Tailhook Topics

by Tommy H. Thomason

Wednesday, June 2, 2021

Douglas A2D Skyshark

 Clear Prop is now shipping its 1/72 scale XA2D Skyshark kit.

Although I haven't done more than look at what's in the box, my impression is that this is a first class production, including the box. For illustrations, go to Clear Prop's website: https://clearpropmodels.com/cp_72005

Also see the Hyperscale review here: http://www.hyperscale.com/2021/reviews/kits/cp72005reviewbg_1.htm

There were two XA2Ds, BuNo 122988 and 989; six A2Ds were completed and flown of the initial production order of 10. Both XA2Ds were originally painted blue but the second one was subsequently stripped of paint before its first flight. All the production A2Ds were painted blue.

While this kit provides parts and decals for the two XA2Ds, my understanding is that all the parts needed for a production A2D are included except for the very different canopy. The XA2D canopy had flat sides and top like the F4D Skyray whereas the production canopy was rounded.

The XA2D sliding canopy was also large and mounted on top of the fuselage; the sliding portion of the A2D canopy was smaller and mounted on a large fixed fairing that was on top of the fuselage.

There were variations in the exhaust fairings on the sides of the fuselage in part to resolve heating problems on the aft fuselage. Flight test began with a simple oval opening in the side of a fuselage but at least two increasing larger fairings were evaluated on the first XA2D.

Interestingly, when flight test finally resumed with XA2D BuNo 122989, the exhaust was once again a simple oval with no fairing.

And at least the first two production A2Ds also had no fairing initially. However,  one was subsequently added to the first production A2D and appears to have been the final configuration.

Steve Ginter's A2D Monograph (Naval Fighters Number Forty-Three) is an excellent reference. Unfortunately, Steve no longer has any in his inventory. It is still available from Amazon but buyer beware that it might be a relatively low-quality print-on-demand version.

Saturday, May 29, 2021

A Kaman HU2K/H-2 Seasprite Introduction

A work in progress:

The Kaman Aircraft Corporation won a Navy competition in 1956 for a small, high-speed, all-weather utility helicopter. It was designated the HU2K but by the time it entered service it had been redesignated the HU-2. Kaman produced a total of 190 of UH-2As and-2Bs.* The only difference between the A and B was navigation avionics, the lack of a full suite in the UH-2B meant that it was restricted to VFR (Visual Flight Rules) only. Externally, they were identical: single engine, four-bladed main rotor, three-bladed tail rotor, and retractable main landing gear.

The following were the Bureau Numbers:

147202-147205: Prototypes (short nose and small tail wheel)

147972-147983; 149013-149306; 149739-149786; 150139-150186;151300-141355; 152189-152206

One problem with identifying the subsequent UH-2 variants from photographs using the Bureau Number is that most were conversions of the original 190.

The first was the UH-2C, which was now powered by two engines:

There were 57 conversions from A/Bs. Note that the rescue hoist is no longer retractable and there is a boom that swung out to put the rescue collar in the pilot's field of view. It has a wider vertical fin below the arc of the tail rotor with an airfoil shape providing a yawing moment to the left in forward flight.

Six A/Bs were modified to the twin-engine HH-2C.

These were armed and armored for combat rescue. A four-bladed tail rotor was required and the heavier gross weight necessitated a dual-wheel main landing gear. The bubble fairing above the rescue hoist allowed for a reel with 200 feet of cable. However, even with uprated engines, these were underpowered for the hot, high conditions in southeast Asia.

The somewhat misdesignated HH-2D addressed the hover-performance issue by deleting the armor and armament. A total of 67 conversions were accomplished to what was really a UH mission capability.

This example is on display at the American Helicopter Museum (https://americanhelicopter.museum/) at the Brandywine Municipal Airport in West Chester, Pennsylvania.

