# AD 83-06-10: Propeller Governor Relief Valve - Type: Airworthiness directive - Status: Current - Products: Aermacchi F.260, F.260B and F.260C - Effective: April 7, 1983 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-4597 - Registered aircraft: 28 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9B101A3D9D9029E486256A4D0048D0BA.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/83-06-10 ## The airworthiness directive 83-06-10 SIAI-MARCHETTI: Amendment 39-4597. Applies to Models F260, F260B, and F260C airplanes certificated in any category that are equipped with one of the following propeller governor Part Numbers (PN): HARTZELL PN EQUIVALENT SIAI PN F4-4A 260-13-272-01 F4-4A (F4-11) 260-13-272-05 F4-112 260-13-272-03 F6-15A 260-13-272-07 F4-4A 260-13-272-09 Compliance: Required as indicated, unless already accomplished. To preclude failure of the propeller governor relief valve spring and possible propeller overspeed, accomplish the following: a) Within the next 100 hours time-in-service after the effective date of this Airworthiness Directive (AD), and thereafter at each 100 hour time-in-service interval on propeller governors with a relief valve body which has a rectangular port and within the next 500 hours time-in-service from the effective date of this AD and thereafter at each 500 hour time-in- service interval, on propeller governors with a relief valvebody which has a round port, accomplish the following: 1) Visually inspect the governor's relief valve spring PN A-3107 for cracks or breakage in accordance with the "INSTRUCTIONS" section of the manufacturer's Service Bulletin (SB) No. 260B35, dated March 5, 1982, hereinafter referred to as the SB. i) If the relief valve spring is cracked or broken, prior to further flight, repair and bench test the propeller governor assembly at SIAI-Marchetti or at an FAA approved Hartzell propeller governor overhaul repair station. (This requirement is necessary because the relief valve spring will require an adjustment to regulate the oil pressure to a range within factory tolerances.) ii) If the spring is not cracked or broken, reinstall the relief valve spring and return the airplane to service and continue the repetitive inspections as prescribed in paragraph a) of this AD. b) Within the next 500 hours time-in-service after the effective date of this AD or at the time of the next propeller overhaul, whichever occurs first, replace those propeller governor relief valve bodies (Part Number (PN) A-3173) having rectangular ports with relief valve bodies (PN A-3173) having round ports as shown in Fig. No. 2 of the SB and continue the repetitive inspections of paragraph a) of this AD. NOTE: It is not necessary to send the propeller governor to the test bench to change the valve body unless the relief valve spring is changed. SIAI-Marchetti or the FAA approved Hartzell propeller governor certified overhaul repair station provides the inspection and modification identification of all governor assemblies installed on airplanes or supplied as spare parts. Modified governors with the new relief valve body with round ports will be identified by a printed "X" with indelible ink on the data plate. c) The intervals between the repetitive inspections required by this AD may be adjusted up to 10 percent of the specified interval to allow accomplishing these inspections concurrent with other scheduled maintenance of the airplane. d) Operators who have not kept records of hours time-in-service of the propeller governor relief valve body type must substitute airplane hours time-in-service in lieu thereof. e) Aircraft may be flown in accordance with FAR 21.197 to a location where this (AD) can be accomplished. f) An equivalent method of compliance with this AD if used must be approved by the Manager, Aircraft Certification Staff, AEU-100, Europe, Africa, and Middle East Office, FAA, c/o American Embassy, 1000 Brussels, Belgium. This amendment becomes effective on April 7, 1983. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A10EU](https://openairdocs.org/tcds/A10EU): Aermacchi S.p.A.; names 3 of 6 models: F.260B, F.260C, F.260 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 28 (28 by airframe model, 0 by engine model) - Makers: SIAI Marchetti 17, Siai-Marchetti 11 Models with the most aircraft: - [SIAI Marchetti F.260C](https://openairdocs.org/model/siai-marchetti-f-260c): 17 aircraft (airframe model) - [Siai-Marchetti F.260](https://openairdocs.org/model/siai-marchetti-f-260): 7 aircraft (airframe model) - [Siai-Marchetti F.260B](https://openairdocs.org/model/siai-marchetti-f-260b): 4 aircraft (airframe model) All 3 models: https://openairdocs.org/ad/83-06-10/models.md Every aircraft: https://openairdocs.org/ad/83-06-10/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.