CL65 follows TCAS RA advisory when their altitude alert is set at 7000 vice 8000 as cleared.

Narrative

Rewritten in plain English from NASA’s original all-caps telegraphic report — facts, figures, and terminology preserved.

On the arrival into PHX airport, we were given a short hold. Out of the hold we were told to expect runway 26. A few minutes later we were told there was an emergency on runway 26 and to change runways to runway 25L. We were given a frequency change and then given an altitude and heading. I thought the altitude was 7000 feet and dialed it into the altitude select. At this time the captain was finishing a checklist and reprogramming the FMS for the new runway. I noticed that we were still in NAV mode on the FMS and asked him to verify the heading with ATC. We were very busy.

At the same time we noticed another aircraft on TCAS in close proximity. We were already descending through 8000 feet at 1.2 vertical speed indicator. Almost simultaneously, at 7700 feet, we got a TCAS alert; I disconnected the autopilot, initiated a climb, and ATC told us to climb. The weather in PHX was out of the ordinary -- windy, turbulent and raining. There was a lot going on in the cockpit, several frequency changes and the controllers were busy.

I possibly misunderstood a heading of 070 degrees and descent to 8000 feet as 080 degree heading and descent to 7000 feet. I think this is a good example of a 'sys' working (TCAS, ATC, cockpit procedures) and another not (unreasonable FARs). We should have verified the altitude and heading sooner but when that didn't happen the TCAS alerted us and then ATC queried us. As a crew I think we were as alert as we could have been; our workload was at the max. These kind of mistakes happen and the crew has to try to catch them earlier.

I also think that burnout from flying too many hours and unreasonable schedules was probably a contributing factor in this incident. Most pilots at our airline fly far too many hours in a day, week, month and year. The more fatigued and overworked pilots you have the more incidents like this will happen. There are numerous studies demonstrating the effects of fatigue on performance yet the FAA chooses to ignore them. 16 hour duty days, 8 days off a month, 8 hour rest periods resulting in less than 6 hours of sleep, lack of sufficient time to recuperate, flying the back of the clock one day and the front the next is dangerous in the long run.