F-8E v F-8J

[Crazy Snap Captain]

Quick one guys (hopefully). Are there any major differences externally between an F-8E and an F-8J? TIA.

[Tailspin Turtle]

Quick one guys (hopefully). Are there any major differences externally between an F-8E and an F-8J? TIA.

Most obvious differences: BLC wing (two-part leading-edge flap), bigger horizontal stabilizer, and ECM antenna on the vertical fin. See http://tailspintopics.blogspot.com/2009/10/f8u-crusader-variations.html

[kellyF15]

Weren't the landing gear different too?

[achterkirch]

I think it was too. There were a few differences. Some where one here there is a forum about the difference between the F-8E and the J

[achterkirch]

http://www.arcforums.com/forums/air/index.php?showtopic=127141&st=0

And here it is.

[Crazy Snap Captain]

Thanks achterkirch. Awesome link! Tailspin, great stuff, many thanks! One question if I may; apart from the fact that the leading edge slats on the J are double hinged, is there a difference in dimensions to the E slats?

Thanks all.

Edited September 16, 2015 by Crazy Snap Captain

[achterkirch]

Anytime!

[Rich in name only]

Haven't measured but the "droops" up area on a J appears to match or be very close to that of the E. I decided a while ago that for models it didn't matter -- that is the area didn't matter but you still need a seam in the right line, with the forward droop being noticeably narrower chord than the rear.

Also keep in mind that early F8Us really did, like the Dogfights general said "has no flaps" but the E and J do.

[Crazy Snap Captain]

Great thanks!

[Crusader nut]

Haven't measured but the "droops" up area on a J appears to match or be very close to that of the E. I decided a while ago that for models it didn't matter -- that is the area didn't matter but you still need a seam in the right line, with the forward droop being noticeably narrower chord than the rear.

Also keep in mind that early F8Us really did, like the Dogfights general said "has no flaps" but the E and J do.

I could be wrong on this, but all of the Crusaders had flaps and slats. This was a carrier borne fighter, the flaps and slats are required to give the plane better low speed capabilities which around the carrier are a necessity. To the best of my recall there was never a version of the F-8 that did not have slats and flaps. The -J leading edge slats were of the same dimension as the -E models, they were just a double-droop. The -J also had "war emergency thrust", which was really nothing more than overspeeding the engine. Because it was about a ton overweight, they tried this as a remedy for how underpowered it was around the landing pattern. Things were going along fine until the first inspection of a -J engine showed that they were destroying the burner cans with the WET thrust. That's when the -P420 engine came along to give more power. No modeling changes are needed of course for the change in engine, just kinda going off on memory again.

Interesting note, the -J was rushed to the fleet without much testing being done first. It was actually possible to fly the jet slower than the emergency ram air turbine needed to perform. So, at night, the pilot could be in the landing pattern, lose electrical power, and have to fly blind to touchdown. The RAT had to be reworked so that it would operate at the lower speed. the -J's would land at around 128 knots.

[mawz]

I could be wrong on this, but all of the Crusaders had flaps and slats. This was a carrier borne fighter, the flaps and slats are required to give the plane better low speed capabilities which around the carrier are a necessity. To the best of my recall there was never a version of the F-8 that did not have slats and flaps. The -J leading edge slats were of the same dimension as the -E models, they were just a double-droop. The -J also had "war emergency thrust", which was really nothing more than overspeeding the engine. Because it was about a ton overweight, they tried this as a remedy for how underpowered it was around the landing pattern. Things were going along fine until the first inspection of a -J engine showed that they were destroying the burner cans with the WET thrust. That's when the -P420 engine came along to give more power. No modeling changes are needed of course for the change in engine, just kinda going off on memory again.

Interesting note, the -J was rushed to the fleet without much testing being done first. It was actually possible to fly the jet slower than the emergency ram air turbine needed to perform. So, at night, the pilot could be in the landing pattern, lose electrical power, and have to fly blind to touchdown. The RAT had to be reworked so that it would operate at the lower speed. the -J's would land at around 128 knots.

All of the production Crusaders did have slats, there's landing pictures of the XF8U-1 showing them. It's possible that flaps were a later addition, when the E went up in weight, the variable-incidence wing and slats would have mostly replaced the need on the lighter early variants.

