- Tony Wallace
You are rapidly climbing to FL370. Your requested flight level is 390, but ATC has restricted you to FL370 due to an Airbus 319 flying in the opposite direction and maintaining FL380.
You are climbing very well today and your rate of climb is 3000 feet/min. When you pass FL361 you receive a TA against the Airbus "Traffic, Traffic." Simultaneously, a TA is issued in the Airbus "Traffic, Traffic." Six seconds later when you are passing FL365 you get a "Level off, level off" RA. You slowly start to reduce the vertical rate but given the closure speed, three seconds later the TCAS on the A319 issues a "Climb, climb" RA. Now, the aircraft are separated 1400 feet vertically and 3.8 NM horizontally.
The Airbus crew responds to the "Climb, climb" RA promptly and establishes the required 1500 feet/min. climb rate. In the meantime, the you level off at FL370 and the A319 passes above. When the A319 reaches FL384, both RAs terminate.
What just happened? You approached your cleared level with too high a vertical rate and were slow in reducing your rate of climb in response to the "Level off, level off" RA. The resulting RA on the A319 caused this aircraft to depart from its cleared level. That in turned could have caused an encounter with another aircraft. Furthermore, any unexpected departures from ATC clearances are disruptive to air traffic controllers and a source of additional workload for everybody involved.
As per ICAO recommendation, the vertical rate should be reduced to 1500 feet/min or less in the last 1000 feet before level-off, especially when you are aware of another aircraft at an adjacent flight level.
Always respond to a “Level off, level off” RA by promptly reducing your vertical rate to 0 feet/min.