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Hoh Aeronautics, Inc.Hoh Aeronautics, Inc.Research UpdateResearch Update

David G. MitchellDavid G. MitchellTechnical DirectorTechnical Director

310-325-7280310-325-7280dmitchell@hoh-aero.com

AC&GS Committee MeetingAC&GS Committee MeetingHilton Head, South CarolinaHilton Head, South Carolina

October 2005October 2005

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Development of An Aeronautical Design Development of An Aeronautical Design Standard for Helicopter SimulatorsStandard for Helicopter Simulators

• Identify thresholds of perception for errors in Identify thresholds of perception for errors in simulation modelingsimulation modeling– Math modelMath model– Motion systemMotion system– Visual systemVisual system– Feel systemFeel system

• Wrapping up initial exploratory simulationsWrapping up initial exploratory simulations– Fixed-base facility, one pilot, one task, simplified Fixed-base facility, one pilot, one task, simplified

helicopter modelhelicopter model– Using “Eye Chart” approach for evaluationsUsing “Eye Chart” approach for evaluations

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Unnoticeable Added Dynamics:Unnoticeable Added Dynamics:Ideal Helicopter, Roll Axis, HoverIdeal Helicopter, Roll Axis, Hover

- Compared with MUAD Envelopes- Compared with MUAD Envelopes

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How Do We CharacterizeHow Do We Characterizethe Added Dynamics?the Added Dynamics?

• One method: Assume peaks in magnitude and phase describe the One method: Assume peaks in magnitude and phase describe the effects of the added dynamicseffects of the added dynamics

• Example: Magnitude peaks for lead-lag and lag-lead dynamicsExample: Magnitude peaks for lead-lag and lag-lead dynamics

-20

-15

-10

-5

0

5

10

15

20

1 10 100

frequency (rad/sec)

Ma

gn

itu

de

(d

B)

Lag-neg peaks

Lag-pos peaks

Lead-neg peaks

Lead-pos peaks

Gain changes

Approx. limits based on peaks

Need to re-test these cases

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There is Much More to be DoneThere is Much More to be Done

• Other axes, other tasks, more pilots, more Other axes, other tasks, more pilots, more representative helicopter models, variations in representative helicopter models, variations in motion and visual systemsmotion and visual systems

• NASA Ames Vertical Motion Simulator is best, NASA Ames Vertical Motion Simulator is best, but too expensivebut too expensive

• Possibly use University of Liverpool simulatorPossibly use University of Liverpool simulator

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Newest Contract: Research Test Plan for Newest Contract: Research Test Plan for Rudder Control Piloted Simulator StudyRudder Control Piloted Simulator Study

• Sponsoring organization: FAA Atlantic CitySponsoring organization: FAA Atlantic City• COTR: Robert McGuireCOTR: Robert McGuire• Subcontractor: Test Pilot, Inc. (Paul Desrochers)Subcontractor: Test Pilot, Inc. (Paul Desrochers)• Kickoff meeting held 18 OctoberKickoff meeting held 18 October• Develop a test plan to examine pedal usage for…Develop a test plan to examine pedal usage for…

– Closed-loop operation (for example, crosswinds)Closed-loop operation (for example, crosswinds)– Emergency operation (for example, upset recovery)Emergency operation (for example, upset recovery)– Focus on transport airplanesFocus on transport airplanes

• Outcome of AA 587 accident in 2001 (and others)Outcome of AA 587 accident in 2001 (and others)• Will result in a detailed test plan for investigation of Will result in a detailed test plan for investigation of

rudder pedal control usagerudder pedal control usage