TCAS on takeoff out of LAX?
Posted by Family_Shoe_Business@reddit | aviation | View on Reddit | 15 comments
I was on AAL4 on Oct 31, LAX -> JFK. Very normal flight except for the initial climb from 25R. I've taken off out of LAX hundreds of times—usually you go out over the water for a few minutes and then make your 180, assuming you're going east. This one was very different.
About 30 seconds after liftoff we turned left abruptly and dropped altitude very sharply. It was jarring enough for people to notice. We stayed at about 1400 feet until Palos Verdes was outside the left window (which was very cool to see up close) then continued the climb.
I looked on flightradar and it seems like we were probably avoiding ITY621 which had just taken off 24L and immediately turned left into our path. I'm wondering if the altitude drop/turn we experienced was TCAS? Would there be a way to know if it was manual pilot maneuver or TCAS? Figured the pilots on here would have some insight. Here's the actual flightradar data.
AutothrustBlue@reddit
Could be TCAS, probably more likely panic vectors. Did you check live ATC?
ywgflyer@reddit
I wonder if the LA Flights or AVL guys caught it?
Family_Shoe_Business@reddit (OP)
Nah I don’t really know how to but I will try to figure it out tomorrow. Good idea.
Slytiger3882@reddit
It looks like ITA tried to go to DOCKR (first RNAV fix from 25R) instead of DLREY (first RNAV fix from 24L).
ywgflyer@reddit
This is why there is a "change of runway, SID or performance" checklist.
I bet they probably planned off 25R and then got 24L and didn't reload the box properly, left a discon in there somewhere and then when it goes to NAV after liftoff, uh-oh.
ks8662@reddit
I watched/listened the playback and you’re correct in your description of what happened. ITY621 deviated from the departure procedure and turned into your path, causing the abrupt stop of climb and turn to the south. If I had to guess there will be a YouTube video on this soon.
Family_Shoe_Business@reddit (OP)
Oh wow. Thanks for finding it and listening. Fascinating!
Pepbill@reddit
What time was you flight. I flew out about 10:30am on Oct 31 and we followed similar path except we came back over land over Orange County
EliteEthos@reddit
You haven’t taken off out of Los Angeles hundreds of times. You’ve been a passenger hundreds of times.
Your time in the back of an airplane doesn’t equate to experience. This is evidenced by the way you describe the incident. If you “dropped altitude very sharply” 30 seconds after liftoff, you’d be in the ground. You likely felt a level off. Not altitude loss.
Why do you care so much about method by which the pilot received traffic information?
Do you know how TCAS works?! It’s simply an alerting system. It doesn’t avoid things for you. The pilot makes the inputs based on info provided by TCAS.
SpiceWeasel83@reddit
It is a vertical maneuver. Any turns are vectors from ATC.
As far as completing the maneuver, only the newer 321s and the 350s have autopilot enabled response to TCAS. All other aircraft it is a maneuver accomplished by the flight crew.
hurl9e9y9@reddit
Get the ATC archives from tower and departure around that time, good chance there was some communication about it.
attackcrow@reddit
TCAS can only provide vertical guidance, so the turn must have come from another source.
Mauro_Ranallo@reddit
TCAS is an alerting (TA) / directing (RA) system, not a controlling one. So, dunno if it triggered, but even if it did, it would be the pilot maneuvering manually.
sloppyrock@reddit
I would say it was manually done notwithstanding an aircraft im not familiar with.
airport-codes@reddit
I am a bot.
^(If you are the OP and this comment is inaccurate or unwanted, reply below with "bad bot" and it will be deleted.)