Airworthiness Directive · Amendment 39-14976 · Teledyne Continental Motors GTSIO-520 Series Reciprocating Engines
Teledyne Continental Motors GTSIO-520 Series Reciprocating Engines
This AD applies to Teledyne Continental Motors (TCM) GTSIO-520 series reciprocating engines. These engines are installed on, but not limited to, Twin Commander (formerly Aero Commander) model 685, Cessna model 404, 411 series, and 421 series, British Aerospace, Aircraft Group, Scottish Division model B.206 series 2 and Aeronautica Macchi model AM-3 airplanes.
The FAA is superseding an existing airworthiness directive (AD) for Teledyne Continental Motors (TCM) GTSIO-520 series reciprocating engines. That AD currently requires initial and repetitive visual inspections of the starter adapter assembly and crankshaft gear and unscheduled visual inspections of the starter adapter assembly and crankshaft gear due to a rough-running engine. That AD also requires replacement of the starter adapter shaft gear needle bearing with a certain bushing and installation of a certain TCM service kit at the next engine overhaul, or at the next starter adapter replacement, whichever occurs first. This AD requires performing the inspection ordered in paragraph (h) of this AD every 100 hours time-in- service (TIS), or annually. This proposed AD results from an error discovered in AD 2005-20-04. We are issuing this AD to failure of the starter adapter assembly and or crankshaft gear, resulting in failure of the engine and possible forced landing.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
If, during an inspection required by paragraph (g), (h), (i), or (j) of this AD, you find needle bearing, part number (P/N) 537721, installed in the crankcase, replace it with a serviceable bushing, P/N 654472 or equivalent FAA approved bearing, before reassembling components. Use the bushing installation procedure specified in Part 4 of TCM Mandatory Service Bulletin (MSB) No. MSB94-4G, dated October 31, 2005.
For any engine that experiences rough running conditions regardless of time-in-service (TIS), do the following:
(1) Before further flight, perform the inspection procedures specified in Part 1 and Part 3 of TCM MSB No. MSB94-4G, dated October 31, 2005, and replace components as necessary.
(2) An engine is considered rough-running if there is a sudden increase in the perceived vibration levels that cannot be cleared by adjustment of the engine controls; particularly the fuel mixture setting. Information on rough running engines can be found in the aircraft manufacturer's Airplane Flight Manual, Pilot's Operating Handbook, or Aircraft Owners Manual.
For any engine that has been inspected using paragraph (h) of AD 2005-20-04 and the 100-hour inspection procedures or 100 hour TIS intervals or annual inspection procedures, continue the inspections as follows:
(1) Perform the inspection procedures specified in Part 2 of TCM MSB No. MSB94-4G, dated October 31, 2005 and replace components as necessary at each 100 hour TIS interval (plus or minus 10 hours TIS) or annual inspection, whichever occurs first.
(2) Thereafter, at each 100 hour TIS interval (plus or minus 10 hours TIS) perform repetitive inspections and component replacements as specified in paragraph (h)(1) of this AD.
(3) If the inspection is performed at more than 100 hour intervals, subtract the additional hours from the next scheduled 100 hour inspection.
(i) For any engine that has not been inspected using paragraph (h) of AD 2005-20-04, within 25 hours TIS or at the annual inspection, whichever occurs first, do the following:
(1) Perform the inspection procedures specified in Part 2 of TCM MSB No. MSB94-4G, dated October 31, 2005 and replace components as necessary.
(2) Thereafter, at each 100-hour TIS interval (plus or minus 10 hours TIS) perform repetitive inspections and component replacements as specified in paragraph (i)(1) of this AD.
(3) If the inspection is performed at more than 100 hour intervals, subtract the additional hours from the next scheduled 100 hour inspection.
For any starter adapter with 400 hours or more TIS or unknown TIS on the effective date of this AD, do the following:
(1) Within 25 hours TIS, perform the inspection procedures specified in Part 3 of TCM MSB No. MSB94-4G, dated October 31, 2005, and replace components as necessary.
(2) Thereafter, at 400-hour TIS intervals, (plus or minus 10 hours TIS), perform repetitive inspections and component replacements specified in Part 3 of TCM MSB No. MSB94-4G, dated October 31, 2005, and replace components as necessary.
For any starter adapter with fewer than 400 hours TIS on the effective date of this AD, do the following:
(1) Upon accumulation of 400 hours TIS, (plus or minus 10 hours TIS), perform the inspection procedures specified in Part 3 of TCM MSB No. MSB94-4G, dated October 31, 2005, and replace components as necessary.
(2) Thereafter, at 400-hour TIS intervals, (plus or minus 10 hours TIS), perform repetitive inspections and component replacements, as specified in Part 3 of TCM MSB No. MSB94-4G, dated October 31, 2005, and replace components as necessary.
At the next engine overhaul or starter adapter replacement after the effective date of this AD, whichever occurs first, do the following:
(1) Install TCM service kit, P/N EQ6642 (new) or EQ6642R (rebuilt). Use the service kit installation procedures specified in Part 5 of TCM MSB No. MSB94-4G, dated October 31, 2005.
(2) Continue performing the inspections and component replacements specified in paragraphs (g), (h), (i), (j) and (k) of this AD.
Special flight permits are prohibited for rough-running engines described in paragraph (g)(2) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
