by Tommy H. Thomason

Thursday, February 27, 2014

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
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.

Tuesday, February 18, 2014

F4H/F-4 370-Gallon External Tank Redux

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 1/48 scale:
See https://www.hypersonicmodels.co.uk/product/mcdonnell-370-gal-tank for more pictures and order information.

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.)

Tuesday, February 11, 2014

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