What happened to a Lockheed Martin-developed F-22 Raptor?
Maintenance failure causes $ 2.7 million in damage to an F-22 Raptor. Giacomo Cavanna's article for AresDifesa
A sequence of errors and carelessness resulted in damage quantified at $ 2.69 million to the F-22 Raptor with registration number 06-4109 of the 422nd Test and Evaluation Squadron at Nellis Air Force Base.
On 26 June 2020, the Raptor began a series of works to prepare for a major flight test campaign.
On 26 October, to facilitate operations, the technicians dismantled the “exhaust” of the Auxiliary Power Unit (APU) or AMED (APU Mixing Exhaust Duct) in order to have easier access to nearby wiring and control units.
In this condition, the APU certainly cannot be used but no one bothered, as expected, to disconnect the fuses, report the impossibility of turning on the system with the classic red tapes and check that the AES (APU Emergency Switch) was in the "EMER OFF" position.
On October 28, it was planned to install some diagnostic tools in the right side bay, the armament management system in the left bay and the removal of a panel above the right engine air intake.
In order to unload the fuel from the aircraft faster and open and close the bays, the technicians decided to turn on the APU instead of the slower “trolley” on the ground.
When the APU was turned on, the exhaust gases from the turbine, instead of exiting upwards, began to invade the interior of the aircraft, seriously damaging some components of the APU itself and numerous wiring.
The commission of inquiry found several discrepancies between the action of maintenance technicians and what was actually planned for this type of intervention.
If the procedure had been applied correctly it would not have been possible to start the APU.
The damage was estimated at $ 2,690,000.
Article published on aresdifesa.it
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/innovazione/cosa-e-successo-a-un-f-22-raptor-sviluppato-da-lockheed-martin/ on Sat, 17 Jul 2021 05:39:46 +0000.