Дата: 07-07-21 10:05
Can you fix an aircraft that has been ditched?
On July 2, 2021, a Transair Boeing 737 freighter got ditched in the water off the coast of Hawaii. Both pilots were rescued and praised for their skilful handling of the incident. They managed to land an aircraft with a double engine failure, on water, at night, and do it relatively smoothly.
The depth of the water at the point of landing was around 150 feet (approximately 46 meters) – a bit deep for a swim, but comparatively shallow for a rescue operation. As the attempts to assess the environmental damage and investigate the cause of the incident are underway, there is a chance the 737 is going to be lifted out of the water in the near future.
So, an obvious question emerges. If the airline recovers its sunken plane, what is it going to do with it? What is the fate of ditched-and-recovered airplanes, and can they be restored to a flying condition? At least partially?
Well, no. But actually yes. The answer is complex and quite far from obvious.
Salvaging the airframe
Quite obviously, the plane gets heavily damaged after the water landing. The fuselage gets deformed and sometimes broken apart, if not during the landing, then shortly after it as the airplane sinks. Additionally, salt water is extremely corrosive and can quickly damage various sensitive components.
So, even if recovered, it is not likely to fly again. In the case that somebody recovers the sunken aircraft, two possible outcomes await it: it can be either recycled or put on display.
Aircraft whose swimming attempts get noticed by the public usually end up at museums: the Airbus A320 No. N106US, ditched by Chesley "Sully" Sullenberger during the Miracle on the Hudson incident in 2009, was fished out of the Hudson River and now resides in Carolinas Aviation Museum. Right across the pond, the visitors of South Yorkshire Aircraft Museum can witness the remains of Royal Air Force Hawker Siddeley Nimrod R1 which crashed into Lake Ontario in 2005.
But if the accident was not remarkable enough, the airplane gets scrapped. For example, the Boeing 737s of Miami Air Flight 293 and Air Niugini Flight 73 that ended up in the water in 2019 and 2018 respectively, were completely written off.
So, with rare exceptions (more about them later) ditched airframes are not fit for restoration in any significant capacity. But what about their parts?
The parts problem
If the landing is relatively smooth, a lot of parts remain intact (or at least appear so); hence, salvaging and reusing them is possible. This scenario is a subject of several prominent horror stories in aviation – such as the one with Eastern Air Lines Flight 401. Supposedly, the parts of the crashed Lockheed L-1011-1 TriStar were used on other Eastern aircraft, leading to the appearance of deceased crew members ghosts.
While this particular story is most likely untrue and no parts were reused, there are plenty of less prominent examples. The crash of American Airlines Flight 965 in 1995 resulted in the appearance of a large number of scavenged Boeing 757 components on the black market, prompting a harsh crackdown from aviation authorities.
Purchase and usage of such parts are actually illegal in many cases, as the seller of a certified aircraft part has to sign a Non-Incident statement clarifying that the part was not involved in any incident. Recently, those statements were phased out due to their various shortcomings and replaced by Accident/Incident Clearance Statement (AICS) – a form preferred by the International Air Transport Association (IATA) and many national aviation authorities.
By signing an AICS the seller signifies that “Neither the aircraft, nor any part installed have been <…> subjected to severe stress or heat (such as in a major engine failure, accident, or fire) or has been submersed in salt water,” – which, in theory – should prevent anybody from reusing the part (or the aircraft) that has been landed in an ocean at some point.
The AICS then adds a caveat: “…unless its airworthiness status was re-established by an approved maintenance organization in accordance with the applicable airworthiness regulations,” leaving a possibility of re-use in a narrow case if the part is carefully inspected and found intact.
While in theory, this caveat opens a possibility to reuse a part of a ditched aircraft, in practice such cases are almost non-existent. Normally, for a decommissioned aircraft the parts that are most likely to be reused are engines, auxiliary power units (APUs), avionics, system equipment, and landing gears. Incidentally, these are the parts that are very likely to be damaged during a water landing due to being either sensitive to damage, or the first ones to impact the water, or both.
So, unless the airline you fly was involved in some shady activities, the chances to fly on a ditched airplane or an airplane that uses a previously ditched part, are practically non-existent.
With only one exception.
In some very rare cases, the aircraft is a bit too important to be scrapped even if it found itself underwater.
In April 2021 a Grumman TBM Avenger – a WWII-era torpedo bomber – crash-landed in the water near a beach in California. The aircraft was built with similar events in mind, and was a lot sturdier than civilian airliners. Additionally, the landing was masterful, and barely any damage from impact was sustained. As soon as possible, the airplane was rescued from the water, and - as of summer 2021 - is being restored to fly again.
Similar stories are not unheard of in the world of vintage airplanes. A seven-decades-old machines are simply too valuable to be scrapped, and their owners would do anything to restore them to their former glory. The parts of aircraft ditched in WWII are sought after by people working on various restoration projects, and although their airframes are often too corroded, their components are not subjected to limitations that modern civilian airliners face.
Also, there is that one case of an airliner that flew after being submerged. It is the NC-19903 - the last of the Boeing 307 Stratoliners, which crashed into Elliot Bay near Seattle in 2002. Promptly lifted out of the water, disassembled and doused in tons of fresh water to wash out the salt, it then spent six years in the hands of volunteers who managed to bring the airplane to life for the second time, making it, quite possibly, world's only airliner to survive such fate.
Источник информации: AeroTime
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