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A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft equipped with wing spoilersAs part of a comprehensive flight-test investigation of short takeoff and landing (STOL) operating systems for the terminal systems for the terminal area, an automatic landing system has been developed and evaluated for a light wing-loading turboprop-powered aircraft. An advanced digital avionics system performed display, navigation, guidance, and control functions for the test aircraft. Control signals were generated in order to command powered actuators for all conventional controls and for a set of symmetrically driven wing spoilers. This report describes effects of the spoiler control on longitudinal autoland (automatic landing) performance. Flight-test results, with and without spoiler control, are presented and compared with available (basically, conventional takeoff and landing) performance criteria. These comparisons are augmented by results from a comprehensive simulation of the controlled aircraft that included representations of the microwave landing system navigation errors that were encountered in flight as well as expected variations in atmospheric turbulence and wind shear. Flight-test results show that the addition of spoiler control improves the touchdown performance of the automatic landing system. Spoilers improve longitudinal touchdown and landing pitch-attitude performance, particularly in tailwind conditions. Furthermore, simulation results indicate that performance would probably be satisfactory for a wider range of atmospheric disturbances than those encountered in flight. Flight results also indicate that the addition of spoiler control during the final approach does not result in any measurable change in glidepath track performance, and results in a very small deterioration in airspeed tracking. This difference contrasts with simulations results, which indicate some improvement in glidepath tracking and no appreciable change in airspeed tracking. The modeling problem in the simulation that contributed to this discrepancy with flight was not resolved.
Document ID
19840024323
Acquisition Source
Legacy CDMS
Document Type
Technical Memorandum (TM)
Authors
Brown, S. C.
(NASA Ames Research Center Moffett Field, CA, United States)
Hardy, G. H.
(NASA Ames Research Center Moffett Field, CA, United States)
Hindson, W. S.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
September 4, 2013
Publication Date
September 1, 1984
Subject Category
Aircraft Stability And Control
Report/Patent Number
NASA-TM-85873
NAS 1.15:85873
A-9222
Accession Number
84N32393
Funding Number(s)
PROJECT: RTOP 505-34-11
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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