2016 PC Guide - Onboard Performance Computer (OPC)

Question 1

What are the OPC assumptions in calculating Approximate Stop Margin?

Answer 1

• Touchdown occurs no later than 1500 ft from the usable end of the runway.
• Selecting reverse thrust within 2 seconds after touchdown and attaining the planned reverse thrust level within 8 seconds after touchdown.
• Speedbrake deployment, thrust at idle, runway condition, and proper winds programmed.
• The OPC then includes a 15% additional safety factor on the total calculated landing distance. The Min(2), Med(3) and Max(M) values are calculated using the deceleration rates for auto brake settings 2, 3 and Max, respectively.

Question 2

What changes are made if you select the AIII button?

Answer 2

The OPC subtracts the 1150 feet from the stopping margins to account for the possibility of a long landing due to AIII flare guidance.

Question 3

On descent, you find the weather goes below 4000 ft RVR. What changes to the OPC should be selected and why?

Answer 3

Selecting the RVR