F8U (F-8) Wing

9 August 2022: Added information about the color of the underside of the wing that was above the fuselage

The F8U had two different wings: Original and BLC (Boundary Layer Control). The BLC wing was developed for the French Navy Crusader E(FN) to provide a lower landing speed. It was incorporated in the remanufacture of U.S. Navy F-8Es that were designated F-8J for the same reason but not retrofitted to any earlier F-8s, including rebuilds.

When the original wing was raised (to 7° incidence), the leading and trailing edge flaps and ailerons automatically drooped from the cruise neutral position, i.e. leading-edge flaps up. Most of the trailing edge control surfaces were ailerons. A small inboard section next to the fuselage was an actual flap, in that it was either up or down. The trailing edge surfaces drooped 20°. The outboard leading edge flaps drooped 27°; the inboard (center section), 25°. The Unit Horizontal Tail (aka stabilator) moved 5° leading edge up for nose-down pitch. The speed brake retracted if it was extended.

Original Leading-Edge Flap

The red outline is the "scuff plate" that is under the upper wing surface when the flap is up.

Original Trailing-Edge Flap and Aileron

Note the small panel forward of the aileron. This is a spoiler added early on for better roll control.

The BLC wing had leading-edge flaps that hinged in two places to provide increased lift when the flaps were down.

 

BLC Leading-Edge Flap Up

BLC Leading-Edge Flap Down

Note that the upper surface of the forward section of the flap rides up and over the surface of the aft section when the flap goes up.

BLC Trailing-Edge Aileron Down

Neither wing had a fairing on the upper surface over the wing-fold joint.

Weinel:

Wing incidence angle, as well as the angle of leading and trailing edge devices, was adjustable. I don't know what the incidence angle of French Crusaders was, but it definitely varied on the J. We (VF-162) were the first J squadron, and when we got them, they had the same angle of incidence that the E had. With the BLC and double droop on the leading edge, we had an approach speed at max trap weight of about 130 knots, 15 knots less than the E. Problem was, the airplane weighed 1500 pounds more than the E, with no increase in power, in fact, in the landing configuration it had less power, since the BLC used bleed air, which robbed a bit of power. As a consequence, the airplane was pretty badly underpowered on approach. This was not a big deal ashore, but on the boat it was a real problem. The wave-off window for the J was much further out than for earlier versions, because there had to be extra time for the power to take effect. Most of us did not use the auto throttle on the J because it just wasn't effective. One of the short term solutions was to reduce the angle of incidence and play with angles of the flaps and ailerons. The flaps are the small inboard section, and they are either fully up (wing down) or fully down (wing up). The larger outer section are the ailerons, and they of course, do move. The normal Crusader landing configuration had the flaps down slightly further than the ailerons. At one point on the J, though, they were significantly above the ailerons to reduce drag and make more power available on approach. All this helped, but the approach speed was now 140 knots, only 5 less than a standard Crusader. The long term solution was more power, and Pratt and Whitney came up with the P420, which had 1500 pounds more thrust. With this extra power available, the wing configuration went back to its original settings, and the approach speed went back down to 125-130 knots, the whole reason for the J. All of this took place over a period of about two years, and I never flew a J with the lower wing incidence/flap angle, or one with the P420, my second cruise was in the H and it was everything that the J was not. With the extra power of the P420 the J had become less of a slug, but its performance was never as good as its predecessor, the E, and nowhere near as good as the , because it still had less specific power and higher wing loading. Even with the 420 it could not close the gap on the H, because the H got the P420, too! Hands down the best model Crusader was the H with the P420. Probably the best, most experienced group of Crusader pilots ever assembled were the Reserve squadrons at Dallas, VF-201 and 202, and they categorically refused to accept the J, would not have anything to do with it. They stayed in the H until they got the F-4.

Having gone through all the teething problems with the J, I often wondered how the French had gotten around these problems, which they must have encountered, but I never found out.

The wing was raised by a single actuator at the right forward side of the wing bay.

Bill Spidle Photo

It pivoted on two large fittings on the aft spar.

Because the pivot point was generally ahead of the center of lift, air loads would keep the wing down unless raised by the actuator.

 

The top of the fuselage looking aft showing the wing attach point on the fuselage.

 The top of the fuselage looking forward.

Weinel: 

Though the forward bulkhead is white here, it was clearly red and has been overpainted. Note also that some of the piping in the bay is interior green. I have spent a lot of time trying to pin this down and the best I can do is say that if you are doing an early 60's E, the bay should be green. If you are doing a J (or any other rebuild version - H, K, L or RF-8G), the bay should be white. In between is a "gray" area (or green-white area!). My hunch is that the change was part of the rebuild program and that all A-E Crusaders should be interior green and all RG-L versions, white. Most of my experience with the airplane is with the H and J and they were white, but truth to tell I didn't have much call to stick my head in there and look. If the changeover occurred prior to the rebuild it was almost certainly done during ONR/PAR cycles so that there were aircraft around with both color bays. In the end, it is YOUR model, so paint it whichever color suits you. Some may challenge you, but I doubt they can prove you wrong.

Also, note that when the wing was up, the fairing on the top of the wing slid over the fairing on the fuselage.

To depict this on a model with the wing up:

Editor Note: Tom didn't mention it but the underside of the wing located above the fuselage was white although it's possible (and unlikely) that it was painted red at the squadron level or one of the overhaul facilities. The Vought paint and markings diagram is clear (although I don't have a high-
resolution copy of it).

I've never seen a picture of it that was ever anything darker than dirty...