The Widebody Skyraider Redux

One of my earliest posts was a recycled but expanded article from my old IPMS Update column, Tailhook Topics: http://tailspintopics.blogspot.com/2009/12/widebody-skyraider.html

Some other significant differences between the narrow and wide-body Skyraiders are provided here:
 https://tailspintopics.blogspot.com/2016/09/skale-wings-172-douglas-ad-5w-skyraider.html

VA(AW)-35 AD-5N Rod Wernicke via Mike Kimbell

Heretofore, I had assumed that the AD-5 was created using the basic structure of the single-seat Skyraider from the firewall forward and the lower half of the airframe, including the wing and horizontal tail.

I hadn't been able to reconcile the  Fuselage Station 0 points shown on Douglas single-seat and wide-body Skyraider desktop model drawings, but I assumed that one of the draftsmen had made a mistake. I was therefore surprised when my go-to Skyraider guy, Ed Barthelmes, sent me an AD-5 fuselage station drawing to find that the engine installation and cockpit had clearly been moved forward somewhat and the horizontal tails didn't line up exactly.

The engine was probably moved forward to offset the weight of the larger vertical fin and rudder. You'll note in the original Widebody post that the two inboard stores pylons were also reconfigured between the AD-4 and -5, apparently for a more forward center of gravity when bombs were loaded on them.

If you bother to examine the illustration closely, you'll note that there are several small discrepancies between the location of some of fuselage stations, the outline of the single-seat canopy and vertical fin, etc. Draftsmen in the early 1950s didn't not have the benefit of computer drawing programs and frankly, precision in these particular drawings was not important. They were reference, not build-to, documents. I therefore can't be sure that there was in fact a stabilizer-location difference

Since one of the more significant change was the shift forward of the engine, I have redrawn the basic firewall changes to depict the exact locations of the major changes. Note that the shapes of the cowling are not exact since I didn't have good lines drawings to use.

F4H/F-4 370-Gallon External Tank Redux

4 February 2026: Hypersonic Models (https://hypersonicmodels.com/) Update:

In an earlier Things-Under-Wing post(http://tailspintopics.blogspot.com/2013/06/things-under-wings-f4h-f-4-phantom.html), I provided information on and illustrations of the Navy F4H/F-4 external tanks. It described two different 370-gallon tanks, with the earlier McDonnell one not usually provided in F-4 kits. Jeffrey Kubiak of Hypersonic Models is now offering it in 1/72 scale, 3D printed:

 

Click HERE for more pictures and order information.

For his resin 1/48 tank, click HERE.

Jeffrey recently sent me a picture of what appears to be a third 370-gallon tank that had been brought to his attention by Joerg Stange.

The differences are subtle but it almost certainly isn't either the original McDonnell or the subsequent Sargent Fletcher tank, at least in their well-known configurations. The center section appears to be less "bulged" than the McDonnell tank, if not actually cylindrical like the Sargent Fletcher tank. The flange on the left side of the tank is located below its center line like the Sargent Fletcher tank but it is not as long, probably because the cylindrical section is shorter than it is on the Sargent Fletcher tank.

My guess is that this is the 370-gallon tank produced by Royal Jet that is listed in one version of the F-4 Flight manual. An informed identification of it would be welcome. However, it doesn't seem to have been widely used, certainly rarely photographed, compared to the Sargent Fletcher tank.

This is a crop of the picture Joerg identified in his first comment below, which was in Part 2 of First and Foremost (NAVA 3); a high resolution image was kindly provided to me by Angelo Romano. You can order a copy of this excellent monograph here: http://www.aeroslides.com/modelpublishing/book-store.html

Note that the tank under the left wing appears to have a shorter cylindrical section and flange than the Sargent Fletcher tank; it is likely that this is the relatively rarely photographed Royal Jet tank. (The one under the right wing is the tank that was furnished by McAir.)

