What is the 'lifespan' of a commercial aircraft (such as a B737)?

Question

Is it judged on the number of hours flown?

Answer 1

Partially. It is also based on cycles (flights). A 737 has a limit of 50,000 cycles before it must be modified with lap joints to reinforce the fuselage. This costs big bucks and increases the empty weight of the plane, but I've seen some 737s (just before retirement) with 60,000 hours and 80,000 cycles (the plane was 20 years old).

Larger aircraft (like the 747) fly fewer cycles per hour so they can last longer.

The highest time aircraft I worked (and flew on) still in daily service was a Convair 580 that had 90,000 hours and 150,000 cycles. It was made in 1952.

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Answer 2

Its called a fatigue life, but the interesting thing is that even though they have been flying for 40-50 years, there are almost none that have been removed from service because of it.
The truth is that there are 16 737's which have over 100,000 hours, and a large amount (thousands) with over 75,000 hours.
The real reason most jets are retired is that the engines on any jet more than 15 years old are EXTREMELY inefficient. Im not talking about like 50% less, Im talking about 3 times more fuel consumption between a 737 made in 1990 and one made this year.
Fuel consumption is rated as specific fuel consumption, or SFC. The SFC is how many pounds of fuel an engine burns per hour per pound of thrust. The original 737 had a SFC of about 1.5 and the new one has a SFC of about .37. Thats a 75% reduction in fuel consumption.
There are also other factors such as noise pollution. Sounds stupid but the FAA makes certain airlines give up its airliners, mainly its DC-9's. There are a few cases where other airlines were given waivers to operate them in order to keep the market competitive, but the majority are just turned into pepsi cans.
Overall, Ive got to say that airlines have almost an unlimited life. 100,000 hours is a long long time, And I dont doubt that some of the airframes flying today will be around when Im old and shriveled.

Answer 3

Generally the spec requires a 25-30 year life. However it is not age but useage that matters (just like your car). Something like a 737 will be certified for 60,000 -70,000 cycles (take off - fly - land). At this point the fatigue damage to the airframe and the condition of the systems will probably make it un-economical to fly under strict airworthiness rules. This is why many older aircraft find their way to 3rd world countries where maintenance requirements and airworthiness authority oversight is less strict (and hence you often read about accidents). I have been working of the C5 Galaxy re-engining and relaiability programme. This is a US military transport aircraft that has been flying since 1960 and they want to keep them flying for another 40 years. This is possible because the aircraft has very low useage compared to a civil airframe (we use a rule of thumb of 300 flight hours per year for military verses 3000 flight hours for civil).

Answer 4

The 'life' of any aircraft airframe is determined by its 'Fatigue Life'. Aircraft have equipment which measures this in terms of the forces thet it has been subjected to during its service. Things such as 'heavy landings' will clock-up more fatigue and shorten the life. All individual components on the aircraft may be individually 'lifed' and these are changed as part of the aircrafts service programme. Aircraft usage is calculated in 'flying hours' not distance covered.

Answer 5

Most Air frames are only limited based on the condition of the frame. There are many air craft that are over 30 years old that still make daily flights. what will cause an aircraft to be retired is what they find when they inspect the air frame for airworthliness recertification. if there frame is noted as having X amount of stress on the frame it is then checked to see if it can be re-enforced. if it can not be it is removed from service. a lot of this depends on how well the air craft was maintained. go to boeing.com for more information.

Answer 6

That depends on maintenance, amount of use etc etc. However, B707s from the 60's are still being used. Old B737-200's are also still in use.

Answer 7

Developement fees and the economics of the tip product is each and every little thing. The Concorde challenge proved this. It travelled at two times the value of sound yet to go the one hundred or so passengers took as plenty gasoline as a results of fact the 747 makes use of to pass an identical distance with 4 cases as many human beings. i think of we may even see an airplane with scram/ram jet propusion for protection stress or scientific study use long until now we are waiting to journey on an airliner using those engines. except progression could be made to get rid of or very much cut back sonic booms and the intense gasoline burn in line with passenger, commericial aviation will proceed to be a subsonic holiday. Given the present economic state of the airline marketplace the emphasis would be on economic device. i've got been following commercial aviation for some years and from what i've got found out the A380 is in simple terms no longer sucessful. extensive physique airlines have been around for over thirty years and the customary public is used to them and at modern-day is in no temper to journey on a much better one. are you able to think of the hastle of being certainly one of 555 human beings waitng to get on certainly one of those monsters? enable's communicate concerning the hastle of having off the element when you arrive at your trip spot. there is all style of communicate approximately well-being golf equipment, bars, and shops on the A380 yet all of us understand that like the upstars residing room on the 747, that area would be crammed with seats until now long. What are they thinking. are you able to think of a A380 getting as much as altitude and 555 human beings start to mill around the airplane procuring, geting a rub down or getting showered? Get genuine. all of us understand those stupid little shops and bars would be in basic terms for the top notch passenger on an identical time as the enormous crowd making the holiday econimically doable would be packed like sardines interior the rear of the airplane. modern-day-day air visitors are searching for a greater direct course to their places averting the enormous hubs that great airliners use now. those great hub airports reason extensive layovers and lost connections and makes the holiday longer that it desires to be.

Answer 8

the number of pressurisation cycles is important. Remember the Hawaii 737 that went topless in flight. Not many flying hours, but many ups and downs.

Answer 9

There is much debate on this as 30 years is often the cut off as the aircraft becomes too expensive to keep it air worthy as the older it gets the more it costs to keep it air worthy.

Answer 10

normally a quarter of a century