Narrative:

Approximately 10 miles from osogy on HILEY5 arrival; level FL260. ATC informed us learjet climbing and would be leveling at FL250. I switched to 10 mile scope and saw lear on TCAS directly on our nose and climbing around 10 mile range. I watched the lear on TCAS and was aware that TCAS showed a yellow target first at 900 feet at around 7 miles; then 800 feet at around 5 miles. I was aware that there could be some inaccuracy in the system; but when the TCAS went to a red square at 700 feet below at 4-3 miles just slightly left of our nose and still climbing; I started an evasive turn to the right. I started this turn just before I got a climb command from the TCAS audio. I did the turn to the right because I was able to clear my flight path in that direction. I was through about 5 degrees of turn when the climb command came on (just once) and it immediately disappeared as I went through about 10 degrees of turn. I had also started a climb by then. Captain informed ATC we had reacted to an RA. ATC cleared us back direct osogy and a further descent.maybe lear had local altimeter instead of 29.92. Maybe a distraction in their cockpit. I reacted early instead of waiting for a TCAS audio command; which I believe was the right decision. I also chose to go right because the red square was offset just slightly left of centerline; and I was able to clear right; and as I started my roll right; I hadn't yet received the climb command.

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Original NASA ASRS Text

Title: B767 flight crew experiences a TCAS RA caused by Learjet that is cleared to level off 1000 feet below but continues to slowly climb.

Narrative: Approximately 10 miles from OSOGY on HILEY5 Arrival; level FL260. ATC informed us Learjet climbing and would be leveling at FL250. I switched to 10 mile scope and saw Lear on TCAS directly on our nose and climbing around 10 mile range. I watched the Lear on TCAS and was aware that TCAS showed a yellow target first at 900 feet at around 7 miles; then 800 feet at around 5 miles. I was aware that there could be some inaccuracy in the system; but when the TCAS went to a red square at 700 feet below at 4-3 miles just slightly left of our nose and still climbing; I started an evasive turn to the right. I started this turn just before I got a climb command from the TCAS audio. I did the turn to the right because I was able to clear my flight path in that direction. I was through about 5 degrees of turn when the climb command came on (just once) and it immediately disappeared as I went through about 10 degrees of turn. I had also started a climb by then. Captain informed ATC we had reacted to an RA. ATC cleared us back direct OSOGY and a further descent.Maybe Lear had local altimeter instead of 29.92. Maybe a distraction in their cockpit. I reacted early instead of waiting for a TCAS audio command; which I believe was the right decision. I also chose to go right because the red square was offset just slightly left of centerline; and I was able to clear right; and as I started my roll right; I hadn't yet received the climb command.

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.