LANDING GEARS

OF AIRCRAFT

WHAT IS LANDING GEARS?

LANDING GEAR OF AN AIRCRAFT IS A ARRANGEMENT WHICH IS USE--TO SUPPORT THE WEIGHT OF THE AIRCRAFT WHILE ON THE GROUND.-ABSORB SHOCK

LOADS CAUSED BY TAKE-OFF,LANDING AND TAXIING.-ENABLE GROUND MANOEUVRES.

TYPES OF LANDING GEAR

1-TAIL DRAGGER 2-BICYCLE 3-TRICYCLE

WHAT IS TAIL DRAGGER LANDING GEAR?

The main gear are located forward of the center of gravity,

causing the tail to require support from a third wheel

assembly

WHAT IS BICYCLE LANDING GEAR?Sailplanes commonly use tandem gear.

this type of landing gear has the main gear

and tail gear aligned on the longitudinal axis of the aircraft

WHAT IS TRICYCLE LANDING GEAR?Provides better visibility from the flight deck,

especially during landing and ground maneuvering

Allows more forceful application of the brakes without

nosing over when braking, which enables higher

landing speeds

PARTS OF A LANDING GEAR

2-SHOCK ABSORBER3-EXTRACTION AND RETRACTION MECHANISM

5-WHEELS6-TYRES

1-STRUT

4-BRAKES

STRUT AND SHOCK ABSORBER

OLEO STRUT IS MAINLY USED IN MODERN AIRCRAFT. IT CUSHIONES THE IMPACT OF LANDING WHILE TAXIING. IF WE GOES THROUGH THE STRUCTURE OF OLEO STRUT A PISTON

AND CYLINDER IS USED WHICH ACT LIKE A DAMPER. NITROGEN IS FILLED IN CYLINDER WHICH ACT LIKE A SPRING

DURING LANDING AND TAKE OFF. NITROGEN IS USUALLY USE BECAUSE IT LES LIKELY CAUSES THE

CORROSION. IT WORKS AS A SHOCK ABSORBER IN AIRCRAFT.

EXTRACTION AND RETRACTION

A retractable landing gear is installed whenever a drag improvement is worthy

The landing gear is held in the up position by mechanical levers under spring tension, and in the down position by mechanical keys or over center braces

BREAK

Purpose is to convert kinetic energy to heat energy, via friction pads and dissipate the heat to atmosphere.

Brakes usually fitted just to the main wheels and may be torque limited.

For large transport aeroplanes the main power source for brakes in normal and alternate operations is hydraulic.

WHEELS AND TYRES

TUBELESS TYRES ARE USED IN AIRCRAFT HAVING FOLLOWING ADVANTAGE.

7½% weight saving. 10ºC cooler running. Less danger of deflation by puncture. Reduced permeability losses.

LANDING ON FAILURE OF LANDING GEARBELLY LANDING OR GEAR UP LANDING

A BELLY LANDING OR GEAR UP LANDING REFERS TO THE LANDING WHEN AN AIRCREFT LANDS WITHOUT ITS LANDING GEAR.

BELLY LANDING OR GEAR UP LANDING OCCURS WHEN A MECHANICAL MALFUNCTION PREVENTS THE PILOT FROM EXTANDING THE LANDING GEAR OR THE PILOT FORGET TO

EXTEND THE LANDING GEAR.

BELLY LANDING CARRY THE RISK THAT THE AIRCRAFT MAY FLIP OVER ORCATCH FIRE IF IT LANDS TOO FAST OR TOO HARD.

CRASHES IN LANDING GEAR

ON 21SEP 2005 AN AIRBUS A320-200 EXECUTED AN EMERGENCY LANDING AT LOS ANGELESINTERNATIONAL AIRPORT WHEN THE NOSE LANDING GEAR JAMMED IN AN ABNORMALPOSITION.

ON 11JULY 1991 NIGERIA FLIGHT 2120 CRASHED SHORTELY AFTER TAKE OFF KILLING ALL247 PASSENGERS AND 14 CREW MEMBERS.

IN SEP 2007 TWO SEPERATE INCIDENT ON SIMILAR LANDING GEAR OCCURRED WITHIN 4DAYS EACH ON BOMBER DASH8-Q400.

FUTURE OF LANDING GEAR SOME TYPE OF COMPOSITE MATERIAL OR ALLOY CAN BE USED TO REDUCE THE WEIGHT OF LANDING GEAR.

MOST IMPORTANT CONSIDERATION IS THAT MATERIAL SHOULD BE CORROSIVE RESISTIVE.

EHA TECHNOLOGY IS BEING USED IN THE LANDING GEAR FROM THE 90S.

NOW EMA TECHNOLOGY IS USED IN THE LANDING GEAR AS A BACK UP MODE.

FUTURE OF LANDING GEAR MAY BE BRIGHT AFTER MAKING THE LANDING GEAR ELECTRICAL AND AUTONOMOUS.

QUERY