AIRCRAFT FLIGHT
MANUAL
BRISTELL B23
Document No.: ADXC-73-001-AFM
Non-approved page
Revision: A2
7-19
Date of Issue: 15.04.2021
The propeller is driven through a gearbox which has a gearing ratio of
2.43. The propeller speed is 2386 prop RPM at an engine speed of 5800
engine RPM.
The fuel consumption of the Rotax engine, dependent on throttle setting,
rpm and altitude is up to a maximum of 30liter/hour. Indicated momentary
fuel flow can differ significantly especially during transient conditions.
Switching the auxiliary fuel pump un will cause the indicated fuel flow to
momentary read too high values due to the volumetric change
associated with the pressure change. Measured fuel flow is calculated by
subtracting the fuel flow in the return line from the fuel flow to the engine.
The accumulated tolerances of the sensing as well as the transient
conditions make fuel flow indication no trustworthy source for fuel
consumption.
The engine installation is equipped with a carburettor pre-heat system
drawing hot air from the exhaust heat shield. When selecting Carburettor
heat on ground with engine power set to 4000 RPM the drop in RPM due
to the pre heat is about 200 in ISA conditions and 150 in ISA+20
condition.
In case of performance doubt or marginal weather condition at run up:
important is not the RPM drop alone, but the regain of RPM only after
carburettor heat is switched off. A regain during carburettor heat on
indicates that actual carburettor icing already has happened.