DOCUMENT 2421
REV. L
Instruction Manual
ICAO Approach Fixture
9
7.2
ANSI Installation Bolt Torque and Installation Method
•
Use fully threaded, cold-worked 18-8 stainless steel 3/8-16 bolts. (P/N 21715 is recommended.
•
Use Heico-Lock or Nord-Lock stainless steel lock-washers per FAA specifications*.
•
Mounting base holes must be degreased, cleaned, and dried prior to bolt installation.
•
Base-to-fixture mating surfaces must be degreased, cleaned, and dried prior to installation.
•
Apply marine grade anti-seize (K=.18) per manufacturer’s instructions to each bolt.
•
Install the 3/8-16 bolts with lock-washers per lock-washer manufacturer’s guidelines.
•
See section 7.3 for Heico-Lock installation guidelines (2014)
•
Achieve a full final torque of 225 in-lbs (25.4 N-m) +10%, -0% with a calibrated torque wrench.
•
Impact wrenches are
not
recommended as installation tools.
•
Check torque and re-torque all bolts within 2 weeks of initial installation.
•
Maintain all bolts by checking and re-torqueing per FAA specifications*.
•
If any lubricants or thread locking compounds are used (not recommended), torque must be recalculated
based on K factor provided by lubricant or compound manufacturer.
•
New bolts and lock-washers shall be used each time a light unit is removed from its base.
*Refer to the following specifications for FAA installation and maintenance recommendations:
•
AC150/5340-26 “Maintenance of Airport Visual Aids”
•
AC150/5345-46 “Specification for Runway and Taxiway Light Fixtures”
•
FAA Engineering Brief No. 83 “
In-pavement Light Fixture Bolts
”
7.3
Heico-Lock Installation Guidelines (2014)
Step 1: Hand tighten to ensure that 2-3 threads extend beyond the nut on through-bolt applications.
Step 2: Tighten each bolt to one-third of the final required torque following the pattern as shown below.
Step 3: Increase the torque to two-thirds following the pattern shown below.
Step 4: Increase the torque to full torque following the pattern shown below.
Step 5: Perform one final pass on each bolt working clockwise from bolt 1, at the full final torque.
