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f10a 12-31-2016 09:26 AM

Altitude Awareness Program - ALT selection
 
Question for anyone that might know of the US Airways Altitude Awareness Program that was developed in the 1980s with ALPA to mitigate altitude busts.

In it, US Airways originally recommended the PM set the altitude preselector when the AP was engaged. Today, I understand this has been changed to the PF controlling the MCP selections etc with the AP engaged.

From a human factors standpoint, I am curious as to when or why there was a change from the PM to the PF selecting the altitude preselect. Does anyone have any background on why this change; what was/is AA's protocol?

billyho 12-31-2016 12:30 PM


Originally Posted by f10a (Post 2272321)
Question for anyone that might know of the US Airways Altitude Awareness Program that was developed in the 1980s with ALPA to mitigate altitude busts.

In it, US Airways originally recommended the PM set the altitude preselector when the AP was engaged. Today, I understand this has been changed to the PF controlling the MCP selections etc with the AP engaged.

From a human factors standpoint, I am curious as to when or why there was a change from the PM to the PF selecting the altitude preselect. Does anyone have any background on why this change; what was/is AA's protocol?

Many procedures change over the years. You are correct in that AA/US Airways now has the PF change the altitude selector with the PM basically verbalizing when they see it actually changed.
Seems to work great.

mainlineAF 12-31-2016 01:11 PM

I've done both at different companies and I much prefer the PF to make altitude changes with the AP engaged.


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f10a 12-31-2016 04:34 PM


Originally Posted by mainlineAF (Post 2272424)
I've done both at different companies and I much prefer the PF to make altitude changes with the AP engaged.


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I also prefer the PF method but mainly was wondering why there was a change from the original document they produced in the early 80s where they recommended the PM make the selection. That document was considered a benchmark from what I can tell given all the references to it in various human factors studies over the years.

However, in the last decade studies have gone back to favoring the PF method. Just wondering why. Thanks!

2StgTurbine 12-31-2016 06:28 PM

I asked a similar question years ago and after a lot of research, here is what I found out.

US Airways wanted to reduce the number of altitude deviation they had. Their SOPs at that time did not address crew coordination when it came to setting the altitude pre-selector. As a result, PF was either forgetting set the altitude pre-selector because they did not hear the clearance or misheard the clearance and set the wrong altitude. They realized that if both crewmembers were included in the altitude setting process, then the likelihood of an incorrect altitude being set would greatly decrease. To include both crewmembers in the process, they had the PM set the altitude pre-selector and had the PF confirm the altitude. The rest of the industry began to adopt this procedure since it proved successful in reducing the number of altitude deviations.

During the mid-2000s however, arrivals with multiple crossing restrictions became more prevalent. Altitude deviations began to increase and studies showed that PMs were setting the altitude pre-selector WHILE they read back the clearance to ATC. The practice of setting the altitude pre-selector WHILE they read the clearance back prevented them from forgetting the altitude assignment. This became an issue when the autopilot was in the process of capturing an altitude. When the new altitude was set before the current altitude was fully captured, the aircraft would enter pitch hold mode and would not actually level off. When issued a crossing restriction that allowed crews to delay their descent, the PM would end up setting the crossing restriction altitude right away not knowing if the PF wanted to level off at in intermediate altitude before making the crossing restriction. Operators began to understand that similar to the heading knob, the altitude pre-selector actually controlled the flight path of the aircraft and should be in the control of the PF to prevent unintentional autopilot mode changes.

Airlines began to change their procedures back to the original method of having the PF set the altitude pre-selector BUT now included the PM in verifying the set altitude. They realized that the initial decrease in altitude deviations US Airways experienced wasn’t due to the fact that the was PM physically setting the altitude pre-selector; it was because BOTH crewmembers were talking about the altitude assignment. As long as both crewmembers verbalize the assigned altitude and verify that it is set in the altitude pre-selector, the person who sets the altitude pre-selector does not matter.

Name User 12-31-2016 07:20 PM

Wow that's actually some neat info. With all the new OPD arrivals I'm glad for the PM to PF change.

f10a 12-31-2016 08:41 PM


Originally Posted by 2StgTurbine (Post 2272540)
I asked a similar question years ago and after a lot of research, here is what I found out.

US Airways wanted to reduce the number of altitude deviation they had. Their SOPs at that time did not address crew coordination when it came to setting the altitude pre-selector. As a result, PF was either forgetting set the altitude pre-selector because they did not hear the clearance or misheard the clearance and set the wrong altitude. They realized that if both crewmembers were included in the altitude setting process, then the likelihood of an incorrect altitude being set would greatly decrease. To include both crewmembers in the process, they had the PM set the altitude pre-selector and had the PF confirm the altitude. The rest of the industry began to adopt this procedure since it proved successful in reducing the number of altitude deviations.

During the mid-2000s however, arrivals with multiple crossing restrictions became more prevalent. Altitude deviations began to increase and studies showed that PMs were setting the altitude pre-selector WHILE they read back the clearance to ATC. The practice of setting the altitude pre-selector WHILE they read the clearance back prevented them from forgetting the altitude assignment. This became an issue when the autopilot was in the process of capturing an altitude. When the new altitude was set before the current altitude was fully captured, the aircraft would enter pitch hold mode and would not actually level off. When issued a crossing restriction that allowed crews to delay their descent, the PM would end up setting the crossing restriction altitude right away not knowing if the PF wanted to level off at in intermediate altitude before making the crossing restriction. Operators began to understand that similar to the heading knob, the altitude pre-selector actually controlled the flight path of the aircraft and should be in the control of the PF to prevent unintentional autopilot mode changes.

Airlines began to change their procedures back to the original method of having the PF set the altitude pre-selector BUT now included the PM in verifying the set altitude. They realized that the initial decrease in altitude deviations US Airways experienced wasn’t due to the fact that the was PM physically setting the altitude pre-selector; it was because BOTH crewmembers were talking about the altitude assignment. As long as both crewmembers verbalize the assigned altitude and verify that it is set in the altitude pre-selector, the person who sets the altitude pre-selector does not matter.

Great info, many thanks!


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