EWIS Flashcards
Where should you never use electric tools delivering more than 0.02 millijoules of energy?
Fuel tanks or flammable areas.
Where are plastic ties not allowed?
Unpressurised areas.
How far must wire bundles run from lines carrying flammable liquids?
50mm
What distance can wire bundles be from lines not carrying flammable liquids?
15mm
What is the minimum bend radius for single wires or cables?
3x outside diameter
Preferred is 10x
What is the minimum bend radius for wire bundles?
6x outside diameter
Preferred 10x
What is the minimum bend radius for single coax cables?
10x outside diameter.
How often must wire bundles be clamped in a fuselage?
Every frame.
When a wire bundle is dressed downward to a connector, what must be installed?
A drip loop to prevent fluid contamination.
Can wires be tied together in a conduit or insulating sleeve?
No.
A bundle with an over braid shield must have what identification.
A W number (within 18 inches)
What are AP wires?
Aromatic Polyimide.
What essential wire systems must be separated?
Stab Trim, auto flight, essential power.
What is EMI
Electromagnetic interference
What is the minimum distance between secondary routes?
25mm (unless physical barrier installed eg. Conduit.)
What are the 6 wire categories?
G- generation P- power distribution M- miscellaneous S- sensitive cables R- audio T/U/V- coaxial
What distance do cable clamps support wires?
Intervals not exceeding 24 inches.
What fillers can not be used in coax cables?
Rubber.
What temps must plastic clamps not be used?
Above 250 Fahrenheit (121 celsius)
What clamps can be used anywhere provided they are fitted with insulation material?
Metal
What wires must be wrapped with insulation tape?
Aromatic polyimide.
What must be fitted is a nylon clamp uses a spacer?
A washer.
Are washers, tapes or ties allowed in fuel tanks?
No.
What must be fitted to edges of wire bundles if 3/8 separation cannot be achieved?
Grommets.
What lines cannot be clamped be clamped to wire bundles?
Liquid lines.
What are harpoon ties used on?
Raceways.
What is normally used to create a sealant mould for pressure sealing?
Vinyl tape.
What materials can be used for wire bundle cords?
Cotton (waxed), nylon or fibreglass lacing cord.
Can wire bundle ties be placed inside conduits?
No.
How often must wire bundle ties be used?
Every 8 inches (2 inches in high vibration areas)
What are the 2 knots for wire bundles?
Clove stitch and square knot.
What size wire must wire ties not be used on?
Larger than 10 AWG
What temperature must plastic wire ties not be used?
Above 85 Celsius (185 Fahrenheit)
What’s the maximum number of splices in 1 wire?
3
What tape can only be used outside pressurised zones?
Aircraft fluid resistant tape
What grade tape can only be used in high temperature areas?
Grade D
What is the maximum number of splices in one wire segment?
2
How far must splices be away from a termination device?
12 inches
What cables can not be repaired?
Low range altimeter, glide slope, coax cable that has already been repaired.
How many inches must dead ends be accomplished with connectors?
4-6 inches
What is the automatic hand wire stripper called?
Stripmaster (strips slug up to 7/8 of an inch)
What is the Superchamp wire stripper forbidden from doing?
Crimping
What is installed on the hot side of connectors?
Socket type contacts to minimise risk of electric shock.
What are the 2 basic groups of connectors?
Split shell construction
Assembled construction
What are split shell connectors identified by?
AN numbers
How many basic types of connector are there?
6
How many classes are the groups of AN connector divided into?
5 (Class A, B, C, D, K)
What is a class K AN connector?
Fireproof (made of steel)
What is the most common type of connector?
Assembled.
What provides an interfacial seal at the end of a connector housing?
A Follower
What size is the shell size of a connector denoted in?
1/16 increments (S denotes short housing)
Which direction is the master key installed?
Forward in relation to aircraft.
What happens to every 10th contact on a connector?
Circled.
What is the order of precedence on connectors?
Upper case, lower case, double upper case
Are all connectors environmentally sealed?
