Tailhook Topics

by Tommy H. Thomason

Saturday, July 7, 2018

What Color Are the Wheel Wells On a (insert airplane type)?

This is a work in progress...

One of the least likely modeler questions to be answered accurately is the color of the wheel wells and the interior side of the landing gear doors on an overall-all blue carrier-based airplane. For earlier color schemes, they were usually the same as the underside. For the gray/white paint scheme, they were white.

One problem is these surfaces are almost always in shadow if they are visible at all (while this is not true of museum examples, the color—like the configuration—is not necessarily to be relied on). Another is that the paint specifications at the time were not very specific with respect to them.

From late 1944 to the introduction of the gray/white scheme, wheel wells appear to have been considered by most airplane manufacturers as "structural spaces" on which more than one coat of zinc chromate primer (yellowish) were to be applied. (There was no mention at all of the color of the interior side of landing-gear doors.) The second and subsequent coats of zinc chromate were to be tinted with black enamel and aluminum pigment paste. This resulted in a green color, which made it obvious that the second coat had been applied. A subsequent bulletin issued in August 1946 specified that the color was to be Interior Green.

Note that while the Navy's specification might have been somewhat vague in this respect, each manufacturer's production documentation was very specific and had be be approved. One example of an approved practice not delineated in the existing specification was McDonnell's painting the interior side of the landing-gear doors red. Probably the most accurate restorations are those done by the National Air and Space Museum. These are my photographs of the wheel wells of its FH-1:

Note that the landing gear and wheels are blue. However, this FH-1 when in service had aluminum-colored landing gear.

Vought, on the other hand, delivered its F7U-1s with Interior Green on the inside of the landing-gear doors.

However, the answer is further complicated by the fact that Navy airplanes usually went through repair and overhaul at a Navy facility during their service life and the process documentation was not necessarily the same as the original manufacturer's or even other Navy R&O facilities. One example is the painting of wheel wells and landing gear. F2H-2s might have been delivered from McDonnell with red interiors on the gear doors and aluminum-painted landing gear:

But coming out of a Navy R&O facility, they were blue.

My impression is that the overhauled airplanes had blue wheel wells in general as well.

Gray scale pictures of landing gears can also be misleading. For example, this North American FJ-1 had Interior Green landing gear since that was another local option, so to speak, at the time.

My guess is that the wheel wells and gear door interiors were also Interior Green at the time but if you Google "Newsletter Volume 23 Number 9 09-16 LISMS NL.pdf", Steve Muth's pictures of a derelict FJ-1 clearly show that at some point, the wheels wells were painted blue.

And if those examples indicated a lack of surety, note that this F3D has a blue hub on the main landing gear and an aluminum-painted one on the nose landing gear.

Note that some landing gears were painted white, which I think provided some degree of increased safety for deck crewmen working around propellers and engine inlets at night on a carrier deck.

More later,

Monday, June 11, 2018

Modeling the Jolly Rogers' History

There are many themes on which to focus your modeling efforts. One of my favorites is an air group on a specific deployment, such as the first one of Enterprise (CVN-65) in 1962. Befitting the first nuclear-powered aircraft carrier, some of the aircraft types CVG-6 were also deploying for the first time. Others were tried and true.

Of course, there are difficulties - there is no 1/72 kit of the A3J-1 for example and some of the colorful markings will have to be created somehow.

Another theme is to build all the airplanes flown over time by a specific squadron, or at least squadrons using the same nickname. This has become easy-peasy from a markings standpoint for an iconic one like the Navy's Jolly Rogers thanks to a Russian decal producer, CtA, which stands for Cut then Add.

The "Bones" adorned so many different types that they have to be covered in two parts.

I've noticed an error on one that I looked at closely, the FJ-3, The band on the nose should be white, which was the trim color for the second squadron when the airplanes were painted blue, not orange-yellow, the trim color when the airplanes were painted gray/white (see http://tailspintopics.blogspot.com/2009/12/changing-from-blue-to-graywhite.html for a complication).

However, this decal is easy to replace by painting the nose white and masking off the marking when applying the overall blue.

 Unfortunately, they relied on an online profile in this particular instance, which led them astray. In other instances, their scholarship is obviously good and even shared. For example, see https://ctamodels.com/images/skywarrior3.pdf

CtA's product line is eclectic at the moment, with decal options for aircraft from different countries. And even the movies:
See their website here: https://ctamodels.com/buy-cta-decal-here

An RA-5C build with Welcome to the Jungle decals is HERE.

CtA accepts PayPal and ships promptly from Moscow. The decals I got in Connecticut were in a package that could have been left by my mailman on the beach at low tide for a week without getting wet. If we support them with direct purchases, they are more likely to be profitable and encouraged to expand their range and even take requests.

