Narrative:

Aircraft X sent me an ACARS message that they were in airborne holding for their destination yul. I calculated the bingo fuel for the listed alternate syr and responded. The calculated bingo was only a few hundred pounds above what the crew stated was onboard. They further advised that the current winds exceeded crosswind limitations. I looked at the most recent metar and calculated a steady state crosswind of 13 KTS for the runway (24L or right) in use. I messaged this to the crew. Canada does not report runway condition code (rcc) so I looked at the current yul d-atis and determined the appropriate rcc code would be 5. Referencing the runway condition assessment matrix (rcam); the lowest maximum allowable crosswind for rcc 5 is 24 KTS. The winds were well within this limit. The crew messaged that they were diverting to syr. This was followed up by an arinc call from the crew. (Incidentally; I may have missed one of the required elements of 121.711 during the call. It only adds more stress to an already time critical situation to have to look-up a half dozen things to state during an arinc call.) after the flight landed in syr the captain called to discuss the course of action. During the course of the call; I asked how they had determined the wind had exceeded crosswind limitations; since I had dispatched the flight on different calculations. The crosswind limitations in the flight crew manual (fcm) are different from the limitations [available to dispatchers]. The captain did state that they were using the fcm limitations. However; according to the dispatch trainer; the [dispatcher] guidelines are the current policy and procedure until the fcm is revised. Apparently; this wasn't standardized with the pilot group. We are now well into the winter season with contaminated runway and crosswind considerations but have not received any further official guidance. This is a significant safety issue; especially considering other operators have already experienced runway excursion incidents.

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Original NASA ASRS Text

Title: Air Carrier Dispatcher reported that an aircraft diverted due to the crosswind limitations listed in the Flight Crew Manual not being in agreement with the limitations available to dispatchers.

Narrative: Aircraft X sent me an ACARS message that they were in airborne holding for their destination YUL. I calculated the bingo fuel for the listed alternate SYR and responded. The calculated bingo was only a few hundred pounds above what the crew stated was onboard. They further advised that the current winds exceeded crosswind limitations. I looked at the most recent METAR and calculated a steady state crosswind of 13 KTS for the runway (24L or R) in use. I messaged this to the crew. Canada does not report Runway Condition Code (RCC) so I looked at the current YUL D-ATIS and determined the appropriate RCC code would be 5. Referencing the Runway Condition Assessment Matrix (RCAM); the lowest maximum allowable crosswind for RCC 5 is 24 KTS. The winds were well within this limit. The crew messaged that they were diverting to SYR. This was followed up by an ARINC call from the crew. (Incidentally; I may have missed one of the required elements of 121.711 during the call. It only adds more stress to an already time critical situation to have to look-up a half dozen things to state during an ARINC call.) After the flight landed in SYR the Captain called to discuss the course of action. During the course of the call; I asked how they had determined the wind had exceeded crosswind limitations; since I had dispatched the flight on different calculations. The crosswind limitations in the Flight Crew Manual (FCM) are different from the limitations [available to Dispatchers]. The Captain did state that they were using the FCM limitations. However; according to the Dispatch Trainer; the [Dispatcher] guidelines are the current policy and procedure until the FCM is revised. Apparently; this wasn't standardized with the pilot group. We are now well into the winter season with contaminated runway and crosswind considerations but have not received any further official guidance. This is a significant safety issue; especially considering other operators have already experienced runway excursion incidents.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.