Tailhook Topics

by Tommy H. Thomason

Sunday, April 24, 2022

AD-4 Skyraider Variant - AD-4B

Because of its range, the AD Skyraider would be one of the U.S. Navy's carrier-based airplanes assigned to missions employing nuclear weapons. One of the relatively lightweight ones was the Mk 8. Like Little Boy. which was dropped on Hiroshima, it utilized a gun-type method of creating a supercritical mass by literally firing one non-critical mass, a cylinder, down a steel tube onto another non-critical mass, a post. When the cylinder reached the post, the combined mass was supercritical and exploded.

While relatively inefficient compared to an implosion device like Fat Man, not to mention very heavy (because of the big "gun" barrel) compared to the yield, it was also much less likely to malfunction when used to destroy an underground target like a submarine pen. The Mk 8 could reportedly penetrate 22 feet of reinforced concrete before detonating.



The center pylon and belly of the AD-4 had to be modified for the Mk 8 because its weight, about 3,250 lbs, far exceeded its 2,000 lb design capacity, and its suspension lugs were 30 inches apart compared to the 14 inch distance between the latches on the existing Skyraider center-line bomb rack. Since the two forward spars of the wing weren't far enough apart for the longer rack required, instead of being embedded in the bottom of the fuselage it was located below the AD-4B's belly and housed in a streamlined fairing. In addition to beefing up the structure to which the bomb rack was attached, the modification also included the creation of a recess in the belly to provide clearance for the Mk 8 tail fin.

The recess was closed off by a panel when a Mk 8 was not being carried.

The AD-4B could also carry the Mk 7 nuclear weapon, which was much bigger than the Mk 8 but only half as heavy.

The external center-line pylon was retained for the AD-5 and -6/7.

Thanks to Ed Barthelmes for his help with documentation needed for this post.

Wednesday, April 20, 2022

Douglas AD-4 Skyraider Variants

 This is a work in progress...

 The AD-4 prototype, BuNo 122853, on 27 September 1949.

I've done a few posts on the AD-4W, the Airborne Early Warning Skyraider:






I've also recommended three softcover monographs on the Skyraider with material of interest to the scale modeler: https://tailspintopics.blogspot.com/2011/10/ad-skyraider-modeling-notes.html

This is a summary of AD-4 variants (other than the AD-4W and one or two others that were not produced in quantity) and associated Bureau Numbers:

AD-4: Single-seat conventional attack

AD-4B:  Single-seat special stores (nuclear) attack: added external center pylon and Mk 8 tail fin recess

AD-4L: Winterized with deice boots on wing and empennage leading edge and propeller and windshield anti-icing

AD-4N: Three-place (no dive brakes) all-weather attack, ECM, and ASW

AD-4NA: All-weather mission equipment removed

AD-4NL: AD-4N with winterization

AD-4Q: Two-place radar location and jamming and provisions for target tow

Bureau Numbers

122853 AD-3 (AD-4 prototype)

123771 - 124006 AD-4 (123935 and 123952–124005 to AD-4L; 124006 to AD-5)

124037 - 124075 AD-4Q

124128 - 124156 AD-4N (124760 to AD-4NL)

124725 – 124760 AD-4N (All to AD-4NL)

125707 – 125741 AD-4N

125742 – 125764 AD-4NA

126876 – 127018 AD-4N (Most to AD-4NA)

127844 – 127853 AD-4 (127845-52 AD-4L)

127854 - 127872 AD-4 (127854-60, 127866, 127868-72 to AD-4B)

127873 – 127879 AD-4

127880 – 127920 AD-4N  (Most to AD-4NA)

128917 – 129016 (128937-43 and 71-78 to AD-4B)

132227 – 132391 AD-4B

Skyraider kits other than AD-5 and AD-4W almost all represent the AD-6. The most notable difference between the late AD-4 and the AD-6—other than antennas and similar small details—were the stores pylons. This post illustrates the pylon differences: https://tailhooktopics.blogspot.com/2015/07/douglas-ad-1-skyraider-pylons.html

Another example of the flush AD-4 center-line store rack is provided here: https://tailspintopics.blogspot.com/2018/04/things-under-wings-va-195-kitchen-sink.html

The AD-4 configuration also changed during its production run. Most of the improvements were retrofitted to delivered airplanes as well. The two most significant were the addition of another 20 mm cannon in each outer wing panels just outboard of the fold join and "armor". For the latter, see https://tailspintopics.blogspot.com/2013/07/ad-armor-all.html. Others included the exhaust glare shield addition, static-pressure source location, antenna changes, and wing-tip navigation light location.

The AD-4 also predated the development of the Douglas high-speed fuel tanks. Some examples of these post-WW II fuel tanks are illustrated here: https://tailspintopics.blogspot.com/2016/09/things-under-wings-post-war-external.html

Even the single-seat AD-4 had provisions for radar. Some of the different types of radar pods that it and the multi-seat AD-4 attack variants could carry are illustrated here: https://tailspintopics.blogspot.com/2012/11/things-under-wings-radar.html

 More to follow...

