Todd Hodges, Retired Engineer, NASA Langley Research Center
OPENING PRESENTATION - DAY 2
Todd Hodges believes that it's important for today's electric vertical takeoff and landing (VTOL) aircraft designers to understand VTOL history, so they can begin where others left off, rather than redo the mistakes of the past.
The benefits include reducing the cost of development, shortening the development cycle and avoiding accidents that have happened before.
Hodges believes that "conventional takeoff and landing (CTOL) design is mostly a well known science" whereas "VTOL design is still somewhat of a black art."
Hodges began his presentation with the VTOL "Wheel of Misfortune" originally created by McDonnell Aircraft and later updated by Mike Hirschberg of the Vertical Flight Society.
He then narrowed his focus to the the history of tilt wing and tilt rotor aircraft developed over the past 75 years, which all use the same propulsion system for hover and forward flight.
Hodges says that aircraft "configuration selection is dependent on mission requirements - Range, Payload, Hover Time, Speed, Endurance, etc."
"If you have to go fast, you will get pushed into the higher disk loadings. If your mission requires an extensive amount of hovering, you will end up at lower disk loadings. The balance between hover requirements and speed requirements for the mission will usually play a substantial role in configuration choice."
Hodges then explained the positive and negative characteristics of tilt wing and tilt rotor aircraft.
After highlighting several aircraft examples from the past, Hodges concluded by stating that "new technologies like distributed electric propulsion (DEP) are appearing that will blow open the design space for new more efficient VTOL aircraft."
Biography
Todd Hodges has 40+ years in VTOL design, development and testing experience at NASA Langley. Todd was a consultant on GL-10 tiltwing and co-inventor on its patent (US9475579B2). He has a diverse, historical knowledge of aeronautic technical disciplines. He works on design and propulsion integration on flight test UAVs and was a consultant on Puffin VTOL PAV. Todd also researched crashworthy composite structures.
