F-117 Nighthawk Stealth Fighter Retires

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[LTGunner]

F-117 Nighthawk Stealth Fighter Retires



WRIGHT-PATTERSON AFB, Ohio -- An F-117 Nighthawk taxis into position during the F-117 Nighthawk Farewell Ceremony here on 11 Mar. The ceremony consisted of mulitple guest speakers, a piece by the Air Force Band of Flight and concluded with a single ship flyover. (U.S. Air Force photo/Staff Sgt Joshua Strang) Source

March 13, 2008: The U.S. Air Force is retiring the last of its F-117 light bombers. Long called the "stealth fighter," the F-117 was designed from the start as a bomber. But the aircraft is now 27 years old. It's really 1970s technology that, after years of effort, was made to work in the 1980s. But better stuff is out there, and the stealth technology of the F-117 is obsolete when it comes to some of the more recent sensor developments. The new F-22 will be a direct, and more effective, replacement for the F-117 as a light bomber. Plus, the F-22 is also a superior fighter.

Earlier attempts to take the F-117 out of service ran up against political opposition. Bases would have to be closed, which means lost jobs. The air force worked out deals to take care of that angle, and the last active duty F-117  will be retired in April, 2008. The last class of F-117 pilots graduated two years ago.  A total of  558 pilots were trained to operate the one seater aircraft. Ten aircraft were retired in late 2006, and another 27 in the last 15 months.

The first F-117 flew in 1981, and 59 were eventually built. Six crashed due to non-combat causes, and one was brought down due to the efforts of a clever Serb air defense officer, who exploited the chinks in the F-117s stealth technology. But starting in 1989, when an F-117 participated in the invasion of Panama, the aircraft proved its worth. The usual bomb load for the 24 ton aircraft, was two one-ton laser guided bombs, in an internal bomb bay. The F-117 almost always attacked at night, and took out a disproportionate number of targets compared to non-stealth bombers.

The stealth technology used was such that no two F-117s were the same. As the aircraft were produced, new techniques for applying the RAM (Radar Absorbent Materials) were developed. The first planes had sheets of RAM glued onto the airframe. More than halfway through the run, a new spray-on technique was developed. This technique was changed several times before the 59th F-117 was manufactured. Several different treatments have been used for the wing edges, ****pit rim, access panels, and other areas. As the material degraded or was damaged over time, several different repair techniques were used. Access panels were another variable, as some aircraft had to have the RAM scraped off to open them while others had treatments that provided easier (and less destructive) access. Stealth works in various ways, and stealth aircraft use a combination of techniques. The basic concept, however, is to make the stealth RAM coating one-fourth of a radar wavelength thick. In this way, some of the enemy radar beam is reflected by the surface of the RAM and more by the metal under the RAM later. Because this second element travels a half of a wavelength farther than the first element, it exactly cancels out the radar wave.

The retired F-117s are being put into storage (the "boneyard"). There, for the next decade or so, the bombers can be recalled to service. Source

[JerryM]

That is scary!
The first one was built after I retired and now the last are being decommissioned.

Does that mean I am obsolete?

 

[DragonSoldier]

Only fighter the Air Force ever had that couldn't fight...  Should been a B-117...

[DefiantSix]

Just wish the boys in blue were in a position to do the same (retire the fleet with honors) for the C-model F-15s that keep falling out of the skies lately.

[KogyBear]

Only fighter the Air Force ever had that couldn't fight...  Should been a B-117...

You would have a hard time convicing me that the F-111 was anything other than a bomber, although some inventive soul did design and build an M-61 pack that fit into one-half of the bomb bay.

Then there was the F-99, which could only fly and blow itself up...

Also, the F-105 was a better bomber than a fighter, as well, but I suppose it could fight in a pinch.  They did manage to kill 31 MiGs...

[DefiantSix]

Plus how many that were still on the ground when they killed 'em?

[DragonSoldier]

Just wish the boys in blue were in a position to do the same (retire the fleet with honors) for the C-model F-15s that keep falling out of the skies lately.

The Fighter Mafia never gets it right... They always want the next generation...  When you got something good, you keep building it...  Instead of tryin' to keep squeezing flight-hours out of tired airframes... It's better to build a lot of 1000-hour airframes than a few 5000-hour ones...

