Ejection Seats (Importance, History and Types)

[Maarkhoor]

Ejection Seats:

Most of the modern jet aircraft equipped with ejection seats, it is very important safety feature of any modern aircraft specially fighter jets. In case of damage or hit by anti aircraft weapons pilots have very little chance to survive without this feature.
Ejections seats installed in the aircraft's cockpit supported by rails and during ejection these rails guide the seat to out of the aircraft and edge of the seat always high above the pilot's head for breaking or ejecting the canopy to save the pilot's head from hitting the canopy.

History:
A bungee-assisted escape from an aircraft took place in 1910. In 1916 Everard Calthrop, an early inventor of parachutes, patented an ejector seat using compressed air.[1]

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 at the Paris-Orly Airport near Paris and in October 1929 at Băneasa, near Bucharest. Dragomir patented his "catapult-able cockpit" at the French Patent Office.[note 1]

The design was perfected during World War II. Prior to this, the only means of escape from an incapacitated aircraft was to jump clear ("bail out"),[note 2] and in many cases this was difficult due to injury, the difficulty of egress from a confined space, g forces, the airflow past the aircraft, and other factors.

The first ejection seats were developed independently during World War II by Heinkel andSAAB. Early models were powered by compressed air and the first aircraft to be fitted with such a system was the Heinkel He 280 prototype jet-engined fighter in 1940. One of the He 280 test pilots, Helmut Schenk, became the first person to escape from a stricken aircraft with an ejection seat on 13 January 1942 after his control surfaces iced up and became inoperative. The fighter, being used in tests of the Argus As 014 impulse jets for Fieseler Fi 103 missile development, had its usual HeS 8A turbojets removed, and was towed aloft fromthe Erprobungsstelle Rechlin central test facility of the Luftwaffe in Germany by a pair of Bf 110C tugs in a heavy snow-shower. At 2,400 m (7,875 ft), Schenk found he had no control, jettisoned his towline, and ejected.[2] The He 280 was never put into production status and the first operational type built anywhere, to provide ejection seats for the crew was theHeinkel He 219 Uhu night fighter in 1942.

In Sweden, a version using compressed air was tested in 1941. A gunpowder ejection seat was developed by Bofors and tested in 1943 for the Saab 21. The first test in the air was on a Saab 17 on 27 February 1944,[3] and the first real use occurred by Lt. Bengt Johansson[note 3] on 29 July 1946 after a mid-air collision between a J 21 and a J 22.[4]

As the first operational military jet in late 1944 to ever feature one, the lightweight Heinkel He 162A Spatz featured a new type of ejection seat, this time fired by an explosive cartridge. In this system, the seat rode on wheels set between two pipes running up the back of the cockpit. When lowered into position, caps at the top of the seat fitted over the pipes to close them. Cartridges, basically identical to shotgun shells, were placed in the bottom of the pipes, facing upward. When fired, the gases would fill the pipes, "popping" the caps off the end, and thereby forcing the seat to ride up the pipes on its wheels and out of the aircraft. By the end of the war, the Dornier Do 335 Pfeil — primarily from it having a rear-mounted engine (of the twin engines powering the design) powering a pusher propeller located at the aft end of the fuselage presenting a hazard to a normal "bailout" escape — and a few late-war prototype aircraft were also fitted with ejection seats.

After World War II, the need for such systems became pressing, as aircraft speeds were getting ever higher, and it was not long before the sound barrier was broken. Manual escape at such speeds would be impossible. The United States Army Air Forces experimented with downward-ejecting systems operated by a spring, but it was the work of Sir James Martin and his company Martin-Baker that was to prove crucial.

Seat on display at RAF Museum Cosford.
The first live flight test of the Martin-Baker system took place on 24 July 1946, when fitter Bernard Lynch ejected from a Gloster Meteor Mk III jet. Shortly afterward, on 17 August 1946, 1st Sgt. Larry Lambert was the first live U.S. ejectee. Lynch demonstrated the ejection seat at the Daily Express Air Pageant in 1948, ejecting from a Meteor.[5] Martin-Baker ejector seats were fitted to prototype and production aircraft from the late 1940s, and the first emergency use of such a seat occurred in 1949 during testing of the jet-powered Armstrong Whitworth A.W.52 experimentalflying wing.

Early seats used a solid propellant charge to eject the pilot and seat by igniting the charge inside a telescoping tube attached to the seat. As aircraft speeds increased still further, this method proved inadequate to get the pilot sufficiently clear of the airframe. Increasing the amount of propellant risked damaging the occupant's spine, so experiments with rocket propulsionbegan. In 1958, the Convair F-102 Delta Dagger was the first aircraft to be fitted with a rocket-propelled seat. Martin-Baker developed a similar design, using multiple rocket units feeding a single nozzle. The greater thrust from this configuration had the advantage of being able to eject the pilot to a safe height even if the aircraft was on or very near the ground.

