F-117 Developments ??

[Steve Pace]

Boeing says 0.855 Mn is typical cruise speed for 747-400ER and the new 747-8.

 

[Triton]

Artist's impression of Lockheed A/F-117X.

Source: Sweetman, Bill Lockheed Stealth MBI Publishing Company 2001

 

[Sundog]

Boeing says 0.855 Mn is typical cruise speed for 747-400ER and the new 747-8.

I didn't say cruise speed, I said top speed. They're not the same. Just as I'm sure the F-117's top speed and cruise speed aren't the same. Yes, the 747's cruise speed is listed as M=.85, just as it's top speed is M=.92

 

[Steve Pace]

Hell - it could go supersonic if it wanted to, but it would disintigrate.

 

[Orionblamblam]

the 747's cruise speed is listed as M=.85, just as it's top speed is M=.92

Top speed of the 747, at least the 747SP, is faster than that. Apparently top speed exceeds Mach 1.

China Airlines was good enough to test that.

You could probably buff that out with a wet paper towel.

 

[Sundog]

Top speed of the 747, at least the 747SP, is faster than that. Apparently top speed exceeds Mach 1.

China Airlines was good enough to test that.

Wow, I never heard about that! Was that something they actually tested, or just dumb pilots not paying attention to their rate of descent?

 

[blackkite]

Hi Scott introduce this accident!
http://en.wikipedia.org/wiki/China_Airlines_Flight_006

 

[Orionblamblam]

Was that something they actually tested, or just dumb pilots not paying attention to their rate of descent?

A combination. Phase One was pilots and a flight engineer who made something of a mess of things, yet managed to pull their bent aircraft out of a death-dive and land at San Francisco International with no major injuries.

Phase Two was - sadly - hearsay. I heard from a Boeing historian that after the event, Boeing did some transonic wind tunnel testing of the 747 configuration, something they hadn't previously done. Turns out that the 747 is a much better transonic configuration than you might think... note that the second-level lounge/hump/thingie tapers off roughly where the wing begins... giving it better area ruling than was expected.

The damage done to the 747 largely seems to have come not from the high speed, but from the 5 G maneuvers. I'm a little surprised that the main landing gear doors fell off at that acceleration, but they did, and it seems they whacked the horizontal stabilizers. And the heavy loading permanently bent the wings up by 2 inches.

Still, doing a Mach-busting powerdive in a 747 is contraindicated in most flight manuals.

I've also heard of numerous other airliner types (767, DC-8, Convair 990, Citation X, 707, 727, etc.) busting Mach 1 in dives, both intentionally during testing and accidentally. But at least online, a lot of this is anecdotal.

If an airliner can stuff itself past Mach 1, I've no doubt that an F-117 in a dive could as well, and should survive the experience.

 

[quellish]

Tail flutter limited the F-117's speed. On 9/25/85 aircraft 781 lost one tail after a pullup at 10,000 feet. Post flight analysis and testing showed that actual loads on the tail were outside of predictions, this is what necessitated the redesigned composite tail that was later integrated into the fleet.

With some superglue and a shallow dive the F-117 could pass Mach 1, but it wasn't recommended that you try.

 

[Orionblamblam]

Tail flutter limited the F-117's speed.

I imagine the grate over the inlets might make a mess of trying to get decent engine performance once you bust Mach 1.

 

[Lauge]

.....doing a Mach-busting powerdive in a 747 is contraindicated in most flight manuals.

And now you tell me....... I suppose you're gonna tell me I'm not supposed to do loops with the Hindenburg NT either? ;D

Regards & all,

Thomas L. Nielsen
Luxembourg

 

[quellish]

I imagine the grate over the inlets might make a mess of trying to get decent engine performance once you bust Mach 1.

It was found that at transonic speeds the grids did not impede flow (and in fact improved it), though faster than that I do not know.

 

[Sundog]

It was found that at transonic speeds the grids did not impede flow (and in fact improved it), though faster than that I do not know.

