MrMorden wrote: 3Dreaming wrote:
Having an unreliable ADSB signal will have little effect on airliners with a closing rate of 800knots. Where they can have that closing speed ATC is already providing separation without it.
Have you heard about any of the near-misses caused by ATC lately? There have been a bunch.
If an airliner gets a TCAS alert contrary to ATC instructions, they are required by regulation to follow the TCAS resolution and ignore ATC. Whoever writes the regs sure thinks TCAS is important...
When two airliners get close enough for an RA remember that the RA is issued to both airplanes since the systems 'talk' to each other in that , for example, one will command climb "Climb, climb NOW" whilst the other may command descent.
It's crucial that the pilot flying puts the airplane's climb/descent right where the TCAS commands it on the IVSI. Doing that, in both airplanes, ensures full separation and the best conflict resolution.
In the days before TCAS I experienced this scenario. Climbing out of KEWR in a 727. Usually we would be given a climb to FL190 and expect further with the next handoff. On this day, it occurred to me that we hadn't been given this clearance. As PNF I was busier than the PF completing after take-off checklist items and company reports etc but I queried the PF and then reminded ATC that we were level at FL190. He resounded with "Climb IMMEDIATELY, Immediately to fl260" and then gave an opposing airplane a sharp turn and expedited descent. It happens.
Fast forward to TCAS and the system should have/would have commanded both opposing airplanes to climb/descend in order to comply.
Complying with the resolution advisory can command a rapid application of power and aggressive use of the yoke, actions contrary to most of airline style flying with FAs and passengers in the cabins. This is why we always trained in the recurrent training simulators to cover TCAS training. During the LOFT, or even in other maneuvers if we had a sneakier instructor, they'd suddenly have a TCAS scenario pop up and we'd be expected to respond immediately and react by putting the IVSI right where it had to be right away. Its actually not as easy as it sounds but I have to say the system work very, very well.