AD 83-03-04

83-03-04 BELL HELICOPTER TEXTRON, INC.: Amendment 39-4562. Applies to all Model 206L and 206L-1 helicopters certificated in all categories that are equipped with emergency flotation equipment kits P/N 206-706-067-1, -5, -101, and 206-706-210-101, and - 103.

Compliance is required within 150 hours' time in service after the effective date of this AD unless already accomplished in accordance with Service Bulletin 206L-81-21 or modified in accordance with Technical Bulletin 206L-82-84.

To determine whether the shear heads in the float inflation valve assembly have been damaged by incorrect installation, accomplish the following:

a. Disconnect the battery. NOTE: DO NOT DISCONNECT ELECTRICAL CONNECTOR TO THE SQUIB VALVE ON THE INFLATION VALVE AT THE CYLINDER ASSEMBLY.

b. Remove the nitrogen gas from inflation cylinder, carefully bleeding off the gas through the Schrader inlet valve.

CAUTION DO NOT ATTEMPT TO REMOVE THE SHEAR HEAD PISTON PINPRIOR TO REMOVAL OF THE NITROGEN GAS FROM THE CYLINDER.

c. Carefully remove the shear head release piston pin. Visually inspect the pin, as removed, to determine if the position of the flat machined side of the piston pin faces the inlet end of the shear head machined groove (Ref. Figure 1, Bell Helicopter Textron Service Bulletin 206L-81-21, dated May 7, 1981).

d. If the shear head release piston pin has been installed by rotating the pin 90 to 180 degrees, placing the round side of the pin against the inlet side of the shear head inlet groove, the pin has been incorrectly installed.

e. If the shear head release piston pin is found installed incorrectly, remove the shear head from the valve body and discard. Install a new shear head and "0" rings. On installation, thread shear head into the valve body and torque to 20 foot-pounds, prior to installing the shear head release pin. Reinstall piston pin as described in paragraph f.

f. If the shear head release piston pin is found correctly installed, place "0" ring in groove of piston pin and install piston pin part way into body with flat side on end of piston pin facing inlet port. Rotate piston pin 90 degrees and lightly push piston pin down into valve body until it bottoms out. While pushing on piston pin, rotate piston pin 90 degrees in the opposite direction. Piston pin should drop deeper into body. Flat side of piston pin must engage groove in shear head, with flat side facing inlet port.

g. Refill cylinder with nitrogen. Check for leaks. Connect battery, and refer to appropriate service instruction. NOTE X-ray Inspection (Alternate Method)

Where X-ray equipment is available, inspection of the valve assembly may be accomplished by use of X-ray pictures. Reference Figure 2, Bell Helicopter Textron Service Bulletin 206L-81-21 dated May 7, 1981, or FAA approved equivalent for examples of correct and incorrect piston pin installation in the valve assembly.This eliminates the need to bleed off the nitrogen and to disassembly the valve assembly.

CAUTION DISCONNECT AND REMOVE THE SQUIB FROM THE VALVE ASSEMBLY PRIOR TO USE OF X-RAY.

h. Equivalent means of compliance with the AD may be approved by the Manager, Aircraft Certification Division, Southwest Region, Fort Worth, Texas.

This amendment becomes effective February 17, 1983.