Squawk Box: 07/04


The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts.


Southern California Propeller Service
Improper Repairs

The FAA is proposing a new airworthiness directive (AD) for Hartzell Propeller, Inc., McCauley Propeller Systems, and Sensenich Propeller Manufacturing Company, Inc. propellers returned to service by Southern California Propeller Service, of Inglewood, Calif. Comments on the proposed AD are due at the FAA by July 19, 2004.According to the FAA, inspections of various propeller models returned to service by Southern California Propeller Service have revealed safety-critical problems. These include blades found below minimum dimensional limits; blades not treated with Alodine after grinding; paint applied over bare aluminum; improperly drilled actuating pin holes and unapproved use of helicoil inserts in the actuating pin holes.Since late 1998, the FAA received 43 reports of safety and airworthiness problems associated with work performed by Southern California Propeller Service and revoked its repair station certificate on June 16, 1998.

Lycoming Reciprocating Engines
Crankshaft Gears

AD 2004-10-14 is effective June 25, 2004 and affects Lycoming direct-drive reciprocating engines (except O-145, O-320H, O-360E, LO-360E, LTO-360E, O-435 and TIO-541 series engines). The new AD supersedes AD 91-14-22, which requires inspection of the crankshaft gear installation and rework or replacement of the gears where necessary after a propeller strike, sudden stoppage, at overhaul, or whenever gear train repair is required. The new AD requires the same actions but makes the correction that the existing gear retaining bolt and lockplate be removed from service and new hardware installed, and revises the definitions for sudden stoppage and propeller strike. This AD results from a change to the definition of a propeller strike or sudden stoppage.

Garmin GTX 330 MODE S Transponders
Upgraded Software Required

The FAA is adopting a new AD aginst GARMIN International Inc. GTX 330/GTX 330D Mode S transponders. The AD requires installing GTX 330/330D Software Upgrade Version 3.03, 3.04, or 3.05. The AD is to prevent interrogating aircraft from possibly receiving inaccurate replies due to suppression from aircraft equipped with the GTX 330/330D Mode S Transponders when the pulses are below the Minimum Trigger Level. The inaccurate replies could result in reduced vertical separation or unsafe TCAS resolution advisories. The AD becomes effective on July 9, 2004.

TCM TSIO-520 Engine
Dual Cylinder Base O-Rings

During an annual inspection, one of the cylinder hold-down studs was found with a missing nut. The nut was found lying in the cylinder baffling area. A torque check of the remaining nuts showed that several had become loose. The cylinder was removed to investigate. Upon removal, the mechanic found the suspect cylinder had two cylinder base seals installed. The O-rings were deformed and compressed. Due to the two O-rings being installed, the original torque values had changed, allowing one nut to come completely off and several remaining nuts to loosen.

McFarlane Aviation Engine Pre-Heater
Engine Oil Pan Damage

Two reports have been received of a hole in the oil pan on Teledyne Continental engines equipped with silicone pad engine pre-heaters that use standard 110-volt electricity as a power source. SAFE-HEET brand FAA-PMA engine pre-heaters manufactured by McFarlane Aviation were installed on the O-470 and IO-520 engines with the stamped sheet metal oil pan. In both instances oil was discovered on the aircraft nose gear and hangar floor during the preflight inspection after the engine pre-heater was operated. Further investigation revealed that electrical arcing had burned/eroded a small hole in the oil pan with extensive engine oil loss. It was reported that one of the pre-heaters had been in service over ten years and one had been in service over two years.

Mooney M20 Airplanes, MY 1966-1978
Dukes Landing Gear Actuators

The FAA has received several Service Difficulty Reports regarding the premature failures of the Dukes P/N 1057-00-5, -5E, -5F, and -5G landing gear actuators. The agency later determined that some operators were inappropriately maintaining these products, installed in models manufactured from 1966 through 1978, with the wrong service instructions (SB 20-190) creating the premature failure of the landing gear actuator. This could prevent the landing gear from functioning properly and could result in a gear-up landing situation.M20 airplanes with Dukes 4196-00-1C and ITT LA11C2110 actuators have a 20:1 speed ratio, made possible with a double lead worm shaft, and the Dukes 1057-00-5 actuator uses a 40:1 speed ratio, made possible with a single lead worm shaft.To prevent premature failure of the landing gear actuators, we strongly recommend that owners and operators of the M20 airplanes referenced above stop using SB 20-190 to perform maintenance of these actuators. You should consult the appropriate M20 Service and Maintenance Manual.

Cessna Model 172R Skyhawk
Cracks in Lower Firewall

During an inspection, the technician found numerous cracks in the lower firewall (P/N 0553031-5) left side zone 124. The cracks radiated from the lower battery mount and cowling mount brackets. The submitter stated that he was aware of three additional like aircraft where the firewalls developed cracks in the same area. A search of the FAA Service Difficulty Reporting Program data base contains 20 reports on Cessna 172R with firewall cracks. Most of the reports were generated while complying with Service Bulletin 98-53-02.Part total time: 500 hours.

Piper Model PA-28R-201 Arrow IV
Cracked Rudder Spar

While inspecting the upper rudder spar (P/N 63543-00) and doublers (P/N 65341-00), a technician found cracks on both sides of the bend radius. Both cracks were about -to-1-inch in length from the top of the rudder to the nut plate. The operator inspected 13 additional PA-28R-201 aircraft in his fleet and discovered two of the aircraft had spar cracks and four of the aircraft had cracked doublers.Part total time: 2639 hours.

Various Piper Model PA-28 Airplanes
Control Surface Skins

Early Piper PA-28-140, PA-28-150, PA-28-160, PA-28-180, and PA-28-235 airplanes, were manufactured with skin stiffener beads on the control surfaces formed out. Later PA-28 surfaces, including current models, were manufactured with the beads formed in. Currently, replacement surfaces are provided only with the beads formed in. Consequently, when a control surface or its skin requires replacement on airplanes with outward facing beads, this creates confusion. The FAA has determined it is acceptable for stiffening beads on control surfaces to be formed in or out, provided both left and right sides are formed the same. The skin for a particular pair of control surfaces cannot be mismatched. Right and left ailerons must match, as must right and left flaps or right and left stabilators.It is not necessary for unlike surfaces to be similarly configured. When installing a replacement aileron, flap or stabilator, or performing a repair that necessitates replacing the control surface skins, the bead configuration should be identical to the opposite surface.


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