An MD80; cleared to climb while maintaining visual separation from a SAAB 340; triggered a TCAS RA with one another. The MD80 flight crew opted to disregard the TCAS descend command and; instead; tried to outclimb the SAAB which was; in turn; climbing in response to the RA.
Synopsis
An MD80; cleared to climb while maintaining visual separation from a SAAB 340; triggered a TCAS RA with one another. The MD80 flight crew opted to disregard the TCAS descend command and; instead; tried to outclimb the SAAB which was; in turn; climbing in response to the RA.
Narrative
While level at an intermediate altitude of 15;000 MSL ATC advised us of a Saab 340 at 10 O'clock position at 15 miles. As the traffic came closer; we called the traffic in sight. The Saab was assigned 16;000 MSL. The Saab pilots also advised they had us in sight. The Controller told us to maintain visual separation and cleared us to climb and maintain FL320. We initiated the climb and as we went through approximately 16;000 we received a RA. The vertical speed indicator showed a green band to approximately 500 FT per minute down and a red band up from 0 to a climb. Since we were already established in a climb between 1;500-2;000 FPM we believed we would be clearly above the traffic by the time we were near it. Visually; it appeared the Saab was in level flight; but the closer we came to the traffic; it appeared the Saab was climbing. (A few minutes after we passed the aircraft we found out they were climbing due to a RA). We never heard the Saab pilots responding to an RA or a report of leaving their assigned altitude due to an RA on the radio with Minneapolis Center. Since we had the traffic in sight; we maintained visual contact and continued the climb while maintaining separation visually. I believed if we had complied with the TCAS instruction we would have put the aircraft in a 0 to negative G situation to avoid the traffic as well as put our aircraft at or close to their assigned altitude. The closest I saw the aircraft on TCAS was a vertical separation of 300 FT and outside the three NM band. Another thing I would like to point out: a few times when I looked at the TCAS it was difficult to see due to the sun shining on the display.
Second reporter narrative
We called the traffic in sight and were given the clearance to climb to FL320 and 'maintain visual separation' with the traffic. I continued the climb and increased the climb rate to expedite until we were clear of the traffic. We then received an RA and the instructions were to Descend at about 400 FT/minute. We still had the SAAB in sight and I made the split second decision to continue on our current climbing path instead of complying with the RA. We were climbing at a high rate; around 3 to 4;000 FT/minute up. I felt that changing direction that quickly would have put the aircraft in a high G load situation and may have resulted in flight attendant injuries; since they were in the aisles.It was only after the initial RA warning that I realized the SAAB was actually climbing also. When we received the 'clear of conflict' our aircraft was at 17;500 FT and I noted the SAAB aircraft was +300 FT and showing and up arrow indicating they were still climbing.If I could make my best guess to avoid something like this again I would say the Center Controller should not have given us a climb clearance through another aircraft's altitude when we were on a converging path and that close. It is my understanding that they would have a bigger picture of the two aircraft in this scenario and I think they should not rely on a pilot's perception. I think on my part I would not accept a clearance like this in the future or I would have leveled off until the aircraft was past us and then continued my climb. It was my perception that there would be no problem climbing past the other aircraft with plenty of room to spare but perceptions can be skewed; especially at these speeds. I think pilots should be diligent in announcing an RA maneuver also. Neither my Captain nor I ever heard the SAAB aircraft say they were climbing for an RA; which changed our relationship to their aircraft. Basically; when you are going at speeds in excess of 250 KTS maybe 'maintain visual separation' is a term that should never be used.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.