Friday, June 1, 2018

AD-4W Skyraider

I thought I'd already done a post on the AD-4W but if I did, I can't find it. So here's a primer based on information that I provided to a kit maker.

Basic AD notes:

1. The vertical fin and rudder were angled three degrees to the left with an an asymmetric airfoil that lifted to the right. See http://tailspintopics.blogspot.com/2017/08/relying-on-museum-pieces-for-accuracy.html

2. The powerplant section including cowl flaps was angled down by three degrees.

The AD-4W was similar to the AD-4 with the following notable exceptions:

1. Addition of a large belly-mounted radome

2. Landing Gear

The landing gear reverted to the early AD configuration with no doors covering the retracted wheel. The wheel retracted into a round opening on the underside of the wing aft of the main wing spar. The retraction mechanism folded into a truncated triangular opening forward of the spar similar to this AD-5Q.
Jim Robbins Photo

The catapult hooks were relocated from under the inboard wing to the main landing gear strut. This resulted in a different forward-facing landing gear door.

Left main landing gear shown. The forward facing door was sometimes removed for flight.

3. Wing

A "stall strip" was added to the leading edge of the right wing only, roughly the maximum width of the well for the gear retraction mechanism.

A fixed slat was added to the leading edge of the outboard wing panels.
(Underside of right wing. Note pitot.)

The outboard wing panel stores pylons and all guns were deleted although the openings for the attach points for the pylons appear to have been retained. Early type AD pylons were retained on the inner wing panels to carry external fuel tanks.

4. The oil cooler outlet was relocated from the belly to each side of the fuselage just aft of the cowl flaps.

5. Addition of a fairing aft of a new sliding cockpit canopy to house electronic-component cooling system (the windscreen remained the same).

Note the inlet and outlet providing air for a radiator at the aft end of the turtle back.

6. Addition of crew-compartment doors on each side of the mid fuselage. Note that the U.S. Navy AD-4W door's window was not bulged like the Brit airplane's.

7. The "armor" plate added during AD-4 production on the side and belly of the forward fuselage was not installed.

8. Auxiliary vertical fins were added to the horizontal stabilizer to restore directional stability lost with the addition of the radome. Both were angled to left by three degrees like the vertical fin.
 (Before you whinge about the dubiousness of photo interpretation, which would normally be appropriate, this fin orientation is stated in the Douglas AD-4W maintenance manual, with a caution that they are not therefore interchangeable.)

9. The dive brakes were deleted. Unlike the AD-5W, the lower speed brake well was covered over.

10. An HF antenna was added to the top of the vertical fin.

Unfortunately, even Douglas Skyraider drawings are not necessarily accurate in shape. This is a work in process using Douglas drawings attempting to define the location and shape of the crew door and the electronics turtle back.
All published AD-4W drawings are at best a close approximation of the unique details.

Saturday, April 28, 2018

Things Under Wings: VA-195 Kitchen Sink

I provided the configuration of the A-1 Skyraider of the Toilet Bomb caper during the Vietnam War here: http://tailspintopics.blogspot.com/2013/04/things-under-wings-va-25-1-skyraider.html.

Here are details and clarification behind the Kitchen Sink equivalent during the Korean War. For movie coverage, see http://www.buyoutfootage.com/pages/titles/pd_dc_500.php#.WuTAysgh1-U

There is some confusion about the size of the bomb and the rest of the ordnance carried. It was a 500-lb bomb according to my go-to guy for ordnance, Jim Rotramel, not 1,000-lb as in some reports. Based on the referenced movie footage, it was loaded with two other 500-lb bombs on the wing pylons and on the most outboard pylon on the right wing, a strike camera pod.

Note that the side number is 507. One mention of this mission has it also carrying Mk 54 "depth bombs", probably because the bomb was also pictured under 502, which was loaded with Mk 54s at the time.
The bomb was almost certainly painted a nonstandard gloss black although it appears in some photos to possibly be dark blue like the airplane. However, this very contrasty picture of yet another AD, 511, loaded with it strongly suggests that gloss black was the color.
Note that sink was asymmetric, with a big back-splash on its back side (to the right on the airplane) and a working surface on its right side (to the rear of the airplane).

A view from the right side when displayed on 502 (no fuse fitted in the nose).
A view from the left side of 507 with pilot LTJG Carl B. Austin.

The airplane was an AD-4 with the armor kit installed. These Skyraiders had a flush center-line rack/shackle (see http://tailhooktopics.blogspot.com/2015/07/douglas-ad-1-skyraider-pylons.html) so the bomb was snugged up against the belly with separate sway braces. The sink was strapped to the bomb (see the movie footage).

