730 

14 CFR Ch. I (1–1–19 Edition) 

§ 33.87 

false engine starts, pausing for the ap-
plicant’s specified minimum fuel drain-
age time, before attempting a normal 
start. There must be at least 10 normal 
restarts with not longer than 15 min-
utes since engine shutdown. The re-
maining starts may be made after com-
pleting the 150 hours of endurance test-
ing. 

(c) 

Rotorcraft engines for which a 30- 

minute OEI power rating is desired. 

For 

each rotorcraft engine for which a 30- 
minute OEI power rating is desired, the 
applicant must conduct the following 
series of tests: 

(1) 

Takeoff and idling. 

One hour of al-

ternate 5-minute periods at rated take-
off power and at idling power. The de-
veloped powers at takeoff and idling 
conditions and their corresponding 
rotor speed and gas temperature condi-
tions must be as established by the 
power control in accordance with the 
schedule established by the applicant. 
During any one period, the rotor speed 
and power may be controlled manually 
while taking data to check perform-
ance. For engines with augmented 
takeoff power ratings that involve in-
creases in turbine inlet temperature, 
rotor speed, or shaft power, this period 
of running at rated takeoff power must 
be at the augmented power rating. In 
changing the power setting after each 
period, the power control lever must be 
moved in the manner prescribed in 
paragraph (c)(6) of this section. 

(2) 

Rated maximum continuous and 

takeoff power. 

Thirty minutes at— 

(i) Rated maximum continuous power 

during fifteen of the twenty-five 6-hour 
endurance test cycles; and 

(ii) Rated takeoff power during ten of 

the twenty-five 6-hour endurance test 
cycles. 

(3) 

Rated maximum continuous power. 

One hour at rated maximum contin-
uous power. 

(4) 

Rated 30-minute OEI power. 

Thirty 

minutes at rated 30-minute OEI power. 

(5) 

Incremental cruise power. 

Two 

hours and 30 minutes at the successive 
power lever positions corresponding 
with not less than 15 approximately 
equal speed and time increments be-
tween maximum continuous engine ro-
tational speed and ground or minimum 
idle rotational speed. For engines oper-
ating at constant speed, power may be 

varied in place of speed. If there are 
significant peak vibrations anywhere 
between ground idle and maximum 
continuous conditions, the number of 
increments chosen must be changed to 
increase the amount of running con-
ducted while subject to peak vibrations 
up to not more than 50 percent of the 
total time spent in incremental run-
ning. 

(6) 

Acceleration and deceleration runs. 

Thirty minutes of accelerations and de-
celerations, consisting of six cycles 
from idling power to rated takeoff 
power and maintained at the takeoff 
power lever position for 30 seconds and 
at the idling power lever position for 
approximately 4

1

⁄

2

minutes. In com-

plying with this paragraph, the power 
control lever must be moved from one 
extreme position to the other in not 
more than one second. If, however, dif-
ferent regimes of control operations 
are incorporated that necessitate 
scheduling of the power control lever 
motion from one extreme position to 
the other, then a longer period of time 
is acceptable, but not more than two 
seconds. 

(7) 

Starts. 

One hundred starts, of 

which 25 starts must be preceded by at 
least a two-hour engine shutdown. 
There must be at least 10 false engine 
starts, pausing for the applicant’s spec-
ified minimum fuel drainage time, be-
fore attempting a normal start. There 
must be at least 10 normal restarts not 
more than 15 minutes after engine 
shutdown. The remaining starts may 
be made after completing the 150 hours 
of endurance testing. 

(d) 

Rotorcraft engines for which a con-

tinuous OEI rating is desired. 

For each 

rotorcraft engine for which a contin-
uous OEI power rating is desired, the 
applicant must conduct the following 
series of tests: 

(1) 

Takeoff and idling. 

One hour of al-

ternate 5-minute periods at rated take-
off power and at idling power. The de-
veloped powers at takeoff and idling 
conditions and their corresponding 
rotor speed and gas temperature condi-
tions must be as established by the 
power control in accordance with the 
schedule established by the applicant. 
During any one period the rotor speed 
and power may be controlled manually 

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