Yes
What are all unused contact holes fitted with?
Nylon or Teflon seal plugs.
What are used to interconnect high frequency signals?
Coaxial and connectors
What are polarisation keys for?
Prevents the wrong computer being inserted into the shelf.
What forms the last 2 digits of the connector part number?
The keying code.
Are all connector contacts inserted from the front or rear?
Rear.
What are the 2 general systems for the removal of connector contacts?
Front release
Rear release
What are the standard crimp size contacts?
12, 16, 20
What is soft solder made of?
Tin lead alloy
What is soft solder recommended for and why?
Electronic applications, lower melting point (358 Fahrenheit)
What is hard solder?
Silver solder- for joints needing greater strength
What is the purpose of flux?
Removes oxides from the surface and promotes better flow of solder around the joint.
What could be evidence of a dry joint?
Dull appearance and movement in joint.
Why are dry joints bad?
Fragile and have high resistance.
What is a mechanical crimped alternative to solder sleeve pigtail?
Crimped breakout sleeve (K grip)
What are PIDG terminals?
Pre Insulated Diamond Grip
Insulation sleeve unnecessary.
26-24 (yellow) 22-18 (red) 16-14 (blue)
When are moisture proof splices used?
When full environmental seal is required.
What categories are stratotherm splices split into?
Insulated and un-insulated
What are SADA crimping tools?
Single action double action.
What is the length of the breakout limited to?
2 1/2 in max
What degree within each other can closed end splices be placed upwards aside eachother?
30 degrees
Where must spare wire caps be installed in regards to connectors?
Within 4-6 inches
How many unstripped wires are allowed per end cap?
1
What is CAU?
Circular area units.
What do CAU charts determine?
Conductor and crimp barrel compatibility.
On wires smaller than 10 AWG how far must the sleeve extend?
Extend 1/16 past the end of terminal insulation.
What is the maximum number of terminals on one stud?
4
What is the maximum a terminal can bend in restricted spaces when installing?
90 degrees.
What is the maximum terminals can be bent on a terminal block when installing?
30 degrees.
How many contacts can a terminal module accommodate?
10 or 21
What is aircraft electrical bonding?
Obtaining necessary electrical conductivity between the component metallic parts of the aircraft.
What process can minimise radio and radar interference ?
Bonding.
What must be done to ensure a low resistance connection for bonding leads?
Remove anodising films and non-conducting paint.
If done correctly, measurements no higher than 0.025ohms can be obtained.
What is grounding?
Process of connecting electrical systems to the aircraft metallic structure and pre-designated points.
Do dual grounds have to be installed in fuel tanks?
Yes.
How is grounding measured?
Measuring resistance between ground and aircraft structure?
What are the usual voltages for testing resistance?
250 or 500 volts.
What is continuity testing?
Measuring if a circuit has a complete current path using a ohmmeter or multimeter.
What is TDR?
Time Domain Reflectometry.
Send electrical impulse down a coax cable and picks up any reflections made by discontinuities.
What pulse would an open coax cable reflect using a TDR?
Positive
What is the only wire currently meeting FAA standards?
TKT wire
Lightweight, resistant to high heat producing smoke if it burns.
In wires, what does aging refer to?
Health of a wire’s insulation.
What 2 wires are especially a problem when rubbing against eachother?
Hard wire (kapton) and soft wire (Tefzel)
What does GVI stand for?
General Visual Inspection.
What is a DET inspection?
Detailed.
What is EZAP?
Enhanced Zonal Analysis Procedure.
Why are dust and dwarf bad for fires?
They are flame catalysts
What are classed as hot gas areas?
Engines, struts, APU compartments, air condition bay
What’s the maximum diameter of a wire harness that a nylon clamp can support?
1.25 inches
What clamp is only permitted to support a wire harness greater than 1.25 inches?
Metal clamp with a cushion
Where is the size of the slack of clamps especially important?
In high vibration areas.
What are the 2 categories of conduits?
Open (split)
Closed
