Size Matters

While complying with Service Bulletin 55-3835 “Installation of Empennage Inspection Access Panels,” the horizontal stabilizer forward spar and ribs were found not riveted correctly from the factory. Many rivets that go through the forward spar are too short, and where the rib and forward spar come together, the rivet misses the rib. We have found this same problem on other aircraft we have inspected.

Editorial Staff

Wednesday, September 26, 2012 at 12:00 AM ET

Verified

Key Takeaways:

Multiple aircraft types, including Beechcraft King Airs and Piper Senecas, reported significant structural defects such as factory-installed incorrect rivets, cracked wing spar fittings, and cracked nose gear trunnions.
Engine and fuel system vulnerabilities were noted, including a collapsed engine breather vent line in Cessna Caravans and internal corrosion in Continental IO-550-N fuel injector lines, a recurring issue on STC-equipped Cirrus SR22s.
A critical propeller failure risk was identified involving a McCauley propeller with a broken bearing race due to an incorrectly sized bearing, indicating imminent complete failure.
Several reported defects, particularly the King Air's bad rivets and the Caravan's vent lines, were noted as recurring or found during fleet-wide inspections, highlighting broader maintenance and safety concerns.

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Beechcraft B200 King Air
Bad Rivet Installation
While complying with Service Bulletin 55-3835 “Installation of Empennage Inspection Access Panels,” the horizontal stabilizer forward spar and ribs were found not riveted correctly from the factory. Many rivets that go through the forward spar are too short, and where the rib and forward spar come together, the rivet misses the rib. We have found this same problem on other aircraft we have inspected.
Part(s) Total Time: (unknown)

Beechcraft 200 King Air
Cracked Spar Shear Fitting
While accomplishing a wing bolt inspection, the l/h lower wing spar attach shear fitting (p/n 1011100731) was found cracked. This crack is approximately 0.75 inches long and is located in the forward flange area.
Part Total Time: 13,141.0 hours

Cessna 208B Grand Caravan
Collapsed Engine Vent Line
While inspecting the overboard breather vent line, the rubber section was found swollen internally. The inspection was part of a fleet-wide campaign to address aging hose sections. Operators of older Caravans would be wise to check their aircraft for similar defects.
Part Total Time: (unknown)

Piper PA-34-200 Seneca
Cracked Nose Gear Trunnion
During an annual inspection, the right pivot point of the nose gear trunnion (p/n: 9572300) was found cracked where it is welded to the pivot bolt housing.
Part Total Time: 4547.0 hours

Continental IO-550-N
Corroded Fuel Injector Nozzles/Lines
A submitter reports finding the upper deck line rusting internally on Tornado Alley turbo-equipped aircraft. The rust consists of both large and small particles that are easily dislodged. Aircraft with this condition exhibit rust stains on and around the fuel injectors observed when the injectors are removed for cleaning. This rust could accumulate and possibly clog the fuel injector air passages. The submitter has noticed this condition on two different aircraft equipped with STCs SA10588SC and SE10589SC installed on Cirrus SR22 airplanes.
Part Total Time: 1002.0 hours

McCauley D3A32C406-C Propeller
Broken Bearing Race
Oil was found on the A36 Bonanza’s cowling. The propeller was sent to a prop shop. Most of the ball bearings measured the proper size of 15/32 inches, but one bearing measured 16/32 inches. The blade and hub were not repairable. Complete failure of the propeller was imminent.
Part Total Time: 170.47 hours