Unfortunately, I don't know the BuNo for 507.

The strike was from Princeton (CV-37) on 25 August 1952. The kitchen sink was reportedly dropped on Pyongyang.

Friday, March 16, 2018

Grumman F9F-2 Panther Length

2 April 2018: I've added some additional illustrations to explain the length change.

Well, there's your problem.
The F9F-2 Panther length is frequently (including on the National Naval Aviation Museum website) as 37' 6" (sometimes 37' 5 3/8"). That's almost certainly based on the original XF9F-2 SAC (Standard Aircraft Characteristics) chart as shown above.

However, the actual length was 37' 11 5/16" as shown, rounded down to 37' 11", on an F9F-2 SAC chart.
Note that this is exactly the same drawing. Only the overall length dimension with the nose cone closed has changed.

If it had been redrawn, the outline would have looked more like this Grumman dimensioned drawing.
The length change appears to have been limited to the vertical fin and extreme aft fuselage. I wouldn't spend too much time worrying about the slightly different wheel locations; in any event, I don't have enough data to establish which is correct. The original SAC drawing may be incorrect with respect to the location of aft end of the fuselage surrounding the tailpipe. It appears that on the XF9F-2 prototypes, it is farther aft, consistent with the production F9F-2's.
Close examination of XF9F-2s indicates that most if not all of the length change was the result of substituting a rudder of increased chord.
Note that the bottom of the production fin and rudder was different from BuNo 122477's , mainly by eliminating the narrow extension downward of the rudder and a triangular bit of the bottom of the fin immediately ahead of it.

Another view of the bottom of the production fin:

Saturday, December 2, 2017

Grumman F9F-2 vs. F9F-5 Wing Root Comparison

On my 2009 post comparing the F9F-2 with the -5 (http://tailspintopics.blogspot.com/2009/10/grumman-panther.html), "davedd" commented that there was a difference between the interface of the fuselage break and the inboard trailing edge of the flap. I hadn't noticed that before, but he is correct.
The F9F-2 example is a crop from the Luc Colin walkaround photo collection in Prime Portal HERE. The F9F-5 example is a crop from the Howard Mason walkaround photo collection in Prime Portal HERE.

The reason is that the -5 had a thinner outboard wing (10%) than the -2's (12%) in order to delay the drag rise at transonic speed, an aerodynamic benefit demonstrated in flight test of Air Force and Navy research airplanes in the late 1940s.
Note that the thickness ratio can be reduced by either decreasing the thickness of the wing or increasing its chord.

Since it was desirable to retain the depth of the wing at the wing fold, the location of the wing-folding hardware and the main landing gear, and still reduce the thickness ratio there, the wing and fairing chords were increased on both sides of the wing fold. The change to the leading edge is obvious but it turns out the trailing edge was moved aft as well.
 Hence the difference in the interface between the fuselage break (which remained at the same fuselage station) and the inboard trailing edge of the flap.

Note that the end of the wing-to-fuselage fairing was relocated aft as well to decrease its thickness ratio as well (on the F9F-8 Cougar, it was moved all the way aft to the end of the fuselage).

Sunday, October 22, 2017

Sword 1/72 North American FJ-2/3 Furies

26 October 2017: Added sketch of nose correction, inlet comparison, and nose landing gear comparison, normal and pressurized.

25 October 2017: Added a discussion (more than you probably want to know) of the nose landing gear here: http://tailhooktopics.blogspot.com/2017/10/fj-23-nose-landing-gear.html

24 October 2017: Added discussion of the shape of the upper nose.

At last, injection-molded kits of the North American FJ-2 and -3 Furies have been released, thanks to Sword Models (www.swordmodels.cz)! It's inexplicable to me why it has taken this long. The swept-wing Fury, like the iconic F-86 Sabre it was based on, is not only beautiful jet but it was dressed in the some of most colorful of 1950s and 1960s markings. Sword has released three high-quality and detailed kits:

FJ-2 SW 72107
FJ-3 SW 72108
FJ-3M SW 72109

The FJ-2 kit has a different fuselage and wing than the -3 and -3M. The FJ-2 had a slightly smaller engine intake, a slightly less deep forward fuselage, and a slightly different air inlet on the after aft side of the fuselage. These differences are correctly represented in the kit rather than making do with the almost identical FJ-3's fuselage. The FJ-2's wing was similar in planform to the F-86E and early Fs with aerodynamically actuated slats. Again, instead of making do with a common wing, the FJ-3 and -3M kits have the notably different, later, so-called "hard wing" with the cambered 6-3 leading-edge extension (and teeny barricade snaggers, although the most outboard one wasn't included). For more on these differences, click here: http://tailspintopics.blogspot.com/2011/04/fj23-fury-redux.html

