A stealth expert on the F-117 and B-2 programmes intends to file suit against Lockheed Martin later this week for concealing alleged deficiencies with the stealth coatings for the F-22.

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.

The lawsuit comes after the Department of Justice declined an opportunity under the Fair Claims Act to take up the case under seal.

Now, Darrol Olsen, who was fired by Lockheed in 1999, has turned to the US District Court in California's central division to seek justice.

Olsen wants to be re-instated with back-pay plus interest since losing his job more than a decade ago, says Samuel Boyd, Olsen's attorney. Olsen also is asking the court to order Lockheed to pay the US government $50 million for each of the 183 F-22's currently ordered, says Boyd. That amount equates roughly to the cost of the allegedly compromised stealth technology on each jet.

Lockheed was not immediately able to comment on the lawsuit.

Olsen began his Lockheed career in 1979 at Skunk Works, where he worked on developing new composite materials for the F-117, according to court documents. Olsen bounced between the F-117 and Northrop's B-2 programme during the 1980s, finally returning to support Northrop's B-2 flight test programme in 1990.

In 1995, Olsen finally joined Lockheed's materials and processes engineering group in Marietta, Georgia, to work on the low observables system for the F-22.

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.

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.

In 1998, Olsen claims he refused to participate in an award ceremony that falsely honoured his team for solving problems he knew still persisted.

Lockheed also schemed to avoid government inspections of the coatings, secretly shipping batches of the stealth materials to the homes, the lawsuit states.

Although Olsen was fired for "failure to follow instructions" in 1999, the lawsuit says, he believes the problems have never been fully addressed.

In March 2008, an F-22 sustained major damage after a small strip of stealth coating inside the engine nacelle peeled off and was ingested by the fan blades of the Pratt & Whitney F119 engine.

In November, John Young, who stepped down in May as under secretary of defence for acquisition, technology and logistics, told reporters he was concerned about the F-22's stealth, or low observable, maintenance requirements.

"I would highlight in general the maintenance on the airplane is too high," Young said. "They're struggling with some of the LO and other issues, and there's clearly work that needs to be done there to make that airplane both capable and affordable to operate."

Source: Flight International