Transcript Ejection Systems

Ejection Systems
Chris Valeski
Ryan Wagner
Ejection Seat Components
 Catapult - moves seat up a set of rails
 Rocket - propels seat away from aircraft
 Restraints - holds passenger in seat
 Parachute - allows passenger to descend at
safe speed
 *it is possible that catapult and rocket be the
same component
 Survival Provisions
Current Generation of Ejection
Systems
parachute is deployed immediately
 Pilot-seat separation not required
Seat senses airspeed and altitude of the
aircraft and selects an appropriate time
delay for ejection
 Seat and parachute are deployed in an
optimal manner
Timing an Ejection - 0 Seconds
Pilot pulls cord
canopy is jettisoned or shattered
catapult initiates
sends seat up rails
Timing an Ejection - 0.15 Seconds
Seat Clears the ejection rails at
approximately 50 ft/s.
Rocket catapult ignites
Yaw motor fires
Burn time of motors last approximately
0.10 seconds
Timing an Ejection - 0.50 Seconds
Seat has cleared the aircraft by 100 to
200 feet
Seat-man-seperator motor fires and
catapults crewmember from seat along
with equipment
Drogue gun fires parachute
Timing an Ejection - 4 Seconds
Main parachute is fully deployed
Ejection Forces on Human Body
Typical ejection consists of forces
between 12 G’s and 20 G’s
A 180 lb. crewmember would feel a 3600
lb force at a 20 G force ejection.
Ejection Movie
http://www.aviationexplorer.com/su27_
airshow_video.htm
http://www.aviationexplorer.com/usaf_t
hunderbird_f16_video.htm
Future of Ejection Systems
 “Smart” seat – Combines digital technology
and highly controllable propulsion systems
 On-board digital computer would instantly
calculate an optimum ejection trajectory, which
would then be executed by a more
controllable rocket motor
 Increased ability to eject in high altitude and
high speed cases.
 New propellants
Factors Impacting Future Ejection Systems
Cost
Weight
Rapid decrease in number of ejections
Sources
 Horn, Henry. Evolution of an In-Flight Escape
System. AIAA Paper No. 75-1405: 1981.
 Sadler, Robert. Propulsion’s Contribution to the
Success of Aircrew Emergency. 39th
AIAA/ASME/SAE/ASEE Joint Propulsion Conference
and Exhibit: July 2003.
 www.ejectionsite.com
 www.brooks.af.mil
 www.martin-baker.com