AD NUMBER: 2017-15-13

PRODUCT: Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters.

ACTION: Final Rule.

SUMMARY:  This AD requires reducing the life limit of certain landing gear parts and is prompted by a stress analysis

This AD defines the unsafe condition as a landing gear part remaining in service beyond its fatigue life. This condition could result in failure of a landing gear part, failure of a landing gear skid, and subsequent loss of control of the helicopter during takeoff or landing.

Required Actions: Before further flight, determine the accumulated retirement index number (RIN) for each part and remove it from service if it has reached or exceeded its life limit as follows. Thereafter, remove each part from service on or before reaching its life limit. For purposes of this AD, a run-on landing is defined as a landing with forward ground travel of the helicopter greater than 3 feet (0.91 m) with weight on skids.

• (1) For Skid Tube Assembly part number (P/N) 429-700-101, 429-700-102, and 429-030-586-
• 107: 16,000 RIN. Count 1 RIN for each landing; count 81 RIN for each run-on landing; and count
• 117 RIN for each autorotation landing.
• (2) For Forward Crosstube Assembly P/N 429-712-101: 10,000 RIN. Count 1 RIN for each
• landing; count 50 RIN for each run-on landing; and count 118 RIN for each autorotation landing.
• (3) Aft Crosstube Assembly P/N 429-723-108: 30,000 RIN. Count 1
• RIN for each landing; count 32 RIN for each run-on landing; and count 186 RIN for each autorotation landing.

DATES: This AD is effective August 31, 2017

COST: The FAA estimates this AD affects 71 helicopters of U.S. Registry. We estimate that operators may incur the following costs in order to comply with this AD. Labor costs are estimated at $85 per work-hour. Calculating the life limit will take about 0.25 work-hour for an estimated cost of $21 per helicopter and $1,491 for the U.S. fleet.

Replacing a skid tube assembly will take about 2 work-hours and parts will cost about $7,050 for an estimated replacement cost of $7,220.

Replacing a forward cross tube assembly will take about 1.5 work-hours and parts will cost about $5,880 for an estimated replacement cost of $6,008.

Replacing an aft tube assembly will take about 1.5 work-hours and parts will cost $6,710 for an estimated replacement cost of $6,838.

FMI: AD