69-24-03 MARVEL-SCHEBLER: Amdt. 39-881. Applies to Marvel Schebler Models MA-3-A, MA-3-PA, MA-3-SPA, MA-4-SPA, MA-4-5, MA-5, MA-4-5-AA, MA-6AA, and HA-6 carburetors of the following listed part numbers and serial numbers installed on the Continental, Franklin and Lycoming model engines as specified below, to wit:
ENGINE MANUFACTURER
& MODEL
CARBURETOR
MODEL
CARBURETOR
PART NUMBER
CARBURETOR
SERIAL NUMBERS
CONTINENTAL
A-65 & A-75 Series
MA-3-PA
A-10-4233
P-22-460 thru P-22-464
O-200 Series
MA-3-SPA
A10-4115-1
AV-4-4094
O-200 Series
MA-3-SPA
A10-4894
BE-14-10218 thru BE-15-11672
C-85 Series
MA-3-SPA
A10-4240
AU-15-235 thru AU-15-244
C-90 Series
MA-3-SPA
A10-4252
Q-23-2422 thru Q-23-2436
C-145 Series
MA-3-SPA
A10-4895
BF-14-3598 thru BF-15-3655
O-470-K
MA-4-5
A10-3965-12
H-3-6894 thru H-3-6896
O-470-R
MA-4-5
A10-4893
BD-13-3946 thru BD-15-4660
FRANKLIN
4A-235 Series
MA-3-SPA
A10-4654
BN-3-112 thru BN-3-130
GA-335 Series
MA-5
A10-4865
BC-14-530 thru BC-16-706
6V-350 Series
MA-5
A10-4809
BA-14-203 thru BA-14-207
6A-350 Series
MA-5
A10-4865
BC-14-530 thru BC-16-706
LYCOMING
O-235 Series
MA-3-A
A10-3103-1
Y-30-3132 thru Y-30-3275
O-235 Series
MA-3-A
A10-4953
BV-0-268 thru BV-0-538
O-235 Series
MA-3-PA
A10-4978-1
BQ-3-252 thru BQ-3-276
O-235 Series
MA-3-PA
A10-5050
BY-0-100 thru BY-1-291
O-290 Series
MA-3-SPA
A10-3346-1
B-35-342 thru B-36-359
O-320 Series
MA-4-SPA
A10-3678-32
A-25-14781 thru A-26-16246
O-320 Series
MA-4-SPA
A10-5009
BL-5-2632 thru BL-5-3435
O-360 Series
MA-4-5
A10-3878
G-34-4651 thru G-36-5362
O-360 Series
MA-4-5
A10-4164-1
K-27-6460 thru K-27-6602
O-360 Series
MA-4-5
A10-5034
BU-0-283 thru BU-0-383
O-360 Series
HA-6
A10-5045
BW-0-198 thru BW-4-550
VO-435 Series
MA-4-5-AA
A10-4025-12
Z-16-2304 thru Z-18-2434
TVO-435 Series
MA-6-AA
A10-4438-1
AH-19-3676 thru AH-21-4067
O-540 Series
MA-4-5
A10-4404
R-24-6530 thru R-26-6916
O-540 Series
MA-4-5
A10-4404-1
AO-20-3571 thru AO-23-3829
O-540 Series
MA-4-5
A10-5042
BS-1-427 thru BS-1-588
O-540 Series
MA-4-5
A10-5054
BZ-0-100 thru BZ-0-209
VO-540 Series
MA-6-AA
A10-4218-1
AK-17-1274 thru AK-19-1478
VO-540 Series
MA-6-AA
A10-4975
BK-2-125 thru BK-3-148
NOTE: The affected carburetors listed above were manufactured between December 5, 1968, and June 23, 1969. Approximately 25% of these carburetors have been inspected and cleaned by Marvel Schebler or the manufacturers of the engines or aircraft on which the carburetors are installed. Marvel Schebler Service Bulletin A1-69 lists the carburetors remaining to be inspected and covers the same subject matter as this AD. Any carburetor serial numbers included in this AD but not listed on Marvel Schebler Service Bulletin A1-69 comply with this AD, and require no further inspection or cleaning. A logbook entry of compliance and nameplate marking must be made on these unlisted carburetors. The "A" prefix to the part numbers listed above does not appear on the carburetor nameplate.
Compliance: Required within the next 25 hours' time in service after the effective date of this AD, unless previously accomplished.
To prevent possible power losses due to blockage of carburetor metering passeges by thread lubricant or other foreign material, accomplish the following or an equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region, or Chief, Engineering and Manufacturing Branch, FAA, Eastern Region:
Remove the carburetor bowl drain plug with the aircraft fuel valve in the "ON" position and allow the carburetor to flush for 20 to 30 seconds. The auxiliary pump, if installed, should be operating. After flushing, inspect the drain plug cavity and drain plug for thread lubricant or other foreign material and remove any such material noted. After cleaning, reflush 20 to 30 seconds, reinstall plug approximately one thread into cavity, apply Parker Seal Lube or equivalent on exposed threads and tighten.
NOTE: If practical, aircraft should be positioned so that bottom of bowl slopes toward drain opening during flushing and cleaning. Recommended torque for 1/8" pipe plug is 50-60 in. lbs., for 1/4" pipe plug is 120-144 in. lbs.
After completion of the above, impression stamp or engrave "A1" on a nameplate or apply approximately 1/4-inch diameter dot of yellow enamel or similar permanent material to nameplate.
This amendment becomes effective November 29, 1969.