ELT Goes Zap

Artex battery packs may leak and corrode, leading to component failure


The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts. Click here to view “Airworthiness Directives.”


The FAA has issued a special airworthiness bulletin to inform owners of Artex ELT equipment of a potential hazard. The FAA says there have been reports of Artex 110-4 ELT battery packs venting and leaking acid. In one case, the battery case failed and a piece of it became lodged in the rudder control cable of the airplane, chipping the pulley.

Engineers have concluded that, as the airplanes descend, outside air occasionally breaks the seal on the battery box, allowing moisture into the box that later condenses and sets up corrosion. So far the problem has been found primarily in Piper airplanes, particularly those that fly routinely at high altitudes.

The FAA recommends that owners check their ELT battery packs, looking for part number 452-0130. In Pipers, the Piper part number 758-696 Rev N3 is an equivalent part. If either of those part numbers is found, periodically inspect the battery pack case using the procedures recommended by Artex product advisory notice #002.

The inspection should be made at 100-hour intervals and at each annual. The part can also be replaced with a new Artex part carrying the same part number but manufactured after April 1998.

New Cessna Seat Rail Instructions
The FAA has amended its installation instructions for new seat rails on most of Cessnas piston fleet, as outlined in AD 87-20-03R2. The seat rails are manufactured with pilot holes only and do not contain all the holes necessary for the installation of the seat rails. The installer must drill enough holes to complete the installation. The FAA has decided that, since riveting the seat rails into place is extremely difficult in some circumstances, mechanics are allowed to substitute structural screws with lock nuts if the holes are ream-fit and spotfaced.

Beech BE-18-C45H
Landing Gear Failure

After takeoff, the landing gear would not fully retract and the landing gear circuit breaker popped. The pilot reset the circuit breaker, extended the gear and made a safe landing.Mechanics found the left main gear doors closed before the gear was up, obstructing the retraction cycle. The problem was traced to improperly rigged gear doors.Part total time – 24,914 hours.

Beech A-36 Bonanza
Defective Navigation Lights

The pilot reported the navigation lights inoperative.The navigation light circuit breaker had popped and the technician found the wiring in the left wing was not properly secured and was chafed through the insulation where it passed through a wing rib. There was no sign of wire clamps ever being used, indicating the problem originated when the aircraft was assembled.Part total time – 2,980 hours.

Beech 58 Baron
Defective Wing Attachment

During an annual inspection, the technician discovered a previous repair that was not airworthy.The repair had been made after a gear-up landing in 1980 and the aircraft had gone through 19 annual inspections since that time. Many of the rivets used in the repair had no shop head and the rivet heads were not seated against the structure.

Beech B95 Travel Air
Defective Cabin Heater

During an annual inspection, the inspector found a defective cabin heater.The 40-year-old Janitrol heater combustion head assembly had a 1-inch hole in the end of the canister fitting. The entire unit was severely corroded. The mechanic recommended the FAA issue an AD with recurring inspection requirements to address this subject.

Beech B100 King Air
Cabin Door Defect

The door structure failed when someone opened the door to board.An aluminum channel that forms the bottom of the door frame broke at the point where the hinge is attached. The area was also severely corroded. Part total time – 11,278 hours.

Cessna 152 Aerobat
Defective Fuel Tank Security

While investigating a fuel leak, the technician removed the right wing fuel tank and found the aft outboard strap assembly broken. The aluminum strap broke at the location of the screw hole, and the metal grain ran parallel to the fracture surface and the bend. He speculated the strap assembly would not have broken if the metal grain had been properly oriented perpendicular to the direction of applied stress.The technician also discovered the source of the fuel leak was a crack in the fuel tank adjacent to the broken strap at the aft bottom fuel outlet fitting. The fuel tank crack was previously repaired by welding.

Cessna 172RG Cardinal
Defective Nose Gear Attachment

During a scheduled inspection, a technician discovered the nose landing gear retraction actuator attachment fitting cracked.The crack was approximately 1 inch long and the fitting was in danger of imminent failure. All of the lower attachment bolts were loose, which may have caused the crack. Part total time – 11,971 hours.

