Is AH fixed at 3,000. I have not been able to change it.

Is AH fixed at 3,000.

 

The acceleration defaults to 3,000 feet above origin elevation. For example, you are taking off at Sky Harbor at an atltiude of 1,140 feet. The altitude to inssert in the FMS is 4,140 feet. It can be set to a minimum of 1,000 feet above origin elevation.

 

The engine out accleration height will default to 800 feet above origin elevation. This can be altered to a minimum of 400 feet above origin elevation.

Thanks.

 

I did not know I had to consider ground elevation when trying to accelerate at 1,000.

Thanks.

 

I did not know I had to consider ground elevation when trying to accelerate at 1,000.

 

Always. Same with the Climb Thrust Altitude.

I was set up at KLAX on runway 25R. The airport elevation is 126 and the runway threshold is 94. I expected 1300 to work as acceleration height but the lowest I could enter was 1,500 feet.

I was set up at KLAX on runway 25R. The airport elevation is 126 and the runway threshold is 94. I expected 1300 to work as acceleration height but the lowest I could enter was 1,500 feet.

 

What altitude did you have set in the MCP Altitude Window? If the Altitude you had set on the MCP was lower than the default Climb Thrust or Acceleration Altitude (defaults to 1,500 and 3,000 above original airport elevation, respectively) it will display the altitude you have set in the MCP. For example, for those situations where you are staying in the traffic pattern or your cleared altitude on departure is below either of those AGL altitudes.

 

Climb Thrust and Acceleration Altitude can be manually edited to no lower than 1,000 above origin airport elevation.

Not sure what I had set in the altitude window, it was either 3,000 or 10,000. I was planning to stay low for approaches.

 

I do not understand why the altitude window should have anything to do with acceleration height but will watch for it moving forward.

 

Thanks fro the post

I do not understand why the altitude window should have anything to do with acceleration height but will watch for it moving forward.

 

Because if your MCP altitude is lower than Accel. Height or Climb Thrust Altitude, the MCP altitude tells the FMS the altitude in which those should take place; so the FMS can calculate its' navigation and performance criteria.