Enstrom F-28 Series Helicopters

AD/ENST 28/9 Amdt 4 (continued)

(c) If the transmission is part number 28-13101-1 or \-1-R, or part number 28- 13101-3 or \-3-R:
(i) Dye-penetrant inspect the shaft upper fillet for a crack, a nick, or a scratch.

(ii) Polish out nicks or scratches less than 0.005- inch deep.

(iii) If the shaft is cracked or has a nick or scratch 0.005- inch or more deep, replace the transmission with a serviceable transmission having a large radius shaft fillet before further flight.
(d) Replace transmission, part number 28-13101-1 or \-1-R, or 28-13101-3 or \-3- R with a serviceable transmission having a large radius shaft fillet.

Note 1: Installing a serviceable transmission with a shaft, part number 28-13104-1 or -1-R, Revision K, L, M, N, P, R, or S, or part number 28-13140-1 or -1-R, is terminating action for the requirements of this Directive.

Note 2: FAA AD 2002-08-03 Amdt 39-12710 refers.

Compliance: 1. Before further flight after 28 August 2002, unless already accomplished.

2. Before further flight after 28 August 2002, unless already accomplished.

3. a. Before further flight after 28 August 2002, unless already accomplished.

b. Unless the initial inspection is already accomplished, before further flight after 28 August 2002. Thereafter at intervals not to exceed 25 hours time in

service.

c. Unless the initial inspection is already accomplished, within 5 hours time in service after 28 August 2002. Thereafter at intervals not to exceed 100 hours time in service.
d. Unless already accomplished, within 300 hours time in service after 28 August 2002 or at the next overhaul, whichever occurs first.

This Amendment becomes effective on 28 August 2002.