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GEAR DOWN & LOCKED

System study · Landing Gear

Nose, Main & the Free-Fall System

Three legs, two LGCIUs, and one clever fallback for when hydraulics won't cooperate: gravity extension. Click into the diagram to see how gear, doors, and steering are actually wired together, then quiz yourself below.

Gear layout click a component

Simplified side view — not for operational use. Click the nose gear, main gear, a computer, or the gravity extension handle.
NOSE GEAR MAIN GEAR (×2) DOORS GRAVITY EXTN LGCIU 1/2 GEAR LOGIC NOSE WHEEL STEERING ANTI-SKID / AUTOBRAKE
Click any component above to see what it does →

Gravity extension — the one-way fallback

FREE-FALL
NO RETRACT AFTER USE

If normal (Green hydraulic) gear extension fails, pulling the gravity extension handle mechanically releases the uplocks and vents pressure from the gear bay. The gear then free-falls under its own weight, helped by airflow, into the down-and-locked position — doors simply hang open rather than following the normal sequenced cycle. This is strictly one-way: once you've gravity-extended, the gear cannot be retracted again in flight.

Quick reference

NOSE GEAR

  • Single strut, twin wheels
  • Retracts forward into the nose bay
  • Carries nose wheel steering
  • Powered by Green hydraulics

MAIN GEAR

  • One leg per side, twin wheels each
  • Retracts inward into the wing/belly fairing
  • Carries the brakes (Normal on Green, Alternate on Yellow)
  • Oleo-pneumatic shock struts absorb landing loads

LGCIU 1 & 2

  • Landing Gear Control & Interface Units
  • Sequence gear/door extension & retraction
  • Feed ground/flight status to other systems (spoilers, autopilot logic, etc.)
  • One is active per gear cycle, the other stands by

Check yourself

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