97-11-13 FAIRCHILD AIRCRAFT: Amendment 39-10042; Docket No. 95-CE-34-AD.
Applicability: The following model and serial number airplanes, certificated in any category:
Model
Serial Numbers
SA226-T
T201 through T275 and T277 through T291
SA226-T(B)
T(B)276 and T(B)292 through T(B)417
SA226-AT
AT001 through AT074
SA226-TC
TC201 through TC419
SA227-TT
TT421 through TT541
SA227-AT
AT423 through AT631
SA227-AC
AC406, AC415, AC416, AC420 through AC705,
and AC707 through AC733
NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (g) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required within the next 2,000 hours time-in-service after the effective date of this AD, unless already accomplished.
To prevent failure of both generators during critical phases of flight (such as night operation or while in icing conditions), which could result in loss of control of the airplane, accomplish the following:
(a) For the model and serial number airplanes presented below, replace the existing generator fault transformer wiring with new dual conductor shielded wire in accordance with Fairchild Service Bulletin (SB) 226-24-027, Issued: May 19, 1988, Revised: February 22, 1989, or Fairchild SB 227-24-008 Issued: March 18, 1988, Revised: February 22, 1989, as applicable.
(1) Model SA226-T airplanes, serial numbers T201 through T275 and T277 through T291; Model SA226-T(B) airplanes, serial numbers T(B)276 and T(B)292 through T(B)417; Model SA226-AT airplanes, serial numbers AT001 through AT074; and Model SA226-TC airplanes, serial numbers TC201 through TC419.
(2) Model SA227-TT airplanes, serial numbers TT421 through TT541; Model SA227-AT airplanes, serial numbers AT423 through AT631; and Model SA227-AC airplanes, serial numbers AC406, AC415, AC416, and AC420 through AC683.
(b) For the model and serial number airplanes presented below, rewire the electrical power generation system to reduce the possibility of 325-amp current limiter failure in accordance with Fairchild SB 226-24-023, Issued: October 25, 1985, Revised: January 23, 1989, or Fairchild SB 227-24-005, Issued: October 25, 1985, Revised: January 23, 1989, as applicable.
(1) Model SA226-T airplanes, serial numbers T249 through T275 and T277 through T291; Model SA226-T(B) airplanes, serial numbers T(B)276 and T(B)292 through T(B)417; Model SA226-AT airplanes, serial numbers AT025 through AT074; and Model SA226-TC airplanes, serial numbers TC209 through TC419.
(2) Model SA227-TT airplanes, serial numbers TT421 through TT541; Models SA227-AT airplanes, serial numbers AT423 through AT591; and SA227-AC airplanes, serial numbers AC420 through AC594.
(c) For Model SA226-T airplanes, serial numbers T249 through T275 and T277 through T291; Model SA226-T(B) airplanes, serial numbers T(B)276 and T(B)292 through T(B)417; Model SA226-AT airplanes, serial numbers AT025 through AT074; and Model SA226-TC airplanes, serial numbers TC209 through TC419, modify the voltage regulator access panel and install a connector in the wire bundle in accordance with Fairchild SB 226-24-026, Issued: May 27, 1987.
(d) For Model SA226-T airplanes, serial numbers T201 through T275 and T277 through T291; Model SA226-T(B) airplanes, serial numbers T(B)276 and T(B)292 through T(B)347; Model SA226-AT airplanes, serial numbers AT001 through AT074; and Model SA226-TC airplanes, serial numbers TC201 through TC348, install new voltage regulators, reroute certain wires, and replace the entire voltage regulator panel assembly in accordance with Fairchild SB 24-018, Issued: October 22, 1980, Revised: January 7, 1981.
(e) For the model and serial number airplanes presented below, modify the direct current (DC) generator control system so that it will operate off its respective generator output in accordance with Fairchild SB 226-24-031, dated July 27, 1989, or Fairchild SB 227-24-012, Issued: May 4, 1989; Revised: July 27, 1989, as applicable. This includes removing field current and reset resistors, removing the reset and generator relays and associated diodes, installing a 10-amp generator control circuit breaker to the left-hand and right-hand essential bus panels, and replacing the 10-amp generator control circuit breakers in the left-hand and right-hand wheelwells with15-amp circuit breakers that are wired in series with the generator control circuit breakers.
(1) Model SA226-T airplanes, serial numbers T249 through T275 and T277 through T291; Model SA226-T(B) airplanes, serial numbers T(B)276 and T(B)292 through T(B)417; Model SA226-AT airplanes, serial numbers AT025 through AT074; and Model SA226-TC airplanes, serial numbers TC209 through TC419.
(2) Model SA227-TT airplanes, serial numbers TT421 through TT541; Model SA227-AT airplanes, serial numbers AT423 through AT695; and Model SA227-AC airplanes, serial numbers AC406, AC415, AC416, AC420 through AC556, AC558 through AC705, and AC707 through AC733.
(f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.
(g) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Fort Worth Airplane Certification Office (ACO), FAA, 2601 Meacham Boulevard, Fort Worth, Texas 76193-0150. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Fort Worth ACO.
NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Fort Worth ACO.
(h) The modifications required by this AD shall be done in accordance with the following service bulletins, as applicable:
- Fairchild Service Bulletin (SB) 226-24-027, Issued: May 19, 1988, Revised: February 22, 1989;
- Fairchild SB 227-24-008, Issued: March 18, 1988, Revised: February 22, 1989;
- Fairchild SB 226-24-023, Issued: October 25, 1985, Revised: January 23, 1989;
- Fairchild SB 227-24-005, Issued: October 25, 1985, Revised: January 23, 1989;
- Fairchild SB 226-24-026, Issued: May 27, 1987;
- Fairchild SB 24-018, Issued: October 22, 1980, Revised: January 7, 1981;
- Fairchild SB 226-24-031, dated July 27, 1989; and
- Fairchild SB 227-24-012, Issued: May 4, 1989, Revised: July 27, 1989.
This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279-0490. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(i) This amendment becomes effective on July 11, 1997.