Climb out speeds at airports close to 10kMSL

I just had a question about what altitude I should increase the speed above 250kts at airports that are close to 10,000ft msl. Take MMMX for example, it is at a little over 7000ft msl and at 3,000ft agl you hit 10,000ft and I was wondering if I should wait to increase the speed until I’m higher off the ground?


Well… that is up to you I personally if I am on a rush I would or I would wait till about 8,000 AGL

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I normally wait until about 10,000 agl but I was just curious if there were like set guidelines to follow or if it was up to the pilot.

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Don’t Quote me on this but I believe it is up to the pilot or ATC instructor

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IRL the same 10,000 AGL rule applies unless approved by ATC.

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That’s what I thought. Thank you for the clarification!


10,000 feet is MSL, as defined by FAR 91.117(a) - not AGL.

In a Class B airspace like MMMX (as defined in Infinite Flight), airspeed restrictions are up to ATC and/or the SID/STAR procedures. The 250 knot rule does not vary by airport elevation. If you were flying below a Class B airspace, or through a VFR corridor of a Class B airspace, you’d have to go at a maximum of 200 knots.

If it was a Class C or D airport, you’d have to wait till 2,500 feet AGL till you could go above 200 knots, or wait till you’re at least 4 NM away from the airport. For example, Aspen (KASE) has a surveyed field elevation of 7838 ft and is within Class D airspace. Aircraft operating within 4 NM of Aspen would be speed limited to 200 KIAS up to 2,500 AGL, which would equate to over 10,000 MSL.

Hope this clears things up!


Out of curiosity I was trying to understand more on the historical background of this rule. It seems to be connected to some particular serious accidents years ago involving, well, lack of speed control near areas of increasing traffic density. Even though the crew were seemingly experienced. That’s one reason. The other was reducing the chance of damage from bird strikes (when low and fast). But surely Mexico city has plenty of traffic so close to the 10,000msl altitude(?) Maybe high altitude places like Aspen have less birds(?) All I know is, I couldn’t explain this to a family member when they brought up the common sense question to me.

Interestingly, in the original discussions of the the rule, some were actually worried it would cause more headaches for ATC.

Anyway, I don’t have any answers. Thanks for your info, though, on the specifics of the OP’s question.


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