Rotax 914 F User Manual

Reference
Modification no.
- 0 -
Page
56
Date
1997 02 01
Main
914 F
01476
9.5.3) Reduction of the target pressure
Provision for target pressure reduction depending on various effects as
protective measure against overstressing the engine.
9.5.3.1) Target pressure reduction at overspeeding
See Pic. 30.
The pilot is responsible to prevent engine speed in excess of 5800 rpm and
has to reduce early enough engine performance at fast flight and descent
when using a fix pitch propeller.
Only in case of omission by the pilot, the TCU will lower the desired pressure
when engine speed exceeds 5900 rpm by opening the waste gate and thus
reducing boost pressure. See relevant diagram.
■ ATTENTION:The automatic opening of the waste gate by the TCU is an
emergency measure only in the event of a pilot error but is
not releasing the pilot to reduce the engine performance.
e.g. at take-off performance (throttle position 115 %)
➪ target pressure 1350 hPa (without limitation)
➪ at engine speed of 6100 rpm ➍ lowering of the target pressure approx.
by 265 hPa (according to diagram).
➪ actual boost pressure now 1085 hPa ➍ corresponds to a performance of
70 kW instead of 84,5 kW.
Pic. 30
00177
-100
0
100
200
300
400
500
600
700
800
900
5000 5900 6000 6100 6200 6300 6400 6500
M
otordrehzahl [1/mi
n]
(
engine speed)
Druckreduktion [hP
a]
(pressure reduction
)

Rotax 914 F Specifications

General

Brand	Rotax
Model	914 F
Category	Engine
Language	English