Another boring P7 question!!

Any VC10 related discussions.....
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vololiberista
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Another boring P7 question!!

Post by vololiberista »

What is/was the P7 reading for an engine at idle at SL on an ISA day? Was it just a little more than ambient pressure or a lot more? I know the max was just under 74

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1103
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Re: Another boring P7 question!!

Post by 1103 »

Next time we run 150 I'll try to remember to make a note

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vololiberista
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Re: Another boring P7 question!!

Post by vololiberista »

1103 wrote:Next time we run 150 I'll try to remember to make a note
That's very kind of you. If you could also remember to record the QNH and ambient temperature at the same time. I hope I'm not asking too much.

The reason for this query has arisen from the Minimum acceptable P7 graph which only goes up to 8,500ft asl. When one tries calculations for a hot and high airport such as El Alto SLLP the numbers don't appear to work very well. So your input would give a genuine base line which for the moment I'm only guessing at!

bobisqueen
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Re: Another boring P7 question!!

Post by bobisqueen »

On a standard ISA day the P7 gauge would be reading approx 29 In/Hg. After engine start, when conducting your post run checks, you would be looking to see an increase of about 1 In/Hg on the gauges at idle.

Hope that helps.

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1103
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Re: Another boring P7 question!!

Post by 1103 »

I finally remembered to take note when we ran ZA150 today- all 4 engines were showing 32 In/Hg

Paul

Jelle Hieminga
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Re: Another boring P7 question!!

Post by Jelle Hieminga »

If you want the ambient conditions, have a look at this site: http://www.ogimet.com/display_metars2.p ... &send=send
I've used Farnborough here as a relatively close position, temperatures and pressures wouldn't have been all that different.
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vololiberista
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Re: Another boring P7 question!!

Post by vololiberista »

Sorry for the late reply. I'm busy on a special project .Thanks to all. The info was very useful.

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