© ADB Airfield Solutions All Rights Reserved
9
2.3 Installation
In-pavement fixtures must be installed according to the plans and specifications; the
applicable regulatory guidance; and the manufacturer’s instruction manual. For FAA
applications, installation guidance is provided in AC 150/5340-30 (current edition).
Following are a number of items to be aware of:
2.3.1 Mechanical
Requirements
1. Correct dimensional placement of the lights is of prime importance. To achieve this,
careful attention to detail is required. Survey instruments may be used to accurately
position all fixtures for their precise location, elevation, and azimuth. The tolerances
required in FAA AC 150/5340-30, and the plans, must not be exceeded. The light beam
must be aligned as described in FAA AC 150/5340-30 with a horizontal tolerance of ±1
degree. The light fixture must be level, and the top outside edge of the fixture must be
b0 inch and -1/16 inch (1.5875 mm) with respect to the surrounding pavement.
See FAA AC 150/5340-30, Chapter 11,
Fixture Mounting Bases
, for additional guidance
on installing Light Bases. Incorrect installation may cause the light output to appear to be
too dim or too bright. Incorrect installation may also increase the risk for fixture
mechanical failures.
2. Insure all base can mounting surfaces are free of dust, dirt or debris.
3. Per FAA AC 150/5340-30, Chapter 10, and FAA Engineering Brief No 83, the fixture
must
be mounted using properly installed anti-vibration lock washers under the mounting bolts.
An anti-vibration lock washer is composed of a pair of unique washers with radial teeth
that grip and seat the mating surfaces. The rise of the cams between the face of washers
is greater than the pitch of the bolt. This creates tension that positively locks the bolt. Use
extreme care when placing the two halves of the lock washer together. The cams (or
steps) of each half of the lock washer must face each other.
4. Per FAA AC 150/5340-30, Chapter 10, and FAA Engineering Brief No 83, it is extremely
important that other types of washers, such as split washers, must not be used. Failure to
use properly installed anti-vibration lock washers will cause mounting bolts to become
loose. Loose bolts increase the risk for fixture mechanical failures. Loose bolts can also
increase fixture slippage which increases the shear load on the bolts. This can cause
individual bolt failure, resulting in increased load on the remaining bolts. Finally, this can
result in an increased risk that bolts come out or shear-off, causing the bolt and fixture to
become FOD on the Runway or Taxiway.
5. Consider the use of ceramic bolts, especially if stainless steel Light Bases are being used.
Guidance on the application of ceramic bolts is given in FAA Engineering Brief No 83.
6. The fixture hold down bolts must be torqued properly and must not be over torqued.
Recommended torque values are given in “Installation on L-868 Base” on page 16. If the
torque limit is exceeded (typically due to the use of impact wrenches), the bolt is
WARNING
Read installation instructions in their entirety before starting installation.
• Become familiar with the general safety instructions in this section of the
manual before installing, operating, maintaining or repairing this
equipment.
• Read and carefully follow the instructions throughout this manual for
performing specific tasks and working with specific equipment.
Failure to follow these warnings may result in serious injury or
equipment damage.
