Effective date: September 09, 1999.

Compliance: Required as indicated in BLA AD 1999-093(A).

Remarks: Where applicable, the requirements of this AD must be integrated into the Aircraft's Logbook(s). Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel.: 420 2 33320922, fax: 420 2 20562270.

FOKKER SERVICES B.V.

(formerly Fokker Aircraft B. V.)

RLD Type Certificate Nr.: A22F.

Over the years, RLD have received a number of incident reports concerning DC Generator overvoltage on Fokker Model F.27 "Friendship" aircraft, which invariably resulted in loss of both DC Generator Systems and loss of several other aircraft systems. Investigation revealed that the overvoltage was caused by the incorrect installation of DC Generator system parts, including bad solder joints, bad wire insulation and incorrect functioning of relays and resistors. These conditions, if uncorrected, may result in further incidents of overvoltage of the aircraft electrical systems. Since an unsafe condition has been identified that is likely to exist or develop on other aircraft of the same type design, this Airworthiness Directive (BLA) requires the affected DC Generator Control Panels to be regularly inspected for proper installation, and corrective action to be accomplished, as necessary.

Applicability: Fokker Aircraft B. V. Model F.27 Mk.100 through Mk.700 series, all serial numbers.

Effective date: July 20, 1999

Compliance: Required as indicated, unless accomplished previously.

Within the next two (2) calendar months after the effective date of this directive and thereafter at intervals not to exceed 4,000 flight hours, inspect the DC Generator Control Panel in accordance with STORK Fokker Service Bulletin F27/24-79 dated April 28,1999 or a later RLD approved revision.

Operators of the affected aircraft may obtain copies of the referenced service information upon request directly from Fokker Services B.V., Technical Services Dept., P.O. Box 231, 2150 AE Nieuw-Vennep, The Netherlands; telephone (31)252-627-350; facsimile (31)252-627-21l.

Compliance with this AD must be recorded in the proper Aircraft Log Book(s).

Where applicable, the requirements of this AD must be integrated into the aircraft's Maintenance Schedule.

Address inquiries concerning this AD to:

Bureau Coordination & Technical Information (CTI); Telephone 31-(0)23-566 3155; Facsimile 31-(0)23-566 3006; Telex 74592 rldli nl, Email "info.register@rld.minvenw.nl"