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Greased Lightning (GL-10) Performance Flight Research: Flight Data ReportModern aircraft design methods have produced acceptable designs for large conventional aircraft performance. With revolutionary electronic propulsion technologies fueled by the growth in the small UAS (Unmanned Aerial Systems) industry, these same prediction models are being applied to new smaller, and experimental design concepts requiring a VTOL (Vertical Take Off and Landing) capability for ODM (On Demand Mobility). A 50% sub-scale GL-10 flight model was built and tested to demonstrate the transition from hover to forward flight utilizing DEP (Distributed Electric Propulsion)[1][2]. In 2016 plans were put in place to conduct performance flight testing on the 50% sub-scale GL-10 flight model to support a NASA project called DELIVER (Design Environment for Novel Vertical Lift Vehicles). DELIVER was investigating the feasibility of including smaller and more experimental aircraft configurations into a NASA design tool called NDARC (NASA Design and Analysis of Rotorcraft)[3]. This report covers the performance flight data collected during flight testing of the GL-10 50% sub-scale flight model conducted at Beaver Dam Airpark, VA. Overall the flight test data provides great insight into how well our existing conceptual design tools predict the performance of small scale experimental DEP concepts. Low fidelity conceptual design tools estimated the (L/D)( sub max)of the GL-10 50% sub-scale flight model to be 16. Experimentally measured (L/D)( sub max) for the GL-10 50% scale flight model was 7.2. The aerodynamic performance predicted versus measured highlights the complexity of wing and nacelle interactions which is not currently accounted for in existing low fidelity tools.
Document ID
20180000765
Document Type
Technical Memorandum (TM)
Authors
McSwain, Robert G. (NASA Langley Research Center Hampton, VA, United States)
Glaab, Louis J. (NASA Langley Research Center Hampton, VA, United States)
Theodore, Colin R. (NASA Ames Research Center Moffett Field, CA, United States)
Rhew, Ray D. (NASA Ames Research Center Moffett Field, CA, United States)
North, David D. (NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
January 25, 2018
Publication Date
November 1, 2017
Subject Category
Aircraft Design, Testing and Performance
Report/Patent Number
NF 1676L-28427
L-20888
NASA/TM-2017-219794
Funding Number(s)
WBS: WBS 533127.02.15.07.01
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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