80-06-05 SLICK ELECTRO, INC.: Amendment 39-3718. Applies to the following Slick magneto models and associated serial and impulse coupling numbers:
MAGNETO MODEL NO. (1)
SERIAL NO. (1) (2)
IMPULSE COUPLING
NO. (1)
447 & 447R
9040001 thru 9040049
M2374
662 & 662R
9020462 thru 9070000
M2362
664 & 664R
9040001 thru 9040086
M2370
680 & 680R
9020462 thru 9070000
M2369
4151 & 4151R
9020017 thru 9070000
M1709
4152 & 4152R
9020017 thru 9070000
M1709
4181 & 4181R
9020017 thru 9070000
M1709
4201 & 4201R
9020210 thru 9070000
M3007
4251 & 4251R
9030001 thru 9070000
M3163
4281 & 4281R
9030001 thru 9070000
M3007
4230 & 4230R
9040001 thru 9040197
M3068
6210
8090073 thru 9070000
M3050
6214
8050001 thru 9070000
M3089
(3) M2371, M3100, & M3165
NOTES: (1) Any of the units listed were manufactured subsequent to January 1979.
(2) Any magneto serial numbers between and including the lower and upper limits as shown are affected by this AD.
(3) These coupling numbers are for parts used as spares and also must be tested.
The magneto models as listed above are installed on, but not limited to, the following engines:
Lycoming
AEIO-360
AEIO-320
IO-320
O-235
O-320
O-360
Continental
A-65-8
A-75-8
C-85-8
C-90-8
O-200-A
O-300-A, -B, -C, -D
O-470-U
IO-360-KB
IO-470
IO-520-A, -B, -F
TSIO-470
TSIO-520-T
Compliance is required as indicated unless already accomplished. To prevent a possible magneto failure and subsequent engine or accessory malfunction, accomplish the following:
Prior to the next ten (10) hours of aircraft time in service, or within the next thirty (30) calendar days from the date of this AD, whichever occurs first, complete the following comparative hardness test procedures:
1. Remove the impulse coupling magneto(s) from the engine per engine manufacturer's instructions.
2. Remove the impulse coupling assembly from the magneto frame per Slick's maintenance and overhaul instructions.
3. Establish a reference level of acceptable metal hardness by sliding a fine cut mill file over the flat surface of either pawl. The file will slide freely and will only burnish the hard surface of the pawl.
4. By a similar filing action, test for the hardness of each of the two rivet heads.
5. If there is resistance to sliding and material is removed from the rivet head, the rivet has not been heat treated and the coupling assembly must be replaced. Return the defective coupling assembly to a Slick Electro, Inc. distributor.
6. If hardness of the rivet heads and pawls are equivalent, reassemble and identify AD compliance by metal stamping a letter "C" on the Slick insignia located on the side of the magneto identification plate.
7. If the results of the comparative hardness test on the rivet(s) are questionable, the coupling assembly must be replaced.
This amendment becomes effective March 28, 1980, as to all persons except those to whom it was made immediately effective by the airmail letter dated February 4, 1980, which contained this amendment.