04-07-2014, 03:26 PM
EJECTION SEAT
EJECTION SEAT.pptx (Size: 282.15 KB / Downloads: 15)
INTRODUCTION
Ejection seats are one of the most complex pieces of equipment on an aircraft, and some consist of thousands of parts.
The purpose of the ejection seat. To lift the pilot straight out of the aircraft to a safe distance, then deploy a parachute to allow the pilot to land safely on the ground.
Ejecting from an aircraft moving at speeds greater than the speed of sound (mach 1 / 750 miles per hour / 1207 kph) can be very dangerous.
BASIC COMPONENTS
CATAPULT – Closed telescoping tube arrangement containing a propellant charge to forcibly extend the tubes.
ROCKET – Propulsive device in the seat which gives the additional thrust after catapult.
RESTRAINS – Protective devices to avoid the injury while ejecting the seat.
PARACHUTE – Helps the pilot to land safely on the ground
EJECTION - SEAT TERMS
BUCKET – Lower part of the ejection seat that contains the survival equipment.
CANOPY – Clear cover that encapsulates the cockpit of the some planes.
DROGUE PARACHUTE – A small parachute which is deployed prior to the main parachute.
EGRESS SYSTEM – Entire ejection system, include seat ejection, canopy jettisoning and emergency life support equipment.
TIMEING AN EJECTION
0 seconds - Pilot pulls cord; canopy is jettisoned or shattered; catapult initiates, sending seat up rails.
0.15 seconds - Seat clears ejection rails at 50 feet (15 m) per second and is clear of surrounding cockpit; rocket catapult ignites,vernier motor fires to counteract any pitch changes; yaw motor fires, inducing slight yaw to assure man-seat separation. (Burn time of all motors equals 0.10 seconds.)
0.50 seconds - Seat has lifted to about 100 to 200 feet (30.5 to 61 m) from ejection altitude.
FUTHER OF EJECTION SYSTEMS
The next generation of escape systems will use controllable propulsion system to provide safe ejection over the expanded aircraft flight. Performance of advanced aircraft
CONCLUSION
The rocket motor has proven to be the only stored energy source which can provide the needed force versus time output consistent with both the human physiological limitation and the necessity to decrease escape system total functioning time to the absolute minimum.
Since the human physiological limits are not likely to change as rapidly as the performance envelope of the next generation of combat aircraft , it seems likely that the rocket motor will continue to be a key part if future escape systems.