Pressure to high to fly
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Pressure to high to fly
This AM several flights in the BC interior were delayed due to the pressure being higher than an altimeter could accept. 31.15. Is this normal? And how is it compensated for?
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Re: Pressure to high to fly
I was always under the impression that you just set the max for the altimeter, which I think is 31.00 inches (but I've never gone that high on the altimeter)
Re: Pressure to high to fly
There is a section in the AIM that describes the procedure for high altimeter settings. It says that if an airport's equipment is not able to measure the pressure above 31.00"Hg, then operations are restricted to VFR.
In the case of the aircraft, if the altimeter cannot be set above 31.00"Hg, then it is set to 31.00"Hg. Other aircraft also need to set 31.00"Hg regardless of capability so that they have the same reference. If the altimeter can be set above 31.00"Hg then it is set on approach if operating IFR. Alternate minima also need to be adjusted accordingly, as described in the AIM. Keep in mind that if approaching with the altimeter set at 31.00"Hg when the actual setting is higher, your altimeter will under read causing you to reach DA/MDA at a higher actual altitude than what is indicated, therefore obstacle and terrain clearance is protected.
This is all paraphrasing, and there are more details in AIM RAC 12.12.
In the case of the aircraft, if the altimeter cannot be set above 31.00"Hg, then it is set to 31.00"Hg. Other aircraft also need to set 31.00"Hg regardless of capability so that they have the same reference. If the altimeter can be set above 31.00"Hg then it is set on approach if operating IFR. Alternate minima also need to be adjusted accordingly, as described in the AIM. Keep in mind that if approaching with the altimeter set at 31.00"Hg when the actual setting is higher, your altimeter will under read causing you to reach DA/MDA at a higher actual altitude than what is indicated, therefore obstacle and terrain clearance is protected.
This is all paraphrasing, and there are more details in AIM RAC 12.12.
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Re: Pressure to high to fly
Never had that problem. However, I have been in pressure so low my altimeter wouldn't go low enough.
Twenty years from now you'll be more disappointed by the things you didn't do than by the things you did do.
So throw off the bowlines.
Sail away from the safe harbor.
Catch the trade winds in your sails.
Explore. Dream. Discover.
So throw off the bowlines.
Sail away from the safe harbor.
Catch the trade winds in your sails.
Explore. Dream. Discover.
Re: Pressure to high to fly
You'd think they'd increase the scale of altimeters. Sure another inch would do
Re: Pressure to high to fly
Sorry guys. I special ordered that high to let me fly a newly acquired C-172 from the west coast across the rocks and out to the prairies. The whole operation went smoothly and the flight was awesome!
(Yes, dumb luck, but I'll take it!)
(Yes, dumb luck, but I'll take it!)
Re: Pressure to high to fly
When I saw the title of this thread, I thought it was going to be a rant about some flight department with a "Damn the torpedoes! Full speed ahead!", git-r-done attitude.
Re: Pressure to high to fly
Title should read: Pressure too high to fly
Sorry, just a pet peave.
Sorry, just a pet peave.
Keep the dirty side down.
- YYZSaabGuy
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Re: Pressure to high to fly
Peeve?EPR wrote:Title should read: Pressure too high to fly
Sorry, just a pet peave.
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Re: Pressure to high to fly
I was beginning to tyre (just kidding tire) of this place but what began as a grammar and spelling lesson just became a life lesson for our ten year old daughter.
People should not have to fear both the government and the criminal. It should be that the criminal fears both the people and the government.