B737 Flap Lever and Position Indicator

B737 Control Stand

Flap Lever

FLAP Lever

Location: Control Stand

  • Selects position of flap control valve, directing hydraulic pressure for flap drive unit.
  • Position of the LE devices is determined by selecting TE flap position.
  • Flap lever positions 10, 15, 25, 30, and 40 arms the flap load relief system.

Flap Gates

  • Prevents inadvertent flap lever movement beyond:
    • Position 1: To check flap position for one engine inoperative go-around.
    • Position 15: To check flap position for normal go-around.

Flap Position Indicator

Shows on the engine display.

  • Indicates position of left and right TE flaps.
  • Provides TE flaps asymmetry and skew indication.

FLAPS LIMIT Placard

  • Indicates maximum speed for each flap setting.
  • Location: MAIN PANEL – CENTER

FLAP LOAD RELIEF Light

Shows on the engine display.

  • Illuminated (amber):
    • If flaps are set at 40: Flaps retract to 30 due to excess airspeed.
    • If flaps are set at 30: Flaps retract to 25 due to excess airspeed.
    • If flaps are set at 25: Flaps retract to 15 due to excess airspeed.
    • If flaps are set at 15: Flaps retract to 10 due to excess airspeed.
    • If flaps are set at 10: Flaps retract to 5 due to excess airspeed.