Yeah, but what’s the deductible?

5-inch metal pin does $6.7 million in damage to Raptor

One night last October in the Utah desert, an Air Force mechanic double-checked the landing gear on a gleaming new F-22 Raptor fighter jet. It was five days into the Langley Air Force Base unit’s first training mission.

The mechanic spotted a 5-inch metal pin and an attached streamer fastened to the front landing gear. It needed to be removed before the plane could depart on its late-night mission.

Inside the cockpit, the pilot shut down one of the plane’s two engines. The mechanic reached into the landing gear and pulled the small pin and 3-foot streamer.

In an instant, the piece leaped from the mechanic’s grip and into the still-turning jet engine. Sparks flew. Metal screeched. Stomachs dropped.

On Wednesday, the Air Force released its investigation of the incident and tallied the repair bill – $6.7 million plus.

Both the pilot and the mechanic were cleared of any wrongdoing by the investigation.

I don’t quite get what happened. Seems that the plane was preparing to take off, which is why the pin was pulled, but that the pilot had just shut down one of the engines. The story says that the problem was that the manual wasn’t clear enough on how to pull the pin while the engines were running, but wouldn’t things have been worse if both engines had been running. I don’t get what was unusual.

Oh, unless the pin was supposed to have been pulled before the engines were started. In that case, though, wouldn’t the root cause be failure to ensure the pin is pulled at the proper time?

Anyway, the Raptor is going to be dealing with these sorts of “look how much this cost” stories for years to come. A 5-inch metal pin is going to cause expensive damage to any jet engine, whether it’s on an F-22 or not. What if this pin had been sucked into an F-15? Would the cost have been significantly less?

Comments

  1. FOD is a normal hassle (cost) of operating any jet. Pin probably should have been pulled before. SNAFU

  2. Without a doubt it wouldve costed more if an F-15C ate a pin. Not just from damage, but just the fact it costs alot more in man hours and replacement costs for the F-15C. And F-22A can have an engine change out in 90 minutes. And F-15C takes 4 hours or something.

  3. Shipmates, Yup… FOD is always present and always a danger, and not just on the ground. My very first operational flight on a P-3B Orion, we sucked a dump duck (seagull) into the #3 engine just after we rotated. All I saw was sheets of blue flames, and pieces of shrapnel pinging through the aft fuselage. I haven’t a clue as to the odds of a live bird making it past a rotating 4-bladed prop and into a turbine, but it did, and I swear I aged 10 years in 10 seconds. Respects, AW1 Tim

  4. Well, while it’s easier and faster to change the engine on an F-22 I doubt that it costs a significant portion of $6.7m to remove and re-install it. Most of that cost is in replacement turbines and such, which are made of titanium and have very tight tolerances. Also, tearing the engine down and rebuilding it will take a while. But I bet the lion’s share of that is parts. My uneducated guess is an F-15C engine would cost about half that to repair for a similar amount of damage, since parts are more plentiful for that engine and it’s lower-tech so they’re not so expensive to manufacture. (I don’t think an F-15C engine costs much more than $6.7m new. An F-22 engine sure does.)

  5. This engine may have still run, just that inspection is lengthy for metal FOD. Engines are very robust and have to be. Catastrophic failure would have meant pressure loss from the compressor. This makes a flow reversal occur and all the debri from the compressor would have been shot out forwards. Possibly injuring the mechanic. Clearly nothing like this happened. The metal pin probably hit at least 1 compressor blade in each stage. Probably creating a little more debri on the way. All of which would have damaged the turbine blades. Therefore calling for a full inspection of every stage with the likelihood that there are small bits of damage in all parts.

  6. Tim, I doubt the bird was alive when it was sucked into the turbine. Probably had two or three large pieces of bird sucked into it. If the plane is moving forward fast enough (which it probably was, if it was after rotation) a bird won’t be pulverized by the propeller blades, just chopped into a few big pieces. Chuck

  7. This excerpt from an article in Aerospace Daily & Defense Report, dated 3/27/2006 explains the situation a little better: After the engines of one of the aircraft were started for a night mission, a crew chief realized that a nose landing gear pin was still in place. He had the pilot shut down the left engine so he could step in and remove the pin. However, the cloth streamer attached to the pin was caught in the suction field of the right engine and was pulled in. Extensive damage and debris were produced throughout the engine, but damage was contained within the engine casing. After four days of impoundment, the engine was changed and the aircraft was put back in service. Failure to remove the pin before engine start was traced to incorrect technical order guidance.