The need for ASW (Anti-Submarine Warfare) helicopters that could be deployed from small non-aviation ships and capable of seeking out and destroying submarines resulted in the next variant, the SH-2D that resulted in 24 conversions; the four-bladed tail rotor and dual-wheel main landing gear of the HH-2C were utilized:

The added mission equipment included a surface-search radar under the forward fuselage, a Magnetic Anomaly Detection "bird" that was deployed from a outrigger on the right side of the fuselage, a sonobouy launcher on the left side of the cabin, and a smoke bomb dispenser for marking the location of MAD contacts. It could be armed with up to two homing torpedoes but each displaced an external fuel tank.

There were two YSH-2Es, conversions from BuNos 149033 and 150181. these were configured with other ASW avionics for evaluation.

Both were eventually converted to be SH-2Fs.

The SH-2Fs were initially conversions of a total of 104 of the original 190 UH-2A/Bs. They were powered by uprated T58s. Other modifications included strengthened landing gear and a new rotor hub, neither of which is notable externally. However, the tail landing gear was moved forward to provide more clearance from the deck edge, making it easy to identify this variant.

At this point, the Navy was finally running out of H-2 airframes to convert but needed more SH-2Fs so Kaman received a contract to build 54 new ones (in some cases, fabrication reportedly included building parts on the original tooling and then modifying them on the tooling created to convert the original parts). The BuNos are 161641-161658; 161898-161915; 162576-162587; and 162650-162655.

In 1986, SH-2Fs equipped with FLIR (Forward-Looking Infrared) systems and other non-ASW mission equipment began to be deployed into the Persian Gulf for night and mine-detection missions; they were also equipped with missile-defense systems.

Last but not least, the U.S. Navy bought six more SH-2s, BuNos 163209-163214, powered by GE T700 engines and designated SH-2G, the so-called Super Seasprite. Additional SH-2Gs were created from former SH-2Fs and New Zealand procured five new SH-2Gs from Kaman.

Gs were also operated by Australia (briefly and unhappily), Peru, Egypt, and Poland.

*Clear Prop Models has recently released an all-new, excellent 1/72 scale kit of the UH-2A/B: https://clearpropmodels.com/uh-2a/bseasprite

A Paul Boyer summary of the kit in the October 2020 issue of Fine Scale Modeler:

Clear Prop is planning on releasing a UH-2C and an HH-2D this year in 1/72.

Tuesday, March 30, 2021

North American AJ Savage Model Kits

A work in progress; more later:

 I was surprised but pleased to see a release of excellent AJ 1/72 scale Savage decals from CTA (Cut Then Add), which is based in Moscow.

For more on this company's products, see https://www.ctamodels.com/

I was surprised mainly because 1/72 kits, with one exception, are hard to come by and building any of them has a higher degree of difficulty than the average kit builder might wish to cope with.

There are also accuracy issues, in part related to the differences between the AJ-1 and AJ-2 and among the AJ-2Ps.

The AJ empennage was redesigned after a fatal accident in flight test when a structural demonstration resulted in the empennage being torn off. The original one had a very large rudder, believed necessary for an engine failure shortly after launch and one-engine-inoperative wave offs (also see https://thanlont.blogspot.com/2010/11/one-if-by-land-two-if-by-sea.html). The vertical fin was enlarged in area, the rudder was reduced in area (but repositioned a bit farther aft to minimize the reduction in its control power), the dihedral was removed from the horizontal stabilizer, and the horizontal strake on each side of the fuselage above the jet engine tailpipe was removed. All surviving AJ-1s were retrofitted with this empennage and all AJ-2s were built with it.

Another change introduced with the AJ-2 (and later production AJ-2Ps) was a redesign of the flight deck. The AJ-1 had seats for two on the flight deck, the pilot on the left and the bombardier on the right. There was a third seat on the lower deck just across from the entry door. With the AJ-2, the third crewman's position was relocated to the flight deck in an aft-facing seat. This required that the canopy be raised and lengthened. The controls for the pilot were also changed from a stick to a control wheel and the throttle quadrant was moved from his left to the center console on his right.