[buckshot]

Perhaps there are some big expectations for the Raptor. Saw an awesome display of the plane's capabilities. I am easily impressed with airplanes. F15s are going to be retired as well I am told. Luke AFB just lost a pilot and his F16 yesterday. I am told the "balance point" of the 16 is out beyond the nose of the plane. Anyone know if this is true?

[KogyBear]

Perhaps there are some big expectations for the Raptor. Saw an awesome display of the plane's capabilities. I am easily impressed with airplanes. F15s are going to be retired as well I am told. Luke AFB just lost a pilot and his F16 yesterday. I am told the "balance point" of the 16 is out beyond the nose of the plane. Anyone know if this is true?

The question is rather vague and could refer to two different things.

First, if you are talking the zero moment arm position used when calculating the aircraft CG, yes, it is out beyond the nose of the aircraft.  This zero moment arm position is the start point for the moment arms to all components of the aircraft.  The moment arm times the weight of the component equals the component's moment about this imaginary zero point.  All of the individual component moments are added up to give the total moment about this imaginary point.  This total moment is divided by the weight of the aircraft and now you know how far from the zero moment arm position the aircraft CG is, and if the aircraft CG is within limits.

Why is the zero moment arm position put a few inches out in front of the aircraft?  So there will be no negative moments, it simplifies the calculation math.

OR,

In order for an aircraft to be "stable" the sum of all moments aboout the balance point (normally center of gravity, CG) must be zero and when disturbed from this "trim point" the new set of moments must tend to return the aircraft back to its trimmed position.

If the aircraft is disturbed from trimmed position and the sum of the new moments tend to increase the deviation from trimmed position, the aircraft is "unstable."

In order for an aircraft to be maneuverable, it cannot be extremely stable, but if unstable the pilot must constantly be correcting for variations in flight.  So the F-16, and other new aircraft, are made unstable, but have a computer to continually correct for the instability.  This is an artificially stable aircraft.  Generally, a positive lift horizontal tail (which requires the center of lift to be ahead of the CG) will be unstable.

The Fighter Mafia never gets it right... They always want the next generation...  When you got something good, you keep building it...  Instead of tryin' to keep squeezing flight-hours out of tired airframes... It's better to build a lot of 1000-hour airframes than a few 5000-hour ones...

The big problem with that approach is that a 1000 hour airfrane does not cost 1/5 that of a 5000 hour airframe.  In fact they cost about the same.

The correct thing to do is buy the 5000 hour airframes and when they hit 5000 hours, have something new on the production line to replace it.  The blame for that not happening must be shared betweem the various services and Congress.  The services have to be confident that projects will be funded, as well as coming up with the ideas for the next generation.

In the twenty years from 1945 to 1965, the USAF introduced 17 fighter and 6 bomber aircraft types into full rate production; in the next 20 years from 1965 to 1985, the number had dropped to three fighter(with one semi experimental aircraft with a very limited production run the F-117,) and two bomber types and one attack type, and in the twenty years from 1985 to 2005, we have introduced one new fighter type and one bomber type.

Similarly, the US Navy from 1945 to 1965 introduced 12 fighters and 6 attack aircraft, from 1965 to 1985 they introduced 2 fighter and 1 attack (two, if you include the USMC's AV-8A,) and from 1985 to 2005 only one fighter and no attack, (one, if you include the AV-8B, which is sufficiently different form the AV-8B and they were new airframes.)

[DragonSoldier]

I disagree... You keep building the airframes and as they approach the end of the service life, you replace 'em with new airframes.  You don't order say, 300 airframes and shut down the line after delivery...  You keep building them until the initial run is complete, then operate the line on constraint, rather than inventory, replacing airframes and the cost per unit goes down. 

[buckshot]

thank you Kogy for your answer to my ?.  The AF Sgt i SPOKE WITH TOLD ME ABOUT THE ARTIFICIAL C.G. you mentioned. I had forgotten that. Might computer failure be a cause for what appears to be (to me at least) unexplained F16 crashes like 2 days ago out of Luke AFB? Do military planes have a "black box"? I never asked anyone that before. After spending a month on an AFB an my curiosity has piqued a bit I guess.

