Boeing’s 767-based tankers use a version of the pitch augmentation system that grounded the 737 Max 8 fleet, the manufacturer and U.S. Air Force officials say.
The disclosure provides a new data point in the unfolding story of how Boeing installed the Maneuvering Characteristics Augmentation System (MCAS) on narrowbody airliner fleet.
Both the KC-767 and KC-46 fleets delivered to air forces in Italy, Japan and the U.S. rely on the MCAS to adjust for pitch trim changes during refueling operations.
In the 1980s, Boeing’s engineers considered using a pitch augmentation system for the commercial version of the 767, but dropped the idea after finding that vortex generators provided adequate control.
Boeing designed the integration on the KC-767 and KC-46 slightly differently than on the 737 Max family.
The single-aisle airliner uses one angle of attack vane — either the captain’s or first officer’s — to generate the data used by the flight computer to activate the MCAS.
By comparison, the KC-767 and KC-46 are designed to use two sensor inputs to feed angle of attack data, Boeing says.
Boeing spokesmen declined to elaborate on which sensor inputs are used to provide the data in the tanker design. The options include using data from the angle of attack vanes on both sides of the cockpit, or an angle of attack vane an inertial gyroscope.
I find the last sentence interesting, although mis-spelled... angle of attack vane AND inertial gyroscope? The unmanned drones use the inertial system for AoA...
https://www.mro-network.com/airframe...d-pitch-system
Last edited by Smythe; 16th Apr 2019 at 03:36.