Max TOW - 600kg
BEW - 383.9kg
MAX LOAD FACTOR - up to VA / VNE +4g / -2g
Vne (Never exceed speed) 135kts IAS (Red line on ASI)
Vno (Max cruise speed) 110kts (Never exceed unless in smooth air)
Va ( Manoeuvring speed) 91kts IAS (No full or abrupt control inputs above this speed)
Vfe (Max flap extension speed) 85kts IAS (White arc on ASI)
Vs (Stalling speed flaps up at MAUW) 45kts IAS. [30*bank, Vs=50kts, 45* bank, Vs= 55kts]
Vso (Stalling speed full flap extended) 40kts IAS [30* bank, Vs= 46kts, 45* bank, Vs= 50 Demonstrated x-wind limitation 15kts
POWER PLANT LIMITATIONS
Max take off power 5800 RPM (100HP). Max 5 min
Max continuous power 5500 RPM ( 95HP)
Fuel tank capacity - 150L (75L each tank). Usable Fuel - 146L (73L each tank). Fuel burn - approximately 18LPH@5000RPM power setting.
Takeoff - F1, retract at 300’, Climb out 75 - 90kts
Vx (Best angle of climb speed) 65kts
Vy (Best rate of climb speed) 72kts
Cruise climb 80 - 90kts
Usual approach speeds for landing - 70kts base leg, two stages of flap, 65kts early final leg, 60kts short finals using full flap.
Can come back to 55kts over threshold if comfortable.
Approach speed in gusty crosswinds - 70kts with F2, F1 or nil flaps depending on severity of wind and turbulence.
BEST GLIDE SPEED
SHORT FIELD TAKEOFF
According to the POH, short field take offs can follow normal take off procedures.
However in practice, conventional short field take off procedures can be implemented.
Line up at the absolute end of the runway. Select first stage of flap. Release the hand brake lock but continue to hold the brake on firmly. Ease the throttle forward while still holding the brake. As the tachometer goes through 4000rpm release the brake. Apply gentle back pressure on the column to take the weight off the nose wheel. As the aircraft reaches flying speed, raise the nose to a higher climbing attitude than normal to gain the VX of 65kts. Maintain this attitude and airspeed until you have climbed above the obstacle and then resume normal climb out procedures.
SHORT FIELD LANDING
Final approach at 60kts and full flaps. Shallow approach (long and lower), short finals bring speed back to 55kts (+5kts or more with turbulence / crosswinds), mains touch down very early on RWY, column hard back, brake.
CIRCUIT / POWER SETTINGS / PROCEDURES
Pre Takeoff: (last check as you enter runway) FFISTT:
Flaps1, Fuel - Fullest tank, Pump ON, Instruments (all green), Strobes, Transponder, Trim.
Takeoff: Full power, (max 5 mins on full power), get the weight of the nose wheel as quickly as possible with back pressure. Airborne, maintain a straight flight path, climbing attitude (nose clipping through the horizon) speed 75-80kts. At 300’, check T’s and P’s in green, flaps up.
Cross Wind: At 700’, turn crosswind on to a selected reference point, check you are at right angles to strip. Continue climbing to circuit height. (ASPT) Power now 4500 RPM. Level out. Fuel pump off, check fuel pressure, be ready to turn fuel pump back on if engine falters. Radio call, prepare to turn downwind.
Downwind: Check for exact height. BUMPFISH checks (fuel pump turned on here), radio call for base, power 4800rpm, turn base.
Base: (PAST) Power 3000rpm, (<85kts) Flaps 2 stages, maintain 70kts, judging your descent rate to start final turn at 700’. (PWR controls ROD, elevator controls speed).
Finals: Check windsock, runway clear, Flaps 3 stages, maintain 65 kts. On Short Finals, speed can come back to 60kts depending on prevailing crosswinds and turbulence.
Brakes on, Flaps Down, ALL Switches Down (across bottom of panel), Master Off (key).
Pilot and Passenger Weight vs Full Load:
Assuming 18 LPH FUEL BURN & 45 Minutes Reserve. Setting 5000RPM -102Kts, 600Kg MAUW
Each wing has a 75 litre tank of which 73 litres is useable. (Total 146 litres useable).
With two persons on board weighing 75kg each, approximately 90 litres of fuel will bring the Sling up to the take-off weight of 600kgs. If fuel is just covering the bottom of the tank, that tank has 30 litres of fuel in it.
HDFC aircraft uses Mogas 95 fuel for all operations. Pilots must be briefed on the correct use of the refuelling cart before any attempt is made at refuelling an aircraft. Contact Doug or a flying instructor for briefing.