Design flaw puts F-22s in shop

From Air Force Times

Design flaw puts F-22s in shop for repairs

The Associated Press

Posted : Monday Oct 22, 2007 8:15:34 EDT

SALT LAKE CITY — The Air Force is speeding up its timeline for bringing the F-22 Raptor to Hill Air Force Base for repairs after a design flaw that military officials have known about for years has reappeared.

The problem with the Air Force’s newest fighter jet is that the composition of some mechanical access panels makes the Raptor susceptible to corrosion. Military officials changed the design to fix the problem, but it is back and about two-thirds of the military’s fleet of the planes is suffering from corrosion.

“So the world’s most expensive, most advanced aircraft is in the shop for repairs for something simple that someone figured out a long time ago?” said Nick Schwellenbach, national security investigator for the Project On Government Oversight. “I’d like to say I was outraged, and it is outrageous, but it’s all too common.”

The Project on Government Oversight has exposed numerous other problems with the Raptor, which costs more than $130 million per plane. Those costs triple when research, development and other costs are factored in.

The plane is advertised as the world’s most advanced fighter jet. It was intended to be ready for combat by 1997, but the Raptor has yet to fly a single combat mission because of cost overruns and delays.

It’s unclear how much the corrosion issue will cost the Air Force to fix. Brig. Gen. C.D. Moore, who is leading production and sustainment efforts for the F-22 at Ohio’s Wright-Patterson Air Force Base, said the “cleanup and mitigation” of already-identified corrosion problems could cost nearly a half-million dollars in labor costs alone.

But Schwellenbach and other defense experts are frustrated that this problem was not addressed when it was identified in the mid-1990s.

At the time, the Raptor’s development was already years behind schedule and critics were beginning to complain that the Raptor was an expensive Cold War weapon in a post-Cold War world.

However, even as the Soviet threat diminished the Air Force continued to push to improve the plane’s “low observable” qualities.

The Raptor was designed to have few exposed joints and edges to lower the aircraft’s radar visibility. But techniques that made the plane stealthier — like filling the seams of the access panels with a soft, rubbery putty — weren’t always good for corrosion control.

Alerted to concerns that the metals, paint and other materials used in and around the panels would interact in a way that would cause severe corrosion, Col. Kenneth Merchant, now a brigadier general and vice commander at Hill’s Ogden Air Logistics Center, oversaw a change in design. Merchant left his assignment in 1997 believing that the problem had been addressed by a change that included switching the metal used in the panels from aluminum to titanium. The change made the Raptor negligibly heavier. It also made the aircraft more vulnerable to radar.

Moore said the decision to overrule Merchant’s change came over the course of several years as engineers sought to find “the right balance” between durability, performance and low radar visibility.

“We thought we got it right,” he said. “We understood there was a corrosion risk.”

That irked Schwellenbach.

“What’s the point in it being more stealthy if it’s in the shop?” he asked.