An Aviation Structural Mechanic works on an ejection seat removed from the cockpit of an EA-6B Prowler aboard USS John C. Stennis.
In the early 1960s, deployment of rocket-powered ejection seats designed for use at supersonic speeds began in such planes as the Convair F-106 Delta Dart. Six pilots have ejected at speeds exceeding 700 knots (1,300 km/h; 810 mph). The highest altitude at which a Martin-Baker seat was deployed was 57,000 ft (from a Canberra bomber in 1958). Following an accident on 30 July 1966 in the attempted launch of a D-21 drone, twoLockheed M-21[6] crew members ejected at Mach 3.25 at an altitude of 80,000 ft (24,000 m). The pilot was recovered successfully, but the launch control officer drowned after a water landing. Despite these records, most ejections occur at fairly low speeds and altitudes, when the pilot can see that there is no hope of regaining aircraft control before impact with the ground.

Late in the Vietnam War, the U.S. Air Force and U.S. Navy became concerned about its pilots ejecting over hostile territory and those pilots either being captured or killed and the losses in men and aircraft in attempts to rescue them. Both services began a program titledAir Crew Escape/Rescue Capability or Aerial Escape and Rescue Capability (AERCAB) ejection seats (both terms have been used by the US military and defence industry), where after the pilot ejected, the ejection seat would fly him to a location far enough away from where he ejected to where he could safely be picked up. A Request for Proposals for concepts for AERCAB ejection seats were issued in the late 1960s. Three companies submitted papers for further development: A Rogallo wing design by Bell Systems; a gyrocopter design by Kaman Aircraft; and a mini-conventional fixed wing aircraft employing a Princeton Wing (i.e. a wing made of flexible material that rolls out and then becomes rigid by means of internal struts or supports etc. deploying) by Fairchild Hiller. All three, after ejection, would be propelled by small turbojet engine developed for target drones. With the exception of the Kaman design, the pilot would still be required to parachute to the ground after reaching a safety-point for rescue. The AERCAB project was terminated in the 1970s with the end of the Vietnam War.[7] The Kaman design, in early 1972, was the only one which was to reach the hardware stage. It came close to being tested with a special landing-gear platform attached to the AERCAB ejection seat for first-stage ground take offs and landings with a test pilot.

 

[Maarkhoor]

Bailing Out:
In case of emergency pilots pulls the lever witch starts a chain of events listed below.
Most of the modern ejection seats supports rocket propelled ejection system when pilots pulls the lever for ejection, extended edge of the seat with force propels away the canopy (some aircraft supports explosive bolts) and ejection seat through guide rails propels up out of the aircraft far enough from the aircraft to safely deploy the rescue parachute.
Modern aircraft support zero zero ejection seat which means in case of emergency pilot can eject even on zero altitude. here is the complete chain of events.

Lifting the canopy - Bolts that are filled with an explosive charge are detonated, detaching the canopy from the aircraft. Small rocket thrusters attached on the forward lip of the canopy push the transparency out of the way of the ejection path, according to Martin Herker, a former physics teacher who has written about ejection seats and maintains a Web site describing ejection seats.

Shattering the canopy - To avoid the possibility of a crew member colliding with a canopy during ejection, some egress systems are designed to shatter the canopy with an explosive. This is done by installing a detonating cord or an explosive charge around or across the canopy. When it explodes, the fragments of the canopy are moved out of the crewmember's path by the slipstream.

Explosive hatches - Planes without canopies will have an explosive hatch. Explosive bolts are used to blow the hatch during an ejection.

Zero-zero ejection seats:

Zero-Zero - just about the lowest point in the Ejection Envelope. Sitting on the ground, with the aircraft immobile.An emergency arises and you don't have time to hop out of the cockpit and run. What can you do? How do you know the seat will work? Will it launch you high enough for the parachute to open? Will you be injured by the force of the launch?

These questions led to a unique test. In the mid-1960s a firm that had made its name providing ejection seats and egress technology to both the military and to NASA decided that instrumented dummies did not provide all the information needed. They felt that certain questions of human physiology needed to be answered by a test of a live human. Weber Aircraft's seats had saved over 500 lives by this time. They had been fitted to such varied craft as the F-106 and the Gemini Space capsule. The F-106 seat included the latest technologies available to allow for a clean ejection, including a gun deployed parachute, rocket motor, and self deploying survival equipment.

In late 1965, Jim Hall a professional parachute safety instructor and Major in the Air Force Reserve volunteered to act as the human guinea pig for the 0-0 seat package. He was instructed in all facets of the seat operation. He viewed films of the 43 sequential successful tests of the F-106 0-0 system. He also was measured for center of gravity in order to align the rocket exhaust with the center of mass of the man-seat package. In the tradition of the day, he visited the assembly line and selected the particular seat he would later ride.

