Introduction - Pipistrel

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Limitations
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Introduction
This chapter provides information about operational restrictions, instrument markings and basic
knowledge on safe operation of aircraft, engine and on-board appliances.
Operational velocities
Speed limits
VNE
IAS up to
4000 m/13100 ft,
TAS above
VRA
Velocity
IAS
[km/h (kts)]
Velocity never to be
exceeded 302 (163)
Remarks
Never exceed this speed. Should the VNE be
exceeded, land as soon as possible and have the
aircraft verified for airworthiness by authorised
service personnel.
Maximum safe velocity
in rough air 250 (135) Maximum speed in turbulent air.
VA Manoeuvering velocity 174 (94)
VFE
VAE
Max. velocity flaps
extended 130 (70)
Max. velocity of airbrake
extention 205 (110)
Airspeed indicator markings
Do not use rough or full stick and
rudder deflecions above this speed.
Do not exceed this speed with flaps
extended (+5, 19 degrees).
Do not extend spoilers above this
speed.
MARKING IAS [km/h (kts)] Definition
white arc
70 -130
(38 - 70)
green arc
86 -250
(46 - 135)
yellow arc
250 - 302
(130-163)
red line
302
(163)
Speed range where flaps may be extended. Lower end is defined
as 110% of VS0 (stall speed in landing configuration at MTOM - 64
km/h), upper end of speed range is limited by VFE (see above).
Speed range of normal operation. Lower end is 110% of VS1 (stall
speed at MTOM with flaps in neutral position - 79 km/h), upper
end is limited by VRA (see above).
Manouvre the aircraft with great caution in calm air only.
Maximum speed allowed.
blue line 140 (76) Best climb rate speed (V Y
)
Indicated airspeed (IAS) to true airspeed (TAS) relation
Airspeed indicator measures the difference between total and static pressure (also called dynamic pressure),
which does not only change as speed increases, but is also linked with altitude. Flying at high altitudes, where
the air is getting thinner, results in misinterpreting airspeed which is being indicated. The indicated airspeed
value is actually lower than the true airspeed to which the aircraft is exposed. The higher you fly, the bigger the
difference between IAS and TAS. Be aware of this effect especially when flying at high altitude at high speeds,
not to exceed VNE unawarely. Bear in mind this can happen even with the indicator still pointing within the yellow
arc! However, for flight planning purposes TAS is the most accurate speed, which then can be corrected by
eventual tail/head wind component to obtain the aircraft’s ground speed (GS).