Yak-52 Emergency Procedures
Engine Failure | Oil Pressure Sinking | Fuel Pressure Sinking | Engine Vibration | Propeller Overspeeding
Fire In Flight | Emergency Landing Gear Extension | Leaving Aircraft With Parachute


(1) stick forward, start descent, set airspeed 160 km/h
(2) retract the landing gear
(3) choose emergency landing area, verify and correct approach 
(4) time permitting call MAYDAY
(5) close the fuel stop-valve (fully back)
(6) switch off magneto, Master Switch (Battery), Generator and Ignition
(7) open the canopy
(8) when appropriate use flaps to decrease ground speed

NOTE:  DO NOT TRY TO TURN AROUND IN ORDER TO LAND ONTO THE AIRFIELD.  Land straight ahead, turn aside if the straight direction is dangerous. If it happens after the first turn (height above 200 meters) or, for example, in aerobatic area, make a decision whether or not it is possible to reach the airfield.

(1) perform a half-roll
(2) set descent with airspeed 170-180 km/h
(3) set the throttle to one-third position of full range
(4) turn the primer 45 degrees to the left and pump  on  fuel till fuel pressure is 0.1 - 0.2 kg/cm2 or more

NOTE:  Priming into the cylinders is recommended (primer to the right)

(5) As soon as the engine starts move the throttle fully forward in to takeoff position within 1-2 seconds, then set the desired power  setting

WARNING!  Engine restart after inverted flight engine failure leads to 300-350m altitude loss

Aerodynamic quality of the Yak-52 is equal to 7 in clean configuration, and 5.5 with landing gear and flaps extended.  So, the descent distance could be calculated as: L=K*H, where H is the height.

Recommended airspeed to cover maximum distance is 160 km/hr.  Headwind 5 m/sec (10 knots) decreases descent distance by about 10%.  Turns should be performed with 45 degrees bank angle at 160 km/hr airspeed, the altitude loss is 220m for such 360 degree turn, vertical speed - about 8 meters/sec.


The main danger of the oil pressure sinking is that the engine may cease at any time.
(1)  check oil temperature, if oil temperature increases, carry out an immediate landing onto the nearest airfield, or when too far from the airfield get ready for a forced landing onto a the nearest field with the undercarriage UP
(2)  if oil temperature doesn't increase, increase the attention to the oil temperature and go to the nearest airfield for the landing as soon as possible

NOTE:  When the oil pressure is truly lost as opposed to the sensor or indicator failure, the RPM will drop as well because the propeller blades are kept in "fine" position by the oil pressure.  That will be recognizable only if in flight the propeller pitch control was not kept in fully back position.


The following signs of the fuel pressure sinking can be recognized: unstable engine run along with loss of the RPM, reduced manifold pressure and the engine vibration.

The pilot must use following actions:
(1) check if the fuel stop-valve is fully open (fully forward)
(2) turn the primer 45 degrees to the left and pump on fuel to the fuel system
(3) carry out an urgent landing

(1)  in all cases (except fuel pressure sinking) if the altitude is sufficient, minimise RPM and start the descent
(2)  if vibration ceases, move the throttle carefully forward so that to keep the aircraft in straight-and-level flight
(3)  if vibration continues after some power setting variations, increase RPM up to 70% to clean the spark plugs
(4)  if vibration still continues, find power setting that provides minimum vibration and perform landing as soon as possible



(1) decrease RPM by slow back movement of propeller pitch control
(2) continue the takeoff
(3) make a circuit
(4) accomplish landing


(1) idle the throttle
(2) move the propeller pitch control back to decrease RPM
(3) decrease airspeed
(4) accomplish landing


(1) call MAYDAY
(2) close the fuel valve, switch off magneto, Master Switch (Battery), Generator and Ignition
(3) set the descent
(4) use, if necessary, side-slip to choke the flame
(5) perform emergency landing

NOTE:  If fire continues and the emergency landing seems to be dangerous - leave the aircraft with parachute.


(1) Check if the main air system valve is open
(2) Check the air pressure in the man system.  Normal - 50 bars, minimum to attempt the gear extension - about 10 to 15 bars.  If it is unsuccessful, use the emergency air system.
(3) Check the emergency air system pressure: normal air pressure is 40-50 bars
(4) Close the main air system valve
(5) Set the landing gear controls in both cockpits to neutral position
(6) Decrease airspeed to 160-180 km/hr
(7) Open the emergency air system valve on the right hand side panel
(8) Check the landing  gear extension with the green lamps
(9) Set the landing gear controls in both cockpits to DOWN position
(10) Carry out normal landing (flapless)
(11) After the engine shutdown close the emergency air system valve

NOTE:  Do not retract landing gear in flight after emergency extension.


There are at least seven good reasons when to abandon the aircraft with parachute is the only way to save your life.  One would be enough to justify the necessity to always fly with parachute.

1. Aircraft is not recovering from a spin or other type of rotation
2. Structural damage of the aircraft in flight (something broke off)
3. Controls are jammed, aircraft is out of control
4. Mid-air collision
5. Fire in flight
6. Engine failure over the area where the emergency landing is dangerous (mountains, hills, bad surface, forests or other obstacles)
7. Harnesses or their lock malfunction - you might leave the aircraft suddenly when you don't expect it

Pilot in command is responsible for the decision to leave the aircraft with parachute.  Instructor gives commands for the aircraft leaving: "Get ready to jump!" and then "Jump!" when the aircraft is controllable and there is some time, or only "Jump!" if the aircraft is out of control.

Leaving the aircraft in straight-and-level flight:

(1) open the cockpit canopy

NOTE: The canopy opening should be No.1 action in any accidental situation (except fire in flight)

(2) increase flight altitude and decrease speed (if possible)
(3) if possible, disconnect the headset from the aircraft socket
(4) pull legs towards the seat
(5) open the harness lock
(6) put hands on the canopy parts
(7) lift and pull the parachute out of the seat (in bent position)
(8) put the feet into the seat
(9) turn the body to the side of the aircraft
(10) put your knee onto the canopy rail (left when leaving to the left)
(11) push yourself out and leave the aircraft with the head down

NOTE:  Time permitting, close the fuel valve, switch off magneto, master switch, generator, ignition circuit breakers before leaving the aircraft.

Leaving the aircraft in inverted flight:

(1) open the cockpit canopy
(2) increase flight altitude and decrease speed (if possible)
(3) pull legs towards the seat
(4) group the body
(5) open the harness lock and push the stick forward immediately

After leaving the aircraft open the parachute.

NOTE:  The front cockpit should be left first.  If the aircraft is on fire, it is best to delay parachute opening by 3-5 seconds.

According to the Yak-52 Flight Manual and S-4U Parachute Technical Data, minimum safe heights for leaving the aircraft with Russian parachute S-4U from straight-and-level flight are:
· 120 meters when parachute opens automatically (2 seconds delay)
· 70 meters when airspeed is 120 km/hr and pilot deploys parachute immediately
· 60 meters when airspeed is 220 km/hr and pilot deploys parachute immediately