The engineers checked and verified all functions of the particular seat. They selected a lake not far from the factory for the test. A set of seat rails were attached to a test stand. The date and time were selected. And then it was time.

Jim Hall, accompanied by a platoon of engineers, arrived at the site and was shown the seat. Now it was mounted on the rails, wired and ready to fire. Every mechanical function had been checked and double checked. Major Hall was attired in an orange flight suit. Its arms were cut away at the shoulder to reveal a small area of skin that had been marked by pigment. He was strapped into his chute and assisted into the seat. All the straps were connected and tightened. The engineering cameras were armed to record every aspect of the test, even the slump of Jim's shoulder markings under launch acceleration. Then the engineers withdrew to a safe distance. The rescue launches on the lake were signaled, and the countdown began...

Major Hall gripped the handles built into the sides of the seat bucket and pulled them up to the firing position... and nothing happened... for one long second. The delay cartridge allowed the high speed cameras to get to speed and then the hot gas was unleashed into the catapult initiator. The Major rose up the rails with anonset rate of 150 g's/second with a maximum of about 14g's. The rocket ignited as the seat cleared the rail providing the huge jet of flame in the above picture. One second and almost 400 feet later, seat separation occurred. The parachute gun fired, and two seconds later the parachute was fully inflated. The survival kit automatically released and dropped to the end of its lanyard. The rubber raft, suspended from the same lanyard,immediately inflated.

Approximately 26 seconds after Major Hall pulled the handles he landed in the lake.A journey of only a few dozen yards had taken him to an altitude of about 400 feet andinto the history books (albeit only a few obscure ones...). To this day, thirty-three years later, Jim Hall's zero-zero ejection test remains the only 0-0 test that was executedwith a human subject in the United States by an American Company. (The first known live 0-0 test was executed in 1961 by Martin-Baker Aircraft Co. Inc.. Doddy Hay, a M-B employee, was the 'Man in the Hot Seat' for that first test. There have been several other live tests, most of which have been at altitude, or with some airspeed.)

Sources:
Gordon Cress (Project Test Engineer: Project 90)
Science how it works
Wikipedia

@WAJsal @Slav Defence @Khafee @Indus Falcon @Windjammer

@Zibago @Jonah Arthur @Tipu7 @django @Oscar
@MastanKhan @Neutron

 

[Tipu7]

Nice one..... I always needed some clean description and info about ejection seat and ejection mechanism.......

Can any one elaborate the appropriate conditions which are suitable for pilot to eject?
Like speed of aircraft? Altitude? Angle of flight?
And now even Russian Ka52 gunship helicopter has awesome ejection mechanism........

 

[Maarkhoor]

Nice one..... I always needed some clean description and info about ejection seat and ejection mechanism.......

Can any one elaborate the appropriate conditions which are suitable for pilot to eject?
Like speed of aircraft? Altitude? Angle of flight?
And now even Russian Ka52 gunship helicopter has awesome ejection mechanism........

Most of the modern 4th Gen aircraft equipped with zero-zero ejection seats so virtually no limitations on pilots for ejection.

The ACES II Seat: Tech Info

The Advanced Concept Ejection Seat (ACES) was designed to be rugged and lightweight compared to earlier systems. It also was designed to be easy to maintain and updatable. It includes the following features:

• 
  
  • Electronic Sequencing and timing
  • Mortar-deployed main chute
  • Auto sensing of egress conditions
  • Parachute reefing to control opening at all speed ranges
  • Multi-Mode operation for optimum recovery of the crewman

The ACES II is a third-generation seat, capable of ejecting a pilot from zero-zero conditions up to maximum altitude and airspeeds in the 600 KEAS range. The peak catapult accelleration is about 12gz. The ACES II has three main operating modes, one each for the low speed/low altitude, medium speed, and high speed/high altitude. In Mode 1, which includes 0-0 up to 250kts, the parachute is inflating in less than two seconds. In Mode 2 the chute is inflating in less than 6 seconds. Mode 2 is effective up to the maximum rated speed of the seat. Mode 3 deployment is delayed by the sequencer until the seat-man package reaches either Mode 2, or Mode 1 conditions, whichever comes first. Primarily, Mode 3 refers to operation above 15000 feet where separation from the seat would result in disconnection from the emergency oxygen, and also possible lead to more severe opening shock of the parachute due to differing atmospheric conditions.
Seat modes are selected by the sequencer based on atmospheric conditions, and the modes vary depending on differences in the conditions such as apparent airspeed and apparent altitude.

