F8U/F-8 Unit Horizontal Tails

Unit Horizontal Tail (UHT) was the Vought term-of-art for the all-moving stabilator. When the F8U-2NE (F-8E) was adapted for the French Navy requirement, the wing was modified with a two-segment leading-edge flap and boundary layer control for a reduction in approach speed.

A new, larger UHT was required as a result. When the U.S. Navy upgraded some of its F-8Es to the F-8J configuration, this wing and horizontal tail was used to accommodate the increase in gross weight.

Thanks to Tom (Superheat) Weinel and Vought data, I'm finally able to create a pretty good illustration showing not only a size comparison of the larger horizontal tail but where it was located on the fuselage relative to the original one.

There are reports that the change was accomplished simply by adding a leading edge cuff. I'm pretty sure that the cuff in question was incorporated to protect the leading edge from the blast of fuselage-mounted rockets and missiles, not to enlarge the UHT.

Although the UHT was mounted with dihedral of 5° 25', I was unable to determine if the spans given were actual (tip to tip when attached), or of the UHT without dihedral. My guess is that the span was with no dihedral, which is how I created the illustration above. In any event, the difference in span is only about 1/2 inch.

For a summary of F8U/F-8 differences, see http://tailspintopics.blogspot.com/2009/10/f8u-crusader-variations.html