Tool tests aircraft warning lights

Simi Valley, CA-Flight paths into airports near urban centers or heavy industry hold many dangers for pilots, such as tall structures like skyscrapers and power lines. Lights placed on such structures warn pilots of the presence of such obstructions-and because reliability of these lights is essential, testing them requires precision.

Tool & Assembly Solutions recently developed an automated testing machine to make sure that such warning lights meet FAA specifications. Key components in the testing machines are precise motion control devices from Industrial Devices Corporation (IDC), Petaluma, CA.

The lights themselves consist of bulbs with mirror arrangements that direct the light. Each light tested can be positioned in a number of different angles-and individual tests can reposition them up to 25 times.

Accurate positioning relies on two sets of actuators from IDC. One, the RB4A positioning table, is a linear actuator that provides bidirectional repeatability to 6 microns, straightness and flatness to 1 micron per 25 mm, and travel length from two to 16 inches. For rotary positioning, the Tool & Assembly system uses IDC's NV electric cylinder. "These offered the only viable option, as they provide the mounts and necessary precision over a long range-0.1 deg vertically and 0.2 deg horizontally over a 60 ft range," says Michael Giboney, designer of the testing machine.

"We created a machine that works in a light tunnel measuring 5 ft wide by 60 ft long and 8 ft high," says Giboney. "At one end is the machine, with the light being tested, and at the other is a light detector to see if it conforms to FAA requirements."

A light might fail due to a bad bulb, which can be replaced, or due to misalignment of the mirrors-so they are tested from many different angles. "We're simulating the approach of an airplane with the pilot looking at the top of a building below him and to the side-that is, looking at the light from an angle rotated from the centerline," Giboney says. "If the pilot sees the light straight ahead, he'll run into it."

The machine, which measures around 2 x 3 x 21/2 ft, has a plate on the top surface that tilts and rotates to position the light. The step motor-powered IDC positioners control the rotation and tilt. The machine tests both steady-burning and flashing or pulsing lights.

Tool & Assembly tests lights for Honeywell Aerospace Electronic Systems in Simi Valley, CA, and Giboney says that the system has replaced a wholly manual system.

For more information on motion control devices from Industrial Devices Corporation: Enter 537