19
FLYING SAFELY
In the previous pages of this manual there seem to have been many “dire warnings” but in the
interests of your safety and because we really want to encourage fun safe flying we are
including a few more tips on how to keep flying for a long, long time.
In particular we would like to highlight what has proven to be one of the most dangerous
acrobatic manoeuvres:~
The Whipstall
is defined as a stall break induced from an angle above 30 degrees. At the stall
break the wing will pitch down sharply and accelerate rapidly. The steeper the entry into this
break, the steeper the subsequent dive. A high whipstall where airspeed decays significantly
can lead to an irrecoverable situation. If the wing loses all airspeed at a high angle of attack, the
nose drops sharply and it accelerates forward. It can easily fly
around
the mass of the Trike unit
and occupants
completely inverting
the aircraft. If a whipstall is entered into by accident or
careless piloting,
under no circumstances
must the control bar be pulled back at the break or
immediately after the nose pitch – down recovery has begun.
Action of this kind may turn a
survivable whipstall into a non survivable one
. The correct approach is to hold the bar out past
the neutral position until the airspeed has built up, holding off the back pressure caused by the
nose rotating downward. Be ready for a very high forward pressure as the airspeed goes up
and the wing starts to recover. There is a chance of a second and steeper whipstall being
entered at the recovery of the first.
One way to prevent a second whipstall is to bank the aircraft as the speed starts to rapidly
decay after initial recovery. This will put you into a high-speed turn from which you should be
able to recover normal flight.
Operating aircraft at or beyond the limits of the flight envelope has severe limitations. It can
lead to loss of pilot control due to control error. (Trike inertia forces beyond the ability of the
pilot to counteract) or a host of other unknowns. As the design speeds of microlights increase,
so it is easier to fly outside the limits of the microlight. There is no reason why they should ever
be reached in safe and normal flight. To sum up: Unacceptable steep angles of attack after
shoot-ups or similar flight manoeuvres result in whipstalls and subsequent inversion of the
aircraft with resultant loss of flight control and possible structural failure.