In-Flight Investigtion of the Effects of Higher-Order Control System Dynamics on Longitudinal Handling Qualities

Item

Title
In-Flight Investigtion of the Effects of Higher-Order Control System Dynamics on Longitudinal Handling Qualities
Date
1968
Index Abstract
Not Available
Photo Quality
Not Needed
Report Number
AFFDL TR 68-90
Corporate Author
Cornell Aeronautical Laboratory, Inc.
Laboratory
Air Force Flight Dynamics Laboratory
Extent
195
Identifier
AD0840752
Access Rights
Export Controls
Distribution Classification
1
Contract
AF 33(615)-3294
DoD Project
8219
DoD Task
821905
DTIC Record Exists
No
Distribution Change Authority Correspondence
AFFDL LTR
Distribution Conflict
No
Abstract
The results of a flight test program to investigate the effects of higher-order control system dynamics on the handling qualities of a fighter airplane are presented and discussed. This research was undertaken using the USAF/CAL variable stability T-33 airplane as an in-flight simulator. This in-flight investigation was based on a similar fixed-base ground simulator program. Higher-order response characteristics were obtained by altering the elevator stick feel system dynamics and elevator actuator dynamics in conjunction with four different sets of longitudinal short period airplane dynamics. In the investigation, the dynamics of any of the three elements (feel system, actuator, and airplane) could be changed independently of the others. Three of the set of four airplane characteristics were investigated as a fighter in 'up-and-away' flight, and the fourth was evaluated as a fighter during landing approach. Thirty-two different configurations were evaluated by one CAL evaluation pilot (Pilot B) and 35 configurations were evaluated by a second CAL evaluation pilot (Pilot H). Essentially the same configurations were evaluated by both pilots and rated using a new pilot rating scale. Pilot H also rated the configurations for their pilot-induced oscillation (PIO) tendencies using a PIO rating scale. Pilot comments were recorded in flight and the comments and ratings were related to various handling qualities parameters and response characteristics of the configurations. The results of the investigation indicate that many of the higher-order control systems investigated produce very pronounced PIO tendencies and these tendencies can be related to the delay in the initial response of the airplane and to the stick force gradients. Configurations that were acceptable with conventional control system dynamics were considered unflyable with certain higher-order characteristics.
Report Availability
Full text available
Date Issued
1968-08
Provenance
Bombardier/Aero
Type
report
Format
1 online resource
Creator
Di Franco, Dante A.
Media
AFFDLTR68-090.pdf