F-22 stealth maintenance problems?

July 3, 2009 · Posted in Blogroll, Uncategorized 

F22_formation Steve Trimble reports on an interesting story related to the stealth-related maintenance of the F-22. A former LockMart engineer who worked on the F-117, B-2 & F-22 programs is to file a lawsuit against the company for allegedly conceiling deficiencies on the radar-absorbent material (RAM) coatings of the stealth fighter:

The pending lawsuit accuses Lockheed of knowingly providing defective coatings used to reduce the aircraft’s radar and visual signatures, and covering up the problem by adding 272kg (600lbs) worth of extra layers.

There is an interesting section that sheds some details on the successive RAM layers:

The F-22 requires three layers of coatings to reduce its radar signature, according to Olsen’s statements in his case. A primer seals the surface of the aircraft skin and helps with the adhesion of the next layer. Next, a conductive coating with silver flakes mixed with polyurethane materials is applied to keep radar waves from bouncing back to the emitter source. Finally, a topcoat layer has properties, including metallic materials, to reduce heat, which lowers the risk of radar detection.

"If those coatings are not effective, the other stealth measures of the aircraft’s design are negated," the lawsuit says.

The engineer claims that Lockheed deliberately and protractedly evaded government attention on this matter:

Olsen claims he witnessed Lockheed management misleading USAF officials about the quality of the stealth coatings. Olsen’s supervisors instructed him not to speak at meetings with USAF officials. […] Lockheed also schemed to avoid government inspections of the coatings, secretly shipping batches of the stealth materials to the homes, the lawsuit states.

Obviously, if the accusations prove to be sound, this revelation may cast doubt to the entire concept of the F-22s presumed degree of stealth, as well as its maintenance requirements. While the fighter is also a supreme aerodynamic airframe (1.5M supercruise at 65.000ft can, by itself, shrink the engagement envelope of enemy weapons significantly), it is the stealth factor that is supposed to be the chief enabler of the fighter’s advanced combat potential. On the other hand, RAM is only part of the stealth design; careful shaping by itself has a significant contribution to the overall RCS (see our Waypoint primer on stealth).

The excessive maintenance requirements, if true, may also have negative consequences on the overall operational availability of the aircraft – a particularly pressing concern in light of the successive cuts that have limited its total production to just under 200 airframes.

The Register, in its own coverage of the news, adds the inevitable political angle:

President Obama and his Defense Secretary Robert Gates want to cease manufacture once the US air force has a total of 187 F-22s; however, politicians from districts where the Raptor is made are resisting them. Furthermore, although Gates has managed to partially bring the US airforce to heel by replacing its two top bosses last year, institutionally the service passionately desires a much larger Raptor fleet.

Gates’ desire to save money for combat troops by purchasing drones and "affordably stealthy" F-35s, more useful for strike missions, is backed by the other US services for different reasons. Furthermore, the White House has signalled that President Obama may deploy his veto against attempts to maintain the pricey Raptor in production. Nonetheless, it’s plain that Gates has a fight on his hands.

Comments

One Response to “F-22 stealth maintenance problems?”

  1. SlamEagleF15K on July 5th, 2009 7:06 am

    Well,for several thoughts on this..the RAM coating problem will definitely provide quite a problem in the export arena,as the upcost factor would be very high in proportion compared to other fighters,and when coupled with security issues on matainence,the political factor would matter very much for the potential buyers.

    Another thought is that if the RAM coating has a lot to do with the steath to make Lockheed sneak through the back door,then maybe the stealth capabilities of the export version of the F-22 could be controlled by usage of the RAM coatings.At least it would be cheaper than re-designing a AN/APG-77 to lower standards(ex) removement of LPI capability).This could mean a lower increase in the overall costs,which would ironically facilitate the export pontential of the Raptor.Gain and Losses.

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