"You're 300 Above... 300 Below... 300 Above..."

[Goofyfish]

Get off my case already!

I took my first long flight today in a 737_700 from Dulles (KIAD) to Atlanta (KATL). Departure, climb and the first hour went smoothly but, shortly thereafter, things began to get irritating. Washington Center contacted me over and over approximately every 10 minutes to advise that I was 300' above assigned, then 300' below, then 300' above... ad nauseum. My altimeter was set correctly based on the advisory when I was handed over and there were no changes made. The problem continued with Atlanta, with the controller continuing to harass me almost all the way in.

Should I just fly around pressing the "B" key all day, or am I missing something crucial here?

Thanks, Rick.

[Brett_Henderson]

I would imagine that you were well above 18,000msl.. so any altimeter setting is useless... 18,000 is the transition altitude where everyone sets their altimeters to 29.92..

You were probably at something else.. per your last setting when you were still below 18,000msl. I dont even think ATC will give you an altimeter setting when talking to you above transition altitude. So as you flew through different atmospheric conditions, your PRESSURE altitude fluctuated (obviously by +/- 300 feet).

[Wii]

What was your airspeed? Exceeding 320knots during a climb or small descent will cause the autopilot to go up and down. Also, if you were flying real world weather, you could have been flying through some sort of pressure system.

[Goofyfish]

I would imagine that you were well above 18,000msl.. so any altimeter setting is useless... 18,000 is the transition altitude where everyone sets their altimeters to 29.92..

Actually, I was at FL180.

[Brett_Henderson]

Flying right AT 18,000 can be problematic (as you can now see)..

I'm not sure about the automatic altimeter setting.. I always just hit 'B' after ATC gives me a setting.. It might be a realism setting.. I'll check later..

I know that hitting 'B' is kind of a cheat, but not really, if you ONLY do it after getting a setting from either ATC, ATIS, AWOS or ASOS. Just hitting it periodically will keep your altitude more accurate (below 18,000), but there's no way to know what that setting would be..

Next time you're above 18,000.. hit 'B' to your heart's content.. it will always go (or stay at) 29.92

[mjrhealth]

Fly at 18,500 that should solve the issue.

[DaveSims]

This is why 18,000 is rarely assigned as an altitude.

[Goofyfish]

Thanks to everyone for the input.  The second trip was FAR more enjoyable than the first.

8-)