CSP
−
E
−
1
Performance Data
ROTORCRAFT FLIGHT MANUAL
MD 500E
(Model 369E)
Revision 14
5
−
23
FAA Approved
5
−
7. POWER CHECK
−
ROLLS ROYCE 250
−
C20B ENGINE
Description:
The Power Check Chart shows the relationship of engine torque, turbine
outlet temperature, and horsepower at various conditions of pressure alti-
tude and OAT for an Rolls Royce 250−C20B engine producing specification
power as installed in the MD 500E helicopter. The primary purpose of this
chart is its use as an engine performance trending tool to aid in determin-
ing whether the engine is producing specification power, or if engine power
deterioration has occurred.
NOTE
:
Power check data taken at regular intervals should be plotted to monitor trends
in engine condition. See Rolls Royce 250
−
C20 Series operational and
Maintenance Manual for additional information on trend analysis.
The power check chart is based on the following conditions:
103 percent N
2
.
Cabin heat and engine anti−ice OFF.
Particle separator SCAV AIR OFF.
10 amperes electrical load.
Engine bleed valve closed.
Use Of Chart:
The primary use of the chart is illustrated by the example below and by
the sample arrows shown on the chart. To determine power check values, it
is necessary to read and record engine TORQUE PRESSURE, TURBINE
OUTLET TEMPERATURE, PRESSURE ALTITUDE, and OAT while the he-
licopter is flown in level flight at 103 percent N
2
.
Do not exceed engine/aircraft limits.
Accessories required for safe flight should be operated during each
check.
Maintain separation from objects in air or on the ground.
Reset altimeter if required after obtaining pressure altitude.
NOTE
:
Best power check data is obtained at 87.2 psi torque or 810
°
C TOT, this will
ensure engine operation with bleed valve closed. Allow engine to stabilize at
least one minute at the test power setting before recording data.
WARNING
WARNING