A light-weight crewman would reach an apogee of close to 200 feet if they ejected at ground level with zero airspeed. Typical performance is as follows:



Aircraft Attitude Velocity
Knots Altitude
Required
0-Deg Pitch, 60-Deg Roll* 120 0
0-Deg Pitch, 180-Deg Roll 150 150
0-Deg Pitch, 0-Deg Roll 150 116
10,000-FPM Sink Rate
-60-Deg Pitch, 0-Deg Roll 200 335
-30-Deg Pitch, 0-Deg Roll 450 497
-60-Deg Pitch, 60-Deg Roll 200 361
-45-Deg Pitch, 180-Deg Roll 250 467
* For this case, impact occurs at the instant the
seat and aircraft are separated. In all other cases,
conditions are at initiation of the catapult rocket.
The seat structure is primarily aluminum alloy stamp formed with ridges for structural strength. The box-like structure is refered to as a monocoque construction. The back section which is nominally 16 inches wide has a set of three rollers on each side which interface with the extruded aluminum rails in the cockpit. These rails are identical to the rails used for Escapac seats (also a Douglas Aircraft {McDonnell-Douglas} product). The seat bucket is wider with a maximum width of 20 inches. The seat itself weighs approximately 127 pounds in most versions, with the rocket-catapult weighing 21LBs. The propulsion is a CKU-5/A/A rocket-catapult which uses a conventional solid propellant catapult charge to start seat movement, and a solid-propellant rocket motor to sustain the movement. The rocket motor is ignited at the end of the catapult stroke as the seat leaves the aircraft. The rocket-catapult is attatched to the seat at the headrest end and to the cockpit at the base via a twin-barrel linear actuator which provides for seat height adjustment. The nominal adjustment range is +2.5-inch vertical adjustment. The actuator is attatched at the fixed base to the cockpit structure and at the upper end via twin screw barrels to the base of the rocket-catapult. I have recently recieved information that the CKU-5/A/A is being phased out and replaced with the more environmentally friendly propellent version known as the CKU-5/B.

Seat functions are normally activated by the Recovery Sequencing Subsytem which consists of the environmental sensing unit , and the recovery sequencing unit, an electronic box located inside the seat rear on the right hand side. The environmental sensing unit consists of two altitude compensated dynamic pressure transducers, and two static pressure transducers. The dynamic pressure sensors (pitot tubes) are located on or near the headrest and read the air pressure as the seat exits the aircraft. The pressure differential between them and the ambient (static) sensors behind the seat is compared by the recovery sequencing unit to determine what operating mode the sequencer should select. The sequencer is fully redundant with two thermal batteries, two electrical systems, and an individual bridge wire from each in each of the electro-explosive squibs. The thermal batteries are activated by hot gas bled off from the catapult firing. There is a small window on the right side of the seat back to check the batteries for signs that they have been fired.

Firing of the seat is normally by pulling one of the ejection control handles mounted on the seat bucket sides. (On ACES seats fitted to F-16s and F-22s the ejection control handle is located in the center of the front of the seat bucket) The side pull handles are mechanically linked so that raising one will lift the other as well. Raising the handles actuates a pair of initiators via mechanical linkages. See below for the basic sequence of events that follows. On the F-16 the center pull handle rotates a bellcrank to pull the pair of linkages visible in this picture to withdraw the sears from both initiators. This seat was fired, and the sears are seen dangling from the linkages. In the left of the picture is the spring which provides the resistance to the pull making it about a 40-50 lb pull. On the right side of the picture is the linkage from the safety handle which locks the bellcrank mechanism.

One particularly unique feature to the ACES II is the STAPAC package. STAPAC is a vernier rocket motor mounted under the seat near the rear. It is mounted on a tilt system controlled by a basic pitch-rate gyro system. This system is designed to help solve one of the great problems inherent to ejection seat systems. Center of mass/Center of gravity is extremely important in terms of keeping the thrust of the booster rocket from inducing a tumble. Rocket nozzles for the main boost of a seat are aligned to provide thrust through the nominal center of gravity of the seat-man package. The STAPAC provides a counter force to prevent extreme pitching in cases where the CG is off by up to +2 inches. This picture displays a F-16 ACES II from below. The STAPAC is visible as is the seat separation rocket on the left side. The seat is resting on its front and a pair of ground handling skids are mounted on the seat sides. The yellow flag is a safety pin preventing accidental firing of the STAPAC. The white colored lines are from the sequencer, and the twin firing initator cartridges are visible at the lower front with the black pyrotechnic lines leading from them.

Another unusual feature is related to the survival kit. In most ejection seats the survival kit is a rigid fiberglass box that makes up the seat inside the seat bucket. The ACES II survival kit is a soft pack that is stored under a fiberglass seat lid that is hinged at the front. When the pilot separates from the seat, the straps that connect him to the survival kit lift the seat lid up and forward. The seat kit then slips free from the rear end. The seat lid is latched in place normally, and released at seat separation when the Restraint Release Cartridge fires and rotates a bellcrank that releases the seat lid, shoulder harnesses, lap belt, and chute mortar disconnect. On the front of the seat bucket is a port that allows the crewmember to select the operation mode of the URT-33C survival beacon. The port also has a switch that allows the crewman to select automatic deployment of the seat kit, or manual deployment. For the URT-33C beacon, in the AUTO mode, the beacon would activate at man-seat separation. (For maintainance, a equipment release knob is located at the top rear of the right side of the seat bucket.)

