The FAA Releases Aviation Maintenance Alerts (#371)

Aviation Safety - General

Top Alerts:       

Cessna : 340A : Failed Nose Gear Linkage : ATA 3220
An unidentified submitter writes, "The landing gear 'down' actuation (in this aircraft) produced an unsafe nose gear indication light. An attempt at manual gear extension proved unsuccessful since the nose landing gear did not extend to a down and locked position. Subsequent damage resulted to the aircraft when the nose landing gear collapsed upon landing. An inspection of the aircraft revealed the nose landing gear linkage adjusting fork (P/N 5045211-2) fractured, thereby (preventing) the extension of the nose landing gear to a down and locked position. Evidence suggests this fracture was progressive in nature due to indications (some) degradation to the component's structure existed prior to failure."
Part Total Time: (unknown).         

Cessna: 208B; Failed Fuel Pump; ATA 7314
(This aircraft is powered by a Pratt & Whitney PT6A-114 turbine.)
"During an operational inspection," states a repair station submitter, "the fuel pump was rejected in accordance with Pratt & Whitney's SB1645. A (zero time since overhaul) replacement pump was installed, and during the operational run-checks the fuel pressure 'low' light and the fuel pump 'on' light in the annunciator panel started cycling when the torque went above 1.400 ft. lbs. This pump was replaced with a second (zero TSO) pump. The operational run-check produced the same results as the first replacement pump. The reservoir tank pressure was checked using a gauge plumbed into the system — it was found that at idle the pressure was 6.5 psi. Power was increased — and at 1,200 ft. lbs. of torque the pressure started dropping off. At 1,400 ft. lbs. the pressure was 3.25 psi. A third pump was installed and on its performance run all parameters were found to be good. Further investigation is needed before a determination can be made of this problem."
Part Total Time: (original pump: unknown).            

Cirrus: SR20; Cracked Nose Gear Strut; ATA 3222
"A report of 'nose wheel pant damage after landing' (caused me) to inspect this aircraft," writes a mechanic. "I found the upper left arm on the nose strut (P/N 11907-005) was seriously cracked. This crack ran from the top of the arm (just forward of the strut data plate) through the entire arm, and stopped at the bottom where a gusset was welded. This (same) crack continued to run parallel to the gusset for approximately 0.50 inches. (I) also found the nose wheel stop and nose fork were damaged. A possible cause (for these discrepancies) could be repeated, unreported hard landings. I would recommend all operators to inspect in this area after any hard landing or any excessive stress on the nose gear.”
Part Total Time: 515.0 hours.