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- Learjet Services
Learjet Spring 2002
- Pulse Light Modifications
- New Learjet Technical Representative
- Wing Walk or Pitch Porpoise?
- Nose Steering Squawks
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Pulse Light Modifications
— Joe Austin
Precise Flight has developed a control box that can be hooked into the tail logo lights and will then cycle in sequence with landing and recognition lights. It is a six channel unit, model number 2401. This box can also take input from the TCAS controller; this allows the unit to operate the pulse light system when a TCAS advisory is displayed, with the intent of making your aircraft more visible during the advisory.
The new control box is the same size as the original, so structural modification to the airframe is not required. Wiring changes are made using wiring prints available through Precise Flight and approved under a 337 document.
One of the benefits of the pulse light system has always been the “soft start” that it gives to the bulb when commanded to illuminate. This “soft start” function helps extend the life of the bulb.
Pulse light switches may need to be added or changed to a different style on the instrument panel if you do not already have the system installed in your aircraft.
For more information, contact Roger Courey in BTL at 800.525.2376, or Jeff Manion in LNK at 800.228.4277.
New Learjet Technical Representative
— Gina Cacek
In May, Duncan Aviation welcomes Dave Schiver as our new Learjet Technical Representative. Dave has over 20 years of aviation experience, having recently spent 14 years at Bombardier/Learjet (Dallas) as the Project Supervisor and Program Manager. Contact Dave for FREE Learjet technical info call 402.479.1680 / 800.228.4277.
At the end of May, we bid farewell to Bill Schroeder, our current Lear Tech Rep as he retires. Bill has been in aviation for 38 years, 18 of them with Duncan Aviation. Thank you, Bill, and best wishes for the future!
Wing Walk or Pitch Porpoise?
— Chris Gress
Has your aircraft experienced Wing Walk or a Pitch Porpoise? Duncan Aviation technicians have found a failed velocity generator (v.g) in the JET SA142 & SA200 Roll Servos may cause a wing walk and a failed v.g in the JET SA142 & SA200 pitch servos can cause pitch porpoise. The pitch porpoise can also be caused by the horizontal stabilizer actuator secondary motor not trimming properly when told to by the Autopilot computer. Bad solder joints on the servo PC board will cause intermittent roll or pitch operation. The SA200 { 501-1112- ( ) } servo also has a tendency to jerk hard one direction when the internal A & B pin input wiring has frayed or broken. Call Chris Gress with questions at 402.479.1664 / 800.228.4277.
Nose Steering Squawks
— Chris Gress
We have found that nose strut shimmy can be caused by the nose strut internal torque block being worn, or the SA400 nose steering servo (6608278-2). The JET SA400 nose steering servo may need a new internal output shaft, brushes or a torque resistor calibration if it seems weak. If you have the Lear Avia NWS servo 800171- ( ), it is likely that the clutch teeth or pinion gear are excessively worn. Nose Steering Servos have a tendency to intake oil or grease from the nose strut, which contaminates the clutches causing them to be weak. Bad PC board solder joints will cause intermittent operation. Call Chris Gress with questions at 402.479.1664 / 800.228.4277.
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