Brings back the standards of both Mil and Civ safety procedures. HK> Cascading F-22 Maintenance Mistakes Led to $2.7 Million Mishap Air Force maintainers address an issue on an F-22 Raptor. (U.S. Air Force/Airman 1st Class Alex Echols) 12 Jul 2021 Military.com | By Stephen Losey A series of maintenance mistakes at Nellis Air Force Base, Nevada, led to an F-22 Raptor fighter overheating and sustaining $2.7 million in damage last October. The advanced fifth-generation fighter was not destroyed and no one was injured in the incident, according to an accident investigation board report released Friday. But it was a Class A mishap, the most serious classification. F-22s cost an estimated $250 million each. Lockheed Martin stopped manufacturing the aircraft in 2012. The Raptor was assigned to the 422nd Test and Evaluation Squadron at Nellis, according to the Air Combat Command report; it was maintained by the 757th Aircraft Maintenance Squadron. Read Next: Top US Commander in Afghanistan Hands Over Command According to the report, maintainers started troubleshooting problems with extensive hardware and software modifications made to the aircraft last summer. On Oct. 28, a maintainer removed the auxiliary power unit's mixing exhaust duct, which steers extremely hot gases safely outside of the aircraft, to try to figure out what had gone wrong. However, the maintainer failed to place the required "collar" clips, with bright orange "remove before flight" streamers attached, to the circuit breakers involved, which would have warned others not to reset them and start the aircraft, and did not put the proper digital or physical warnings in place, the report states. Clip-on collars are designed to stop circuit breakers from being reset inadvertently. Maintainers told investigators that installing the collars is difficult and often not done; one maintainer said he didn't know what they are. The maintainer also did not replace that exhaust duct, the report adds. Two days later, the F-22's auxiliary unit was improperly started up with its exhaust duct uninstalled and its emergency cutoff switch incorrectly set to normal. Scorching hot exhaust gas went straight into the exhaust bay and the wheel well of the left main landing gear, when a properly installed duct would have safely diverted it out of the plane. As smoke spewed out of the exhaust bay, the maintainer mistakenly tried to run diagnostics and review the warning codes. It wasn't until another maintainer manually shut off the power unit that the overheating stopped. By then, the damage was done. Temperatures in the exhaust bay had reached 600 to 700 degrees Fahrenheit. The overheating damaged the F-22's airframe, systems, wiring, hydraulics and surrounding structure, and parts of the auxiliary power unit's exhaust bay. The report found that the maintenance unit's culture, in which circuit breaker collars and warnings were used rarely or inconsistently, contributed to the mishap. The Air Force did not respond to an inquiry about what has been done to address the unit's cultural issues by publication time. According to the investigators, the incident could have been avoided if the collars had been in place. The report also placed some blame on the extensive nature of the earlier F-22 modifications, stating that the "sheer amount of data" being processed by one maintainer made a mistake more likely. -- Stephen Losey can be reached at stephen.losey@military.com. Follow him on Twitter @StephenLosey. Related: More Than a Year After its Landing Gear Collapsed, an F-22 Is Back in the Air
Some guy once pointed out that 100,000 "flying Volkswagens" could sweep the skies and win any war because the enemy would have to run out of ammo sooner or later--and then there would be no place to hide. Just one machine gun and one air-to-air missile is about all they would need. And a lot of expendable pilots. 100,000 wood & fabric prop jobs at $10,000.00 a pop would only cost a billion dollars. That's about the same as four F-22s or one economy Stealth Bomber. You know: the ones with the polyester fabric interior & no radar. Of course, guns and missiles do add up (and don't we all know!). How about this bad boy? I think the price of plywood is coming back down... Facetmobile - Planes
There is more to that. Were the forms filled out stating that the aircraft was ready for an apu test? Removing that type of stuff should cause a red x. You don’t operate with a red x and only certain people can remove a red x. Tech data was obviously not followed in multiple instances. The maintainer doing the apu maintenance did not verify condition of aircraft before running it. Leaving out the collars and warnings is a violation of tech data but running the apu when the exhaust duct is most likely laying on the hangar floor next to the aircraft is also bad. I want to know what the FORMS said!!!
