Learjet Winter 2002

• Grimes Rotating Beacons
• ADEL Clamp Damage
• The 6608268-6 Starter
• Learjet 31 Generator QAD Kit Air Exit Seal
• Brush Life
• Honeywell Grimes Authorized Sales & Service Center
• Advanced Planning

Grimes Rotating Beacons

— Chris Gress

Many lighting products do not have manufacturer-mandated inspection intervals and their maintenance is considered “on condition.” So after many hours of use components may suddenly fail after some subtle signs. Rotating beacons may show signs of slow rotation or popping the circuit breaker. These units are mechanical devices containing a motor, bearings, gears, bulbs and oscillating mechanisms. The 40-0100-( ) type Grimes rotating beacon has a common wear problem in the gear mechanism, particularly the cam gear & the worm gear. And as with any mechanical item they are prone to wear, friction and corrosion. Another sign is poor performance when exposed to cool or cold temperatures. We suggest the unit be cleaned, lubricated & inspected every 1000-1500 hours to prevent escalating wear to numerous parts.

ADEL Clamp Damage

— Dick Hyde

Be aware that the ADEL wire clamp and ADEL oxygen line clamps in the aft equipment bay have rubber insulators that can deteriorate with age. If unchecked this could lead to wire and line chafing and has the potential to cause oxygen line leaks and wire ground shorts.

The 6608268-6 Starter

— Bill Schroeder

On the 35/36 and 55 models, the 6608268-6 starter Gear Box (Bendix part of the starter) is vented through the Jaw Retaining Stud. The Drive Jaw has two small holes outside of the teeth. A problem to be aware of with the vent in the Jaw Stud is that a little oil can run out. This may occur especially if the starter is slightly over serviced with oil.

Learjet 31 Generator QAD Kit Air Exit Seal

— Bill Schroeder

Until June 2001 there was no replacement for the seal between the QAD adaptor and cowling. The only repair was a new QAD Kit. A seal is now available, P/N 23080-1025. It’s attached to the QAD adaptor with Dow 732W. This info is obtained from the DC starter-generator, 23080 Series IV Repair/Overhaul Manual, dated June 30/01.

Brush Life

— Chris Gress

Learjet starter/generator 30B37-49BT has a tendency to eat brushes if precise procedures are not followed. If the brushes are installed without reconditioning the commutator or if the brushes are installed without proper contouring to the commutator and “run in,” you will find the unit to have short brush life and difficulty carrying the load demands with the normal field current draw from the Voltage Regulator. Brush life can be extended by careful reconditioning, seating and run in procedures.

Honeywell Grimes Authorized Sales & Service Center

— Chris Gress

Effective immediately, Duncan Aviation is an Authorized Honeywell Grimes Sales and Service Center.

This agreement gives Duncan Aviation customers access to the complete line of Honeywell Grimes products including strobe power supplies, battery power supplies, rotating beacons, navigational lights, etc.

In addition, customers will be able to use Duncan Aviation accessory services seven days a week for service on Honeywell Grimes products.

Advanced Planning

— Dick Hyde

High quality maintenance facilities are usually the busiest. In order to ensure that the inspection your aircraft requires is performed at your convenience and at the facility you choose, plan your maintenance needs at least six months in advance. This will reduce scheduling frustrations and allow downtime to be kept to a minimum.

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