For more details on the Savage, see https://tailspintopics.blogspot.com/2011/07/aj-savage-notes.html and https://tailspintopics.blogspot.com/2013/04/aj-2-savage-cockpit.html and https://tailhooktopics.blogspot.com/2013/01/aj-savage-bombardier-station.html

The AJ-2 also had a modified hydraulic system. The only external indication of this is a two-piece nose landing gear door in place of the AJ-1's single rectangular door.

Unfortunately, these differences between the AJ-1 and -2 were not realized by kit manufacturers. There are four 1/72 kits:

Airmodel vacuum-formed AJ-1:

You don't get much (basic shell and canopy, no landing gear, no propellers, no decals, etc.) and what you do get is pretty crude, particularly the canopy. With a significant amount of correction to the plastic provided and scratch-building/scrounging of detail parts, a presentable model from the "kit" can be created.

The Mk 4 bomb and trailer were from 12 Squared: good luck finding that. A drawing for scratchbuilding one is here: https://tailspintopics.blogspot.com/2011/07/getting-it-right.html

One interesting aspect of this model is that it looks about right even though it has major shape issues: for example, the wings are too thick but that is offset by the nacelles not being deep enough.

Rareplanes vacuum-formed AJ-2/2P:

The late Gordon Stevens basically created the vacuum-formed kit concept, producing examples of airplanes that no injection-molded kit company would consider offering at the time. His products are also the standard for this kit type in quality and appearance. His AJ-2/2P is no exception, augmented by additions from Hannants.

It has white metal details, excellent decals, comprehensive instructions, and fuselage halves that are actually the same size. Regrettably he did not have source material equal to his intentions and expertise and may not have been involved in the sourcing of the propellers, which are the kit's most obvious error:

The propeller diameter is about right (a little undersized but then so is the kit itself) but the propeller blade tips should not be quite as wide and the width of the blades should then taper in a straight line (somewhat less than it looks like from head-on because of the blade twist) to the hub.

The drawings that he relied on were also inaccurate with respect to the vertical fin (the red outline is from North American's excellent AJ-1 side view; the green detail is the AJ-2 from North American engineering drawings and almost certainly indicates the correct location for the horizontal stabilizer):

An unforced error was that he assumed the AJ-2 canopy was the same length as the AJ-1's, just with different frames. As a result, it is a bit too short.

The kit is also slightly undersized but that's not a deal breaker in my opinion. Tony W currently has a build post on Britmodeler HERE.

Mach 2 injection-molded AJ-2/2P:

Mach 2 appears to have used the Rareplanes kit as a basis. The fuselage halves are virtually identical in size and shape, as are the wings and the nacelles, so it is slightly undersized as well along with a vertical fin that is not quite long enough. However, the clearish cast canopy is that of an AJ-1 or early AJ-2P (it's also awful; I reshaped it and used it as a vacuum-form master for my Airmodel AJ-1 build).

It is possibly better than the average Mach 2 kit and certainly buildable. Replacing the canopy requires some skill but the other issues like redoing the imaginary flight deck and reshaping the top of the vertical fin are straightforward. And it is still available

This is a model from the Mach 2 kit with a replacement -2 canopy (it looks like the one in the Rareplane kit, which came with two of them) on display at Mosquitocon in 2014

                                                            Photo by Adrian Davies

Anigrand resin 1/72 AJ-2:

This is by far the most accurate AJ kit (full disclosure: I provided drawings to Anigrand for it and reviewed photos of the first casts). Note the cast canopy. The only flaw that I remember (the box is currently in the back of warehouse behind the Ark of the Covenant crate) is the tail hook.

This is what the AJ tail hook should look like:

This is an Anigrand kit built by Brett R:

 And another with a review by Scott Van Aken: https://modelingmadness.com/scott/korean/us/usn/aj2.htm

Nostalgic Plastic was the U.S. distributor for Anigrand and included extra decals and a CD with additional information and photos on the type that I created.

