The MIG-29 ejection seat (K-36 DM-2) provides emergency escape for a crew member in a wide range of speeds and altitudes of aircraft flight, from zero altitude, zero speed (zero-zero) upwards, and can be used in conjunction with protective equipment, such as pressure suitsand anti-g garments. The seat consists of the ejection rocket firing mechanism, gear box, headrest rescue system with a dome stowed in the headrest, and other operating systems all of which are aimed at providing a safe bail-out.
The ejection seat ensures safe emergency escape of a pilot within the range of velocities (Ve) from 0 to 1,300 km/h (700 km; 810 mph) to 1,400 km/h (760 km; 870 mph) (depending on the type of protective equipment), altitudes from 0 to 20,000 m (66,000 ft) and Mach numbers up to 2.5. the installation weight of the seat is less than 103 kg (227 lb). The ejection seat includes oxygen equipment, parachute system, survival kit, and pyrotechnic charges).
Technical specifications of K-36 DM-2 Ejection seat are –
- DM – Duplicating Mechanism of series 2
- Used in MiG 29 fighter aircraft
- Weight – 135 kg
- Minimum ejection height is 0-0
- Maximum safe height is 18.5 km
- Maximum safe speed is 1400 kmh-1
Components of K-36-DM-2
Main components of K-36-DM-2 ejection seat are –
- KSMU – Combined Servicing Mechanism Unit
- Mechanism box
- Arm-guard mechanism
- Waist mechanism
- ECCM – Ejection Control Command Mechanism (Heart of ES)
- Blocking mechanism
- LLM – Leg Lifting Mechanism
- ABD – Air Blast Deflector System
- Head rest
- Survival Kit – NAZ-7M
KSMU – Combined Servicing Mechanism Unit
It consists of 3 firing guns.
1. 1st stage – Main Gun
- Consists of cartridge PK-16M
- Initiates the moment of the ejection seat at a speed of 13.6 m/s
2. 2nd stage – Booster charge
- Ejection seat is at 1000mm to 1075mm from the base of the aircraft
- Igniter gun is fired through booster charges
- It gives an additional velocity is 30 m/s
- It rises the ejection seat to 70km from the aircraft
3. 3rd stage – Parachute diplomat gun
- PD gun is fired at the altitude of 5 km.
- The altitude is indicated through a barometric system PPK-UT-424 installed on the side of the head rest.
Ejection Circuit Control Mechanism
1. This control unit comprises of three sections.
- Upper Section – Handle
- Middle Section – spring boosters, cam/shaft and cable drums
- Lower Section – 9 Micro switches (8 horizontally and 1 vertically)
2. The ejection seat handle is attached to the cable which is connected to the spring boosters. As the handle of the ejection seat is pulled, the cable attached to the handle gets pulled upward compressing the spring boosters which are present on either side of the middle chamber.
These spring boosters make the cable drums rotate, winding up the cables in it. These cables are connected to the R-gun and the main gun through another cable. The pull causes the striker to move, firing the cartridges of the R-gun.
3. There is an electrical standby system which operates simultaneously. The cable drum is also connected to 9 micro switches (8 horizontally and 1 vertically). These switches operate 9 different mechanisms including arm-guard mechanism, shoulder and waist restrain mechanism, etc. The vertical switch sends signals to the Flight Data Recorder (FDR).
Restrain Gun (R-Gun)
Restraint gun has two cartridges Mechanical and Electrical. When fired, gaseous of mechanical cartridge goes to five places mentioned below:
- LLM (Leg lifting mechanism)
- Arm Guard mechanism
- Shoulder restrain mechanism
- Waist Restrain mechanism
- Piston No.7 (To eject canopy)
NOTE: Electrical Cartridge is for Standby system if in case mechanical fails to work.
Arm Restrain Mechanism
Arm guards are fitted at the side of the seat. Its purpose is to protect pilot’s hands. As the gas enters the pipelines of the arm guards, the armguards extend sideward by 50 mm. After this, they are inclined at an angle of 65°.
Waist Restrain Mechanism
Restrain straps are present in ejection seat to restrain the pilot from its waist which is attached to the jacket of the seat.
Shoulder Restrain Mechanism
Shoulder straps are present in mechanism box, which is operated by pressurized gas produced by R-gun to restrain the pilot to the ejection seat.
Leg Lifting Mechanism (LLM)
To lift the thigh of the pilot near about 160mm to give pilot a correct posture so that pilot’s legs are not tangled with the aggregate of cockpit system. It consists of two tubes – Inner Tube and Outer Tube. Pressure generated through R-gun is 150kg.
Piston no. 7
Piston no.7 located in mechanism box on the Right side of ejection seat which moves out and hit the bell crank in the cockpit which fires the canopy fire gun and ejects the canopy.
Mechanism box is located under the headrest and contains the following:
- Motor- moves the seat up and down
- Shoulder restrain mechanism
- Shoulder restrain mechanism cover
- Graduation scale
- Gear mechanism
- Stabilization system
- Piston No.7
- Shoulder Cutter
- Stabilization gun chamber
Air Blast Deflector (ABD)
ABD system is present to protect the face and chest of pilot from the incoming high air pressure during ejection, an apron is attached to ABD system to protect chest it has holes so the air pressure can pass evenly. It will only operate if aircraft speed is more than 800km/h. ABD system is operated by main gun cartridge.
