AD 90-13-07

90-13-07 MCDONNELL DOUGLAS: Amendment 39-6616. Docket No. 90-NM-21-AD.

Applicability: Model DC-10-10, -10F, -15, -30, -30F, -40, -40F, and KC-10A (Military) series airplanes, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent total loss of aircraft hydraulic power and flight control systems, accomplish the following:

A. For model DC-10-10 and -10F series airplanes:

1. Within 6 months after the effective date of this AD, accomplish either subparagraph a. or b., below:

a. Modify the Number 3 hydraulic system by installing flow rate sensing hydraulic fuses and check valves in accordance with paragraph 2, Accomplishment Instructions, of McDonnell Douglas DC-10 Service Bulletin 29-129, dated February 14, 1990; or

b. Install an electrically operated hydraulic system shutoff valve and return line check valve in the Number 3 hydraulic system. The shutoff valve must be activated by a hydraulic fluid level sensor in the Number 3 hydraulic system reservoir and annunciated in the cockpit. The installation must be made in a manner which is approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region, or in accordance with McDonnell Douglas DC-10 Service Bulletin 29-128, dated February 22, 1990.

2. For those airplanes modified in accordance with paragraph A.1.a., above, within 1 year after the effective date of this AD, install an electrically operated hydraulic system shutoff valve and return line check valve in the Number 3 hydraulic system. The shutoff valve must be activated by a hydraulic fluid level sensor in the Number 3 hydraulic system reservoir and annunciated in the cockpit. The installation must be made in a manner which is approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region, or in accordance with McDonnell Douglas DC-10 Service Bulletin 29-128, dated February 22, 1990. The modification required by paragraph A.1.a., above, may be removed after accomplishment of this subparagraph.

B. For Model DC-10-15, -30, -30F, -40, -40F, and KC-10A (Military) series airplanes, within one year after the effective date of this AD, install an electrically operated hydraulic system shutoff valve and return line check valve in the Number 3 hydraulic system. The shutoff valve must be activated by a hydraulic fluid level sensor in the Number 3 hydraulic system reservoir and annunciated in the cockpit. The installation must be made in a manner which is approved by Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region, or in accordance with McDonnell Douglas DC-10 Service Bulletin 29-128, dated February 22, 1990

C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.

D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Douglas Aircraft Company, P. O. Box 1771, Long Beach, California 90801, ATTN: Manager, Service Change, Mail 73-30. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California.

This amendment (39-6616, AD 90-13-07) becomes effective on July 20, 1990.