GPS-4000S GPS receiver availability

Effectivity: Learjet 60-293, 60-307, 60-319 – 60-430 aircraft 

ATA: 34 

By: Mike Naish  

Bombardier would like to inform select Learjet aircraft operators that there is an issue with the part number (P/N) 822-2189-101 GPS-4000S GPS receiver that makes it no longer available for purchase or exchange from Collins Aerospace. 

Collins Aerospace identified a potential issue with the above referenced GPS receiver that may cause a temporary loss of satellite-based augmentation system (SBAS) mode which can cause loss of localizer performance with vertical guidance (LPV) for up to five minutes. 

It was also discovered that Message Type 6 (Integrity Information) was beyond the timeout periods specified in radio technical commission for aeronautics (RTCA) DO-229C standard, leading to a concern related to incorrect processing of the SBAS system integrity information. This part number GPS-4000S GPS receiver may be unable to notify the flight crew when the integrity of the SBAS qualified Global Navigation Satellite System (GNSS) position may be compromised. 

Collins Aerospace is currently in the process of certifying a replacement GPS-4000S, P/N 822-2189-102, that is projected to be available sometime in Quarter 3 of 2024. Collins Aerospace has suspended all sales or exchanges of the P/N 822-2189-101 GPS receiver as well as suspended use of AML STC ST01833WI, which installs this GPS receiver in several aircraft platforms including the Learjet 60XR. Sales of replacement GPS-4000S GPS receivers will not resume until the P/N 822-2189-102 becomes available. 

In the interim, Collins Aerospace will continue to repair P/N 822-2189-101 GPS receivers for units that may fail in customer aircraft. As mentioned above, there will be no exchanges for these GPS receivers. Contact the Collins Service center for the repair turn-time of these units. 

If you have any questions regarding this issue, please contact the Customer Response Centre.