Other notes:

In order to minimize weight, North American provided the Savage with a cumbersome method of folding the wing and vertical fin. See https://thanlont.blogspot.com/2010/03/hell-it-wont-fit-ii.html

Because of its size, aircraft carrier captains tended to prefer that the AJs be based ashore and only flown out to the ship (where nuclear bombs were stored for safekeeping) when the balloon was about to go up. However, after it was repurposed to be an airborne provider of jet fuel, its popularity increased significantly, particularly in the western Pacific where alternatives to landing back aboard the carrier could be few and too far between. See https://thanlont.blogspot.com/2013/12/texaco-redux.html

Sunday, December 20, 2020

Angelo Romano Rules!

 Angelo Romano has been creating excellent books on U.S. Navy operating units since at least 2004. He has an enormous and well-organized collection of photos (some of which he has taken himself over the years); books and documents; and an address book of subject-matter experts second to none. His latest, published in conjunction with Ginter Books, is World Class Diamondbacks, A Pictorial History of Strike Fighter Squadron 102 (VFA-102):

It is available from Ginter Books: http://www.ginterbooks.com/NAVAL/NF306/USN_SQ_Hist_306.htm

You can buy with confidence that it is as comprehensive, informative, beautifully illustrated, and high-quality as his other books.

I’ve written brief reviews about most of them, which probably don’t do them justice; I’ve assumed that if you have any interest in the subject matter, you will not hesitate to buy any of them:

Thursday, November 26, 2020

Douglas A-4 Skyhawk: Early ECM Antennas

Defensive Electronic Countermeasures (DECM) against Surface-to-Air Missiles (SAMs) was a given for large Navy attack airplanes but not initially for the A-4 Skyhawk because of the size and weight of the electronics required. Losses over North Vietnam dictated its addition, in part as Project Shoehorn.

The exterior change was the addition of five antennas, three forward and two aft. One forward or one aft detected the radar pulse of four different kinds of fire-control radar. The ALQ-51 electronics then automatically transmitted a pulse from the other two forward antennas or the other one aft that misled the radar operator or confused him as to the location of the airplane, preventing guidance of the SAM to it. For an instructive video on the process, click HERE.

The antenna resembled an ice cream cone:

The forward transmitting antennas were located on either side of the nose landing gear actuator well. Two were probably required because there was no place to mount one aft of that or if there was, the airframe or stores might block or diminish the signal from it in some directions.

The antennas were exposed and therefore sometimes broken off. In that event or if they were not required, they would be replaced by a half-round black rubber ball as in the mount labeled 9 here:

A subsequent addition to the Skyhawk's ECM suite provided the pilot with a warning that a fire-control radar was tracking him to improve his chances of spotting a SAM fired at him and evading it in case it wasn't being spoofed. This was the APR-25. It utilized four antennas about the size and shape of small drink coasters, two facing forward and two aft. They were angled outward so the APR-25 electronics could analyze the strength of the pulse being received at each antenna, determine the direction it was coming from, and display that to the pilot on a scope in the cockpit.

The two aft antennas were mounted one on each side of the sugar scoop.

The two forward APR-25 antennas were colocated with the forward facing ALQ-51 receiving antenna in a larger fairing.

Thanks to Dave Dollarhide, Bill Egen, Carlton Floyd, and Jim Winchester for their help with this topic; any errors in the above were made by me. Comments, corrections, and additional information are welcome.

Monday, August 31, 2020

The Colorful TBM-3U

2 September 2020: Sword plans to issue a kit of the TBM-3U at the end of the year.

2 September 2020: The white store under the right wing is an AN/APS-4 radar. See https://tailspintopics.blogspot.com/2014/11/things-under-wings-anaps-4.html

Sword Models (https://www.facebook.com/swordmodels/) has just released three 1/72 scale kits of postwar TBMs (for a summary of all the U.S. Navy variants and a guideline for the presence of an internal or external tailhook, see https://thanlont.blogspot.com/2015/07/post-war-eastern-tbm-variants.html):

SW72130 Avenger AS.4

SW72131 TBM-3S2

SW72132 TBM-3R

The TBM-3R was the first real COD (Carrier Onboard Delivery) in the U.S. Navy. For more, see https://tailhooktopics.blogspot.com/2013/01/tbm-3r-cod.html

One of the significant differences among these versions is the various canopy iterations from the standard one with a prominent machine gun turret. As a result, the TBM-3R kit makes it easy to create a fourth and very colorful variant, the TBM-3U.