Sunday, February 27, 2022

SUNDOWNER Phantoms by Angelo Romano with Michael Grove

The full title says it all:

It's a good synopsis of 68 pages of text and high-resolution color photos on heavyweight gloss paper.

It also includes a brief history of VF-111 going back to October 1942 when its predecessor, VF-11, was established and the origination of its name and insignia that alluded to its purpose, helping win WW II in the Pacific.

The remainder of the large, landscape-format paperback is devoted to a fairly well detailed, extremely well illustrated history of the squadron's operational history flying the F-4 Phantom. It includes a listing of Bureau Numbers assigned (and summary history), their tail codes and side numbers, large color photos of almost every one at some point in its assignment to the squadron, notable configuration changes, and marking changes over time with closeup pictures of significant ones.

It concludes with a multi-view (top and bottom, left and right side) color illustration of the paint and makings of F-4B BuNo 153019 after its crew had shot down a NVAF MiG-17 on 6 March 1972, including color and marking specifications.

Although billed as a modellers' guide, the text includes a summary history of both the squadron's operations and world events when it was assigned Phantoms.

One picture of a Sundowner F-14 is included along with the promise, "The history of the SUNDOWNERS and the F-14 , from 1978 through 1995, will be the subject of a future book in this series".

For more detail on the configuration differences among the F-4s, see https://tailspintopics.blogspot.com/2012/12/you-cant-tell-phantoms-without-score.html

I urge you to buy this monograph directly from Fly Shop if you can, which benefits Angelo more financially, enabling him to continue to research and produce his excellent books on U.S. naval aviation.

Thursday, December 23, 2021

Sword 1/72 AD-4W Redux

 25 December 2021 Update: Ralph asked me to add the following to his review below:

"The build wasn't all doom and gloom. The resin parts were excellent, as were the decals, which are supremely thin, and include many of the fine stencils."

My detail notes after fondling the Sword 1/72 AD-4W kit sprues and trial fitting some of the parts are HERE (a subsequent post with that and two other links that might be of interest for understanding the various AD-4W configurations and detailing a model are HERE.

However, at that point I got distracted and haven't finish it yet. I was therefore very pleased to recently see a build by Ralph Koziarski (aka SoftScience) on Britmodeller. He wrote:

Whoa boy...I started in January and didn't finish until October of 2021. This is built from the Sword kit, and it was a fight from start to finish.

Like any short-run kit, the parts were clunky, and imprecise. Fit was mediocre at best, and a lot of details were missing.  The clear parts are very thick and fit especially poorly. What really made the whole experience unnecessarily frustrating were the poor instructions. Not only were they vague on where smaller parts should fit, they also had contradictory directions on landing gear doors (they want you to fit both kinds that are in the box, at the same time), and allude to details which are not part of the kit (e.g., drop tank sway braces). Its as if the left hand didn't know what the right hand was doing, as the kit was being manufactured.  

Disappointing as the kit and the project were, I'm happy I pushed through, as the final product is hideous and cool, and now I can say I successfully finished a short run kit.

While not very complimentary (and I'm sure that Sword will take the comments on the instructions to heart), the result clearly indicates that, in the right hands, an excellent model can result!

Photos by Ralph Koziarski

Friday, November 12, 2021

Grumman C-2A(R) Monograph Volume II by Boerries Burkhardt


If you have any interest in U.S. Naval Aviation, I recommend without hesitation that you buy this monograph. And I emphasize "without hesitation", because Burkhardt self-published it and only printed 200 copies. It hasn't been available long and I just received #124, so you will regret dilly-dallying.

Order here: https://www.c2greyhound.com/

It is a large (8" x 12") landscape-printed soft-cover book filled with excellent, large, color images of C-2A(R)s printed on high-quality paper. Most of the 100 pages are devoted to pictures but there is text briefly describing the history of the program (some of which was new to me and that doesn't happen often now) and that of the handful of squadrons that operated the Greyhound. Of particular interest to modelers will be the walk-around section providing closeups of interior and exterior details.

I was momentarily concerned that I had missed Volume I but it turns out to be a work in progress. This one primarily covers the second production lot of C-2As (the R stands for Reprocured; one wonders why, given the number of changes and improvements, that it was not simply designate C-2B). Volume I will cover the first production lot. I look forward to it.

Thursday, August 12, 2021

North American FJ-2/3 Cockpit and Landing Gear Color

For some reason, North American was allowed to deliver FJ-2 and -3 Furies with a decidedly nonstandard green cockpit color. This is a picture of the cockpit of an FJ-2 in a museum that appears to be authentic.

Bill Nourse via Jeff Wasal

For background, see https://tailhooktopics.blogspot.com/2015/04/cockpits.html

I haven't come across a specific specification for the color but in response to a question, have done some more research into how long North American continued to deliver FJ-2/3s with this cockpit color. Some have speculated that the changeover to a Dark Gull Gray interior occurred when FJ-3s began to be delivered in the gray/white scheme (note that the requirement for a DGG cockpit predated the one for a Light Gull Gray/White exterior by almost a year. However, color photos of FJ-3Ms clearly show that at least before overhaul and for the ejection seat headrest, the green persisted although I don't know for long in production.

