Friday, June 2, 2017

Lockheed P/F-80 Shooting Star Tip Tanks

It may seem like I'm going off the reservation again with this topic but it does, peripherally, pertain to a airplane operated by the U.S. Navy.

It is also a work in progress, since I personally don't have a lot of material to work with. Gerry Asher has yet to fully weigh in, so there will be changes. Since I posted it today, I've modified the source of the second and the final tank to be Fletcher Aviation Corporation, an aerospace manufacturer that subsequently became Sargent Fletcher a decade or so later.

The P-80 wing tip incorporated a shackle from which to hang a jettisonable fuel tank or 1,000-lb bomb (the requirement to do both dictated its location under the wing; otherwise the tank would have been mounted in-line on the wingtip to maximize the end-plate effect).
The original 165-gallon tip tank was a thing of zaftig beauty, with a rounded nose and sculptured afterbody, that was mounted directly under the wing tip and smoothly faired into it.

Note the flange going from nose to tail on the top and bottom of the tank since it was assembled from two halves.

This tank was sometimes dropped in flight or otherwise damaged and needed to be replaced. As a result, a cheaper design was procured from Fletcher.

Note that it has a pointed nose, a constant-diameter midsection (barrel), and a more conical afterbody. It would appear that this tank was manufactured in three sections: forward, mid, and aft that were then assembled together.

It is this tank that was the basis for the so-called Misawa tank, which added two more of the barrel sections to increase its fuel capacity by a much-needed 90 (some sources state 100) gallons (Misawa was the Air Force base in Japan where this kludge was created: see http://yellowlegs-and-others.com/Equipment_Vehicles_Weapons/Misawa_Tank.html).

However, Lockheed, Fletcher, or some other source designed and manufactured yet another tank that had a higher fineness ratio and a rounded nose. This tank is frequently seen on RF-80s:

And also on most U.S. Navy TO/TV-1s:

And on early T-33s and F-94s:

Note that it appears to be slung somewhat lower than the other tanks with a fairing enclosing the attachment to the wing. This is my best guess as to its size and shape.

The final F-80 tank, similar in configuration to the Misawa tank, was also procured from Fletcher. It was mounted inline with the wingtip rather than under it and sported a side-mounted fin on the afterbody. It increased the capacity of the tip tank to 230 gallons.

I'd appreciate information on and links to drawings and dimensions of these tanks.

Thursday, March 2, 2017

A-1E Yankee Escape System

The US Air Force installed Stanley's Yankee escape system in its A-1E Skyraiders as well as its single-seat ones. The Navy incorporated it in single-seat Skyraiders in at least two attack squadrons late in their fleet service but not in any of their wide-body A-1s.

From a Stanley Aviation Brochure:



From Ed Barthelmes excellent A-1 Skyraider Walkaround*:

* If you don't have it, you should buy it:

Sunday, January 15, 2017

C-130 Dihedral

In response to a discussion about C-130 wing dihedral:

The outboard wing panel had 2.5 degrees of dihedral, probably measured at the trailing edge.

 Note that this drawing is from a Lockheed C-130 (no revision letter) so it shows an outboard location for the external fuel tank.

As a result, the wing was not flat across the top as shown by the red line in the front view above and by comparison of the airfoils on the side view here, at least statically when there was no fuel load:

Some say that when the airplane was fueled (all of it was in the wing, most in the outboard wing panels) that the wing was flat across the top.

Sunday, January 8, 2017

F4H Aft Fuselage Cross Sections

The shape of the aft part of the engine nacelle of the excellent 1/48th Zoukei-Mura F-4J Phantom has been questioned. For what it's worth to the discussion, this is a depiction of the cross sections from pretty good drawings produced by McAir. Note that it depicts the Blue Angels F-4J, almost all of which had the F-4B J79-8 engines installed. However, the nacelle shape of the F-4B/N/J/S forward of FS 493, i.e. the unpainted "finger plate" surrounding the afterburner nozzle was the same.

For a description of the difference between the F-4B/N and F-4J/S afterburner nozzles and their respective "finger plates", see http://tailspintopics.blogspot.com/2012/12/j79-exhaust-nozzles.html