[EX-CG-GM]

Only fighter the Air Force ever had that couldn't fight...  Should been a B-117...

Dragon-

Good point.  Any insight into why it was designated a fighter rather then a bomber?

[DragonSoldier]

Only conjecture... Technically, it could have been a Attack aircraft as well.  The designation "F-117" would seem to indicate that it was given an official designation prior to the 1962 U.S. Tri-Service Aircraft Designation System and could be considered numerically to be a part of the earlier "Century series" of fighters.  Y' know.. The F-100, F-102, F-104, F-105, etc, with the F-111 being the last in the series..

Most thought it would likely receive the designation F-19 as that number had not been used.The explanation is an example of general secrecy on the part of the U.S. Government. Captured Soviet fighters were given F-series numbers for their evaluation by U.S. test pilots, and with the advent of the "Teen Series" fighters, most often 'Century Series' designations. I'm sure there's other logical explainations...

My personal insight, since my Dad was a fighter pilot and I grew up around 'em is that I think it's as simple as that the top fighter pilots that were needed to fly it simply wouldn't volunteer to be bomber pukes....

[KogyBear]

The Air Force has a healthy dislikes of the "Attack" designation, in fact you could say it hates it with a passion.

The F-111, and the F-105 both filled the same tactical niche the the North American A-5 Vigilante filled, and should have been classed as "attack aircraft."

Similarly, the F-84F Thunderstreak filled the same role as the A-4 Skyhawk.

The -117 designation was chosen because it was completely out of sequence with both current and past aircraft numbering.  Black projects hate being predicable. 

You keep building the airframes and as they approach the end of the service life, you replace 'em with new airframes.  You don't order say, 300 airframes and shut down the line after delivery...  You keep building them until the initial run is complete, then operate the line on constraint, rather than inventory, replacing airframes and the cost per unit goes down.

First off, with a 1000 hour airframe you will never get all your aircraft built before they run out of life.  1000 hours equates to about 2.5 to 3 years service life. Full rate production runs around 45 aircraft a year these days, so in the 3 years you have given yourself you can only build about 135 aircraft.  So you will never have more that 135 aircraft.

But, if you order 450 aircraft with 5000 to 6000 hour airframes, it will take about 10 years to complete the buy.  And by the time the last aircraft is delivered, the first aircraft will be around 5000 hours.  So, you better have something ready for production, or at this time re-order, while the production line is still there.

OK how did they do it in the fifties and sixties?  The production rate was much higher.  For example the production rate of the F-105D averaged around 120 a year.  (NOTE: If this were a 1000 hour airframe and used at today usage rates, you could only maintain a fleet size of 360 aircraft.  The F-105D fleet was 610 aircraft.  The average (not counting those lost in combat) F-105D served for 15 years and amassed about 6500 hours before retiring.  And five years after the production line closed Republic still could offer to restart it at the bargain basement price of around half the cost of a new Phantom II.)

A good service life extention program (SLEP) cand get you another 2500 to 3000 hours, or 5 to six years service life.  So if, at the end of the production run, you do not want to order more of the same, but need a few years to get the next one started, it can buy you some buffer.

The problem is we have not been following the above doctrine, even though it has been the understood to be the best way of doing things since the mid fifties.  The F-15C should have seen its replacement doing its first flight around 1990 and entering full rate production around 1992 or 93.  The F-22 should have been replacing this non-existant F-15C replacement.

Addenda:

Just as an aside, aircraft components valves, cooling turbines, engines turbine wheels, usually last about 1500 to 2000 hours. So what you're suggesting is making a disposable aircraft.

[docstew]

Only fighter the Air Force ever had that couldn't fight...  Should been a B-117...

You would have a hard time convicing me that the F-111 was anything other than a bomber, although some inventive soul did design and build an M-61 pack that fit into one-half of the bomb bay.

Then there was the F-99, which could only fly and blow itself up...

Also, the F-105 was a better bomber than a fighter, as well, but I suppose it could fight in a pinch.  They did manage to kill 31 MiGs...

and let's not forget that the pheonix missile was at one time paired to the f-111 for fleet defense