The U for Utility TBM was a modification of existing one involving the removal of all offensive and defensive equipment and addition of a target-tow capability. The canopy was basically identical to one of the TBM-3R variants.

This is a notional inboard profile:

Note that the tow reel might be mounted higher to fit within the width of the lower fuselage at that point. The circular structure on which the turret was mounted would probably still be present.

The tail hook might be internal or external depending on the TBM used for the conversion or removed entirely.



 External (note the cutback of the lower gun tunnel)

 This is probably a TBM-3J (note that it still has a rear turret) with the external tailhook removed:

The tow reel might look something like this, less the structure aft of the reel (this is the pod-mounted AD Skyraider tow mechanism):

Although later target-tow airplanes had engine gray fuselages, as of May 1946 they had gloss Sea Blue fuselages as well as an 18-inch wide walkway on the upper surface of the wings adjacent to the fuselage. The upper and lower surface of the wings and horizontal stabilizer were to be Orange Yellow as well as the vertical fin (the rudder was to be Insignia Red). A 36-inch wide Insignia Red band was also to be painted on the upper and lower surface of the wing about one third of the distance outboard from the fuselage to the wing tip.

Sunday, June 28, 2020

FJ-4 and FJ-4B Stores Pylons

Mads Bangsø asked for information on the FJ-4 and FJ-4B pylons. I knew the subject was complicated but had forgotten how complicated it was.

First, the FJ-4 was equipped with four external stores stations, outboard and mid-wing, and the FJ-4B attack derivative with six: outboard, mid-wing, and inboard.

FJ-4 pylons:
FJ-4B pylons:
 Unfortunately, I don't have any drawings or dimensions for any of the pylons.

Second, only the mid-wing stations on the FJ-4 were plumbed for external fuel tanks. On the FJ-4B, the outboard stations were also plumbed for external fuel tanks.

After that, it gets complicated. What I'll call "pylon adapters" could be mounted at the stores stations as on this FJ-4 target tug.
Note that when the mid-wing pylon was removed, the plumbing connections were covered by a small fairing. I'm pretty sure that one wasn't required on the FJ-4 outboard station.

Pylons suitable to the store to be carried were attached to the pylon adapter.

I don't know if the Sidewinder was carried on a bespoke pylon attached directly to the wing or it also utilized the adapter.

The pylons get really complicated on the FJ-4B:
All the stations could carry rocket pods or Bullpups (if armed with Bullpups, the right inboard station was used for a Bullpup-control pod.) The outboard stations were capable of carrying a 150-gallon Douglas fuel tank on a dedicated pylon and the mid-wing stations, the standard FJ 200-gallon tank, a Mk 7 nuclear weapon (left side only), or the North American inflight-refueling tanks. Note that the different stores required different pylons and some did not utilize the adapter but were attached directly to the wing.

Also, the inboard adapter was different:

Missing from the above display are the unique Bullpup pylons.

 However, the adapter on the right inboard station was utilized for a pylon to which was mounted the Bullpup control pod.

The refueling pods pylon (the right pod carried the hose and reel in addition to some fuel):
It appears to have been attached directly to the wing.

The Mk 7 pylon was also attached directly to the wing:
As was the outboard pylon for the 150-gallon tank (the tip of the outboard tank seems to be bulged but that is the nose of a tank mounted on the mid-wing station).
Whereas the 200-gallon tank on the mid-wing station utilized the adapter the same as the FJ-4:

The standard nuclear strike configuration was the Mk 7 and three external tanks:

Rocket pods were hung from pylons mounted on the adapters;

This FJ-4B has a pylon on the mid-wing station for bombs, no adapter (it appears to be identical to the pylon used for the inflight-refueling pods):

And lastly, when there were no adapters or bespoke pylons, a small fairing was substituted near the aft end of the station (the dark areas on the most outboard fairing are from the location of the national insignia), even for some reason, the inboard one, at least on the right side.