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TCAS RA question

Discussion in 'Pilot-Controller Questions' started by NovemberEcho, Apr 10, 2017.

  1. Cptnchia

    Cptnchia Well-Known Member

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    The most insane RA climb I ever got was a 500 fpm climb for 500 feet in a 767. Guys have a tendency to pitch up too fast and outclimb the guidance.
     
  2. A1TAPE

    A1TAPE Member

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    well you want to get out the red and into the green band when it says CLIMB CLIMB NOW
     
  3. Cptnchia

    Cptnchia Well-Known Member

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    It doesn't take a herculean pull up to get out of the red band. Even on a high fpm climb. It's still a 1G pull.

    One important issue is that people tend to look for the traffic before responding to the RA. Then, they're behind the power curve and act like Bob Hoover.
     
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  4. A1TAPE

    A1TAPE Member

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    So they dont immediately respond to the RA then when they do, they send the pax into their seats like a space shuttle launch. Do they get a FOQA when they get low on the speed.
     
  5. Cptnchia

    Cptnchia Well-Known Member

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    FOQA reports everything!
     
  6. A1TAPE

    A1TAPE Member

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    unless its a 100% perfect flight?
     
  7. Cptnchia

    Cptnchia Well-Known Member

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    Even then. It reports whatever the airline wants it to report, whenever they want it to report, even "Yep, well within standards."
     
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  8. A1TAPE

    A1TAPE Member

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    So it reports when someone overshoots the RA band and pulls a hoover
     
  9. BobDDuck

    BobDDuck Gone whale watching...

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    It would probably report the Gloading over a certain number. I'm not sure that RA band colors and climb/decent rates are something that FOQA actively tracks. That's why most properties require ops/incident reports for all non standard events like RAs and go arounds. That way the FOQA gatekeeper can correlate an unusual FOQA result with an operation and not have to go calling the pilot to see what happened.

    But back to the RA escape maneuver... The system is designed to give you plenty of time to respond and you shouldn't have to ever exceed 1 G. Like @Cptnchia said though, some times guys are primed to go go go and they push or pull way to hard, exceed one G, exceed the escape guidance and end up having to reverse much harder than would normally be required. A well flown RA maneuver should be pretty much undetectable in the back.

    A break out instruction on a PRM on the other hand probably is going to be noticed.
     
  10. NovemberEcho

    NovemberEcho Well-Known Member

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    I'm just saying, I've had an airplane level at 6,000. Has VFR traffic level at 5,500 opposite direction, IFR traffic level at 7,000 same direction and almost directly overhead, reported both in sight, received a climb RA and climbed to 6,800 directly underneath the IFR traffic at 7,000. The guy at 7,000 never heard a peep from his TCAS, or if he did he didn't mention it or do anything about it.
     
  11. Roger Roger

    Roger Roger Navajo Whisperer

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    I'm a little confused, you guys keep using the term "not exceed 1G". If you're straight and level you can't change your flight path upward without exceeding 1G. That's basic physics.
     
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  12. BobDDuck

    BobDDuck Gone whale watching...

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    Increase or decrease. I didn't phrase that very well.

    If I recall, the system modeling expects a response rate of at least .25 g within a few seconds, increasing to .4 g after that.
     
  13. BobDDuck

    BobDDuck Gone whale watching...

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    I guess it's possible the traffic at 7000 feet was offset or divergent enough to not trigger. I'm trying to find a really good TCAS presentation that ASF-430 put out a while back.


    EDIT: Here it is. I had it saved already.
     

    Attached Files:

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  14. A1TAPE

    A1TAPE Member

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    Yea you are already doing 1G in straight and level if you do a botched RA escape and over push or pull it will throw 1 more G on top it. Thats 2G on your airline butt.
     
  15. Roger Roger

    Roger Roger Navajo Whisperer

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    That makes more sense. So it shouldn't feel any different than a 45° bank turn...which by airline standards I would think is pretty noticeable.
     
  16. digduggy

    digduggy Well-Known Member

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    Why did you climb 800 feet?

    You are only supposed to climb 500ft max....

    If there is traffic coming the other way you still may put them in your cone of shame but there is a prescribed profile for an RA response it is not "make like rocket"…


    Sent from my iPhone using Tapatalk
     
  17. NovemberEcho

    NovemberEcho Well-Known Member

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    I didn't do it. A plane I was working did it.
     
  18. Cptnchia

    Cptnchia Well-Known Member

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    A perfect example of s pilot over amping and pulling too hard.
     
  19. A1TAPE

    A1TAPE Member

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    to some pilots its like FALCON....CLIMB!!!!!
     

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