1

Creating the

Somatogravic Illusion in

Your Simulator –

Early Research Results

Federal AviationAdministration

Federal AviationAdministration

Flight Safety Foundation

International Air Safety Summit

November 16, 2016

Jeffery Schroeder

2

Pitching illusion

• Forward accelerations create illusion of pitching

Go around with T/W=0.35

g

0.35g

Apparent direction

of gravity

Reality

3

Pitching illusion

Go around with T/W=0.35 19 degs pitch up

g

0.35g

Apparent direction

of gravity

Reality

• Forward accelerations create illusion of pitching

Perception

4

Pitching illusion

• So what?

• Illusion believed to be a factor in following:

– Skylink Airlines #70 accident, SA 227, Sept. 1989

– Air Transport Intl #805 accident, DC-8, Feb. 1992

– USAir #1016 accident, DC-9, July 1994

– Gulf Air #72 accident, A320, Aug. 2000

– Armavia #967 accident, A320, May 2006

– Afriqiyah Airways #771 accident, A330, May 2010

5

Pitching illusion

• Illusion training recommendations now in:

– “Aeroplane State Awareness during Go Around”

• BEA Study, Aug 2013

– “Manual on Aeroplane Upset Prevention and

Recovery Training”

• ICAO Doc 10011, 2014

– “Scenario-Based Go-Around Training”

• FAA Safety Alert for Operators #15004, March 2015

– “Upset Prevention and Recovery Training”

• FAA Advisory Circular 120-111, April 2015

6

Pitching illusion

• What to do?

– Pure illusion takes too much fore/aft travel

– Takes 10 secs to create 0.35g with cab tilt below

sensory threshold

7

Pitching illusion

• What to do?

– Pure illusion takes too much fore/aft travel

– Takes 10 secs to create 0.35g with cab tilt below

sensory threshold

• Maybe we can temporarily “fake it” and still

provide training value

8

Pitching illusion

Time, sec

0 20 40

Aircraft model

Pitch,

deg

20

10

0

9

Pitching illusion

Time, sec Time, sec

0 20 4020 40

Aircraft model Simulator cab

Pitch,

deg

20

10

00

Old motion

New motion

10

Pilot brief, Task, Method

– Brief: Told it was a degraded visual environment study, reviewed

go-around maneuver…intention was to create a little surprise

– Task: ILS 28R SFO. Flight directors used throughout.

“ATC” calls go around at 200 ft AGL:

• TO/GA switch, flaps 20, rotate to ~15 deg pitch

• Gear up

• LNAV at 400 ft

• VNAV and desired speed at 800 ft

• Flaps retract

• Level off

– Method: (1) Go-around with unmodified motion, night VMC

(2) Go-around with modified motion, night IMC (400/1.5 mi)

11

12

13

Pitching illusion

Column

position,

inches

Time, secs

Old motion

New motion

14Strongly

Disagree

Disagree Neither Agree

Nor Disagree

Agree Strongly Agree0

5

10

15

Nu

mb

er

of

Pilo

ts

Q5: The DVE scenario gave an effective demonstration of the “pitch up” illusion.

Pitching illusion

Number

of

pilots

10

5

0

15

“The scenario was an effective demonstration of the pitch up illusion”

15

Conclusions

• Illusion training justified by accidents

• Study examined value of “faking” the illusion

• Illusion affected some pilot responses, and

majority felt illusion demo was effective