Abnormal Events And Components Flashcards
What ATA chapter dictates the checks and inspections for abnormal events?
5
What are stages 1 and 2 inspections for abnormal events?
Stage 1- general visual for any signs of damage
Stage 2- more in-depth, dictated by the relevant maintenance manual
What abnormal events could be caused on take off or landing?
Blown tyre Over speed Brake drag/seizure Hard landing High energy stop
What types of abnormal events could occur during flight?
Bird strike Tail strike Lightning Volcanic ash condition High intensity radiated fields (HIRF) Severe turbulence
What is the general altitude range when lightning strikes are more likely to occur and what phases of slight are most affected?
5,000-15,000
Climb and descend phases
What sort of areas would the initial entry point be found?
Radome Fwd fuselage Empanage Nacelle Wing tips
What causes the glow in the initial stages of a lightening strike?
Ionisation of the air around those areas due to an increased electromagnetic field from those areas
How does lightning exit the aircraft?
By travelling through the conductive outer skin to extremities such as the tail
What actions must be done when a lightning strike occurs?
General visual inspection for damage (phase 1)
Detailed inspection upon discovery of damage (phase 2)
What are the two types of lightning damage?
Direct (burn marks, etc.)
Indirect (electrical system damage)
What must be done if a lightning strike causes a system malfunction?
Full inspection of defective system
What are the hole size left by a typical and high intensity lightning strike?
Typical 1/8
High intensity 1/4
Can a lightning strike hole be confined to one area?
No, it can be randomly placed over a large area
What areas does a lightning strike inspection cover?
External areas Static dischargers Fuel system valves IDG and related wires Hydraulic fittings in tail section Radio and nav systems Bonding jumpers
Which external components are most likely to experience lightning strikes?
Nose radome Nacelles Wing tips Horizontal stab tips Elevators Ends of leading edge flap tracks Trailing edge track fairings Landing gear Water waste masts Pitot probes External lights
What could happen if a heavy electrical current was sent through an aircrafts metal airframe?
It would create a magnetic field that magnetises components
What internal areas could be affected by high intensity lightening strikes?
Fuel valves
Generators
Power feeders
Electrical distribution systems
Since when have aircraft had to comply with HIRF standards?
1992
What are the main reasons for HIRF protection on aircraft?
Increasing dependence on electrical systems on modern aircraft
Increased use of non metals such as composites which reduces shielding capabilities
More numerous and powerful emitters
Do mods need checking for HIRF exposure effects?
Always
What factors are affecting the basic philosophy of aircraft maintenance?
Economic state of industry
Progress in technology
Changes in design philosophy
What is hard time?
Hard time is when a component has a set period it can be used up to before it must be replaced and sent for further actions such as overhaul or repair.
Part can be removed earlier if other conditions such as wear or damage
What is on-condition monitoring?
The part is tested regularly to prevent failure during operation
What is condition monitoring?
The component is allowed to fail, however this is done on components that don’t have a direct effect on the operation of the aircraft
This is used as a means of implementing corrective procedures
