AD 80-06-05

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.