L-852A-D, J & K ITCF, F-Range, ICAO LED Taxiway Centerline Light
96A0460 Rev. C
Checking Bolt Torque
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3.4 Checking Bolt
Torque
An established schedule for checking light fixture bolt torque and bolt condition is mandatory.
This is particularly true for areas that are subject to high impact loads from aircraft such as
runway status lights, runway touchdown zone lights, runway centerline lights, and taxiway
lead-off lights. Although AC 150/5340-26 offers a recommended schedule for periodic
checks, these checks should be tailored to the facility based on local conditions such as
environmental issues and runway traffic load.
FAA Cert Alert No. 14-03 refers to AC 150/5340-26 for the frequency of checking bolt torque.
AC 150/5340-26C paragraph 5.3.4.1.4,
Bi-Monthly Checks
states: “
The torque of the bolts
attaching the light fixture to its base should be checked with a calibrated torque wrench –
never use an impact wrench.
”
Regular inspection as outlined in FAA Cert Alert No. 14-03, Canada Civil Aviation Safety Alert
Document CASA 2014-05, and any other applicable regulatory guidelines is critical in insuring
torque on all bolts is restored to optimum values. Bolts that loosen more often should be
inspected and re-torqued on a more frequent basis.
It is especially important to maintain a regular inspection schedule for LED fixtures. Since
LED fixtures operate more reliably and are not subject to removal/replacement/retorquing as
frequently as would be seen with incandescent fixtures, it is even more important to
implement regular torque inspections.
It is critical that remedial action be taken if bolts are found to be loose or missing during
inspection. If this occurs, it is important to carefully inspect all structural elements of the
mounting system as defined in paragraph 1.2. Also inspect the base can for general
structural conditions such as:
•
Is the base can solidly mounted in the pavement, and not moving or rocking during
rollovers?
•
If a base can extension is present, are all extension attachment bolts tight?
If poor base can structure or mounting system components are not in accordance with
regulatory requirements or are in poor condition, it is the airport’s responsibility to:
•
Increase the frequency of bolt torque inspection to insure that no bolts become loose or
missing.
•
Quickly replace/repair the mounting system components, which may include replacing the
entire base can.
Airport operators must also ensure these maintenance activities are properly documented.
