How often did wing-folding mechanisms fail in flight?

[special ed]

Willy Victor = Lockheed if I remember - WV-2 Constellation

 

[PStickney]

WV?

Lockheed Constellation lugging around a Full Radar Station and GCI Center.

 

[GreenKnight121]

Lockheed Constellation lugging around a Full Radar Station and GCI Center.

WV in USN, EC-121 in USAF.
Had a height-finding radar in the fin and an area-search radar in the belly bulge.

Upper radar inside radome:

 

[GreenKnight121]

The original design of the F8F had the wingtips blow off in the event the wing was being overstressed, but I don't think it was anywhere near the wing fold joint.

I remember reading that it was near the fold, and also was not always wing-symmetrical, so the "feature" was dumped.

It wasn't at the wing fold - it was the wing tip, at about 1/2 the span of the ailerons. Yes, it was a design feature - if the airplane was sufficiently over-Gd, a weak spot in the wing spars was supposed to fail, jettisoning the tips, allowing higher Gs to be pulled (Less wing bending moment from the tips);
The problem was getting the tips to come off symetrically - the weak link wasn't predictable enough, so the wings were modified to jettison the tips with Detcord, fired by a G switch, cutting the spars. That still was deemed to be more trouble than it was worth, so they dropped the idea and strengthened the separation points in the spars - turns out they really didn't need it anyway.

Here...
F8F with wingtip broken off:

F8F with red line showing explosive separation point:

F8F Safety Tip Illustration:

 

[Thumpalumpacus]

Here...
F8F with wingtip broken off:

View attachment 828602

F8F with red line showing explosive separation point:

View attachment 828603

F8F Safety Tip Illustration:

View attachment 828604

Thanks for the detailed correction. I was clearly not reading right.

 

[fannum]

I mentioned flying the F-11A briefly with VT-26 at NAAS Beeville in Advanced Training. A delight to fly, but just barely supersonic with the puny J65, and very short legged. It had several unique features.
Per this thread, the very tips folded ... DOWN ... and were actuated manually! A flight line sailor would lift tips into position and wiggle until the locking pin seated. Also, it had full span flaps and slats, with very effective roll control via large wing spoilers. To eke out every bit of range, the Tiger had a wet fin, which was emptied first to avoid aft CG. The "long nose" version was added to accommodate a larger AN/APQ-50 all-weather radar, also used on early Phantom II aircraft, but no change in designation.
Finally, due to contract finagles and inter-service changes, the SAME design was designated four different times, as: F9F-8, F9F-9, F11F-1 and then F-11A.

Also, here's a pix of an F-4 flying with wings folded. With 2 J79s, wings are redundant!

To complete the wing fold fiascos, here's one of the F-8 incidents.

 

[fannum]

The Brits led the field with Crowded Carriers and Complex Counteractions.

Seafire solution (I'm pretty sure, all manually activated)

The Kluge Champion would seem to be the Fairey Gannett which seems to never have seen a makeshift mod that it didn't like!

 

[Thumpalumpacus]

The Brits led the field with Crowded Carriers and Complex Counteractions.

Seafire solution (I'm pretty sure, all manually activated)
View attachment 828953

The Kluge Champion would seem to be the Fairey Gannett which seems to never have seen a makeshift mod that it didn't like!
View attachment 828954

And some folks think origami is Japanese art.

 

[R Leonard]

Alex Vraciu reported that landing his F6F after his rather adventurous day in the Marianas he looked over and saw the red lock pin sticking up . . . could have ruined his day.