Yakovlev Yak 50 — yak50_fltrep50 NOT FOR FLIGHT — source fidelity: unreviewed | operational review: none | completeness: full Source: Yakovlev/Yak 50/yak50_fltrep50.txt Rights: licensed Checklist hash: 72724063fec855cdfc319465613054c67fdc12445136a42ad32760c202c98b88 Verify against the aircraft's own approved documentation before use. ======================================================================== AIRCRAFT DESCRIPTION -------------------- GENERAL ** NOTE: The Yak 50 is an all-metal tail dragger designed solely for advanced aerobatics training and competition. ** NOTE: The fuselage is semi monocoque, a combination of stressed skin and steel re-enforcement. ** NOTE: The strong but simple main gear is semi-retractable, the lockable tailwheel permanently extended. ** NOTE: The Yak 50 has no flaps. ** NOTE: Flying controls are conventional and operated by control cables for the elevator and rudder, push rods for the ailerons. ** NOTE: Only the elevator trim is adjustable in flight, the rudder and ailerons served by fixed tabs which are manipulated on the ground. ENGINE POWER ** NOTE: Powerplant: Ivchenko M14 radial, supercharged nine cylinder radial, 360hp at max rpm. ** NOTE: Propeller: variable pitched two-bladed paddle via a simple gearbox. ** NOTE: Fuel capacity on the basic aircraft is 11.4 imperial gallons contained in a single tank mounted aft of the firewall. ** NOTE: Maximum flight endurance is quoted as 50 minutes and this figure can be halved during advanced aerobatic flights. ** NOTE: A welcome mod fitted to the vast majority of Yak 50s is the installation of a cruise tank which more than doubles the fuel capacity, although the G limits are reduced when full fuel is carried. ** NOTE: The Yak 50 uses pneumatics for engine starting, gear and brake operation. ** NOTE: The aircraft's air bottle will give around 12 start attempts before a recharge is necessary and a reserve bottle is also installed for emergency gear extension. ** NOTE: The main bottle gets recharged automatically once the engine has started. COCKPIT ** NOTE: The undercarriage lever is positioned on the left of the main panel, two green lights confirming that the gear is down and locked when the aircraft is on the ground. ** NOTE: The throttle, rpm and lock lever form a meaty quadrant on the left shelf with another panel ahead comprising levers for the engine cooling gills and oil cooler flap. ** NOTE: For most of the year the cooling levers will reside in the fully forward (open) position. ** NOTE: The big red lever is the fuel shut off, replacing the emergency function of a mixture lever. Fuel mixture control is fully automatic. ** NOTE: The instrument panel uses metric units. Most owners replace the altimeter since it reads in meters. The airspeed indicator reads in km/h. ** NOTE: The engine has two main control indicators: an rpm gauge reading from 0 to 100%, and a manifold pressure gauge reading in mm of mercury. ** NOTE: The Yak 50's electrics are in the centre of the panel and the fuel primer is located to the top right. ** NOTE: The mag switch is mounted on the left of the panel next to the engine starter button. PREFLIGHT / BEFORE ENTERING COCKPIT ----------------------------------- ** NOTE: Climbing into the cockpit and strapping into the chunky five point harness, one is immediately aware of the ruggedness of the Yak 50. ** NOTE: Visibility from the cockpit is excellent in every direction except forwards. ENGINE START ------------ [ ] Battery master .................................................. OFF [ ] Ignition and mags ............................................... OFF [ ] Primer lever .............................................. TURN LEFT [ ] Primer pump ............................................ PUMP 5 TIMES [ ] Primer lever ............................................. TURN RIGHT [ ] Primer pump while helper turns prop ............. PUMP SIMULTANEOUSLY [ ] Prop blades past windscreen ................................ 9 BLADES [ ] Prop turner ................................................... CLEAR [ ] Battery, ignition and generator .................................. ON [ ] Throttle .............................................. OPEN 2 INCHES [ ] Starter switch .................................................. HIT [ ] As engine fires, mags .......................................... BOTH [ ] Keep engine going with primer pumps ................... LIBERAL PUMPS ** CAUTION: Don't bother pumping the throttle – no accelerator pump is fitted and this will have zero effect. ** CAUTION: After start, leave the primer centralised, not turned to the right. Result of leaving it right: rough running engine, excessive fuel burn and early engine overhaul. AFTER START / WARM UP --------------------- [ ] After a few seconds the engine settles down ................... CHECK [ ] Switches ........................................................ SET [ ] Radio ........................................................ ADJUST [ ] Straps .................................................... RETIGHTEN ** NOTE: A cold Ivchenko does not warm up to taxying temperature in less than five minutes, with ten minutes being more typical on a standard UK day. [ ] Oil temperature reaches 40 degree point ........................ WAIT [ ] Engine run ....................................................... DO TAXI ---- ** NOTE: Differential braking is applied by a stick-mounted hand lever and controlled by the amount of rudder applied away from its neutral position. ** NOTE: With the stick in the aft position, the Yak 50's tailwheel will lock straight. ** CAUTION: To turn, push the stick forward; taxying with the stick aft locks the tailwheel straight. BEFORE TAKEOFF -------------- [ ] Throttle and rpm levers ............................... FULLY FORWARD [ ] Left rudder (prop goes round the 'wrong' way) .................. PUSH [ ] Throttle ....................................... ADVANCE FULL FORWARD TAKEOFF ------- [ ] Once aircraft is underway, stick .............. FORWARD TO RAISE TAIL ** NOTE: Take-off roll is around 100 metres at MTOW. ** NOTE: Climbs at 3,000 feet per minute. AFTER TAKEOFF / CLIMB --------------------- [ ] Gear .......................................... RAISE BEFORE 200 KM/H [ ] Prop rpm .......................................... REDUCE TO MAX 82% ** NOTE: A more modest '70%, 70mm' setting conserves engine life. CRUISE ------ ** NOTE: In the cruise any 'square' setting will do, for example, for 70 on the manifold gauge set 70% rpm, for 60 manifold set 60%. [ ] Cruise speed ................................ UP TO 280 KM/H (151 KT) ** NOTE: Full throttle and 82% are the quoted maximum continuous power setting, giving max level speed of 300 km/h (162 Kt). ** NOTE: Major engine overhaul every 500 hours. DESCENT / CIRCUIT ----------------- ** NOTE: In the circuit the Yak is easy to operate. The sum total of good all-round visibility, draggy aeroplane and high power results in a slick approach every time. APPROACH -------- [ ] Undercarriage ............................. LOWER AT 200 KM/H OR LESS [ ] Approach speed ............................................. 150 KM/H [ ] Threshold speed ............................................ 100 KM/H ** NOTE: The speed reduction on finals requires the throttle to be closed early and the aircraft held off until the speed bleeds back. LANDING ------- ** CAUTION: The Yak's large wing and short undercarriage can cause an excessive float if the airspeed is too high on landing. ** NOTE: With repeated practise the Yak can be brought to a halt in 150 metres on a dry surface. CONTROL HARMONY AND AEROBATICS ------------------------------ ** NOTE: Control harmony is typically 3.2.3 for ailerons, elevator and rudder instead of the classical 1,2,3. ** NOTE: Spades are an option on the Yak 50, recommended for serious aerobatic pilots. ** NOTE: In pitch the Yak 50's stick force per G is very light; pulling up to the nine G maximum does not require excessive strength. ** NOTE: During advanced aerobatics many pilots release the throttle to fly with two hands on the stick. ** NOTE: With the aircraft wound up to its Vno of 400 km/h (226kt) the Yak 50 can perform huge lazy loops, barrel rolls and wing overs with low G forces. ** NOTE: Stalls and spins are surprisingly docile. Stall and spin recovery are predictable and standard. Some advanced aerobats have to be positively wrestled out of an established spin; the Yak 50 is one of the exceptions. FUEL AND RANGE -------------- ** NOTE: With a standard 55 litre fuel tank fitted, an airfield will be needed every 60nm when cruising at 162kt. ** NOTE: A more sedate 200 km/h (108kt) improves the range to 85nm. ** NOTE: With a cruise tank fitted the aircraft's best range jumps to 250nm at economy cruise. ** NOTE: Given such a short range, a GPS is a very desirable installation for a Yak 50. SPECIFICATIONS — YAK 50 ----------------------- EXTERNAL DIMENSIONS [ ] Span ..................................................... 31 FT 3 IN [ ] Length ................................................... 24 FT 5 IN [ ] Wing area ................................................. 161 SQ FT WEIGHTS AND LOADINGS [ ] Empty weight ............................................... 1,624 LB [ ] Useful load ........................................ 496 LB* / 377 LB [ ] Gross weight .................................... 2,120 LB / 2,001 LB [ ] Power loading ............................................. 5.9 LB/HP [ ] Wing loading .......................................... 13.1 LB/SQ FT [ ] Fuel capacity ...................................... 26.2 IMP GALLONS [ ] G limits ................................................ +9G / -6.6G [ ] Number of seats ................................................... 1 ** NOTE: (*denotes aerobatic figures) POWER [ ] Engine manufacturer/type .................. IVCHENKO (VEDENEYEV) M14P [ ] Max power ................................... 360 HP @ 2,900 PROP RPM [ ] Propeller type and diameter ...................... 2-BLADE VP 94.2 IN PERFORMANCE [ ] Vne .......................................................... 232 KT [ ] Maximum level speed .......................................... 162 KT [ ] Cruise speed @ 75% ........................................... 151 KT [ ] Stall speed, power off ........................................ 48 KT [ ] Stall speed, power on ......................................... 45 KT [ ] Rate of climb (sea level) .............................. 3,000 FT/MIN [ ] Ceiling (oxygen limited) .................................. 10,000 FT [ ] Take off run ................................................. 328 FT [ ] Landing run .................................................. 492 FT [ ] Range (cruise tank, 45 min reserve) .......................... 200 NM [ ] Endurance .................................................... 2.5 HR PRICE [ ] Price ............................................... £35,000-£45,000 [ ] UK suppliers ... MARK AND JOHN JEFFERIES AT YAK UK, LITTLE GRANSDEN AIRFIELD, BEDFORDSHIRE. TELEPHONE (01767) 651156