Multiscan TM Weather Radar operation and failure reporting
Effectivity: Global 5000 and Global 6000 with Vision Flight Deck, Global 7500 aircraft
ATA 34-41
The Collins Aerospace RTA-4118/4218 MultiScan TM Weather Radar system (WXR) provides many advanced features and includes system diagnostic reporting to the associated maintenance reporting system i.e. the On-board Maintenance System (OMS).
The OMS highlights internal WXR Receiver Transmitter Antenna (RTA) faults or issues related to WXR communications with the Adaptive Flight Displays (AFD) and the Data Concentrator Modules. While this information is important when routing a failed unit for repair, flight crew observed Flight Deck Effects (FDE) are equally valuable. This information would improve the shop technician’s ability to investigate and possibly reproduce the fault in order to carry out a repair, perform preventive maintenance and reduce instances of No Fault Found (NFF).
In addition, recent failures of the RTA have been accompanied with grinding or banging noise from the radar assembly. These events are currently being investigated by Collins and Bombardier, and in order to expedite the resolution of this condition, we would like to request your assistance in providing all the following checklist information.
If experiencing issues with a specific weather radar feature or function, we would appreciate flight crew and maintenance technicians’ assistance by identifying any associated FDE, as follows:
A. Specific to the grinding or banging noise:
Is the grinding/noise repeatable? How?
Does it appear at power-up?
Does it appear at Pilot Initiated Test (PIT), radar self test?
Does it appear when standing still with no command or no apparent external input/interference? Or during aircraft acceleration/deceleration?
Does the grinding/noise go away when power to RTA is reset on ground?
Does the grinding/noise go away after a PIT is initiated? On ground? In flight?
Does the grinding/noise go away, in flight, when returning to transmit after short selection of Standby?
Whenever possible, provide video with sound of grinding noise observed
B. General feedback, whenever possible provide pictures of:
Mode, tilt and gain settings
WX Fault message, if present on the radar data block
Related CAS message, if applicable
Flight conditions including altitude, flight phase (climbing, cruise or descending), surrounding topography, including if over water or terrain or when transitioning from one to the other
Photo/Video of WXR display anomaly when possible along with description of the condition versus what was expected
Active OMS maintenance messages and history OMS fault messages
Pictures of MSG Data tab, showing all elements detailed data
C. During ground troubleshooting with the radome open, technician can report on the following. A few seconds after power is applied to RTA, does the antenna accomplish a figure 8 motion and go to centre position? (ensure safety precautions for RF radiation are enforced when doing that verification)
To further reduce RTA NFF and improve reliability, Bombardier would appreciate if operators and maintenance facilities would:
Complete the Bombardier Material Return Authorization (MRA) with the reported FDE
Complement all RTA removals with the OMS Fault message download (reference to AMM Task 45-47-00-970-804)
Send the OMS Fault message download along with associated FDE per the above, aircraft serial number and RTA serial number to tech.services.global.series@aero.bombardier.com or your Bombardier Field Service Representative (FSR)/Customer Response Centre (CRC)
In addition, flight and maintenance crews should be familiar with the RTA-4100 Series MultiScan TM Automatic Weather Radar Operator’s Guide (CPN: 523-0816797). It is available on the Collins Aerospace website from their Tech Pubs page at: https://portal.rockwellcollins.com.