The landing gear - ATA 32 Part 4

Let's continue the observation of our main gears.

Now we will continue through the hatches which will allow after the retraction of the landing gear to restore smooth continuity to the fuselage and ensure the perfect aerodynamics of the aircraft.

Each main gear is fitted with two doors.

Main Door

A main door only opens during gear operating phases and which is actuated by a hydraulic jack.

The door is pivoted on the fuselage by three hinges. The door is operated electro-hydraulically.

It is only open in flight for retraction or lowering of the landing gear andon the ground during inspections and maintenance.

The door is articulated on the fuselage by three hinges. The door is electro-hydraulically operated. It is only open for retraction or lowering of the landing gear.

Here on the SA the two main hatches are in the closed position.

So as not to affect the integrity of the plane, you can see the passage outside of this electric cable which supplies the night lighting of the plane, the cable passes through the two openings arranged in the central part of the hinged hatch.

Secondary Door

The secondary door is mounted on the landing gear leg and operates with it. It is attached at its upper end by two fittings ensuring longitudinal articulation.

Along the leg we see this large plate attached to the upper part and in the middle of the leg, its role will be once the train is reassembled to ensure the continuity of the hull to ensure the aerodynamics of the fuselage.

A secondary door is mechanically linked to gear operation.

In the undercarriage retracted position, the doors are locked, thus restoring the aerodynamic fuselage-wing contour.

Landing Gear Controls

The normal control is operated from a three position selector in the cockpit.

What surprises at first glance compared to other aircraft is its small size; it is positioned on the front central panel right next to the gear position light indicator

In this photo the selector is in the low position (undercarriage extended) you can see the protection that needs to be rotated to the left to go from the neutral position to the undercarriage extended position.

The following photos show the three positions: extended - DPWN, neutral - NEUTRAL and retracted - UP.

A small reminder at the end of each UP or DOWN manoeuvre the lever is returned to the neutral position.

Neutral position - NEUTRAL

Gear down position - DOWN

Gear up position – UP

While waiting for the coming content, here below the L/G warning light panel, is right next to the control of L/G, which we will talk about later.

This diagram shows the operation and locking of the L/G and which will be visible on the indicator above.

The gear up lock is ensured by a roller mounted on the landing gear leg which automatically engages in the hook of an up lock box attached to the landing gear well in the wing.

A mechanically locking telescopic strut braces the landing gear in the down position.