Part-66 Module 9 case studies
Part-66 Module 9 · Put your knowledge to work in context.
Module 9 - Human Factors is one of the knowledge modules in the EASA Part-66 aircraft maintenance licence syllabus. Part-66 forms Annex III to Commission Regulation (EU) No 1321/2014 on continuing airworthiness, the regulation that sets out requirements for the approval of organisations and personnel involved in maintenance. The Part-66 Module 9 case studies are 5 cases and about 4,030 words.
1The Last Torque on the Second Night Shift
03:40 on the second consecutive night shift (22:00–06:00) in a line maintenance hangar. A technician is replacing the left hydraulic pump on a narrow-body twinjet due out at 07:15.
770 words, about 4 min2The Box That Gets Signed Later
A line station handles three turnarounds per shift against a 45-minute target. For the last two years the duplicate (independent) inspection of the flight-control disconnect has in practice been signed by the crew chief alone when a turnaround is tight; a second technician countersigns later, sometimes after the aircraft has departed.
784 words, about 4 min3Avionics Bay, 33 Degrees, 180 Lux
Night shift in an un-airconditioned hangar in summer: ambient 33 °C, relative humidity 70 %. An aircraft on the adjacent bay runs its APU for cabin cooling, giving about 88 dB(A) at the avionics bay work position, with impact-wrench peaks of 112 dB(C).
733 words, about 4 min4The Wheel That Went Out
A main-wheel change on a narrow-body jet. The task card requires the axle nut to be torqued to 550 N·m, the wheel spun to confirm free rotation, and a duplicate inspection before release.
816 words, about 4 min5Forty Minutes Left in the Tank
Confined-space entry into the wing fuel tank of a business jet to seal an internal leak. The tank was purged overnight and ventilated with a forced-air duct.
927 words, about 5 min