I was going to say that I wasn't sure they would be a problem, as look at the grids Russia uses on some of it's missiles for good supersonic performance/control.

 

[Steve Pace]

From my understanding....
1. The money allocated for maintaining them went elsewhere.
2. Pilots and crew are not being kept current in the type, so the readiness of the airframes does not matter much
3. Part of the "readiness" contract was to keep the TTR facilities running. That has been happening, and there is now another unit there.

Finally found the photo of the F-117s in storage at TTR.

Is there a high res of this image available?

 

[quellish]

Is there a high res of this image available?

Not that I have seen.

 

[flateric]

A/F-117X nozzle patent


http://www.google.com/patents?id=pBkZAAAAEBAJ

of note, Stephen G. Justice was one of the guys in charge of JASSM design

 

[overscan (PaulMM)]

Nice!

 

[Matej]

Just received. This is not seen very often.

 

[quellish]

Just received. This is not seen very often.

I actually had the opportunity to talk to the pilots of 410th soon after this. After they were flying around without RAM, they had new RAM applied and were flying without radar enhancers. When I asked the pilots if this meant they had been out to DYCOMS to test some new coatings I got a smile and ".... you can draw your own conclusions".

 

[Mr London 24/7]

Just received. This is not seen very often.

This is report circa 2000, or more recent flights?

 

[Matej]

Its written in the text. October - december 2000.

 

[Spook]

Just received. This is not seen very often.

Sir Please do check this link too

http://virtualglobetrotting.com/map/white-f-117-nighthawk/view/?service=1

Regards,
AK

 

[Grey Havoc]

Has anything recently surfaced on the ATA B design?

 

[Bazinga]

Looks like not only the F-117 is stripped. This looks like an SR-71 undergoing the same treatment.

 

[Vahe Demirjian]

Has anything recently surfaced on the ATA B design?

The ATA-B program was cancelled long ago. As pointed out by Crickmore and Crickmore (2003, p. 25), further work on the ATA-B was axed because the USAF eventually found the ATA-B expensive compared to the ATA-A (which became the F-117). Anyway the F-22 and the F-35 are secondarily designed for the fighter-bomber role, effectively fulfilling the role of a stealthy fighter-bomber. The F-15SE is also a stealthy fighter-bomber, but it hasn't been ordered into production lately and it seems that the US Air Force and other customers are not interested in buying the F-15SE.

Crickmore, Paul F. and Alison J. Nighthawk F-117 Stealth Fighter. St. Paul, Minnesota: Motorbooks, 2003. ISBN 0-7603-1512-4.

 

[Grey Havoc]

Sorry, I meant had more details about the design emerged in the last couple of years, such as reliable drawings.

 

[quellish]

Looks like not only the F-117 is stripped. This looks like an SR-71 undergoing the same treatment.

I believe the F-117 may have been part of the short program that tested F-22 coatings on the F-117. I can't find a photo of the aircraft I am thinking of, but it should appear silver under conventional lighting.

The blackbird is coated in a protective plastic. Very common to see around Edwards and the Mojave!

 

[Bazinga]

That was my first thought too but I'm not completely convinced. The way the white is distributed and the location of the bird doesn't tell me it in storage.
Perhaps some of you are around the AMARC and see a snap of a stored Blackbird

 

[quellish]

That was my first thought too but I'm not completely convinced. The way the white is distributed and the location of the bird doesn't tell me it in storage.
Perhaps some of you are around the AMARC and see a snap of a stored Blackbird

I think that is NASA 831, I can find out in the next few weeks.

