Cross XYZ at 10,000

[meritflyer]

How much leeway is given on a crossing restriction. For example, if someone is given a clearance to cross XYZ at 10,000 at what altitude does ATC see "violation" in their mind.

Is there some sort of published criteria that at lets say, 300' above, the pilot could be violated?

[DE727UPS]

If I'm not mistaken, 300 feet is where the "snitch" goes off. This causes the supe to take notice and the controller might feel compelled to cover his butt.

I'm not aware of anything "published", as you mention.

If you see you're not going to make it, let ATC know as early as possible. That gives them a chance to fix the problem another way.

[icephalt24]

Probably not going to happen unless you are WAY off the mark or cause a deal. I'd say within altimeter tolerance is OK, so yeah 300 feet. Say if you are told to cross XYZ at change it up 7,000 might be because center wants you above some approache's airspace which might ruffle some feathers if you bust that. I'm just a CTI student and a very marginal IFR pilot. I'm sure 99% of these boards could give a better answer. Hey though, only way I learn is to chip in and get told I'm wrong. Rather have someone here tell me that than have a strip bay tossed at me by a professor

[JEP]

Originally Posted by DE727UPS

If I'm not mistaken, 300 feet is where the "snitch" goes off. This causes the supe to take notice and the controller might feel compelled to cover his butt.

I'm not aware of anything "published", as you mention.

If you see you're not going to make it, let ATC know as early as possible. That gives them a chance to fix the problem another way.

Yep, heard the same thing yesterday when I was flying with a NWA 75CA (as I slipped off my alt. while under the hood.)

[wheelsup]

Originally Posted by JEP

Yep, heard the same thing yesterday when I was flying with a NWA 75CA (as I slipped off my alt. while under the hood.)

That's when you say "Hmm, let me try my other transponder!". Turn your transponder off, get back on altitude quickly, and turn it back on.

Or "what's your current altimeter setting?".

I've only "heard" about people using the above.

[Doug Taylor]

Of course I'm not an air traffic controller, but I think when you get into the realm of losing separation with another aircraft is when you start the process rolling.

File a NASA report!

[Fox Xray]

Originally Posted by meritflyer

How much leeway is given on a crossing restriction. For example, if someone is given a clearance to cross XYZ at 10,000 at what altitude does ATC see "violation" in their mind.

Is there some sort of published criteria that at lets say, 300' above, the pilot could be violated?

A crossing restriction is generally issued for two main reason, to comply with Letter of Agreement (LOA) or for separation. There are other reasons, but these are the two main ones.

Any instance where you do not comply with the restriction you can be violated. Lets say you are cleared to cross XYZ @ 11,000. XYZ is a boundry point between two sectors and the LOA states that all A/C transitioning must cross XYZ at 11,000. If you are issued the clearance and cross at say 11,300 you violated your clearance and therefore violated the LOA. The receiving controller can violate you.

If you ever think you will not make the restriction notify ATC... we'll work something out.