AIRCRAFT GENERAL
KNOWLEDGE - Systems
Summary / Notes
, Table of contents
Section 1 – Airframe
System Design and maintenance .................................................2
Airframe ................................................................................... 3
Section 2 – Systems
Hydraulics .................................................................................. 3
Landing Gear .............................................................................. 7
Flight controls ............................................................................8
Pneumatics .............................................................................. 10
Anti-icing and De-icing ............................................................. 11
Fuel system .............................................................................. 11
Protection and Detection .......................................................... 13
Oxygen system ......................................................................... 14
Section 3 – Electrics
General ............................................................................................ 15
Batteries… .......................................................................................17
Generation ............................................................................... 18
Distribution .............................................................................. 19
Electrical motors ...................................................................... 20
1
, AGK - Airframe
Loads:
-Static loads: constant in time (everything balanced)
-Dynamic loads: Acceleration forces
-Cyclic loads: Repetitive -> fatigue -> failure
Design concepts
-Safe life structure = number of cycles it can make until failure
-Fail safe structure = Multiple load paths (1 fail -> other part will take over until inspection)
-Damage tolerant structure = Large single surface. (1 fail -> surrounding area takes load)
Metals:
-Steel = alloy iron + carbon (strong but heavy)
-Aluminium = mixed, to make stronger (Light, but bad compression and heat resistance)
-Magnesium = Very light, high stiffness. (corrosion sensitive)
-Titanium = perfect! But very expensive
Composites
-Glass = GFRP glass fibre reinforced plastic
-Carbon = CFRP carbon fibre reinforced plastic (sensitive to impact difficult to detect)
-Aramid = (Kevlar) ->laminate, honeycomb or sandwich. (high expansion, poor compression
strength)
Attachments:
-Permanent
1. Welding
2. Riveting (Head + flush)
3. Adhesive bonding (glue – high pressure and temperature)
-Non-Permanent
1. Latching (opened regularly)
2. Pinning (locker pin)
3. Bolting (bolt + nut + washer)
4. Screwing (head + flush)
Maintenance
-Line and hangar maintenance
-Hard time maintenance -> time between overhaul (Removal or replacement)
-On condition maintenance -> check the condition (when good enough it isn’t replaced)
-Condition monitoring -> trend following (upper/lower limit)
Construction:
-Monocoque = The skin takes all the loads. Semi-monocoque = reinforced with frames
-Cantilever = self-supporting wing. Non-cantilever = with struts/bracing
2
KNOWLEDGE - Systems
Summary / Notes
, Table of contents
Section 1 – Airframe
System Design and maintenance .................................................2
Airframe ................................................................................... 3
Section 2 – Systems
Hydraulics .................................................................................. 3
Landing Gear .............................................................................. 7
Flight controls ............................................................................8
Pneumatics .............................................................................. 10
Anti-icing and De-icing ............................................................. 11
Fuel system .............................................................................. 11
Protection and Detection .......................................................... 13
Oxygen system ......................................................................... 14
Section 3 – Electrics
General ............................................................................................ 15
Batteries… .......................................................................................17
Generation ............................................................................... 18
Distribution .............................................................................. 19
Electrical motors ...................................................................... 20
1
, AGK - Airframe
Loads:
-Static loads: constant in time (everything balanced)
-Dynamic loads: Acceleration forces
-Cyclic loads: Repetitive -> fatigue -> failure
Design concepts
-Safe life structure = number of cycles it can make until failure
-Fail safe structure = Multiple load paths (1 fail -> other part will take over until inspection)
-Damage tolerant structure = Large single surface. (1 fail -> surrounding area takes load)
Metals:
-Steel = alloy iron + carbon (strong but heavy)
-Aluminium = mixed, to make stronger (Light, but bad compression and heat resistance)
-Magnesium = Very light, high stiffness. (corrosion sensitive)
-Titanium = perfect! But very expensive
Composites
-Glass = GFRP glass fibre reinforced plastic
-Carbon = CFRP carbon fibre reinforced plastic (sensitive to impact difficult to detect)
-Aramid = (Kevlar) ->laminate, honeycomb or sandwich. (high expansion, poor compression
strength)
Attachments:
-Permanent
1. Welding
2. Riveting (Head + flush)
3. Adhesive bonding (glue – high pressure and temperature)
-Non-Permanent
1. Latching (opened regularly)
2. Pinning (locker pin)
3. Bolting (bolt + nut + washer)
4. Screwing (head + flush)
Maintenance
-Line and hangar maintenance
-Hard time maintenance -> time between overhaul (Removal or replacement)
-On condition maintenance -> check the condition (when good enough it isn’t replaced)
-Condition monitoring -> trend following (upper/lower limit)
Construction:
-Monocoque = The skin takes all the loads. Semi-monocoque = reinforced with frames
-Cantilever = self-supporting wing. Non-cantilever = with struts/bracing
2
