Re: Way OT : Any maths bods around?

[Ben McCormack <ben@xxxxxxxxxxxxxxxxxxx>]

Hi All

Thanks for all your help, as expected it is not a simple answer and may
well have something to do with Fishes!!

Ben

On 28 Feb 2005, at 18:44, Christopher Purves wrote:

>
> But don't forget there are 4 of them. You need the joint (4-way)
> distribution to calculate the likely hood. All 4 failing is a
> vanishing small probability.
>
> Chris
>
>
>   ----- Original Message -----
>   From: Martin Howell<mailto:martin.howell@xxxxxxx>
>   To: ukha_d@xxxxxxx<mailto:ukha_d@xxxxxxx>
>   Sent: 28 February 2005 17:33
>   Subject: Re: [ukha_d] Way OT : Any maths bods around?
>
>
>
>   Its simpler than that, but worse if you worry a lot.  The MTBF is
>   calculated on the basis of the number of hours each test engine runs
>   before it fails, and then extrapolated as an average over all
engines
>   built.  So one engine may last a million hours, but another only 100
>   hours with an average somewhere in between.
>
>   Martin
>
>   Hawes,Timothy Edward (GEG) wrote:
>
>> 1 in 10,000  ?  (100,000 MTBF / 10 hrs)
>>
>> It's probably more complicated than that, e.g. what happens if
it's
>> already flown for 99,989 hrs and you're flight is the last 10
before
>> it's service ? I guess they're serviced at 50% of their quoted
MTBF
>> though and a 747 can still fly with one engine lost ?
>>
>> Not planning a trip are you ?
>> ;-)
>>
>> Cheers,
>>
>> Tim H.
>>
>>
>>
>>> -----Original Message-----
>>> From: Ben McCormack
>>>
>>> OK this is way OT but I have got a query concerning maths and
stats.
>>>
>>> Right here goes
>>>
>>> An engine on a 747 has a Mean Time Between Failure of 100,000
Hours.
>>>
>>> So is there a simple calculation for the probability that an
>>> engine will fail in a 10 Hour flight?
>>>
>>>
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>> Yahoo! Groups Links
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>
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