The FJ-2 was assigned to the Marine Corps and shore-based since it had retained the F-86's J47 engine but was burdened with an increase of about 1,000 lbs in empty weight for carrier-basing capability. It was also one of the airplanes assigned to the Navy's experimental bare-metal exterior project. These are the decals provided with the kit:

As far as I know, all the FJ-3s with the cambered leading edge 6-3 wing were painted gray and white (blue ones would have had the same slatted wing as the FJ-2). These are the markings in the FJ-3 kit:
These are the markings in the FJ-3M kit (the only difference in the plastic from the FJ-3 kit is the addition of Sidewinder missiles and the associated pylons):
 Both the -3 and -3M, but not the FJ-2, come with the inflight refueling probe and optional rudders and horizontal stabilizers that have the external ribbing on the trailing edge. (The rudder was an early change; my understanding is that few if any FJ-3s had the ribbed stabilizer when they were assigned to deployable squadrons.)

If you're thinking that not coming from a Japanese model kit manufacture means these must be short-run, relatively crude moldings with 1/4-inch sprues,  you will be very pleasantly surprised. The control surface and panel lines are engraved and petite. All the many detail parts such as the pitot look as close to scale as can probably be done in 1/72. The canopy is injection molded in two parts and clear. The ejection seat consists of two pieces, seat and headrest, with very fine face-curtain handles and knee guards (however, it is missing a cushion, backpack parachute, and straps). I haven't checked the fit except for fuselage halves and the wings but so far, so good except that the trailing edge of the wings will require some work to be reasonably thin enough.

I regret to report that the kits are not quite perfect in size and shape. The most notable (but not to the eye) is that the fuselage of both the -2 and -3s is about 3/16 inch (5 mm in 1/72; 13 inches full scale) too long due to a misunderstanding about a length measurement. Since the error is pretty much spread along the fuselage, it would be a lot of work to correct and in any event, really isn't noticeable.

What is slightly off and noticeable, at least to my eye, is the nose. It doesn't appear to curve downward enough, the lower intake lip seems to protrude slightly forward, and the inlet is too far forward relative to the cannon ports (which some don't think angle downward enough):
This is another assessment of the upper nose shape based on a pretty good NAA FJ-3 drawing compared to a Craig Kaston photo of a museum's FJ-3 (it looks like the top of the nose curves down a bit too much in the drawing) and the Sword FJ-3 forward fuselage. You'll have to ignore interior detail not matching up due to distortion and the slight stretch in the Sword fuselage.

There appears to be, however, enough plastic in the inlet to cut it back and reshape it if you desire, which also solves the problem of the cannon ports appearing to be too far aft of the inlet lip. Here's one possibility for the -3:
Note that the cannon ports are supposed to be angled downward at 6.5 degrees. The -2 inlet was a little less deep, which the Sword kit represents.
Note that the top of the inlet curves down from the outer edge of the lip notably more than the sides curve in or the bottom curves up.

However, some or most modelers will doubtless be happy with the shape of the Sword nose as is. Neither the downward curve on the top of the nose or change in the curve of the side of the inlet lip  is  as prominent in this picture on an early FJ-2 being evaluated at NAS Patuxent River because the shape of the inlet lip varies with the viewing angle to some extent.

There are some other nits that have been discovered so far. For one thing, the FJ-2 fuselage (but not the -3s) has some "bumps" or bulges that should be removed.

Some wish that Sword had produced the FJ-2 wing with separate slats, since being aerodynamically actuated, they were almost always extended when the Fury was parked or even taxiing. Note that although this was also the static configuration of the F-86's slatted wing, very few kits of the Sabre have this feature either.

The nose landing-gear assembly illustration (seven pieces!) in the instructions appear to suggest that the nose-wheel yoke should be placed on the bottom of the strut. It really goes on the bottom of the small canted cylinder at the front of the bottom of the strut. The yoke itself may be too long but I've haven't confirmed that yet. The top of nose gear door should go into the well a short way, not be mounted outside of it. Also see http://tailhooktopics.blogspot.com/2017/10/fj-23-nose-landing-gear.html

Also the nose landing gear was presssurized for catapult launch to for a greater nose-up attitude.
However, the strut might also also be extended at other times for other reasons...

The windscreen interface with the fuselage appears to need trimming either the forward end of the windscreen or the fuselage where it touches.

There are several threads running in Britmodeller that discuss the kits, with particularly informative and detailed posts by Sabrejet. There are links to a couple of them in my FJ-2/3 post for which  a link is provided above. Searching the Britmodeller website (http://www.britmodeller.com/forums/) will uncover more.

More later...