AIRCRAFT OPERATING INSTRUCTIONS – VIRUS 912 S-LSA GLIDER
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destination. A comfortable rate of descent is 500 fpm (2.5 m/s). So it takes you some 2 minutes for a
1000 ft (300 m) drop. At 105 kts (200 km/h) this means 3.6 NM for each 1000 ft drop. Upon entering the
traffic pattern the aircraft should be slowing down. In order to do this, hold your altitude and reduce
throttle to idle. When going below 80 kts (150 km/h), set flaps to neutral position. Set proper engine
RPM to maintain speed of 70 kts (130 km/h). Trim the aircraft for comfortable stick forces. Before
turning to base-leg, reduce power to idle and set flaps to 1st stage at 60 kts (110 km/h). Once out of the
turn, reduce speed towards 55 kts (100 km/h). Power remains idle from the point of turning base all the
way to touch-down. If you plan your approach this way, you will always be on the safe side - even if your
engine fails, you will still be able to safely reach the runway! Turn to final at 55 kts (100 km/h). When in
runway heading, set flaps to 2nd stage. Operate the air-brakes to obtain the desired descent path.
How to determine how much airbrakes you need for a certain airspeed?
Open them half-way and observe the runway. If the runway threshold is moving up, you are dropping
too fast - retract the airbrakes a little. If the runway threshold is disappearing below your aircraft, you
are dropping too slowly - extend airbrakes further. When working on airbrakes, it is important to keep
the airspeed/pitch angle constant throughout final all the way to flare! The airbrakes will not impact your
speed, just rate (angle) of descent. For pilots who are not used to operating airbrakes but throttle
instead, keep in mind that airbrakes in Virus work just like throttle does: handle back equals less throttle,
handle forward equals more throttle.
CAUTION!
Never drop the airbrakes handle when using them, keep holding the handle even if you are
not moving it!
8.5 Landing.
Roundout and touchdown (flare) occurs at following airspeeds:
o
Calm Air at MTOW: 40 kts
o
Rough Air (including cross-winds: 42 kts
CAUTION!
Land the aircraft in such a manner that the two main wheels touch the ground first, allow the
nose-wheel touchdown only after speed has been reduced below 25 kts. When lowering the nose wheel
to the runway, rudder MUST NOT be deflected in any direction (rudder pedals centered).
When on ground, start braking action holding the control stick in full back position. Steer the aircraft
using brakes and rudder only. Provided the runway length is sufficient, come to a complete standstill
without engaging the brakes holding the control stick slightly backwards as you decelerate.
WARNING!
After touchdown, DO NOT retract airbrakes immediately, as this causes sudden lift increase
and the aircraft may rebound off the ground.
Should this occur, hold the elevator steady; under no circumstances attempt to follow aircraft’s
movement with elevator movements, for Virus 912 LSA tends to stabilize rebounding by itself. However,
it is important to maintain run-way heading using the rudder at all times. Retract air brakes only after the
aircraft has come to a complete standstill.
CAUTION!
Should you be performing the touch-and-go maneuver, retract air brakes care-fully before re-
applying full power.
Crosswind approach and roundout