Note that the FJ-3M to the left of the one pictured immediately above, same squadron, appears to have a Gull Gray ejection seat headrest.

This could mean that it had been through overhaul or that the seat had been replaced with a spare that was gray.
However, there's no question that FJ-3s at least eventually had DGG headrests although the cushion stayed green on at least some examples.

The other anomaly recently called to my attention was "black" landing gear on some FJ-3s. The usual color was "aluminum" paint with the interior of all the landing gear doors painted red, not just the edges, although there are white examples much later on.

In the following example, it appears that the coating was extended to the inside of the gear doors and the wheel wells but this may not have always been the case. 

I first made note of it in a screen shot of an F9F-5 Panther in the movie Bridges at Toko-ri.

It was a tar-like application similar to automobile undercoating. When "unpainted" F7U-3 Cutlasses experienced unacceptable corrosion susceptibility and were repainted in the grey/white scheme, the protection was extended in some squadrons to spraying a coat of parel-keytone on the landing gear struts, wheels, inside of the landing gear doors, and wheel wells.

It proved to be a terrible idea. It not only hid the development of existing corrosion on the landing gear structure, it precluded the readability of identification on wire and tubes in the wheel well.


Sunday, August 8, 2021

LF Models Piasecki HRP-1

 15 September 2021 update: Paul Boyer built the LF Models HRP-1 as one of the three operated by the U.S. Coast Guard, the original customer for it (the silver cylinders around the landing gear wheels are pop-open floats for emergency landings on the water).

His summary of the build:

Some build difficulties -  Lack of positive parts locators, weak instructions with respect to assembly process, poor fit of interior parts, no flanges on cabin or door windows (replaced with clear packaging tape slightly larger than the window and applied on the outside of the fuselage along with the addition of decals)

Very fragile rotors (THT note: delicate parts at 1/72nd scale)

Good decals

An illustrated history of the Coast Guard's use of the HRP-1 is available HERE

 The Coast Guard decals are in LFM-PE7250; the USMC decals are in LFM-PE7251

Although only 20 HRP-1s were produced by Piasecki, it represents a major milestone in the early history of helicopters and an amazing achievement for a young man and his small band of helicopter enthusiasts, rivaling and paralleling that of James McDonnell's fledgling company successfully creating a twin-engine carrier-based jet fighter, the FD/FH Phantom. In the unlikely event that anyone is interested, I wrote a paper on the Piasecki and the HRP for a Vertical Flight Symposium that is available for the asking.

I never imagined that an injection-molded kit would ever be produced of the Rescuer. As a result, a few years ago I bought Unicraft's resin HRP kit, even though I was aware from experience that it would be a challenging build at best and likely of marginal accuracy. I was therefore not disappointed when I opened the box, which I have done at least once a year without doing more than considering whether it was worth the effort to build it at all, much less correct its shape and size errors.

I was therefore very surprised to learn that LF Models in the Czech Republic was to release one in early 2021 and disappointed that its projected availability came and went with no update. Nevertheless, it came to pass and was well worth the wait. It is not only injection molded with a good representation of detail including the steel-tube framework in the forward fuselage and the internally mounted engine, it includes injection molded (not vacuum formed) clear parts, canopy masks, decals, photo-etched parts, and a printed representation of the instrument panel dials. It exceeded my expectations by much more than the Unicraft kit failed them.

The HRP was a huge helicopter for the time, dramatically so relative to the little two-seat Sikorskys. I regret to report that the kit is slightly huger than 1/72 but only by a 1/4" or 18 actual inches, which is only about 3 percent not to mention a bit difficult to rectify. I'm certainly going to live with it. Note that I have not built it yet so this is a preliminary review after a close look at the contents of the box.

The instruction sheet is pictorial. This early inboard profile (ignore the rotor-hub fairing depiction) may be of help in understanding and orienting the drive system:

The pilot and copilot seats in the forward fuselage were actually offset slightly to the left side for access from the cabin:

 Note that the pilot had an instrument panel with nine instruments on it as provided in the kit but there was also an upper instrument panel visible in the picture above as a narrow black rectangle above eye level.

The copilot only had a four-instrument panel in front of him.

The vents on the bottom of the engine compartment are well represented but not the big air intake (it was an air-cooled engine) on the top of the fuselage:

I'm not sure about the shape of the blade tips: the kit's are squared off but I'm sure that some, if not all, were rounded:

Note that the rotor diameter should be 6 13/16 inches (41 feet) when assembling it and the rotors did not in fact overlap. That was a later refinement of the tandem rotor concept.

Note that statically, the rotor blade themselves are relatively stiff but angle down from the hub attach point.

In the unlikely event that you see a picture of the attachment of the main landing gear to the bottom of the fuselage that is different from the kit's, that was an early configuration:

A couple of challenges for those wanting to add a degree or two of difficulty:

1. Folded (necessary for stowage aboard ship):

2. Lightened for ASW research with a dipping sonar: