Narrative:

As we arrived at the end of runway 16 for takeoff the pilot in command (PIC) called for the before takeoff checklist to the line. I noticed that the number 4 brake temp changed from 6 to 7; which means it also changed from green to white. I pointed this out to the PIC. A moment later; it changed from 7 to 8. The other brake temps were much lower. The PIC wanted to douse the brake with water. I expressed discomfort with that. He said; '... Just like taxiing through a water puddle.' he said that he would need the ok from ATC to exit the aircraft to pour water on the brakes since we were located on a movement area. I indicated that I was ok with seeing how ATC felt about opening the passenger door just short of the runway. I was expecting that the controller would not give us permission for that. I was wrong. ATC gave the PIC permission to open the passenger door and for the PIC to walk about the aircraft; which the PIC did without hesitation. The brake temp came down immediately; but began to slowly rise again. Before the number 4 brake temp could increase to more than 6 again; we took off. The threats were: a no-go brake temperature indication; a PIC who lacked the professionalism to do the right thing even with a sic voicing discomfort with his decision; an sic who lacked the professionalism to more appropriately stand up to a renegade take-matters-into-his-own-hands PIC. The error was taking off without direction from maintenance control concerning the brake temp indication. As we climbed off the runway I noticed the brake temp decrease from 6 to 5; and the number 4 brake temp didn't indicate anything abnormal on arrival at the gate [at the destination]. Therefore; no undesired aircraft state existed. In the future; I can risk insubordination more than I did in this incident. I've given up on the company having the means to prevent this from happening in the future.

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Original NASA ASRS Text

Title: Regional Jet flight crew reported applying water to hot brakes in order to cool the brakes prior to takeoff.

Narrative: As we arrived at the end of runway 16 for takeoff the Pilot in Command (PIC) called for the Before Takeoff Checklist to the line. I noticed that the number 4 brake temp changed from 6 to 7; which means it also changed from green to white. I pointed this out to the PIC. A moment later; it changed from 7 to 8. The other brake temps were much lower. The PIC wanted to douse the brake with water. I expressed discomfort with that. He said; '... just like taxiing through a water puddle.' He said that he would need the ok from ATC to exit the aircraft to pour water on the brakes since we were located on a Movement Area. I indicated that I was ok with seeing how ATC felt about opening the Passenger door just short of the runway. I was expecting that the controller would not give us permission for that. I was wrong. ATC gave the PIC permission to open the Passenger door and for the PIC to walk about the aircraft; which the PIC did without hesitation. The brake temp came down immediately; but began to slowly rise again. Before the number 4 brake temp could increase to more than 6 again; we took off. The threats were: a no-go brake temperature indication; a PIC who lacked the professionalism to do the right thing even with a SIC voicing discomfort with his decision; an SIC who lacked the professionalism to more appropriately stand up to a renegade take-matters-into-his-own-hands PIC. The error was taking off without direction from Maintenance Control concerning the brake temp indication. As we climbed off the runway I noticed the brake temp decrease from 6 to 5; and the number 4 brake temp didn't indicate anything abnormal on arrival at the gate [at the destination]. Therefore; no undesired aircraft state existed. In the future; I can risk insubordination more than I did in this incident. I've given up on the company having the means to prevent this from happening in the future.

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.