the nose. Note that it still has a plug installed in the nose of each tip tank; these will be removed before launch.

The major gaff is the canopy. Gene K provided the following comparison with the Hasegawa F9F-2 and F9F-8 canopies on an Aircraft Resource Center forum:

The problem is that the break between the windshield and the sliding portion of the canopy should be perpendicular to the base of sliding portion, not vertical relative to the waterline of the fuselage. I'm hoping that a bit of filing, filling, and painting will result in a more accurate representation.

More of Gene K's photographs and his and other comments on the kit can be found http://www.arcforums.com/forums/air/index.php?showtopic=230469.

Obscureco produces resin F9F-2 ejection seats. I thought the headrest shouldn't have been angled forward but it turns out that this is an actual feature on the seat. Airwaves produces etched parts for the wing fold area.

For my notes on the conversion of an F9F-2 to an F9F-5, click here.

Sunday, May 15, 2011

Grumman C-2 Greyhound

Continuing the practice of creating a COD (Carrier On-board Delivery aircraft) from an existing airplane in production, the Navy contracted with Grumman to modify two prototype E-2As, BuNos 148147 and 8, with much wider and deeper fuselages equipped with a rear ramp. Production of 17 new C-2As, BuNos 152786-2797) followed. The first of these entered service in 1966.

The original airplanes had square-tipped Aeroproducts propellers and approach lights in the left-wing leading edge like the E-2A. The original propellers began to have fatigue problems and were replaced by the rounded tip Hamilton Standard propellers beginning in late 1974. At some point, the approach lights were relocated from the wing leading edge to the bottom of the forward nose landing gear door.

As a result of unexplained losses of a few C-2s, a hump was added over the center section of the stabilizer to house a crash recorder/locator that was apparently never incorporated.
 Note the gap in the deicing boot on the left wing where the approach lights were originally located.

Two other views of the crash recorder/locator housing on the survivors of the original C-2 fleet:

Note that the left inboard fin has no rudder surfaces. It was sometimes referred to as the "executive tail" because it had nothing to do.

The following picture from the internet is an even better depiction of the tail surfaces and shows the aft ramp doors closed:

A service life extension program was accomplished on all surviving C-2As, with deliveries of the refurbished aircraft between 1978 and 1982. However, only 12 of the original C-2As remained, not enough to meet the demand for COD support since the C-1s were being retired and only a handful of the volume-limited US-3As were available. After considering other options, the Navy elected the unusual step of putting the C-2 back into production although the degree of difficulty was somewhat reduced by the fact that the E-2 was still in production. The Navy bought 39, BuNos 162140-2178.

The major external difference between the original C-2s and the "reprocured" C-2s was a larger APU. Less obvious was a redesigned nose landing gear. The housing for the crash recorder/locator was not carried over to the new C-2s. The first one flew in February 1985; the last of the new C-2s had been delivered by 1990. The last of the original Greyhounds was retired by the end of 1987.

APU exhaust on the original C-2s:
Note the indentation of the fuselage in the plane of the propeller necessary due to the fuselage-width increase relative to the E-2.

APU exhaust on the reprocured C-2s:
The open door ahead of the APU exhaust is the inlet for the APU.

Before the C-2 received a glass cockpit, there doesn't appear to have been much difference from a modeling standpoint between the first and second batch of airplanes. Before:
Glass cockpit, courtesy Craig Kaston:

Conversions of the current fleet of C-2s to the eight-bladed Hamilton Standard propeller have begun:

Kinetic has announced a 1/48th C-2 to go with its E-2. Click here for a preview.

In 1/72nd, RVHP has produced a highly detailed resin C-2 conversion for the Hasegawa E-2C. It includes a complete interior. You don't have to bother with removing the dihedral in the Hasegawa kit's horizontal tail because a replacement empennage is provided. Decals vary with the boxing.. They are available from Hannants. Click here for an example and search the website for RVHP C-2 for the rest. A build article by an expert modeler is provided here.

The RVHP kit is expensive. If you want to spend less and don't place any value on your time, there are two 1/72nd vacuform conversions, both intended to be used with the Fujimi E-2 kit and not far removed from scratch building a new fuselage for it. The first was from MHW Models in England. It's pretty crude. The fuselage halves, which is all you get in the kit, are fairly thick but devoid of detail. The wing juncture looks a little dubious. There are no decals. However, the fuselage shape appears to be based on the conversion article in IMPS 8Q1 that was authored by a Grumman engineer, using factory drawings. The other vacuform is in Falcon Triple Conversion Kit IX along with the fuselage and other parts for an FJ-3 and the radome and aft canopy for an AD-5W. It is still available. The fuselage looks good and the canopy provided is better than the one in the Fujimi kit as long as you don't mind dealing with a vacuformed one. The hump over the horizontal tail is not accurate. The instruction sheet does not make it clear that the horizontal tail dihedral has to be removed. No decals are provided.

Four-bladed propellers with rounded tips in 1/72nd scale were produced by Aires (Quickboost). Click here. They are also available from Sprue Brothers.

Friday, May 13, 2011

Stoof Redux Redux

In the interest of providing a largely one-stop service for modelers asking Kinetic S-2 kit questions, I've updated my Stoof web entry with pictures and information on the wing-fold jury struts and the searchlight. Click Here