NOTE: ABD valve system blocks the pressure given by the main gun so, the ABD system will not act if speed is less than 800k/h.
To accommodate the main lifesaving parachute and also during flight it gives rest to the pilot. PD gun is fired which gives the pressure at the main nut which is attached with the head rest. This shoots the head rest upwards, launching the parachute. Since the part of the seat is heavier than the weight of the pilot, the seat gets detached through signal joint, lifting up only the pilot’s body.
Ejection Firing Sequence
When the handle of the ejection seat is pulled, the restrained gun will fire and produce pressurized gas to 5 places in the system i.e. the arm guard, shoulder restrain mechanism, waist restrain mechanism, leg lifting mechanism and piston no.7 which is located in the mechanism box. Once the pressurized gases go to these places the piston no.7 will move out and hit the bell crank and then the canopy will open along which the inter-locking strap will move out.
After the canopy moves out along with the strap, the wire connected to the strap which connects to the blocking mechanism will be pulled and there is a lever which is present in the blocking mechanism and this lever will operate once the wire is pulled and this will further operate the cordon shaft which in turn will operate the main gun which has 2 cartridges and gases will go to the inner and outer tube of the KSMU.
Operations on the basis of height
- At 10-20mm, inside the cockpit the signal joint connector will disconnect.
- At 10-30mm, the PPK-UT-424 will operate, the signal joint connector will pull the wire which will operate the bell crank which will operate the barometry inside the PPK-UT424 located on the left side and the right side of the ejection seat. The left side will work only from 5 km above sea level with the remaining time of 0.8-1.2
- At 20-60mm, KPA-4M will operate, this device is connected to the cartridge actuator device, it will be ejected from these and this device will operate the PPK-1M-T-424 which will work only at 3km above sea level with the remaining time 0.3- 0.8.
- At 90-180 mm, gases will go to the telescopic tube and gases will go to the pipeline and that will operate the air blast deflector tube which protects the pilot from incoming air.
- At 170-210mm, the connector 25 will be disconnected and all the obstruction and the electrical connections will be disconnected
- At 350-380mm – the CAD will operate, stabilization gun is connected to CAD and after that gas will enter the chamber and these gases will go through two pipelines, there are two grid present and holes are present in these grid which will operate the parachute on the side and this will stabilize the seat.
- At 1075mm – the actuator box will operate along with the cable and then the 2nd stage firing body will operate and there will be a flame which goes to KSMU chamber (25 sticks on both sides-PAZM booster charge). It is a type of cartridge where the flames will close the cartridge and speed of the seat will move 30m/s faster i.e. 3300kg force. When the PPK-UT424 will work the gases will go in KSMU then it will throw the head rest upward and the seat downward and then the cutter will cut the shoulder strap and then the waist strap and after that the leg lifting mechanism will be cut and after cutting all the traps the 5th place which the gas goes to, the gas will go to the arm guard again and return to its original position and then the pilot will be free from the seat and left with the NAZ-07M and parachute and its straps. There is an emergency oxygen attached to the seat which can give oxygen for about 5 minutes to the pilot.
Overhauling of the Ejection Seat
Servicing of the Ejection Seat consists of the following processes:
- Acceptance (Checking of the components).
- Dismantling (Aggregate dismantling).
- Cleaning and Defecation
- Aggregate Assembling
- Aggregate testing
- Assembly of ejection seat
- Testing of ejection seat
- Passing Out
The following safety precautions are to be adhered to while performing servicing processes on ejection seat:
- Cartridges are highly explosive, therefore the individual handling it must discharge current from himself/ herself in ESD.
- All activities have to be performed under a skilled supervisor.
- Always regulate the pressure or make the pressure flow in a regulate mode.
- While testing all aggregates should be tested inside the armed chamber.
- Always follow SOP (Standard Operating Procedure).
- Always refer the manual.
- Before loading of the seat put all the ground safety device such as safety pins so that the cartridges do not fire.
Upgraded Ejection Seat (MiG-29 UPG)
Some changes have been made in the ejection seat of MiG-29 not because there are injuries caused to the pilot but because for the easier handling and the space needed for each part has to be compromised. The components in which changes are made are mentioned below:
- Leg lifting mechanism
- Shoulder restraining handle
- Survival equipment
- ORK-11 connections
- DASH-4 connections
- Oxygen actuator lever
- SPS Sensor
- Switch box
Comparison between Su-30 MKI and MiG-29 Ejection Seat
|S/N ||Su-30 MKI||MiG-29|
|1.||Safety ejection i.e. max height is 20km and |
speed is 1300km/hr.
|Safety ejection i.e. max height is 18km and speed is 1400km/hr.|
|2.||Operation of ES is according to the weight i.e. different modes of operation depending upon the weight of the crew member||Operation of ES is not according to height.|
|3.||In Su-30 the handle has only 1 spring booster and 2 balls.||In MiG-29 Ejection seat handle has 2 springs which is connected to 2 separate drums.|
|4.||Autonomous Power Supply is present.||Power supply is directly from the cockpit or a/c where the emergency systems are present.|
|5.||Su-30 has 13 cartridges.||MiG-29 has 6 cartridges (5 different types).|
|6.||Trajectory Divergence Motor is present.||TDM is not present|