We had LOTO procedures when I worked in the mines. Violation meant you could easily end up in serious trouble with the company (up to and easily including termination) because if MSHA (Mine Safety and Health Administration, US Department of Labor) found out about the violation, the mining company was subject to some pretty horrific fines. Of course not following those procedures could also mean someone gets killed, electrocuted or crushed, run over,etc. The electric powered shovels were as big as most two-story single family homes. If you're working on it, you locked out the control power so that the machine could not be started until you, and only you, removed your personal lock. Strictly enforced, because it has to be. Even with those and countless other precautions, the open pit mine where I worked averaged 1 fatality every 8-9 months. Those working on the F22 were fortunate that the only result was damage to the aircraft and no body bags were needed to contain charred corpses. Yeah, I used to work on aircraft also (including for the Air Force) but that was before LOTO was common practice. Everyone communicated with each other and made damn sure everyone else knew what the status was. Example "Don't turn on power, because I have major wiring disconnected." Or "No smoking, we have an open fuel cell".
Improper LOTO cost a buddy his life! You want the whole story, its posted on line in the local news. Short version, buddy was doing electrical/mechanical work @Intel and diagnosing a large complex machine. The Machine was locked out and tagged out, and yet, some asshole came along and turned the machine on which cut my buddy into pieces! Some one completely ignored the LOTO procedures and killed a husband, father, and friend!
We actually had individual physical locks to which only the individual maintainer and the Captain had a key. When I tagged and locked a breaker system it stayed locked and tagged until I or my third up-rank unlocked it. If more than one maintainer was working, they all had their locks and flags on the panel. Tags were also individualized so we could easily track down who was involved. 15KV DC fries quickly....
Something isn't quite right with this story! Firstly, you NEVER EVER E-V-E-R start, run, or test an aircrafts APU inside a maintenance hanger, EVER! There are very specific protocols for starting and running those units, it MUST be done outside with fire apparatus near by on stand by, and a watch crew manning the equipment through out the entire procedure! Any time a APU is to be test ran, it is to be removed from the airframe and installed on a specific test cart with the proper safety and containment equipment with the proper support personal in fire protection suits, and the maintainers must be specifically trained and equipped to test run those units! I know this well, having been one of the rescue personal on close standby when such was taking place, and I have seen those APU's run away, over spool and explode, or a flame out then fire ball on all the excess fuel that was still flowing and pooling! I witnessed one such event, and the fireball engulfed the entire test and fire crew, luckily, every one was wearing the proper equipment and the fire suppressant kicked in automatically around the test area! That would have killed every one on scene, about 9 airmen had they not all been wearing their gear! Most if not all U.S. fighter type airframes us the exact same APU with various different accessories and generators that are specific to a certain airframe type! The F-14, F-15, F-18, F-22, A-10, A-6, S3-A and a few others all use the same G.E/Solar APU turbine of between 70 and 180 HP!
I worked on 1500 Hp air-compressors and 600 Hp water pumps amongst other big equipment and used lock-outs and records kept for each event. A supervisor was kept in the loop at all times. More than one person is going to take the heat for this blunder.
At a minimum the Sqdn CO is gone and the Wing King had best watch his 6. The USAF ditched QC and STAN EVAL quite some time ago. Long before I retired. I'm happy to see no one died, but someone is looking at a Full CM and I don;t mean the grunt that f'd-up. Maintenance Chief and Maintenance officer are toast.
I suspect the damage is related to the sneaky stuff, likely coatings and other stuff were not supposed to know about! 2.7k ain't much in modern airframes, hell, the APU prolly cost more then that!
It fries a bunch of wiring harnesses and some components, I have seen the aftermath of this. So every component connected to those wiring harnesses gets replaced too. Most of them go back to depo.
