History, Mechanism and Technical Terms of Ejection Seat.

1. EJECTION SEAT
MADE BY
ABHINAV SINGH SHAKYA
MECHANICAL-A
1329240004

2.  In aircraft, an ejection seat (or ejector seat) is a system
designed to rescue the pilot or other crew of an aircraft
(usually military) in an emergency.
 Once clear of the aircraft, the ejection seat deploys a
parachute.

3. G-FORCE
• g-force (with g from gravitational) is a measurement of
the type of acceleration that causes weight.
• Since g-force accelerations indirectly produce weight, any
g-force can be described as a "weight per unit mass"

4. More about g-force
• The term g-force is technically incorrect as it is a measure of acceleration,
not force.
• g-force accelerations ("g-forces" for short) are often expressed as a scalar,
with positive g-forces pointing downward (indicating upward
acceleration), and negative g-forces pointing upward. Thus, a g-force is a
vector acceleration.
• An average human can bear G-force of about 5 , while pilots can bear it as
high as 9.

5. • Fighter plane pilots wear anti-G suits to protect them from
excessive G-force.
• Ejection seat also produces high G-force while ejecting
from aircraft.
• G-force produced while ejecting is as high as 8 G.

6. History of ejection seat
• The modern layout for an ejection seat was
first proposed by Romanian inventor
Anastase Dragomir in the late 1920s
• The design, featuring a parachuted cell (a
dischargeable chair from an aircraft or other
vehicle), was successfully tested on 25
August 1929.
• Early models were powered by compressed
air in early1940s.
• In the early 1960s, deployment of rocket-
powered ejection seats designed for use at
supersonic speeds .

7. How it works??
• The "standard" ejection system operates in two stages.
• First, the entire canopy or hatch above the aviator
(aircraft) is opened and the seat then occupant are
launched through the opening.
• Modern aircraft uses Egress system for the ejection
mechanism in which these two stages are confined as
a single stage.
• The seat is propelled out of the aircraft by an
explosive charge or rocket motor, carrying the pilot
with it.

8. Encapsulated Seat egress system
• These seats are enclosed in an air-operated
clamshell.
• It permits the aircrew to escape at supersonic
airspeeds and altitudes.
• These are specially designed in which pilot
can control the plane even with the shell
closed and the capsule would float in case of
water landings.
• These are used in the B-58 Hustler and B-70
Valkyrie supersonic bombers.

9. Zero-zero ejection seat
• It is designed to safely extract upward and
land its occupant from zero altitude and zero
airspeed.
• It was developed to help aircrews escape
upward during low-speed flight, as well as
ground mishaps.
• It uses small rockets to propel the seat
upward to an adequate altitude and a small
explosive charge to open the parachute
canopy quickly for a successful parachute
descent.