Questions tagged [fatigue]

The mechanical failure mode; for pilot fatigue, use [pilot-fatigue].

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3answers
183 views

What is the life limit due to metal fatigue in large bombers?

This article explains how the B-52's will be kept flying for 100 years. Replacing the engines, electronics, etc. is one thing, but when would metal fatigue become a problem? These planes are huge and,...
7
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1answer
344 views

Stress on wing/fuselage-joint of aerial water tanker aircraft - and possible mitigating measures

Following the unfortunate crash of a C-130 aerial water tanker aircraft in Australia, a friend brought to my attention a 2002 C-130 tanker crash in the US. As can also be seen in this video, the wings ...
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2answers
617 views

Why was the B-52's wet wing more susceptible to fatigue than its dry wing, and not less?

After years of carrying all its fuel in the fuselage, the B-52 transitioned to a wet wing (where the wing structure is used as one or more fuel tanks) with the B-52G. This caused severe problems with ...
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2answers
383 views

Why don’t double-bubble fuselages cause severe fatigue problems?

In response to my previous two questions about fatigue issues, or the lack thereof, generated by the cusps in double-bubble-fuselaged aircraft (Stratocruiser, DC-9-80), I received a number of answers ...
8
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1answer
338 views

Is In-Seat Rest used regularly where it is legal, and is it restricted by airline SOPs?

This answer says that a pilot who is not flying (PNF) can make use of a procedure called In-Seat Rest to take a nap during flight. A comment on the same answer says that this is illegal in the US, ...
3
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2answers
231 views

What are the characteristics of the F-16 airframe lifetime?

What limits the lifetime on the F-16 airframe? I assume it is material fatigue, but what kind, and where on the airframe? Moreover, what exactly happens? What will happen if this problem is ignored? ...
13
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4answers
3k views

Why does the DC-9-80/MD-80 have this cusp in its fuselage?

The fuselage of the McDonnell Douglas DC-9-80 (also known as the "MD-80") has a pronounced cusp at floor level, as can be seen in this diagram (courtesy of Boeing, eater of McDonnell Douglas - at ...
3
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1answer
328 views

Why weren’t the Comet’s overhead ADF windows roundified along with its passenger windows?

Following the crashes of two Comet 1s in early 1954 due to metal fatigue, all future Comets (and the few surviving Comet 1s that were rebuilt rather than scrapped, all of them in military service) ...
9
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2answers
754 views

Did the cusp in the Boeing 377/C-97/KC-97’s fuselage structure cause fatigue problems?

The Boeing 377 Stratocruiser - a civilian adaptation of the C-97, a military transport which would also later be developed into the KC-97 - were derived from the B-29/B-50 family by grafting a large, ...
4
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3answers
366 views

Do large non-pressurized metal planes have a maximum fatigue cycle?

For example the DC3. The way I understand it, the only thing that "ages" the airframes of DC3 is the landing/takeoff cycles and the accompanied periodic force loading/unloading. Do planes such as this ...
6
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1answer
251 views

What are the fatigue regulations in the US and Australia for military transport helicopters/rotorcraft?

For transport category military helicopters, what are the fatigue regulations as specified by the US and Australian regulatory bodies? I've managed to find that FAA has 14 CFR 29.571 (Fatigue ...
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3answers
3k views

What is the fatigue life of a fuselage based on?

The fatigue life of the fuselage is based on the number of what? Pressurization cycles?
24
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4answers
9k views

How is metal fatigue detected in an aircraft?

There have been many accidents involving metal fatigue. How do the engineers, maintenance team, etc. know if an aircraft has metal fatigue? What is done to "minimize" metal fatigue or repair it?
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0answers
814 views

Is the Boeing 737 unusually susceptible to stress fatigue?

According to this Newsweek article - which seems like a reputable source - the FAA has issued a number of Airworthiness Directives to address stress fatigue concerns with the 737NG series: Between ...