Mooney M20V - Page 130

MOONEY INTERNATIONAL CORPORATION
M20V SERVICE AND MAINTENANCE MANUAL
Page
Date
7
MAR 2017
Rev Date
6
5
42.25
STA
6
4
3
42.25
STA
4
12
11
1
25.75
8
STA
7
13
9
INDEX SKIN MATERIAL INDEX SKIN MATERIAL
NO. THICKNESS NO. THICKNESS
1. 0.025 2024 T- 3 CLAD 8. 0.025 2024 T- 3 CLAD............ ........... ........... .....
2. 0.025 2024 T- 3 CLAD 9. 0.020 2024 T- 3 CLAD............ ........... ........... .....
3. 0.025 2024 T- 3 CLAD 10. 0.032 2024 T- 3 CLAD............ ........... .......... .....
4. 0.025 2024 T- 3 CLAD 11. Polyester Glass- Fiber Reinforced............. ........... .
5. 0.025 2024 T- 3 CLAD 12. 0.020 2024 T- 3 CLAD............ ........... .......... .....
6. 0.020 2024 T- 3 CLAD 13. 0.025(a) 2024 T- 3 CLAD............ ........... ......... ....
7. 0.025 2024 T- 3 CLAD (a) Heat treated to T- 42 condition............. ...........
EMPENNAGE SKIN PANELS
FIGURE 20- 3
20-00-02 - CORROSION DETECTION &
PREVENTION
Most metallic fabrication materials are susceptible to
corrosion. Corrosion may occur on aircraft in any cli-
mate, but it will be a problem more often in climates
where the aircraft is exposed to salt air or high humidity,
or where there are industrial contaminants in the atmo-
sphere. The aircraft should be inspected frequently to
detect and correct corrosion before serious damage
occurs.
Any form of corrosion should be removed at once. If it is
necessary to remove paint, only an approved aircraft
paint remover such as Eldorado PR- 3400, (Eldorado
Chemical Co., Inc., 6700 Lookout Road, P.O. Box
32101, San Antonio, TX. 78216 or 11611 N. Meridian
St. #600, Carmel (Indianapolis), Indiana 46032,
800- 531- 1088) should be used. Paint removing sub-
stances left in metal crevices will cause further corro-
sion. Turco 6898 (Turco Products, Inc., 6135 South
Central Ave., Los Angeles, California) will remove cor-
rosion from aluminum and treat the metal surface in
one application. This Section discusses corrosion
types and their prevention along with suggested proce-
dures for corrosion protection of internal airframe sur-
faces.
1. Types of Corrosion - Aluminum
Corrosion normally appears in one or more of four
forms. Each type of corrosion can be precluded or con-
trolled by a preventative maintenance program.
A. Chemical Corrosion.
Chemical corrosion normally occurs where battery acid
or exhaust gases come in contact with metal surfaces.
A few simple precautions will prevent chemical corro-
sion.
(1) Be sure battery vents (If applicable) are free
from obstructions at all times.
(2) Repaint all scratches and worn spots found in
areas painted with acid- resistant paint.
(3) If acid is spilled on metal surfaces, flush en-
tire area with sodium bicarbonate and water. The solu-
tion should be rinsed away at once and the area dried
by driving all water from crevices with an air hose be-
fore wiping surface dry with a clean cloth.
(4) Frequently clean exhaust gas deposits from
metal surfaces.
B. Local- Cell Corrosion.
On bare metal surfaces, in an early stage development,
local- cell corrosion appears as a light, whitish powder
deposit. Surface pits warn of advanced local- cell cor-
rosion. On painted surfaces, the first indication of corro-
sion will be evidenced by paint blistering.
20-00-02