737 Flight Crew Operations Manual
Performance Inflight
Text
737-8/LEAP-1B27
FAA
CATB
PI.18.6
MN-FLT-OH-201
Tem
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R
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Assumed Temperature Reduced Thrust
Regulations permit the use of up to 25% takeoff thrust reduction for
operation with assumed temperature reduced thrust. Use of assumed
temperature reduced thrust is not allowed with anti-skid inoperative or on
runways contaminated with standing water, ice, slush, or snow. Use of
assumed temperature reduced thrust is not recommended if potential
windshear conditions exist.
To find the maximum allowable assumed temperature enter the Maximum
Assumed Temperature table with airport pressure altitude and OAT.
Compare this temperature to that at which the airplane is performance
limited as determined from available takeoff performance data. Next, enter
the Maximum Takeoff %N1 table with airport pressure altitude and the
lower of the two temperatures previously determined, to obtain a maximum
takeoff %N1. Do not use an assumed temperature less than the minimum
assumed temperature shown. Enter the %N1 Adjustment table with OAT
and the difference between the assumed and actual OAT to obtain a %N1
adjustment. Subtract the %N1 adjustment from the maximum takeoff %N1
found previously to determine the assumed temperature reduced thrust
%N1.
Apply %N1 adjustments as provided when applicable.
Max Climb %N1
This table shows Max Climb %N1 for a 280/.78 climb speed schedule.
Enter the table with airport pressure altitude and TAT and read %N1.
Apply %N1 adjustments as provided when applicable.
Go-Around %N1
To find Go-Around %N1, enter the Go-Around %N1 table with airport
pressure altitude and reported OAT or TAT and read %N1. Apply %N1
adjustments as provided when applicable.
Flight with Unreliable Airspeed/ Turbulent Air Penetration
Information is provided for use in all phases of flight in the event of
unreliable airspeed/Mach indications resulting from blocking or freezing
of the pitot system. Loss of radome or turbulent air may also cause
unreliable airspeed/Mach indications. The cruise table in this section may
also be used for turbulent air penetration. These speeds provide ample
protection from stall and high speed buffet, while also providing protection
from exceeding the structural limits. For climb, cruise, and descent these
tables are based on a speed schedule of 280 KIAS below crossover altitude
and .76 Mach above crossover altitude.
October 26, 2021