The only non-slatted Crusader I'm aware of was the TF-8A

Edited March 13, 2016 by mawz

[Scott R Wilson]

I could be wrong on this, but all of the Crusaders had flaps and slats. This was a carrier borne fighter, the flaps and slats are required to give the plane better low speed capabilities which around the carrier are a necessity. To the best of my recall there was never a version of the F-8 that did not have slats and flaps. The -J leading edge slats were of the same dimension as the -E models, they were just a double-droop. The -J also had "war emergency thrust", which was really nothing more than overspeeding the engine. Because it was about a ton overweight, they tried this as a remedy for how underpowered it was around the landing pattern. Things were going along fine until the first inspection of a -J engine showed that they were destroying the burner cans with the WET thrust. That's when the -P420 engine came along to give more power. No modeling changes are needed of course for the change in engine, just kinda going off on memory again.

Interesting note, the -J was rushed to the fleet without much testing being done first. It was actually possible to fly the jet slower than the emergency ram air turbine needed to perform. So, at night, the pilot could be in the landing pattern, lose electrical power, and have to fly blind to touchdown. The RAT had to be reworked so that it would operate at the lower speed. the -J's would land at around 128 knots.

All of the production Crusaders did have slats, there's landing pictures of the XF8U-1 showing them. It's possible that flaps were a later addition, when the E went up in weight, the variable-incidence wing and slats would have mostly replaced the need on the lighter early variants.

The only non-slatted Crusader I'm aware of was the TF-8A

Sorry, but that is incorrect. Crusaders had leading edge flaps, not slats. Slats have a gap (slot) between the slat and wing when deployed, while leading edge flaps are hinged and remain attached to the wing, with no slot.

You might recall F-4 Phantoms started out with leading edge flaps, while later F-4E and F-4F versions had slats installed at the factory and older F-4Es and Js had slats retrofitted, with the slatted F-4Js being redesignated F-4S. The two types of leading edge devices are quite different.

Scott W.

Edited March 13, 2016 by Scott R Wilson

[Superheat]

I could be wrong on this, but all of the Crusaders had flaps and slats. This was a carrier borne fighter, the flaps and slats are required to give the plane better low speed capabilities which around the carrier are a necessity. To the best of my recall there was never a version of the F-8 that did not have slats and flaps. The -J leading edge slats were of the same dimension as the -E models, they were just a double-droop. The -J also had "war emergency thrust", which was really nothing more than overspeeding the engine. Because it was about a ton overweight, they tried this as a remedy for how underpowered it was around the landing pattern. Things were going along fine until the first inspection of a -J engine showed that they were destroying the burner cans with the WET thrust. That's when the -P420 engine came along to give more power. No modeling changes are needed of course for the change in engine, just kinda going off on memory again.

Interesting note, the -J was rushed to the fleet without much testing being done first. It was actually possible to fly the jet slower than the emergency ram air turbine needed to perform. So, at night, the pilot could be in the landing pattern, lose electrical power, and have to fly blind to touchdown. The RAT had to be reworked so that it would operate at the lower speed. the -J's would land at around 128 knots.

Well, you are wrong on this. As Scott pointed out, the F-8 had leading edge flaps (not slats, which he saved me the trouble of defining, having done so brilliantly) known as "leading edge droop" in the F-8 community. And all F-8's had trailing edge devices as well, since the ailerons dropped down when the wing was raised, but not all F-8's had "flaps". The flap on the F-8 is the small section between the inboard edge of the aileron and the wing root and the XF8U prototypes as well as early production F8U-1's lacked these.

F-8 flaps:

XF8U-1, early F8U-1 - no flaps:

And early J's did not have War Emergency Thrust, that was an add-on when it became readily apparent that the aircraft was grossly underpowered - so underpowered that an in-close wave-off almost always resulted in a trap. I never flew a J with it installed, nor one with a P420, so cannot comment on their performance or inherent problems. I was in VF-162, the first squadron to deploy with the J, and we were the ones who identified most of the problems with it, but I do not recall any issues with the RAT, though I am one of the few F-8 pilots who never had an electrical or hydraulic failure that required its use. The approach speed at max trap was 126 knots and at lower weights couold get down to 120 and I do recall there were reports of "brownout" at very low speeds, but I don't ever recall hearing of anyone not having any poer at all - maybe at Pax River when they did the trials on the aircraft, but not in the fleet, or at least in 162,and there were a couple failures I remember, one at night. The J was an overweight (the increase was 1500 pounds, not a ton), under-powered POS compared to the E, and even with the P420 it could not match the performance of the H with a P20A - and the late H's also had the P420 - now THAT was an airplane!

Cheers,

Tom