The Inertia Reel Harness Assembly is located in the center of the seat back just below the headrest. The inertia reel fulfills two functions: (1) it acts like the shoulder belt in a car, restraining the pilot against a 2gx forward (-x) motion. (2) upon ejection, it retracts the pilot to an upright posture to minimize the possibility of spinal damage due to spinal misallignment upon catapult ignition. On the left side of the seat bucket there is a handle which allows the crew member to manually lock the reel prior to intense manuvers or landing to prevent possible injuries.

The Drogue System consists of a hemisflo chute, a small extraction chute, and the Drogue Mortar. The drogue mortar is fired in Mode 2 and Mode 3 to slow and stabilize the seat-man package. This is intended to prevent or limit the injuries to the crewmember as he/she is exposed to the windblast after exiting the aircraft. The mortar fires a 1.2 Lb slug of metal that draws the extraction chute out which by means of a lanyard deploys the drogue chute. The extraction chute is packed in a small wedge-shaped container on the upper left rear of the seat covered with metalized fabric. The lanyard is also covered in the metalized fabric. The drogue mortar is below this, and the drogue is packed in the metal covered box below this. The lid to the drogue is retained by a small plunger unit that is held in place by machining on the slug and released when the mortar fires. The drogue bridles are attached on either side of the seat. Many of these features are visible in this pictureThe bridles are wrapped around a set of rods and are cut by a set of pyrotechnic cutters when the sequencer determines that it is time to jettison the drogues prior to main chute deployment.



The seat is safed by means of a Safety Lever on the left side of the seat bucket which prevents the seat from being fired when the lever is in the up/forward position. When it is down/back flat against the side of the bucket, it allows the seat to be fired. The picture shows a F-16 handle in the Safe position. This picture shows a fired seat with the handle in the armed position. Note the firing handle is pulled out and resting on the seat cushion. The small tab on the handle engages a microswitch in the hole in the seat bucket side to electrically report to the aircraft the arming state of the seat.

The Emergency Manual Chute Handle is located on the right hand side of the seat bucket, and functions to fire the main chute mortar and initiate seat separation in case of failure of the electronic sequencer. Unlike other seats, the manual chute handle is inhibited in the aircraft and prevents the systems from functioning while the seat is still in the rails. In the event of ground egress, the crewman would have to unstrap the two shoulder harness connections, the two seat kit connections and the lap belt prior to egressing the aircraft. Given the 0-0 capability of the seat, in any case requiring extremely rapid egress, ejection would be a viable alternative. In early seats this function did not include the mortar cartridge and the handle was labled 'Restraint Emergency Release'. Pulling it would unlatch the same items, but relied on the pilot chute in the headrest to deploy the main parachute. The recommended procedure was to pull the handle with the right hand and push up on the pitot tube extensions with the left for more positive extension. On seats like the B-1B which had folding pitot tubes this was not an option, and the additional mortar cartridge was added. This picture shows both handles, the early one from a fired seat, the second from a live seat, showing the safety pin installation as well.



The emergency oxygen system consists of an oxygen bottle attached to the seat back, an automatic activation lanyard, and a manual pull ring (the green ring visible on the left hand seat pan side in this picture). As the seat rises up the rails, the lanyard activates the oxygen bottle and allows the crewman access to oxygen as long as he is still connected to the seat. During an in-flight emergency that does not require ejection, the oxygen bottle provides breathable air for enough time to return the aircraft to 10000 feet or below where the atmosphere is thick enough for the pilot to breath.



ACES II Event/Time Sequence
Typical Event Mode 1 Mode 2 Mode 3
Rocket-Catapult Fires 0.0 0.0 0.0
Drogue Deploys Note 2 0.17 0.17
STAPAC Ignites 0.18 0.18 0.18
Parachute Deploys 0.20 1.17 Note 1
Drogue Releases from seat Note 2 1.32 Note 1
Seat Releases from Crewman 0.45 1.42 Note 1
Parachute Inflates 1.8 2.8 Note 1
Survival Kit Deploys 5.5 6.3 Note 1
Note 1: In Mode 3 the sequence delays until the conditions drop below the Mode 3 boundry, then the parachute deploys after a 1.0 second delay.
Note 2: Drogue Chute is not deployed in Mode 1 Ejections, but the drogue line cutters will fire to make sure.
Note 3: The info in this table is for the F-15/F-16/F-117. Other seats have slightly different timings.

