Engineering:Parts Departing Aircraft

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In aviation safety, Parts Departing Aircraft or Parts Detached from Aeroplanes (PDA), also known as Objects Falling off Airplanes (OFA), Things Falling Off Aircraft (TFOA), and other analogous variations, can range from small fasteners like screws and rivets up to major sub-assemblies like hatch covers and doors.[1] PDA are a safety concern because they may be a critical parts needed to safely continue flight, may damage other critical parts of the aircraft as they depart, may cause foreign object damage to other aircraft, or may cause serious injuries or damage to people and property on the ground.[2] These occurrences are a longstanding worldwide problem in aviation.[3][4] In a 2018 study, the European Aviation Safety Agency concluded that the likelihood of fatally injuring people on the ground due to a PDA event is low enough that it does not constitute an unsafe condition according to their standards; they also noted the absence of any people fatally injured from PDA.[5] But in Japan, preventing objects falling off airplanes is required by all air carriers after a series of serious incidents at Haneda Airport which is very close to Tokyo.[6]

Regardless of whether PDA are considered acceptable risk by aviation regulators, things that fall from the sky are generally not well tolerated outside the aviation community. The United States Navy found complaints about TFOA (their preferred acronym) increased as residential development has encroached around naval air stations.[3] Leaking aviation lavatory liquids have been known to build up on the exterior of the aircraft in sub-freezing temperatures at altitude, only to fall to earth as blue ice after the airplane descends to land.[7] And London Heathrow Airport has had a recurring problem of wheel-well stowaway bodies dropping in residential areas around the airport when airplanes extend their landing gear as they prepare to land.[8][9]

External links

References

  1. "Pieces regularly fall off planes, and officials duck the issue Airlines, government say problem is insignificant". The Baltimore Sun. Los Angeles Times. 1995-11-24. https://www.baltimoresun.com/news/bs-xpm-1995-11-24-1995328029-story.html. 
  2. Jérome, Real (July 2014). "Parts Departing from Aircraft (PDA)". Safety First, the Airbus Safety Magazine #18: 040. https://www.airbus.com/content/dam/corporate-topics/publications/safety-first/Airbus_Safety_first_magazine_18.pdf. 
  3. 3.0 3.1 "Parts Falling From Aircraft Are a Headache for the Navy : Battle Waged to Prevent 'TFOAs'". Los Angeles Times. 1986-09-21. https://www.latimes.com/archives/la-xpm-1986-09-21-me-9105-story.html. 
  4. "Germany: Hundreds of airplane parts fell from the sky since 2008 - 03.08.2018". https://www.dw.com/en/germany-hundreds-of-airplane-parts-fell-from-the-sky-since-2008/a-44941669. 
  5. PARTS DETACHED FROM AEROPLANES. Certification Memorandum. EASA CM No.: CM–21.A-A-001. European Aviation Safety Agency. 29 November 2018. "In PDA events, given the current observed rates of loss of parts per FH, the risk of injuries to persons on the ground or damage to other aeroplanes, under the assumptions taken for this analysis, do not constitute an unsafe condition as per 21.A.3B(b).". 
  6. "PREVENTING OBJECTS FALLING OFF AIRPLANES". Thirteenth Air Navigation Conference (Montréal, Canada: International Civil Aviation Organization). 9–19 October 2018. https://www.icao.int/Meetings/anconf13/Documents/WP/wp_104_rev1_en.pdf. 
  7. Katz, Jesse (1990-01-07). "'Blue Ice' Lays Waste in Paths of Jetliners". Los Angeles Times. https://www.latimes.com/archives/la-xpm-1990-01-07-mn-450-story.html. 
  8. Bostock, Bill (2019-07-02). "A stowaway fell from a plane as it was landing in London, a shocking occurrence that happens more than you may think - here's why". Business Insider. https://www.businessinsider.com/heathrow-london-hotspot-plane-stowaways-falling-from-sky-2019-7. 
  9. Kelly, Jon (2012-09-13). "How often do plane stowaways fall from the sky?". BBC News. https://www.bbc.com/news/magazine-19562101.