The Society of Flight Test Engineers 
                                                   

 


 

ABSTRACT


Paul Bolds-Moorehead
Senior Lead Engineer,
Boeing Commercial Airplanes Stability & Control
Van Chaney
Boeing Commercial Airplanes 777 Deputy Chief Test Pilot
Terry Lutz
Airbus Experimental Test Pilot

Stephane Vaux
Airbus Flight Test Engineer, Handling Qualities

  Airbus and Boeing are cooperatively presenting on this topic dealing with stall requirements, predictive validation and flight testing.  We plan to address areas where our two approaches are common as well as exploring areas where we differ on our technical approach.
 
The various ways of designing modern jet transports for the stall regime will be discussed.  There are aerodynamic approaches, flight deck indications, and augmentation control laws to deal with the high AOA arena.  The goal of augmented control laws for high AOA is common – no full aerodynamic stall or loss of climb performance should occur in the Operational Flight Envelope, in Normal flight control modes.
  The validation techniques employed by both companies in preparation for a flight test campaign will follow.  These include flight characteristic predictions based on wind tunnel data as well as pilot-in-the-loop simulation rehearsals.  We will also briefly discuss simulation fidelity and the accuracy of stall and stall recovery characteristics.  The potential for unexpected stall characteristics in the simulator will be broached (lack of buffet, non-linear roll-off, pitch rate effects).
 
The speakers will then review various flight testing that has been conducted.  Flight test videos as well as animations will be utilized along with time-history data.  Flight test peculiarities such as the highly trained nature of company test pilots and the fact that test airplanes are highly instrumented (including tail loads monitoring) will be addressed.
 
The presentation will close with a brief foray into what the future of transport stalls could be – perhaps protection features in degraded modes?  What are the benefits as well as drawbacks to increased augmentation for high AOA?