Date: 202104
Aircraft: B767 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Parked
Aircraft component: Weather Radar
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Human-Machine Interface
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Company Policy; Software and Automation; Procedure
Primary problem: Software and Automation

Narrative: We experienced a weather radar power on anomaly; which is noted by an Amber WXR FAIL or CYAN WX-A on one or both NAV Displays. This issue is a long known issue on our B767 fleet. The weather radar anomaly is tied to a known issue involving the parking brake; IRS Selectors and electrical power transfers. There is a note in our flight manual to look for this anomaly after the IRS selectors are moved to the align mode. That is typically handled by the Captain early on during the preflight; however; the anomaly seems to be occurring at various other times as well. This morning we experienced the anomaly after arriving at the gate while preforming post flight duties. The Captain had completed the Shutdown Checklist and was waiting for me to complete the ACARS Post Flight Summary. After receiving the message the Captain complied with Company Bulletin. This bulletin came out [recently] and per the bulletin; we have to comply with this procedure to assure there are no [duplicate] messages tied to our CPDLC. We had used CPDLC on this flight. The Captain complied with the procedure; which is simply put; cycling the BUS TIES from closed to open to closed with a 15 second wait in between cycles. This was the first time we had done the procedure. When completed there was a SIGNIFICANT electrical power shift. The noise for the relays was amazing. It was significant! With the BUS TIE switch back in AUTO; I noticed on both NAV Displays the previously mentioned radar power on anomaly. The message was displayed on both NAV Displays; however it stayed on for just a few seconds on both NAV Displays; then switched to other message on both NAV Displays. I told the Captain what had occurred and once he saw the message I de-powered the Radar. Both messages on both NAV Displays cleared as expected. Cycling the BUS TIE switches in compliance with the directed procedure per Company Bulletin [causes this]. Further there is a known Radar Power On Anomaly which is not being corrected in a timely manner. The new message procedure seems to be causing a known and dangerous Radar Power On Anomaly. It is NOT OK that we have had a radar power while at the gate issue for over X years NOT get fixed in timely manner. This Radar Power on anomaly is a risk to anyone working around the airplane. Further; adding a procedure that appears to be causing this radar anomaly is very; very troubling. I would have thought this procedure would have be verified for not causing any other issues. Really is unacceptable and disturbing that it doesn't appear to be properly researched. It also leads me to believe that the company does not understand the causes of the radar power on anomaly to begin with. I question why this procedure was released before checking all aspects from a safety perspective. I expect more from a safety perspective. I would recommend we stop this new procedure until all issues are truly understood. Should we continue with this procedure; we are adding another unknown variable to an already unknown situation regarding the Radar Power on Anomaly.




Synopsis: B767 First Officer reported concerns over Weather Radar powering ON when switching electrical power or releasing parking brake; possibly endangering ground crew.