Cessna 177RG Cardinal
Flight Control Balance

While replacing the stabilator bearings, the inspector discovered cracks in the stabilator balance weight attachments.Three of the four balance weight support brackets were cracked in the bend radius. The length of the cracks was measured at 1.25 inches, 1.5 inches, and 1.75 inches. The stabilator was removed for replacement of the bearings, which made discovery of this defect much easier.Part total time – 5,000 hours.

Cessna 182S Skylane
Elevator Trim System Defect

While checking for proper elevator trim system operation after complying with SB 00-22-01A on the KAP-104 autopilot servo, the technician discovered the trim would not move full travel.The technician found the elevator servo trim cable swaged ball outside the servo drum. The autopilot cable was not centered in reference to the elevator trim neutral position. After rigging the trim system in accordance with the manufacturers technical data, the trim system functioned properly. The submitter said, It was obvious that the elevator trim system was not properly rigged prior to delivery from the manufacturer. Part total time – 105 hours.

Maule MX 7-180 Star Rocket
Engine Exhaust Failure

The pilot reported an abnormal odor in the cockpit. During the next takeoff, he heard a loud rattling sound and aborted the takeoff.After parking the aircraft, the pilot found the right outer muffler shroud loose. After removing the shroud, he discovered the muffler severely ruptured. Part total time – 223 hours.

Mooney M20J
Defective Ignition Switch

The pilot reported the engine ignition switch operated intermittently. It was necessary to engage the switch several times to get the engine started, and the problem became progressively worse.When a maintenance technician replaced the ignition switch during an annual inspection, he discovered it was the new-type switch and had a low number of operating hours. This presents the inherent danger of grounding one or both magnetos due to ignition switch failure.Part total time – 428 hours.

Piper PA-28-160 Cherokee
Structural Wing Damage

During an annual inspection, the inspector discovered severe corrosion inside the left wing.The forward edge of the aft main wing spar, located behind the fuel tank, suffered corrosion exfoliation, which consumed approximately 50 percent of the spar thickness. This damage was attributed to the presence of a large nest and fecal matter deposited by the rodents.

Piper PA-28RT-201 Arrow
Nose Gear Trunnion Failure

During an annual inspection, the technician turned the nose landing gear using a tow bar. When the nose gear reached the stop, a piece of the trunnion broke and fell to the floor.The technician found the trunnion cracked in three locations. These areas displayed evidence of discontinuity in the interior structure of the metal. Another area had metal porosity at the surface. According to the aircraft maintenance records, the nose gear trunnion was installed as original equipment when the aircraft was manufactured.Part total time – 6,984 hours.

Piper PA-32-300 Cherokee Six
Wing Skin Cracks

During a scheduled inspection, the inspector discovered numerous cracks on the left wing skin.The cracks were located at the inboard and outboard edges of the upper skin panel at each end of the stringers. Also, one of the stringers was cracked. When the skin panel was removed, the technician noticed it did not have reinforcement doublers which are normally installed at the inboard and outboard ends of the skin panel where it attaches to the stringers. Part total time – 3,372 hours.

Piper PA-44-180T Turbo Seminole
Poor Engine Operation

The pilot reported that the left engine began running rough and emitting smoke from the exhaust. The maintenance technician found the electrical fuel primer for the left engine was active when the master switch was in the on position. While checking further, he found the push-to-prime switch on the instrument panel had failed internally. The switch shorted internally causing electrical power to be applied to the primer when the master switch supplied input power. After changing the switch, the systems functioned properly and engine performance returned to normal.Part total time – 1,350 hours.

Piper PA-46-350P Malibu Mirage
Flight Control Stiffness

After a flight, the pilot reported stiffness or binding in the aileron control system movement. The stiffness seemed to get progressively worse as the flight continued.The technician could not find any cause for the stiffness. The linkage, cable routing, and tension were correct. He lubricated the entire flight control system and the stiffness problem was gone.The submitter said he thought the manufacturer did not lubricate the flight control system prior to delivery of the aircraft.Part total time – 18 hours.

Twin Commander 690B
Aileron Hinge Cracks

During a scheduled inspection, the technician found cracks on both ailerons.The cracks were located in the inboard aileron hinge U-channel webs around the lower attachment bolt. The submitter recommended the manufacturer design and issue a doubler to reinforce this area.Part total time – 4,616 hours.


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