A3D/A-3 Skywarrior Folding Vertical Fin/Rudder

The Skywarrior is a big model, particularly in 1/48 scale. Some may want to build it with the tail folded as well as the wings, in which case the jury strut that was installed when the fin was folded would be recommended. For an illustration of it and the fold joint, see http://tailhooktopics.blogspot.com/2014/02/a3da-3-skywarrior-vertical-fin-fold.html

F4H/F-4 Topic Index

 The Ill-fated 1st Sage Burner (Robert F. Dorr Collection)

As it turns out, Kim Simmelink has done the work for me. See http://phantomphacts.blogspot.com/2013/10/here-are-some-very-interesting-topics.html

I recommend that you take the time to review the posts on his blog.

Here are a couple that he didn't list:

http://thanlont.blogspot.com/2013/03/f4h-1-f4h-1f-f-4a.html

http://thanlont.blogspot.com/2012/11/approach-lights-redux.html

Production F-111B Fuselage

Mark Nankivil has been scanning material from the Gerald Balzer collection and keeping me in mind when he comes across something that will be of interest to me. In this case, it was the McDonnell lines drawing for the production F-111B forward fuselage. McDonnell was involved with the F-111B program because they were the subcontractor for the crew escape capsule. When Grumman raised the canopy to improve visibility on approach for the production F-111Bs, McDonnell had to modify the capsule.

I had previously only had a few bits of data (fuselage length increase, windshield angle change, and height increase); a small and somewhat crude three-view drawing; and pictures of the sixth and seventh F-111Bs with the longer nose (but not the raised canopy) to work with. I also assumed that the capsule interface with the fuselage remained the same all around to minimize tooling changes. I was therefore surprised to see that Grumman, in addition to raising the canopy, had lowered the interface of the windscreen with nose, thereby further improving visibility over the nose. I had noted by reference to the pictures of the F-111Bs with the longer nose that they had lowered the radome slightly, which now makes even more sense.

On the two interim-production F-111Bs that flew, the upper side of the nose was modified from the production configuration to marry up with the forward bulkhead of the original escape capsule.

I'll note once again that the at-sea F-111B trials were conducted with an F-111B that did not have all the changes known to be forthcoming in the production aircraft (see http://thanlont.blogspot.com/2009/03/f-111b-carrier-trials.html). As a result, any deficiency related to visibility on approach was already being corrected.

For more on the F-111B, see http://tailspintopics.blogspot.com/2009/10/grumman-f-111b.html and http://thanlont.blogspot.com/2011/01/f-111b-versus-f-14a-one-more-time.html and buy my monograph, available on Amazon (http://www.amazon.com/dp/0942612418) or from Steve Ginter:

World War II Navy Carrier Airplane Antennas

In the process of creating a post on F4U Corsair antenna alternatives (see http://tailhooktopics.blogspot.com/2014/01/f4u-corsair-wire-antenna-alternatives.html and if you haven't looked at it very recently, it has changed), I decided that a more general post here might be of interest.

From the top, the high frequency (HF) radio antenna was a long wire (the lower the frequency, the longer the antenna needed to be for good transmission/reception). It was generally attached to a mast and the tip of the vertical fin or rudder to keep it away from the fuselage, with insulators at each end and a tensioner (either a spring or a rubber cylinder) at one end to keep the aerial taut. A lead-in wire was attached between the antenna and the fuselage, either at the far end, in the middle as shown here, or somewhere in between. Again, a ceramic insulator was provided at the fuselage entry point.

The HF antenna was also used to navigate by radio beacon or range and as a sense antenna for the direction finder. (The sense antenna was needed with early direction finders to resolve whether the needle on the instrument in the cockpit was pointing to or from the transmitter; otherwise, the pilot had to make one or two turns and fly the new heading for a minute or two to determine the way to the beacon.)

Going from left to right on the underside of the airplane, the ZB antenna was also used to determine which direction to fly to the carrier. An ordinary radio beacon could not be used since the carrier did not want to make a transmission that the enemy could home on. The YE-ZB system was implemented to provide an indication to the pilot as to which direction to fly to find the carrier, with the YE transmitter on the carrier sending out a coded signal to the ZB receiver (see http://aafradio.org/docs/YE-ZB.pdf).

