Lateral Flying Qualities of Highly Augmented Fighter Aircraft
Report Number: AFWAL TR 81-3171 Volume 1
Author(s): Monagan, Stephen J., Bailey, Randall E., Smith, Rogers E.
Corporate Author(s): Calspan Corporation
Laboratory: Flight Dynamics Laboratory
Date of Publication: 1982-06
Pages: 84
Contract: F33615-79-C-3618
DoD Project: None Given
Identifier: ADA118070
Abstract:
This in-flight simulation experiment, using the USAF NT-33 variable stability aircraft operated by Calspan, was undertaken to generate later-directional flying qualities data applicable to highly augmented fighter aircraft. In particular, the effects of time delay and prefilter lag in the lateral flight control system were studied for representative Flight Phase Category A and C tasks. The combined effects of those elements as well as the effects of nonlinear command gain and high Dutch roll damping were also evaluated. Tasks included were actual target tracking, air refueling and precision landing as well as special Head-Up Display (HUD) tracking tasks. Results indicated that a properly designed HUD bank angle tracking task is a valid flying qualities evaluation task. Data show that lateral flying qualities are very sensitive to control system time dealy and very short values of roll mode time constant typically result in poor lateral flying qualities. Excellent separation of the data into flying qualities level is achieved for the Category A task data using time domain equivalent systems parameters. An optimum equivalent time constant value of 0.5 sec is indicated by the data; sensitivity to equivalent time delay is a minimum at this value. Volume I contains the body of the report, while Volume II consists of the Appendices.
Provenance: AFRL/VACA
Author(s): Monagan, Stephen J., Bailey, Randall E., Smith, Rogers E.
Corporate Author(s): Calspan Corporation
Laboratory: Flight Dynamics Laboratory
Date of Publication: 1982-06
Pages: 84
Contract: F33615-79-C-3618
DoD Project: None Given
Identifier: ADA118070
Abstract:
This in-flight simulation experiment, using the USAF NT-33 variable stability aircraft operated by Calspan, was undertaken to generate later-directional flying qualities data applicable to highly augmented fighter aircraft. In particular, the effects of time delay and prefilter lag in the lateral flight control system were studied for representative Flight Phase Category A and C tasks. The combined effects of those elements as well as the effects of nonlinear command gain and high Dutch roll damping were also evaluated. Tasks included were actual target tracking, air refueling and precision landing as well as special Head-Up Display (HUD) tracking tasks. Results indicated that a properly designed HUD bank angle tracking task is a valid flying qualities evaluation task. Data show that lateral flying qualities are very sensitive to control system time dealy and very short values of roll mode time constant typically result in poor lateral flying qualities. Excellent separation of the data into flying qualities level is achieved for the Category A task data using time domain equivalent systems parameters. An optimum equivalent time constant value of 0.5 sec is indicated by the data; sensitivity to equivalent time delay is a minimum at this value. Volume I contains the body of the report, while Volume II consists of the Appendices.
Provenance: AFRL/VACA