Learjet 60 Aircraft: Nose Wheel Steering Troubleshooting

January 2014

I want to discuss the issue of No Fault Found (NFF) and Troubleshooting the Nose Wheel Steering (NWS) system on the Learjet 60 and Learjet 60XR aircraft and also on the Learjet 31A aircraft when equipped with Digital Nose Wheel Steering.

The topic of NWS computers has been an ongoing discussion on the NBAA Learjet Technical Committee and the No Fault Found Sub-Committee, on both of which I sit. One of the top agenda items we continually see in the NFF Sub-Committee is when NWS computers have been replaced without resolving the discrepancy.

Bombardier CIC Troubleshooting Guide

I want to remind you there is a very helpful NWS Troubleshooting Guide located in the Bombardier CIC in the Learjet 60/Learjet 60XR SmartFix Plus section. Here’s where you can find it on the CIC.

1. Log into the applicable model SmartFix Plus section on the CIC
2. Select LRU Troubleshooting
3. On the pop-up window, the bottom selection is Nose Wheel Steering Troubleshooting Guide

There is a lot of good information and helpful tips to SUCCESFULLY troubleshoot a Nose Wheel Steering System the first time, saving significant time and money! Of course, if you ever need any assistance in troubleshooting your NWS system, please feel free to contact Duncan Aviation anytime.

Reducing NFF

How you complete the Material Return Authorization (MRA) can assist the industry while reducing the chances of getting a NFF in return. When filling out the MRA, refrain from ever using terms such as INOP or BROKEN for the discrepancy. When able, list the Aircraft Maintenance Manual step that is actual failing.

For example:

LR 60 AMM 32-50-00, Page 204, 1.A.(20)(p)4), “Disconnect Tone does not sound.”

This small change will go a long way to assist your repair facility bench technicians in isolating the circuit where the suspected discrepancy was reported.

Hope this helps you and in turn helps the next operator by reducing the NFF & DOA pool and that should make everyone happy.