D Bergendorf
Well-Known Member
Would an airliner's TCAS become engaged if it had a "close encounter" with a private plane THAT DID NOT have TCAS?
TCAS
- Thread starter D Bergendorf
- Start date
jtrain609
Antisocial Monster
There is no primary return, hence why if the transponder isn't on we won't see it.
ctab5060X
Well-Known Member
Absolutely. Got one a couple of weeks back. First time I've seen a TCAS RA that required over 2500 fpm to comply. We were doing 1500 fpm in the decent at the time.
For the controllers: how much paperwork or whatever you report is required when we report that we either get or are responding to a TCAS RA?
Roger Roger
Bottom of the list
The correct term is "Mode A".
Vector4Food
This job would be easier without all the airplanes
Forget paperwork
Only time I've had one was from a 777 who turned out getting an erroneous RA.
I spent more time buying underwear and pants than paperwork
GolfChuck
Trustworthy Source
We are usually told to fill out an ATSAP (ATC ASRS). The amount of time that takes depends on the circumstance and familiarization with the ATSAP form. I have witnessed 2 different instances of RAs in the last year and both were results of pilot deviations. One even got a traffic call and still blew through the assigned altitude in the climb.
ctab5060X
Well-Known Member
Reason I ask is I've gotten 2 RAs in the past month with traffic climbing to 10K with me level at 11K. It triggers a "Monitor Vertical Speed" Resolution Advisory, but it is still uncomfortable. I know it is just the climb rate of the aircraft on the departure, but I feel the need to report these to ATC.
Is this information you need to know, or only the RAs that cause us to climb or descend?
genot
Well-Known Member
As a terminal guy, RA's are far more common. I've even gotten pilots responding to an RA on the guy holding hands with them 1,200 feet away for a parallel that they are maintaining visual from. I've heard several TCAS concerns over traffic just departing satellites off the downwind which is fair cause for concern when the mode C isn't yet discernible. I've even seen North West get an RA on himself.
I don't fill out ATSAPs on them. They happen too often in the terminal RADAR world.
I don't fill out ATSAPs on them. They happen too often in the terminal RADAR world.
We need to know about the ones that cause you to deviate from a clearance (climb/descend). But I wouldn't discourage you from reporting/sharing anything with ATC even if it isn't something either of us require.
I've never been asked, or have heard of anyone at my facility be asked to file an ATSAP as a result of an RA (and we get them all day, every day). RA's are reportable, however. We tell a supe, who asks if we issued traffic. Then they go to the Operations Manager, who files an MOR (mandatory occurrence report).
Screaming_Emu
Well-Known Member
I hate those. "There's a plane....where you are. Could be taxiing on the ground, could be the international space satin, could be about to put its nose gear through your face....or anywhere between."
GolfChuck
Trustworthy Source
This is why we issue traffic advisories on merging targets, so that the pilot can decide on the seriousness of a TCAS alert. We never use visual in my area, but I would expect that if I were using some sort of non-standard separation that causes an inadvertant RA, I wouldn't fill out an atsap either. I agree with TripSix, unless you have to deviate from a clearance, there is no reason to mention it, but feel free to mention it if it is something you think we should know about.
Edit: In the situation you describe, if you dipped down to 109 we would get a traffic alert, so it would be a good idea to be vigilant about your altitude in that instance, but if it were me and you did actually dip to 109, I wouldn't report it unless asked about it, and even in that case I wouldnt make a big thing of it as long as the altitude dip was corrected expediantly.
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FM_Weasel
Well-Known Member
Altitude variations of 100ft wouldn't cause me to be alarmed because sometimes the Mode C is off by that much anyway. People assigned 10,000 cruise around on the scope all day long showing "099" (9,900ft) or "101" (10,100ft) between sweeps and it's never set off our snitch or caused anyone to be alarmed.
The issue with RAs is that they can go off even when separation will be ensured (500ft vertical between VFR/IFR). If a loss of prescribed separation doesn't occur, I wouldn't file an ATSAP. The supervisors still work up the mandatory occurrence report though, and it's logged for data mining purposes I guess. I also don't get into the habit of using 500ft vertical for merging targets for that reason.
The issue with RAs is that they can go off even when separation will be ensured (500ft vertical between VFR/IFR). If a loss of prescribed separation doesn't occur, I wouldn't file an ATSAP. The supervisors still work up the mandatory occurrence report though, and it's logged for data mining purposes I guess. I also don't get into the habit of using 500ft vertical for merging targets for that reason.
genot
Well-Known Member
If you take action contrary to your clearance as a result I need to know. If you have a concern about someone on your TCAS display tell me. Earlier today I got a panicked "Do you see any targets near me?". I did. It was 9,000 feet below and on a half mile final at podunk regional. I respectfully explained as time allowed. That was one of probably 100 concerned about satellite traffic calls I'll get this year. I'll take every query seriously, but TCAS is to a degree imperfect and limited.
BobDDuck
Island Bus Driver
This is pretty common at an airport with RNAV arrivals and departures where the outbound track climbs up underneath the inbound track right at the point they joint the downwind. We'd get them in CLT a lot. Although normally it was a simple TA, I'd say about twice a month or so I'd get a "monitor vertical speed" RA. I'd guess that in future versions of the TCAS software they will some how dampen this alert out a bit. I know they've changed the verbiage for this alert as well to something like "maintain altitude" in the latest revision.
spades9048
Well-Known Member
I have a question for you pilots if you know the answer. In the center environment, if you guys are going to get together with a VFR then I am always going to choose the IFR over the VFR to separate. En route rules are different from terminal and we only suggest headings/altitudes to VFR aircraft so to make everything easier and avoid suggestions, we'll turn/stop the IFR. A buddy of mine and I both had TCAS RA's last year involving IFR with VFR traffic. In both situations, we cleared the IFR to 500 feet above the VFR, issued traffic, and both times we had a TCAS RA. We had two different airlines involved in each occasion. The one my friend was handling had an aircraft that was still in it's descent which I understand can trigger RA's based on climb/descent rates. However, mine was already level when it happened.
Are airlines able to set their own parameters when it comes to what will trigger a TCAS RA? Many times you guys will be fine with 500 feet between a VFR and then every now and then, we get a TCAS RA like the one that I had which involved both aircraft level. I'm somewhat tempted to stop you guys 1500 feet but to me, that seems excessive especially when you're getting close to your destination.
Are airlines able to set their own parameters when it comes to what will trigger a TCAS RA? Many times you guys will be fine with 500 feet between a VFR and then every now and then, we get a TCAS RA like the one that I had which involved both aircraft level. I'm somewhat tempted to stop you guys 1500 feet but to me, that seems excessive especially when you're getting close to your destination.