Why do technical faults occur in U.S. commercial planes when there are already spacecraft launched ?

Question

As compared to the spacecrafts, planes are technically simpler.

Answer 1

Why do technical faults occur in your car when there are already aircraft launched?

As compared to aircraft, cars are technically simpler.

Answer 2

I understand your point that planes are technically simpler than spacecraft but spacecraft don't spend twenty or thirty years almost exclusively outdoors in all kinds of weather and are not operated in wet and extremes of weather for most of the hours of any given day. They have to be lite, stable, forgiving, and long lasting.

For the most part airliners are safe and reliable.

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Answer 3

Because you touch yourself at night.

Answer 4

Technically simpler than spacecraft, probably.  Technically SIMPLE?  Not at all.  US (or any nation's) commercial aircraft are so complicated, technical faults are inevitable.  

And let's not forget, spacecraft take off and land, what--once per year, if that?  A lot of smaller jets on shorter routes take off and land many times each day, that's maybe 40 or 50 TONS of aircraft settling onto the landing gear, that's hours of climbing and descending, pressurizing and depressurizing, operating engines at high power for many hours, and then when all is said and done, they might sit at the gate for five or six hours overnight, then tomorrow they are right back at it so you and I can get where we need to be.

So yes, in theory aircraft are technically "simpler", except that they don't get a year off in between each flight.  They're lucky if they get a full hour.

Answer 5

They're still technical. And techology fails.

Answer 6

Its what happens when you let the free market loose on safety.  Safety costs money all the time a crash only costs money once (usually to the insurance company) and if there are no crashes then look at all the money you saved.  Some times regulation is a good thing.

Answer 7

It has been told in Human Factor Course, that at this age of modern technology, aircraft problems are becoming less and less technical but more on human error. Like any machine, airplane needs attention too and if this checks or inspections coming out from manufacturer Service Bulletins or even FAA or EASA AD's are not being complied then human factor again is the root of all this problems.

That is why when getting an A&P job nowadays, some big carriers or even MRO (Maint. Repair Org.) insist that one must be current with his Human Factor Course

Answer 8

There are 2300 MD-80 grounded at least for this weekend. Federal Mechs. brought out that planes Wiring Board isn't the way it should be. There for all MD-80 will go under inspection.

Answer 9

Are you suggesting that because we now have space flight technology, we should somehow know how to make mechanical things so that they will never wear out?  Sorry.  It doesn't work that way.

In fact, the Space Shuttle has far fewer moving parts and complex assemblies than a Boeing 747 or an Airbus A380.  The Shuttle is relatively simple.

But the point is that it is not possible to make a piece of machinery that will never be subject to wear, metal fatigue, hardening of flexible parts, and other causes of "aging" in machines.  That includes airplanes.

To get its money's worth out of an airliner, an airline company has to get 15-30 years of service out of it.  And the airliners are made to last that long.  But they do need to be inspected and maintained on a very rigorous schedule.  And these things are costly and complex, and therefore subject to human foibles.

The airline industry is suffering temporarily from a shortfall in the workings of a government agency that, like all government agencies in the last 7-1/2 years, has been under political pressure to do as bad a job as it could get away with.  Things will improve after the election.

In the meantime, I take the train as much as possible, or fly my own airplane.  Or drive.  But airline flight is still basically safe, and we will make it to 2009.  Have a nice flight!

Answer 10

ok,spacecraft and aircraft are technical and everything technical occasionally have failures...I'm not totally sure I get what your relation to spacecraft and AC is, but I think you're talking about overall failures and incidents right? so far, spacecraft have had just just a few incidents over many decades, compared to airplanes that have failures and crash everyday. The thing is you can't look at it that way, and I'll explain why. There are virtually thousands of flights in operation as we speak, how many spacecraft are in operation right now? When it comes to aviation safety, the breakdown in numbers comes to the accidents per 100,000 hours of operation. If you were to look at it that way, you'd see that airplanes are way way way more safer than any spacecraft. I have an analogy for this: If you were to only leave your house every month to walk around the block, you'd have a lower chance of getting mugged (spacecraft technical failure).

Answer 11

I guess you have studied 'theory of probability' & 'Reliability Engineering'. If not here are some key points on this subject:

Common intuition suggests that if a fair coin is tossed many times, then roughly half of the time it will turn up heads, and the other half it will turn up tails. Furthermore, the more often the coin is tossed, the more likely it should be that the ratio of the number of heads to the number of tails will approach unity.

What we are talking about is RELIABILITY ENGINEERING of two different equipments, which will depend heavily on the theory of probability, like other systems:

Reliability engineering is concerned with four key elements of this definition:

        * First, reliability is a probability. This means that failure is regarded as a random phenomenon: it is a recurring event, and we do not express any information on individual failures, the causes of failures, or relationships between failures, except that the likelihood for failures to occur varies over time according to the given probability function. Reliability engineering is concerned with meeting the specified probability of success, at a specified statistical confidence level.

        * Second, reliability is predicated on "intended function:" Generally, this is taken to mean operation without failure. However, even if no individual part of the system fails, but the system as a whole does not do what was intended, then it is still charged against the system reliability. The system requirements specification is the criterion against which reliability is measured.

        * Third, reliability applies to a specified period of time. In practical terms, this means that a system has a specified chance that it will operate without failure before time t \!. Reliability engineering ensures that components and materials will meet the requirements during the specified time. Units other than time may sometimes be used. The automotive industry might specify reliability in terms of miles, the military might specify reliability of a gun for a certain number of rounds fired. A piece of mechanical equipment may have a reliability rating value in terms of cycles of use.

        * Fourth, reliability is restricted to operation under stated conditions. This constraint is necessary because it is impossible to design a system for unlimited conditions. A Mars Rover will have different specified conditions than the family car. The operating environment must be addressed during design and testing.

Further, we should not forget that airplanes fly continuously all the time but space-craft launch is done once or twice in a year. So there are two different situations which we cannot compare with each other. You can compare these two events only if the frequency of both is comparable for any hypothesis testing.

Answer 12

In addition to the great answers you already received, consider the maintenance done on space shuttles.  A space shuttle will fly ONCE and then have months of maintenance done on it.  Just try to imagine the airline industry if an airplane had to have even a week or day of maintenance after every flight.

Answer 13

There's absolutely nothing simple about an aircraft.....they are very complex pieces of machinery with thousands of working parts any of which can potentially fail.

The fact that a spacecraft is also complex and possibly slightly more so has no relevance at all.

Answer 14

Actually, the Space Shuttle isn't anymore complex than a new model airliner.  

Different propulsion, and skin.  That's really about it.

The Shuttle has a few more redundant computer systems.

Answer 15

A lot of them are occurring do to deregulation and lack of oversight by the FAA. Underpaid, under trained aircraft technicians all in the name of cutting costs and saving money over safety. Do we really want to wait and watch the market sort this one out because there can be a terrible price to pay in the end.

Answer 16

Also, at times what appears to have been a good design in certain components that may pass every test they can throw at them, the ultimate test is long term usage. Almost every aircraft has certain airworthiness  directives that come out periodically to replace, improve, or fix weak spots that may not have been obvious until long term use has demonstrated them. Aeronautics may be a science but its not always exact. And spacecraft have their faults also; look at history over the past 30 or more years.

Answer 17

If its man made it can fail.

Answer 18

Why do electric pencil sharpeners fail if we can create supercomputers?

Murphy's first law says that if something CAN fail it WILL fail.

Anything man made will fail eventually.

Answer 19

One of these - is not like the other one.