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Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 12:37 am
by Mark Hargrove
I was flying back to DEN from SFO on United a short while ago, listening (as usual) to ATC. We were flying the TOMSN SIX arrival into DEN, which calls for crossing TOMSN intersection at FL190 and 250 Kts. I've been on this same flight many times, so I'm very familiar with the "rhythm" of this particular arrival. On this particular flight, we got the descent clearance at about the usual place with the expected crossing restriction. Normally, the flights I've been on start a descent almost immediately after getting the "cleared direct TOMSN, cross TOMSN at, maintain FL190" instruction. In this case, the plane didn't start a descent right away -- it just continued level (we were at FL320 or thereabouts). Time ticked by and we still didn't start to descend. I was starting to wonder what was going on, when ATC makes another call to us, something like "United 123, will you be able to make your crossing restriction at TOMSN?" (so I wasn't the only one wondering WTF was going on). The pilot said "Affirmative", and NOW the plane starts a descent. A rather interesting, rather
rapid descent. With speed brakes out. A few minutes later, ATC says "United 123, at TOMSN intersection, you missed your crossing restriction. Descend now and maintain 14,000 -- if that's not inconvenient". From the controller's tone of voice, she was NOT happy with our pilots. From their very sheepish readback, they knew she wasn't happy with them.
The rest of the arrival and approach was uneventful, but I've wondered more than once if there were any consequences for the pilots for busting their altitude assignment, if the controller simply noted the non-compliance as a matter of covering herself from a liability perspective, or if it was just her way of publicly shaming our pilots for being boneheads for everybody else on frequency. Heck, I had nothing to do with it and *I* was embarrassed after listening to her tone....
-M.
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 7:37 am
by rgrazian
Hi Mark,
I traveled every week for several years when I lived in Denver. Living in Denver, I was a United guy and I also listened to ATC whenever I flew. The pilots could technically receive a violation for not complying with the assigned clearance. I'm finishing up my instrument rating and I have learned that FAR 91.123 is usually the regulation used to violate pilots with an altitude bust. The pilots should have said "unable" when the controller called them the second time or immediately upon realizing they could not comply.
The FAR states:
(a) When an ATC clearance has been obtained, no pilot in command may deviate from that clearance unless an amended clearance is obtained, an emergency exists, or the deviation is in response to a traffic alert and collision avoidance system resolution advisory. However, except in Class A airspace, a pilot may cancel an IFR flight plan if the operation is being conducted in VFR weather conditions. When a pilot is uncertain of an ATC clearance, that pilot shall immediately request clarification from ATC.
A violation can mean anything from remedial training all way up to revocation.
I was landing at Addison airport two weeks ago. The tower controller had me 1000ft above pattern altitude on downwind due some departing traffic. He didn't clear my decent until I was almost abeam the numbers. He then asked me to make a short approach due to a jet on extended final. If I was by myself, I would have easily done it and landed a little long. However, I had my wife and son and decided dive bombing to the runway would scare the poop out of my wife. Therefore, "unable" was whipped out. He just extended me out and cleared my base as I was passing the jet. No big deal.
p.s. - One of my best friends lives in Longmont. I may fly my family out there in my buddy's Lance in May.
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 7:52 am
by Keith Smith
Very interesting, and presumably fairly rare. Had the incident caused a loss of separation, there would've been more than a sarcastic remark from ATC. In fact, I was under the impression that ATC was now required to report all of these instances, whether or not a loss of separation occurred, but I'm hardly the authority on that. I'm fairly certain there was SOME sort of policy change around that in the last year or so.
I have had 2 altitude deviations, both in Allentown's airspace, both at night, both after 20+ minutes of descending continuously from a relatively high altitude.
Actually there was a third altitude issue that occurred in Allentown's airspace, but it was due to controller error. That was a fun discussion.
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 8:27 am
by julio.elizalde
Sounds like they checked the FMC but didn't reset the MCP altitude and missed it. Sometimes all that paper work can become a real drag....HAR HAR HAR.
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 8:41 am
by ChristophPreinfalk
What do you guys use to listen to ATC while being on a plane?
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 8:47 am
by rgrazian
United is the only airline that I know of where this is possible. They provide ATC via the plane's audio system.
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 9:27 am
by Peter Grey
This is obviously a major mistake for the pilots to have made. Where I work normally a restriction like this is put into the FMS immediately along with the altitude alerter. This ensures that the airplane FMS will let us know when to start down. Of course I can't speak to what exactly happened in the cockpit of that plane, nor for United's procedures.
In terms on consequences, most likely nothing, formally if a controller is going to file a pilot deviation report (or "violate" the pilot) they are suppose to use the phraseology of "(Identification) POSSIBLE PILOT DEVIATION ADVISE YOU CONTACT (facility) AT (telephone number)." This is from 2-1-26 of FAA order 7110.65U (the ATC manual).
Assuming a violation was filed the punishment would be determined from FAA order 2150.3B (compliance and enforcement program). Appendix B lists out the standard punishments for reg violations. rgrazian mentions the exact reg violated. The FAA lists "failure to maintain altitude" as a 30-60 day suspension, however this could also be classified as "deviation from ATC instruction or clearance" which is a 30-90 day suspension.
So in order words, make sure you pay attention to controller instructions.
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 1:51 pm
by Mark Hargrove
rgrazian wrote:United is the only airline that I know of where this is possible. They provide ATC via the plane's audio system.
...but it's completely at the pilot's discretion whether ATC is on the audio system (always on Channel 9 if it's available). I always tune to channel 9 right away to see if ATC is on. If not, I ask the flight attendant to ask the pilot if they will turn it on. About 25% of the time, the pilot will NOT turn it on (with no explanation). Once, though, the pilot came back to my seat and asked me point blank (in a not-particularly friendly tone), "why do you want to listen to ATC?". I told him, rather mildly, that I was a flight simulator enthusiast and simply enjoyed listening to professional pilots and controllers talking whenever I got to fly in a real airplane. He just sort of stared at me for a second, then turned around and marched back into the cockpit. Didn't say another word -- but ATC was up on the channel a couple of minutes later
As an FYI, the aircraft that belonged to Continental before the merger don't have ATC available as a channel in their entertainment systems yet, but I'm told that it's coming by the end of this calendar year.
-M.
Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 9:29 pm
by Ryan B
Interesting discussion.
From a rw controller perspective:
If a deviation results in loss of separation (an error for me), and it was your fault, I'd report the pilot deviation.
If there wasn't a loss of separation I probably won't say anything. We're not out to get pilots... at least I'm not.
In fact I've had a few pilots really help me out

Re: Real World Consequences of a Missed Altitude Assignment
Posted: Thu Feb 28, 2013 9:54 pm
by Keith Smith
Ryan, do you recall any changes in the reporting requirements in the last 12-18 months?