Source:
ejectionsite

F16 Ejection Seat:

 

[Slav Defence]

@Maarkhor
I appreciate your effort.Truly informative


Regards

 

[GoldenRatio1618]

can chinese engineers convert fighter ejection seat with jetman pack in case of fighter crash pilot can safely eject in air and flown to safe place. because in case of jorden f16s crash pilot ejected safely but captured by terrorist and they later burnt him same in case of russian fighter shoot down by turkish airforce pilots ejected safely but no way to escap them self from enemy on land and one killed in firing while landing. and jet man pack gives opportunity in the air after ejection start engine in the air and fly to safe place and ejection seat have no such option. and even with that jet man pack suit mission computer data pilot can take with him after ejecting from fighter.

 

[knight11]

Fascinating Facts

• The Martin-Baker MK-14 is made of over 1300 parts
• An Ejection Seat from an SR-71 is believed to be being used as a throne by the ruler of a small island in the Pacific
• An ejection system was tested in late 1912, at Issy-les-Moulineaux near Paris by Baron d'Odkolek. A parachuted dummy was extracted by a small cannon launched parachute from an aircraft in flight. The system also included a rudimentary skirt spreader gun to rapidly expand the parachute to full open. (Skirt spreaders are in use on some seats today, including the Stencel S-III-S used in the AV-8A and AV-8B Harriers.)
• The Germans during World War II used ejection seats some 60 times.
• Ejection Seats have been used over 12000 times to date.
• The most common reason for unsuccessful Ejection is delayed Ejection Decision.
• The Martin-Baker MK 14 seat is microprocessor controlled, with thermal batteries for power. (Not unique to Martin-Baker designs. The ACES II seat also uses thermal batteries and an analog control unit)
• When inspected, all functions of an Ejection Seat must function within 1/10 of a second (for a mechanical/pyrotechnic seat). Electrical controlled seats use tolerances in the millisecond (.001) range and must test out accordingly).
• Some Ejection Seats can weigh almost 200 lbs, especially the Russian K-36D. A Martin-Baker MK. J5D weighs about 150 lbs. (Most are lighter, including the ACES II which weighs in at around 130lbs.)
• A Zero-Zero ejection seat will launch a normal sized pilot to a height of over 200 ft and give him a full chute in around three seconds.
• The Harrier jet (used by the USMC and the RAF in various versions) uses an explosive to shatter the canopy inches above the pilots helmet. The canopy can not be jettisoned, so if the explosive doesn't work, the ejection seat will punch through it anyway. Canopy breakers are installed on the headrest to facilitate the effect
• At least one woman pilot has successfully ejected using an ACES II ejection seat. The exact number of female ejectees is changing as more women are involved in military aviation. Women are known to have ejected from a T-45A using a Mk. 14 NACES seat
• The Gemini Astronauts flew into space riding on ejection seats. In space, the ejection seat handles were stowed in a covered compartment in the base of the seat. Early Russian Cosmonauts returned from space, and ejected from their capsules and decended under personal parachutes. The Gemini system was never used.
• Live testing of ejection systems over the years has included humans, chimpanzees and even bears. The chimpanzee and bear ejections were in the Stanley Supersonic Capsule during its extensive test program. The Stanley capsule was test fired with humans as well prior to its installation in the B-58 Hustler.
• The A-1D Skyraider used the YANKEE tractor rocket system to pull the pilot out of the seat and open the parachute.
• The Ka-50 and Ka-52 attack helicoptors are equipped with the Zvezda K-37 egress system. It uses a tractor rocket like the YANKEE to extract the crew after explosive bolts jettison the rotors.
• The F-111 series of aircraft used Escapac ejection seats in the very early ones. Later production aircraft utilized a crew module which ejected the entire cockpit and both its occupants to decend intact.
• Most egress systems are designed to separate from the crew and allow them to decend under a normal parachute.
• Nose capsules (jettisoning the entire front of the airplane just aft of the cockpit)were explored for such aircraft as the F-104 and F-8. This was the method used by the Germans for the first fielded system.

Highest Bailout:

102,000 feet - Captain Joseph Kittinger bailed out of a baloon wearing a MC-3 partial pressure suit and heated socks and gloves along with a parka for an experimental project (Project Excelsior) to see the physiological effects of extreme high altitude air/space craft egress. His first attempt was nearly fatal due to the rapid spin he developed during his three minute freefall. His chute had prematurely deployed and wrapped around his neck. He found himself close to blacking out from the g-forces generated by the centripital force of his spin. Amazingly enough, when it was determined that more information was required, he volunteered to do it again! His later jumps were much more stable, and with a functioning 6 foot drogue, he achieved a terminal velocity of 702 MPH! He is still the holder of several world records, including longest (4.5 minutes) and highest freefall (81,000 feet) as well as highest bailout.


