A customer called us recently because he wasn’t able to download the monthly data from either of his Pratt & Whitney Canada PW305A engines on board a Learjet 60 aircraft. Without this data, the customer may not have been covered by his ESP (Eagle Service Plan).
Fortunately, our newly positioned Rapid Response Engine Tech in Tampa, Florida (TPA), Warren Wiatrek, traveled to Fort Myers Airport (RSW) and discovered that the cannon plug to the EDU (Engine Diagnostic Unit) was not seated properly, preventing the download.
Over time engine vibration can cause the cannon plug to migrate aft causing a lost signal. When this happens to you will be unable to download your engine's trend data or faults. This is an airframe mounted engine component that can make the corrective action labor intensive requiring the removal of the APU if applicable, fuel lines, and aircraft batteries just to gain access the EDU.
At the next EDU replacement, before reinstalling the APU and aircraft batteries, visually inspect to verify that the EDU extension cable is properly connected and secure.
In the photo below, you can see the plug has vibrated away from the EDU and has lost signal.