AD 47-42-03

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AD Number:
47-42-03
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
Subject:
Fire Prevention Changes
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
The Boeing Company
Model:
C54-DC | C54A-DC | C54B-DC | C54D-DC | C54E-DC | C54G-DC | DC-4
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 47-42-03
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   47-42-03

SUBJECT HEADING:   Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
47-42-03 DOUGLAS: (Was Mandatory Note 22 of AD-762-7.) Applies to C-54 and DC-4 Aircraft.

All the provisions of items A through O apply to airplanes used for carrying passengers under the provisions of Parts 41, 42 and 61 of the Civil Air Regulations. On these airplanes the changes are to be accomplished not later than November 1, 1948.

Only items A, (12), A (15), C, D, F, J, K (1), K (2), L, M, O (2), O (4), O (5), and O (7) apply to airplanes other than those indicated above. On these airplanes the changes are to be accomplished not later than the first engine change after November 1, 1948.

As a result of investigation of powerplant fires which have occurred in this type aircraft, the following changes are to be accomplished:

A. 1. Seal all cracks and baffles in oil cooler fairing and provide additional drain holes.
2. Rework cowl tail pipe shroud to eliminate all cracks and gaps and seal shroud to cowl panel joint.
3. Seal inner ring corners at oil cooler joints.
4. Reinforce exhaust shroud to prevent damage when used as a step and seal same.
5. Provide accessory compartment vent opening in oil cooler fairing panel.
6. Seal joints between all engine accessory sections cowling panels to prevent leakage of flame into accessory section.
7. Eliminate engine accessory compartment vent opening in the side accessory section cowl panel.
8. Seal pressure transmitter and fire warning switch holes on firewall.
9. Close gap between aft oil cooler fairing and nacelle skin aft of firewall.
10. Rework the hydraulic suction line connecting to the shutoff valve aft of the firewall to prevent failure at fittings due to rigidity of the line.
11. Relocate the hydraulic pressure and automatic pilot lines to move them farther away from the exhaust shroud.
12. Add a check valve in the automatic pilot delivery line behind the firewall.
15. Change the nacelle firewall miscellaneous line connector assembly on the right side of the firewall from dural to steel.
16. Change carburetor air scoop adapter sleeve to provide a tight and flexible connection.
17. Replace exhaust stack nuts with special long-type nuts, extending past stud ends, on exhaust pipe attachments to engine and safety wire the nuts in place.
18. Change nuts and bolts used on the four-bolt flanges at the top of the exhaust collector ring to stainless steel.
19. Seal main landing gear door hinges on inboard nacelles.
20. Install means to prevent exhaust nipples from telescoping and pulling out of cylinder exhaust ports, in the event of exhaust port stud failure. (Douglas clamp assembly P/N 4244017 may be used.)

(Douglas Service Bulletin C-54-250 covers the above items respectively. Items 13 and 14 of that Bulletin are not required by this Note.)

B. Rework forward edge of exhaust shroud to eliminate gaps leading into engine accessory section.

(Part I, Douglas Service Bulletin C-54-234, covers this same subject.)

C. Add two fire detectors on forward face of firewall in vicinity of shutoff valve location.

(Douglas Service Bulletin No. C-54-252 covers this same subject.)

D. Relocate engine primer solenoid to prevent fuel from running into electrical junction box on rear face of firewall.

(Item 12, Douglas Service Bulletin DC-4 No. 66, covers this same subject.)

E. Install extended tail pipes on exhaust collectors.

(Douglas Service Bulletin C-54-289 covers this same subject.)

NOTE: Some of the above-mentioned changes were accomplished at the time Army or Navy airplanes were converted for civil certification. However, it will be necessary to check for compliance, in order to insure that items A to E, inclusive, are complied with.

F. Improve the seal at the point where the top of the oil radiator duct fits against the cutout in the bottom of the accessories section diaphragm.

(Part 1 of Douglas Service Bulletin DC-4 No. 49 covers this same subject.)

G. Revise sealing of engine section drain line support adjacent to oil cooler shroud by installing a drain manifold.

(Part B of Douglas Service Bulletin DC-4 No. 66 covers this same subject.)

H. Replace dural oil inlet elbow on oil cooler with new type steel elbow.

(Part F, 9 of Douglas Service Bulletin DC-4 No. 66 covers this same subject.)

I. Improve sealing of engine accessories section diaphragm at the four cutouts for the exhaust collector ring supports.

(Part 2 of Douglas Service Bulletin DC-4 No. 49 covers this same subject.)

J. Replace micarta fairleads with fairleads of fire resistant material for propeller governor and carburetor air preheat control cables on inner ring and for all engine control cables on firewall.

(Douglas Service Bulletin DC-4 No. 55 covers this same subject.)

K. 1. Install seven fire-warning detectors in zone 1, (engine power section) on the cowl flap ring brackets and install separate set of warning lights in the cockpit for each engine.
2. Add an additional fire warning detector in zone 2, (engine accessories section) on top of the oil cooler housing at approximately the center of the section.

(Douglas Service Bulletin DC-4 No. 57 covers the above two items.)

L. Replace open relays in junction box behind firewall with sealed relays and provide a drain for the junction box.

(Douglas Service Bulletin DC-4 No. 61 covers this same subject.)

M. Attach nacelle junction box cover plate on forward face of firewall directly to firewall rather than to the junction box.

(Douglas Service Bulletin DC-4 No. 65 covers this same subject.)

N. Inspect and seal all holes in the inner ring around the carburetor air preheat control and install fire resistant fairlead in retainer.

(Douglas Service Bulletin DC-4 No. 55 covers this same subject in part.)

O. 1. Inspect and rework if necessary, inner ring cutouts for cowl flap actuating bellcranks to provide metal-to-metal contact between inner ring and cowl flap bellcrank bracket on aft side of inner ring. Dimple inner ring to accomplish metal-to-metal contact, or fill gap with washers made from Johns Manville No. 96 wire woven asbestos sheet impregnated with neoprene.

2. Inspect and rework diaphragm, inner ring and firewall for excess holes, gaps and rubber grommets. Close and seal all holes and gaps, and install fireproof grommets or equivalent.

3. Inspect and seal, with Johns Manville No. 96 or equivalent, gaps that may exist where the carburetor airscoop casting passes through the accessory section inner ring.

4. Inspect and seal with Johns Manville No. 96 split seal or equivalent the hole where the engine oil line (from the intermediate rear section to the main oil sump) passes through the plate in the accessory section diaphragm at the bottom of the engine.

5. Inspect and seal with Johns Manville No. 96 or equivalent any gaps that may exist where the plate mentioned in item 4, above, mates with the outer section of the accessory section diaphragm.

6. Inspect and seal gaps existing between the diaphragm and the three engine crank case bosses. The magneto vent lines pass through the gaps around two of these bosses; the manifold pressure takeoff line at right top of engine being the third.

7. Provide a fluid shutoff means at a point behind the firewall in the line leading from the oil tank to the feathering pump on airplanes having the feathering pump located on the engine side of the firewall. This may be accomplished by a shutoff valve tied into the present shutoff valve linkage aft of the firewall, or a flapper type check valve.

NOTE: Items 0-1 through 0-7 are to be developed and accomplished by the operators affected, since Douglas has not prepared Service Bulletins to cover these changes.


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