Lowest Altitude Ejection:

Submerged 10-20 feet - A British navy flyer, LT. Bruce Mackfarlane had an engine failure on takeoff, leading to an immediate ditching off the carrier HMS Albion. Surprisingly, he survived the water impact and was coherent enough to clearly recall seeing the water close over the canopy, and begin to darken as the aircraft began to decend into the depths. His training instincts took over and he yanked the canopy jetison handle with his left hand, and immediatly fired the seat with his right. At this point, his memory becomes understandibly blurred, but he recalls tumbling free of the seat, still underwater. He had the presence of mind to release his chute and activate his life vest. (He surfaced aft of the carrier, almost directly under the 'Angel' rescue helo, which had moved into a hover over the disturbance in the water from his aircraft splash. The helo crew reported seeing his aircraft pass in two pieces along either side of the hull of the carrier. This indicates that if the pilot had delayed his attempt to escape a few seconds, he would likely have been killed when the bow of the ship sliced his bird in half. LT Mackfarlane is not the only aviator to have such an experience, click here to read the amazing story of an A-7A drivers increadable escape... Note 2


Oddest Proposed Ejection System:

The Gyro Copter Ejection Seat - aka SAVER (Stowable Aircrew Vehicle Escape Rotoseat) During the Vietnam War, many pilots were forced to eject over enemy territory, even with safe areas in sight. This led to a large number of POWs, and a great effort to find a safe method of allowing pilots a chance to reach safe landing areas. One of these attempts that was pursued was an ejection seat that deployed a set of non-powered rotors overhead and a small gas powered engine on the back for forward propulsion. As the seat moved forward the relative motion would cause the rotors to spin and produce lift. This ungainly contraption would hopefully allow a pilot to fly to an area that would allow for safe retrieval. Note 3


Most Spectacular Ejection at an Airshow:

Tie: The two most spectacular ejections at airshows were both Russian K36 seats being demonstrated first at the 1989 Paris International Airshow when a Mig 29 lost an engine during a low altitude knife edge pass. The pilot ejected at an altitude of less than 200 feet with his aircraft in a vertical nosedive. His parachute fully opened at about the same time his feet hit the dirt.
Several years later, a pair of MIG-29s collided at the International Air Tattoo, Fairford, 1993. Both pilots ejected safely, including the fastest reaction time I've ever seen. The planes were executing an opposing loop when at the bottom of the loop they collided. In the rapidly expanding debris cloud from the collision you can just make out the shape of the seated pilot. Note 4


Most Miraculous Ejection:

This one goes to an Israeli pilot flying an A4 Skyhawk at low level approx. 350 kts. The pilot reports he was flying straight and level, then he was lying on his back on the valley floor with a massive headache. Israeli analysis of his damaged helmet and the debris of the aircraft detected traces of bird blood and a single feather as well as fragments of HUD glass in his face. Apparently he was the victim of a bird strike directly to the front wind screen. The bird continued thru the canopy, demolished the HUD and smashed the visor on the pilots helmet, knocking him unconcious. How did he eject? Answer: enough of the birds corpse deflected upward off his helmet to strike the upper ejection handles and fire the seat!!! Note 5


Most Tragic, Successful Ejection:

A British Harrier Pilot was executing a hover demonstration at an airshow when he was asked by the control tower if he was aware that the aircraft was on fire. Replying in the negative, he elected to decend to a safe landing. Upon setting down on the field, he determined that the fire had spread too rapidly for a normal exit. Activating the handles he ejected cleanly, getting a good chute. His landing was uneventful, albeit unfortunatly the seats landing was not. A spectator in the crowd was hit and killed by the decending seat.



Coolest Ejection seat

This catagory could go many ways, but since I've seen both pictures and video of this one (and I have a link to a picture...) It goes to the Verticle Seeking Seat tested at China Lake Naval Weapons testing area. The seat was capable of righting itself from a bank angle of 180 degrees at 50 feet of altitude! Note 6

NASA Ejection Seats: The X-15

North American Aviation was chosen to design and build the X-15 research aircraft. The X-15 was designed to fly at speeds exceeding Mach 5, and altitudes of up to 800,000 feet (although it maxed out in testing at 347,000 feet). Design discussions were held on the merits of a capsule versus a seat design, and with Scott Crossfield's input, the seat design was chosen. The picture on this page shows the result. The NAA X-15 seat was possibly the most elaborate ejection seat ever designed. Its features included a pair of wings and a pair of telescoping booms to stabilize the seat at speeds of Mach 4.0 and an altitude of 120,000 feet. The seat pan included two large capacity Oxygen cylinders. The foot rests included a set of ankle restraints (shown locked) that were activated by the pilot bringing his feet back to the foot rests. His ankles would strike a set of bars which would lock in the shackles, and by linkage raise a set of deflectors in front of the toes. Raising the ejection handles raised a set of thigh restraints as well as rotating inward the elbow restraints. This action also pulls a pin out of the emergency oxygen supply system activating it. This configuration protected the pilot from the wind blast (the wind forces experienced on ejecting at high Mach are many times the wind force in a large hurricane! {a catagory 5 Hurricane is one with wind speeds in excess of 135 kts., at Mach 2.5 and 56,000 feet the equivilent is 480+ KEAS}).

