Loss Of Engine Throttle Control

Amendment 39-11952.
Docket No. 99-NE-29-AD.
Applicability: Pratt & Whitney (PW) Models JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A turbofan engines, installed on but not limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9 series airplanes.

Note 1: This airworthiness directive (AD) applies to each engine 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 engines 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 (f) 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 as indicated, unless accomplished previously. To prevent loss of engine throttle control, uncommanded acceleration, uncommanded deceleration or inflight shutdown, which could result in reduced airplane control during a critical phase of flight, accomplish the following:
Initial Inspection (a) Inspect and, if necessary, replace the main fuel pump control shaft in accordance with procedures and intervals described in paragraphs 1.B. and 1.C. of the Accomplishment Instructions of PW Alert Service Bulletin (ASB) A6381, dated March 15, 2000, as follows: (1) For fuel pumps that have incorporated the modifications of paragraph (c)(1) but not the modifications of paragraph (c)(2) as of the effective date of this AD, perform the initial inspection at the next main fuel pump accessibility after accumulating 6000 hours time in service (TIS) since last main fuel pump overhaul.
(2) For fuel pumps that have not incorporated the modifications of paragraph (c)(1) as of the effective date of this AD, perform the initial inspection at the next main fuel pump accessibility after accumulating 3000 hours TIS since last main fuel pump overhaul.

Repetitive Inspections (b)
Thereafter, reinspect the main fuel pump control shaft and remove and replace, if necessary, in accordance with intervals and procedures described in paragraphs 1.B. and 1.C. of the Accomplishment Instructions of PW ASB A6381, dated March 15, 2000.

Installation and Terminating Action (c)
At the next main fuel pump overhaul perform the following:
(1) Install a reworked impeller, impeller gear train plate assembly and impeller cover assembly in accordance with paragraph 2.A of PW ASB A6381, dated March 15, 2000.
(2) Replace the main fuel pump control shaft with a serviceable main fuel pump control shaft.
(3) The next main fuel pump overhaul must occur no later than:

(i) 12,000 hours time in service (TIS) since last fuel pump overhaul; or
(ii) 2000 hours TIS from the effective date of this AD; or
(iii) 3000 hours TIS from the effective date of this AD, provided the main fuel pump has incorporated the modifications of paragraph (c)(1) as of the effective date of this AD and the inspection results from paragraph (a) of this AD are less than or equal to 15 degrees; whichever occurs latest.

(4) Modifications required by paragraph (c)(1) and (c)(2) of this AD constitute terminating action to the inspections required by paragraphs (a) and (b) of this AD.

Optional Fleet Campaign (d)
It is not necessary to perform the inspections required by paragraphs (a) and (b) or to adhere to the schedule of paragraph (c)(3) of this AD if the main fuel control modifications of paragraph (c)(1) and (c)(2) are performed throughout an operator’s fleet in accordance with the schedule of Table 1 or Table 2 of this AD as follows:
(1) For fuel pumps that have incorporated the modifications of paragraph (c)(1) but not the modifications of paragraph (c)(2) as of the effective date of this AD, perform modifications in accordance with the schedule of Table 1.

(2) For fuel pumps that have not incorporated the modifications of paragraphs (c)(1) as of the effective date of this AD, perform the modification in accordance with the schedule of Table 2.

:

Definitions (e) For the purpose of this AD:
(1) Accessibility of the main fuel pump is defined as removal of the fuel control from the fuel pump on the engine or removal of the fuel pump from the engine.
(2) Main fuel pump overhaul is defined as compliance with the manufacturer's recommended overhaul procedures described in Argo-Tech Overhaul Manual 73-11-1.
(3) A serviceable main fuel pump control shaft is defined as Argo Tech part number 219093 or Rogers Dierks part number RD219093.

Alternative Methods of Compliance (f)
An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office (ECO). Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the ECO.

Ferry Flights (g)
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.

Incorporated by Reference (h)
The actions specified in this AD must be done in accordance with the following Pratt & Whitney Alert Service Bulletin: Document No. Pages Revision Date JT8D A6381 All Original March 15, 2000 Total pages: 14. 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 Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-8770, fax (860) 565-4503. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC. Effective Date of this AD

(i) This amendment becomes effective on December 4, 2000.

FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7175, fax (781) 238-7199. Issued in Burlington, Massachusetts, on October 20, 2000. Jay J. Pardee, Manager, Engine and Propeller Directorate, Aircraft Certification Service.