The IFF (Identification Friend or Foe) antenna was originally a pair of wires, one on each side of the fuselage, that led to the outboard leading edge of the stabilizer. When turned on, the IFF responded to a transmitted radar pulse with a much stronger return than the reflection of the pulse would be from the airplane itself. This enhanced blip on a radar scope indicated that the airplane was friendly and not a potential threat. The first IFF was British, installed on Spitfires in late September 1940 and subsequently on Seafires as evidenced by this photo.

The U.S. Navy had it installed on early F4Fs (see the post referenced above), F6Fs (shown here), and F4Us (see the post referenced above).

Note the rod antenna on the spine of the fuselage just above the entry point of the IFF antenna that will be discussed subsequently.

This "cheese-cutter" IFF antenna arrangement was subsequently replaced with a rod antenna, usually mounted on the belly of an airplane, as shown on the Avenger picture at the top of this post and here.

A radar altimeter was generally only provided on so-called all-weather aircraft. The antenna looked like an inverted "T".

Two were required, located ten or so feet apart, in this case on the horizontal tail of an F2H-4 Banshee.

One antenna was used to transmit a pulse and the other to receive. The time between transmission and receipt was used to calculate the height of the airplane above the ground or sea.

The Yagi array was the antenna for the earliest airborne radar. This one has presumably just been removed or is being functionally tested prior to installation.

This antenna had to be manually turned to the bearing of interest. The radar return indicated the distance to large objects, like ships or a coastline, in the direction that it was being pointed. To provide 360-degree coverage, one was mounted under each wing. Because of the workload and skill involved in pointing the antenna and interpreting the resulting return, this early radar was only installed on airplanes with a radioman who was responsible for operating it.

Not shown in the Avenger picture above is a VHF (very high frequency) antenna like the one mounted aft of the canopy of a Corsair in a rigid mast. (The forward mast is not an antenna, per se, but just a means of positioning the origination of the HF wire antenna above the fuselage.)

Another variation of the VHF antenna was a simple rod or whip like the later IFF antenna shown above but perhaps twice as long. It may have been the antenna on the spine of the fuselage in the F6F Hellcat picture shown above with the IFF wire antenna. The rigid mast reportedly provided transmission/reception over a broader range of frequencies than the rod antenna but not as good at the specific range of frequencies that the rod antenna was designed for.

After February 1943, the equipment involved was designated in accordance with the Joint Army-Navy Nomenclature System, abbreviated as AN. An example is the Mk III IFF, which was AN/APX-1. The first of the three letters indicated that it was for an Aircraft. The second, the type of equipment, in this case A for radio. The third, the purpose of the equipment, in this case X for identification or recognition. A dash number following the three letters further refined the designation down to a specific piece of equipment, generally in order of qualification in that particular grouping. The first radar altimeter was the AN/ARN-1, with R for Radio (not P for Radar as you would expect) and N for Navigation aid. An ARC was a Radio for two-way Communication. An ARR was a Radio with Reception only, with the AN/ARR-1 being the receiver for the YE-ZB homing system.

For an excellent illustrated description of similar equipment as used on the post-war Royal Canadian Navy Avengers, see http://jproc.ca/rrp/rrp3/avenger_equipment_details.html.

F-4 Phantom ECM Antennas

I was planned to expand my Tailhook Topics Draft post on F-4S ECM antennas (see http://tailhooktopics.blogspot.com/2013/01/f-4s-ecm-antennas.html) but when I came across this one by Kim Simmelink, it was obvious that it would have been a waste of my time, even if I got it all right, which was unlikely: http://phantomphacts.blogspot.com/2013/10/us-navy-f-4bn-phantom-ii-ecm-development.html. Note that he updates it from time to time and his blog lists other F-4 subjects of interest.