1. Table 1: FMEA Summary of Redesigned TLS System
Ident. No. Item/Functional
Identification
Failure Mode Failure Cause Failure Event Target Action Required
A.1.2 Wingtip
protection
Delamination High peel stress Wingtip damage D Frequent inspection
A.2.1.1 Retracts and
deploys wheel
Stripped gear Excessive torque Landing gear does not
deploy
A Inspection on ground before take-
off or back-up actuator
A.2.2.1 Attach gear
frame to fuselage
Loose bolt Vibration from cyclic
loading
Frame detachment from
aircraft
A Implement lock wire for bolts
A.2.2.2 Landing load
distribution and
landing gear
placement
module
Column
buckling
Compressive stress
from landing impact
Fracture of gear frame
structure
A Increase frame structure thickness
or use of stronger material
A.2.2.3 Mount servo
motor to gear
frame
Loose bolt Vibration from
repeated landing
impact
Landing gear does not
deploy
A Implement lock wire for bolts
A.2.3.1 Secures landing
gear position
during
deployment
Shear failure Shear stress due to
landing impact
Landing gear collapse
upon touchdown
A Increase margin of safety or
thickness of pin
A.2.3.2 Attachment of
wheel to gear
frame
Buckling Compressive stress
from landing load
Sudden collapse of wheel
strut upon touchdown
A Increase strut thickness
A.2.3.2 Absorb landing
impact
Tire puncture Presence of foreign
object debris (FOD) on
landing runway
Loss of control during
ground roll
D Selection of tire with increased
thickness and inspection for FOD
on landing area.
A.3.1 Folds propeller
upon landing
Propeller does
not fold
Increased hinge joint
friction due to
corrosion
Propeller strike during
landing
D Frequent lubrication
B.1.1.2 keeps roof rack
attached to car
Shear failure Shear stress from
inertial and drag forces
of roof rack and
aircraft
Roof rack gets detached
from car
A, D,
P
Increase margin of safety for bolts
For the take-off subsystem, only B.1.1.2 was considered as the failure of all the other parts simply results in aborted take-off (stopping of the vehicle)
and no further damage on the aircraft or the operator,
Legend: A - Aircraft D - Downtime P - Personnel