 

[Grey Havoc]

Lockheed Martin Skunk Works

Article 780, a Lockheed YF-117A stealth test aircraft, first flew on June 18, 1981, with pilot Harold Farley at the controls. The planned 30-minute sortie was cut short after 13 minutes due to a canopy warning light and overheating in the exhaust duct. Article 780 was painted light gray to reduce its daytime visual signature. Ben Rich, Lockheed’s vice president for advanced projects, wanted to deliver the production F-117A aircraft in gray, but General William Creech, chief of Tactical Air Command, wanted the airplanes painted black. “You don’t ask the commander of TAC why he wants to do something,” Rich recalled. “He pays the bills. If the general had wanted pink, we’d have painted them pink.”

http://www.airspacemag.com/multimedia/The-Origins-of-Area-51-200064721.html

 

[SOC]

That was my first thought too but I'm not completely convinced. The way the white is distributed and the location of the bird doesn't tell me it in storage.
Perhaps some of you are around the AMARC and see a snap of a stored Blackbird

That's Lockheed's ramp at Palmdale. I think that's actually the two-seat A-12, before it was transferred for museum display. Which would also make this an older image.

 

[jemhouston]

Lockheed Martin Skunk Works

Article 780, a Lockheed YF-117A stealth test aircraft, first flew on June 18, 1981, with pilot Harold Farley at the controls. The planned 30-minute sortie was cut short after 13 minutes due to a canopy warning light and overheating in the exhaust duct. Article 780 was painted light gray to reduce its daytime visual signature. Ben Rich, Lockheed’s vice president for advanced projects, wanted to deliver the production F-117A aircraft in gray, but General William Creech, chief of Tactical Air Command, wanted the airplanes painted black. “You don’t ask the commander of TAC why he wants to do something,” Rich recalled. “He pays the bills. If the general had wanted pink, we’d have painted them pink.”

http://www.airspacemag.com/multimedia/The-Origins-of-Area-51-200064721.html

During the interwar years, a covert RAF recon plane that took photos of Germany was painted pink. Nobody on the ground would believe the military plane was pink, but once it reached cruising height, it wasn't almost impossible to see from the ground.

 

[Stargazer]

once it reached cruising height, it wasn't almost impossible to see from the ground.

I suppose you meant "it WAS almost impossible to see from the ground"...

 

[Jemiba]

The dark paint work of the F-117 is something, I was wondering about a long time ago. I always thought, that
it was a kind of radar absorbing coating and that the use of other pigments, than black ones (carbon) may have
impaired stealth characteristics.
That a black painted aircraft is more susceptible to visual identification at night, than a much brighter coloured one,
was already known to the WW II German airforce. So I can hardly believe, that here it was just because of the
preference of a USAF general. ???

 

[Stargazer]

More about flying pink aircraft...

http://vintageairphotos.blogspot.fr/2012_01_01_archive.html

 

[jemhouston]

The RAF before WW2 did paint their training aircraft black making them easier to see in the daylight. I think that was the reasoning behind painting F-117 black was to make sure they won't be flown during daylight.

 

[sublight_]

Could they have painted them black deliberately so the Soviets wouldn't think they were the same as other classified craft we had sneaking around? (assuming their intelligence had some idea the Nighthawk existed)

 

[TaiidanTomcat]

I had heard from an F-117 crewman that it was a general's idea to paint them black. The crewman was around when they were testing the gray dragon jet a few years before retirement and said it was extremely hard to spot. He said the reason the general originally picked black was because it was scary looking. YMMV

 

[Stargazer]

I had heard from an F-117 crewman that it was a general's idea to paint them black. The crewman was around when they were testing the gray dragon jet a few years before retirement and said it was extremely hard to spot. He said the reason the general originally picked black was because it was scary looking. YMMV

That general must have read too much Batman when he was a kid... :

 

[overscan (PaulMM)]

Well, a few posts earlier we already had the definitive answer:

Ben Rich, Lockheed’s vice president for advanced projects, wanted to deliver the production F-117A aircraft in gray, but General William Creech, chief of Tactical Air Command, wanted the airplanes painted black. “You don’t ask the commander of TAC why he wants to do something,” Rich recalled. “He pays the bills. If the general had wanted pink, we’d have painted them pink.”