Chap 12: Aircraft cleaning and protection

Question 1

what NOT to do when aircraft is covered in debris

Answer 1

do not:
use clean and dry cloth (may scratch paint away or the metal beneath, may also scratch away the corrosion resistance material on the metal surface)

Question 2

practices of cleaning exterior of aircraft

Answer 2

wash away debris using water and mild soap, and rinsing with water again, then drying it with cloth or chamois (absorbent and non abrasive)
wax surface to certain lustre if needed

for stubborn stains (grease / oil): wipe clean with solvent moist cloth (solvent stated in manual)

Question 3

what NOT to do when cleaning windshield/ plastic windows

Answer 3

do not:

clean debris off with dry cloth (may scratch surface of plastic)

Question 4

practices of cleaning windshield/plastic windows

Answer 4

for plastic:
water is used to wash away debris
cloth moistened with mild soap solution to wash surface
wax plastic surface (to fill scratches and prevent new scratches)

for windshield:
for stubborn stains (grease / oil), wipe with cloth moistened with kerosene or methanol

Question 5

what liquid to not use on plastic when cleaning and why

Answer 5

will attack the material and craze (crack) it:

1) gasoline
2) alcohol anti-icing fluid
3) lacquer thinner
4) glass cleaner

Question 6

how should tires be cleaned

Answer 6

with soap and detergent and water OR with cleaner stated from manual

for stubborn stains, wipe clean with cloth moistened with petroleum
(affected stain area must be wiped clean and dry from petroleum immediately)

Question 7

what liquid or solvent CANNOT be used for tire cleaning and why

Answer 7

causes deterioration of rubber:

petroleum

Question 8

how to wash de-ice boots

Answer 8

clean with mild soap and water, wash thoroughly with water

to remove stubborn grime, use cleaner stated in manual (eg isopropyl) then wash thoroughly with water

Question 9

what can be done to prolong the life of de-icing boots

Answer 9

should be serviced at regular interval and kept free from oil, grease or solvent that can cause rubber to deteriorate

Question 10

how to clean interior of aircraft

Answer 10

use vacuum cleaner for seats, carpet, floorboard (remove dust, debris, sand) (must be done regularly to prevent dirt built-up)

for stubborn stains, wipe clean with cloth and household spot remover

for leather surfaces, clean with cloth moistened with soap suds, then wipe clean with damp cloth

Question 11

how to do cockpit cleaning

Answer 11

instrument panels and control knobs are cleaned with damp cloth
(stubborn stains should be cleaned with cloth moistened with solvent stated in manual)

Question 12

when do we wash the engines

Answer 12

carried out during scheduled servicing as stated in manual

Question 13

how to clean engines

Answer 13

special wash rig used

1 part cleaning solution : 2/3 part water (cleaning sol. stated in manual)

Question 14

3 methods to protect the aircraft

Answer 14

1) surface treatment
2) surface coating
3) treated tape

Question 15

surface treatment processes and metals

Answer 15

protect surface from oxidisation
Aluminium:
- Alodising
- Chromating
- Anodising

Steel:

• Cadmium plating
• Chrome plating
• Phosphate plating

Question 16

What is alodising and anodising

Answer 16

Alodising: bathing metal in hot alodise solution to give protective coating and surface for painting (used when electrical and thermal conductivity is important)

Anodising: acid treatment that forms non-conductive aluminium oxide layer on the part
(used when corrosion and wear resistance is important)

properties of anodising: higher corr. resist., better electrical insulation, hardened surface with better abrasion resistance, improved paint adhesion

Question 17

what is plating and does it do?

Answer 17

electro-depositing layer of cadmium

higher corrosion resistance

Question 18

purpose of surface coating

Answer 18

apply layers of coating to a part, 
corrosion prevention
protection from environment
functional fluid resistance
resilient to flexing

Question 19

types of surface coating

Answer 19

top coat/finishing coat: coating applied over an intermediate coating for appearance/ protection

electrically conductive / insulative coating: for radar and antennae enclosures

Question 20

3 material used for coating

Answer 20

1) Lacquer
2) Enamel
3) Polyurethane

Question 21

what are primers

Answer 21

primers: agents that provides good base for paint, used for corrosion protection
NOT used to fill up blemishes

wash primers: priming agent that has been diluted
increase adhesion of coating (not used as permanent protective coating)
e.g. phosphoric acid, zinc chromate

Question 22

3 elements of paint

Answer 22

1) pigmentation: colour, durability
2) binder: holds pigment in liquid form together, able to stick to part surface
3) solvent: dissolves binder and carries pigment part surface

3a) when used with lacquer: called thinner
when used with enamel: called reducer

Question 23

purpose and properties of treated tape

Answer 23

used to assist in preventing dents and delamination from FODs

individual/combination of high strength, impact/puncture/abrasion resistance
electrical and hear insulation