sunnydaze

Altimeter question

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Hi all.

Could someone set me straight on this.

I have never been sure of when to set standard pressure. Here is an example of my confusion.  I depart Manchester (EGCC) using the LISTO 2 R Departure. This SID holds you at 5000 ft until you reach Listo.  Now the transition altitude in that area is also 5000 ft.  I flew this departure a few days ago with a very large pressure difference,I think it was 29.47 or something like that,so I climb to 5000 ft like I am supposed to, but my ATC program gives me a "reminder" to be at 5000 ft which I am actually at using local pressure, so should I have changed to standard pressure when reaching 5000 ft,or wait until I am above that?

Thanks.

Dennis

Edited by sunnydaze

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FL180 is the official change over point. Sounds like a problem with your ATC program. 

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I would guess, depending on your Sim, which you did not mention, try pressing the B key to see if your altimeter readjusts itself.  I have noticed many times that ATC will mention to be at a certain altitude and I'm already there.

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57 minutes ago, tailspin45 said:

FL180 is the official change over point. Sounds like a problem with your ATC program. 

In the United States and Canada, it is. In London, it's 6,000 feet. In other parts of the UK, it can be as low as 3,000 feet.

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Wow! Been a pilot for over 50 years and didn't know that! :blush:

Can you tell I've never been in the cockpit overseas? 

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Capt Kevin is spot-on. UK TAs and in Europe and other part of the world are lower and vary.

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25 minutes ago, tailspin45 said:

Wow! Been a pilot for over 50 years and didn't know that! :blush:

Can you tell I've never been in the cockpit overseas? 

I haven't, either. Actually, I've only flown an actual plane once. I've stepped foot in the flight deck of a Boeing 737-800 once, but that was before we left the gate.

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7 hours ago, sunnydaze said:

Hi all.

Could someone set me straight on this.

I have never been sure of when to set standard pressure. Here is an example of my confusion.  I depart Manchester (EGCC) using the LISTO 2 R Departure. This SID holds you at 5000 ft until you reach Listo.  Now the transition altitude in that area is also 5000 ft.  I flew this departure a few days ago with a very large pressure difference,I think it was 29.47 or something like that,so I climb to 5000 ft like I am supposed to, but my ATC program gives me a "reminder" to be at 5000 ft which I am actually at using local pressure, so should I have changed to standard pressure when reaching 5000 ft,or wait until I am above that?

Thanks.

Dennis

The rule is remarkably simple. If you’re cleared to an altitude you should keep the altimeter on QNH. If you’re cleared to a Flight Level you should be on standard pressure. 29.92” or 1013.2hPa.

So in your example you were correct in keeping the altimeter on QNH. You would only change to Standard Pressure when cleared higher to a FL.

When descending same rule applies. Stay on Standard Pressure until cleared to an altitude. You can change the altimeter immediately especially if there’s a large difference in pressure.

If your ATC program is telling you off for being at the wrong altitude you might consider swapping to Radar Contact v4 which is now free and available via a link in the RC Forum. It had US and U.K. ATC controllers involved in the rules so is correct whatever the Transition Altitude anywhere in the world.

 

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Thank you Ray.  Just what I wanted to know.

Thank you all for taking time to respond.

Dennis

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