Takeoff Horizontal Stabilizer Trim Setting l A horizontal

Takeoff Horizontal Stabilizer Trim Setting l. A horizontal stabilizer trim setting is used during all takeoffs. These settings are designed to produce: - The proper all-engines operating climb-out attitude at V 2 + 15 to 25 kts - The proper one-engine inoperative climb-out attitude at V 2 - Reasonable column forces for the pilots l Trim setting is provided as a function of the airplane weight, C. G. , flap setting, and engine thrust level. E-2

Takeoff Horizontal Stabilizer Trim Setting Lift Thrust Lift (downward) Weight Downward force from the horizontal tail is used to rotate the airplane about the main gear for takeoff rotation, and to hold the airplane in the correct pitch attitude for the climb-out from the E-3 after liftoff. airport (Drag contribution to moment about CG is negligible)

Horizontal Stabilizer Movement E-4

Horizontal Stabilizer Jackscrew E-5

Trim Setting on Flight Deck 767 -300 Example E-6

Takeoff Horizontal Stabilizer Trim Setting Increasing downward tail force Decreasing downward tail force 777 -200 ER Example E-7 AND = Airplane Nose Down ANU = Airplane Nose Up

Takeoff Horizontal Stabilizer Trim Setting 777 -200 ER With High Thrust Engines (>90 K) E-8

Determining the Stabilizer Trim Setting Takeoff weight = 220, 000 kg Center of gravity = 39%MAC Stab Trim Units = 3. 0 E-9 777 -200 ER Example

E-10 AIRPLANE GROSS WEIGHT - KILOGRAMS Determining the Stabilizer Trim Setting 777 -200 ER Example 250000 39 %MAC 18 20 22 24 26 28 30 32 34 36 38 40 42 44 240000 230000 220000 kg 210000 200000 190000 9 180000 170000 160000 150000 140000 130000 120000 110000 8 7 6 5 4 3 Stabilizer Trim Units Flaps 15 & 20 Full Thrust to 15% Derate

力矩 Q The influence of an item depends on 2 factors : 4 力 Weight 4 力臂 Harm（ARM） : item CG position 力矩Moment = Weight Harm 11

The Mean Aerodynamic Chord and the CG index Airplane c. g. is often expressed in terms of %m. a. c. Datum for B. A. BA of airplane c. g. lemac Where: BA is the balance arm of the airplane’s c. g. is in terms of %m. a. c. A-12

Definition of the Reference Chord Z 18. 850 m 17. 8015 m 25%RC 4. 1935 m H-arm 0 2. 540 m 0 X 14

Definition of the Reference Chord 25%RC Z MAC H-arm 0 LEMAC 0 X 15

4. 32 水平安定面 问题(P 170)： 737 -300, P 141, R-1条件, 重量=90, 000 KG, CG=635. 7 INCH, LEMAC=625, MAC=134 解: CG - LEMAC = 635. 7 – 625 = 10. 7 %MAC=10. 7 / 134 =8. 0 % (P 138) 查表=7 ¾ ANU 16

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Data in the （M）CDU 1 2 0 5 7 3 2 8 5 3 6 3 43, 500 + 250 43, 750 + 3, 700 + 10, 080 57, 530 + 14000 71, 530 19

MANIFEST 1 -成图 20

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