4-15. PILOT’S CHECK OF IDLE MIXTURE, IDLE SPEED, AND
FUEL BOOST PUMP (cont)
NOTE: En gine speed will im me di ately de crease to idle
level. Ro tor speed, how ever, will de cline grad u ally.
The next step must be per formed be fore ro tor ta chom e -
ter nee dle su per im poses with en gine ta chom e ter nee -
dle.
Ob serve en gine ta chom e ter nee dle and smoothly move mix ture con -
trol to ward IDLE CUT OFF po si tion.
Re turn mix ture con trol to FULL RICH be fore the rpm de creases to a
point where the en gine will stop.
NOTE: En gine rpm rise is re quired to be be tween 25
and 100 rpm for this check.
If rpm rise is not within the re quired lim its, no tify the ap pro pri ate
main te nance per son nel to per form proper idle speed and mix ture ad -
just ments.
Accomplish an idle speed check as follows:
Op er ate he li cop ter at op er a tional rpm with ro tor sys tem en gaged,
fric tion on the col lec tive and cy clic con trols.
CAU TION
AIR CRAFT MAY RO TATE IF LANDING GEAR
IS SET ON A SMOOTH, HARD SUR FACE AND
OP ER A TOR DOES NOT COR RECT FOR LOSS
OF TORQUE WITH PEDALS.
Rapidly ro tate throt tle closed and into full over ride po si tion.
Read and re cord en gine idle rpm prior to en gine and ro tor ta chom e -
ter nee dles su per im pos ing.
With en gine head tem per a ture near 300°F, but not above, re peat the
three pre ced ing steps, with out go ing into full over ride (set throt tle at
nor mal idle stop).
Normal Procedures
Pilot's Flight Manual
Reissued:
16 Jan 2019
4-23
This Document contains technical data subject to EAR. See WARNING and classifications on first page.
SCHWEIZER
Model 269C Helicopter
FAA Approved
CSP Book 1 CSP-C-1.indd 111
8/4/19 12:45 PM
