|
Thermal Acoustic Imaging
Thermal acoustic imaging (TAI) is a proprietary active thermographic inspection process developed by Pratt and Whitney (P&W) in 2005; TAI is a nondestructive testing (NDT) method to detect internal and external cracking of hollow core turbofan engine fan blades. TAI is performed to inspect the PW4000 diameter fan blades in an enclosed air-conditioned room within P&W's overhaul and repair facility in East Hartford, Connecticut. Technical description In the TAI process, sound energy is applied to excite the fan blade. If a discontinuity exists in the metal, the excitation will cause each side of the contacting discontinuity to move, resulting in frictional heating. The frictional heating is detected on the surface of the fan blade by a thermal imaging sensor. To examine a complete fan blade, the convex and concave surfaces of the fan blade airfoil are divided into zones and the computer controlled thermal sensor takes an image of each zone while sound energy is applied. Aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UAL1175 PW4077 Fan Blade 11 Fracture
On February 13, 2018, around noon local time, a Boeing 777-222 airplane, operating as United Airlines Flight 1175 (UA1175), experienced an in-flight separation of a fan blade in the No. 2 (right) engine while over the Pacific Ocean en route to the Daniel K. Inouye International Airport (HNL), Honolulu, Hawaii. During level cruise flight shortly before beginning a descent from flight level 360 (roughly ), and about from HNL, the flight crew heard a loud bang, followed by a violent shaking of the airplane, followed by warnings of a compressor stall. The flight crew shut down the failed engine, declared an emergency, and began a drift-down descent, proceeding direct to HNL where they made a single-engine landing without further incident at 12:37 local time. There were no reported injuries to the 374 passengers and crew onboard and the airplane damage was classified as minor under National Transportation Safety Board (NTSB) criteria. NTSB investigators traveled to the scene to begi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