The canopy was automatically jettisoned as the ejection handles reached within 15 degrees of full travel. The seat was inhibited from firing with the canopy in place, but if the handles were raised and locked into the firing position, the seat would remain armed and extremely dangerous as it would immediately fire if the canopy were to jettison. Hence, the ground rescue personel were strongly cautioned to check through the cockpit windows for the condition of the seat handles in case of the need to jettison the canopy to rescue the pilot. There was an external handle aft of the right side of the cockpit which could cut the catapult initiator line to prevent such an undesired firing.

Upon canopy jettison, the seat would fire. As it left the aircraft, the wings would fold down and cartridges would fire to extend the telescoping booms out behind the seat. A face heat battery is activated to keep the pilot's visor clear of ice that would prevent him from determining a safe altitude to initiate manual seat seperation (in case of a failure of the automatic seperation system). Seat separation is delayed by an aneroid device until the seat is below 15,000 feet. If the seat is fired lower than that, there was a fixed 3 second delay prior to seat separation. Three initiators fire to jettison the headrest, release the seat belt, personel leads (located as a quick disconnect in the left side of the seat bucket), ejection handles, and all restraints. There is a manual handle to fire these initiators in case of an aneroid failure.

Project 90, A study in 0-0 Ejection

Zero-Zero - just about the lowest point in the Ejection Envelope. Sitting on the ground, with the aircraft immobile.An emergency arises and you don't have time to hop out of the cockpit and run. What can you do? How do you know the seat will work? Will it launch you high enough for the parachute to open? Will you be injured by the force of the launch?

These questions led to a unique test. In the mid-1960s a firm that had made its name providing ejection seats and egress technology to both the military and to NASA decided that instrumented dummies did not provide all the information needed. They felt that certain questions of human physiology needed to be answered by a test of a live human. Weber Aircraft's seats had saved over 500 lives by this time. They had been fitted to such varied craft as the F-106 and the Gemini Space capsule. The F-106 seat included the latest technologies available to allow for a clean ejection, including a gun deployed parachute, rocket motor, and self deploying survival equipment.

In late 1965, Jim Hall a professional parachute safety instructor and Major in the Air Force Reserve volunteered to act as the human guinea pig for the 0-0 seat package. He was instructed in all facets of the seat operation. He viewed films of the 43 sequential successful tests of the F-106 0-0 system. He also was measured for center of gravity in order to align the rocket exhaust with the center of mass of the man-seat package. In the tradition of the day, he visited the assembly line and selected the particular seat he would later ride.

The engineers checked and verified all functions of the particular seat. They selected a lake not far from the factory for the test. A set of seat rails were attached to a test stand. The date and time were selected. And then it was time.

Jim Hall, accompanied by a platoon of engineers, arrived at the site and was shown the seat. Now it was mounted on the rails, wired and ready to fire. Every mechanical function had been checked and double checked. Major Hall was attired in an orange flight suit. Its arms were cut away at the shoulder to reveal a small area of skin that had been marked by pigment. He was strapped into his chute and assisted into the seat. All the straps were connected and tightened. The engineering cameras were armed to record every aspect of the test, even the slump of Jim's shoulder markings under launch acceleration. Then the engineers withdrew to a safe distance. The rescue launches on the lake were signaled, and the countdown began...

Major Hall gripped the handles built into the sides of the seat bucket and pulled them up to the firing position... and nothing happened... for one long second. The delay cartridge allowed the high speed cameras to get to speed and then the hot gas was unleashed into the catapult initiator. The Major rose up the rails with anonset rate of 150 g's/second with a maximum of about 14g's. The rocket ignited as the seat cleared the rail providing the huge jet of flame in the above picture. One second and almost 400 feet later, seat separation occurred. The parachute gun fired, and two seconds later the parachute was fully inflated. The survival kit automatically released and dropped to the end of its lanyard. The rubber raft, suspended from the same lanyard,immediately inflated.

Approximately 26 seconds after Major Hall pulled the handles he landed in the lake.A journey of only a few dozen yards had taken him to an altitude of about 400 feet andinto the history books (albeit only a few obscure ones...). To this day, thirty-three years later, Jim Hall's zero-zero ejection test remains the only 0-0 test that was executedwith a human subject in the United States by an American Company. (The first known live 0-0 test was executed in 1961 by Martin-Baker Aircraft Co. Inc.. Doddy Hay, a M-B employee, was the 'Man in the Hot Seat' for that first test. There have been several other live tests, most of which have been at altitude, or with some airspeed.)

 

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The explosive cord over the canopy which shatters it before the seat ejects... Here shown in an alpha jet