Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Resolution Advisory?  
User currently offlineFrequentflyer5 From United States of America, joined May 2001, 236 posts, RR: 0
Posted (12 years 5 months 2 weeks 2 days 2 hours ago) and read 2111 times:

Can anyone explain to me what is Resolution Advisory? I was listening to ORD ATC and AA416 called for this and aborted approach into 9R.

I would be interested in knowing what this means. Thanks!

14 replies: All unread, jump to last
 
User currently offlineMD11Nut From , joined Dec 1969, posts, RR:
Reply 1, posted (12 years 5 months 2 weeks 2 days 1 hour ago) and read 2112 times:

That's a TCAS (Traffic Collision Avoidance System) term, requiring the aircraft to take evasive action due to an impending midair collision.

Regards,
Nut


User currently offlineEssentialPowr From United States of America, joined Sep 2000, 1820 posts, RR: 2
Reply 2, posted (12 years 5 months 2 weeks 2 days 1 hour ago) and read 2111 times:

Nutshell description:

TCAS will provide verbal "TAs" and "RAs".

TA = traffic alert; the verbal is "Traffic" with the symbology presented on the TCAS. It is simply advisory; most of the time no action is taken. It could become an RA:

RA = resolution advisory, which has several verbal commands, one of which sounds like "Climb. Climb now!" along with a graphic display of the traffic and vertical speed. In short, an RA commands a response and most 121 ops (Canada? Botswanna? don't know!) require compliance with the RA. Typically, a response is made to ATC after the avoidance maneuver. The only routine exception is on PRM approaches (MSP, Philly), in which an a/c can impede on the protection envelope of another a/c. In this case, typically only "TA" mode is selected.

Cheers-


User currently offlineFrequentflyer5 From United States of America, joined May 2001, 236 posts, RR: 0
Reply 3, posted (12 years 5 months 2 weeks 2 days ago) and read 2097 times:

Very clear...thanks for that!

User currently offlineJetguy From , joined Dec 1969, posts, RR:
Reply 4, posted (12 years 5 months 2 weeks 1 day 23 hours ago) and read 2086 times:

I've got a question for EssentialPowr and any other pilot flying TCAS equipped aircraft...

How often have you personally received a "TCAS" climb or descent? I had two last week. The first one was when we were being vectored for the approach at FTY (Atlanta - Fulton County) We were in marginal VFR conditions. A yoyo in a Bonanza wasn't talking to anyone and busted Atlanta's Class B airspace. We saw him coming and started the climb just as we received the RA. We never saw the second one and have no idea what type of aircraft it was. We were flying into Knoxville and had to "get in line" to fly through an opening in a line of T-storms. We were descending out of about 15,000" - solid IFR - and, all of a sudden, there was another idiot squawking 1200 at our altitude and we got a RA to climb. Like I said, we never saw him and center had no idea who he was. They were tracking him, but I have no idea if they ever figured out who he was.

I have only had one other RA in my life, but I have heard a few called out on the radio. If I get too many more of those I think that I will simply pull the breaker on the box. After all, what you can't see can't hurt you.  Big grin

Jetguy


User currently offlineJhooper From United States of America, joined Dec 2001, 6204 posts, RR: 12
Reply 5, posted (12 years 5 months 2 weeks 1 day 23 hours ago) and read 2077 times:

Does TCAS depend on ATC radar to work?


Last year 1,944 New Yorkers saw something and said something.
User currently offlineFredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26
Reply 6, posted (12 years 5 months 2 weeks 1 day 22 hours ago) and read 2070 times:

Jhooper,
nope. Both aircraft have to have transponders though.

Cheers,
Fred



I thought I was doing good trying to avoid those airport hotels... and look at me now.
User currently offlineFredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26
Reply 7, posted (12 years 5 months 2 weeks 1 day 22 hours ago) and read 2067 times:

On 2nd thought... Technically, you could have TCAS without having a transponder of your own, although to agree on an RA you'd still need to talk through something capable of speaking Mode S transponder lingo. It would be rather daft not to have a transponder to go with it though. There are some devices for GA which will somehow passively use the return from the transponders of other aircraft without interrogating itself, although I never checked it out in detail.

No, couldn't leave it clear and simple.  Smile

Cheers,
Fred



I thought I was doing good trying to avoid those airport hotels... and look at me now.
User currently offlineEssentialPowr From United States of America, joined Sep 2000, 1820 posts, RR: 2
Reply 8, posted (12 years 5 months 2 weeks 1 day 21 hours ago) and read 2063 times:

Jetguy, in the past 6 months I've had about 3-4 TAs. To date I haven't had an RA.

cheers-


User currently offlineRick767 From United Kingdom, joined Jan 2000, 2662 posts, RR: 51
Reply 9, posted (12 years 5 months 2 weeks 1 day 20 hours ago) and read 2060 times:

In my ops I get about 4 RAs a month. 3 of them at KSFB (Orlando Sanford) the rest somewhere in Europe!


I used to love the smell of Jet-A in the morning...
User currently offlineEssentialPowr From United States of America, joined Sep 2000, 1820 posts, RR: 2
Reply 10, posted (12 years 5 months 2 weeks 1 day 17 hours ago) and read 2039 times:

Do you fly a pax 767 into Sanford FL?

User currently offlineAirplay From , joined Dec 1969, posts, RR:
Reply 11, posted (12 years 5 months 2 weeks 1 day 17 hours ago) and read 2038 times:

TCAS II relies on the coordination provided through the Mode S transponders when it is processing an RA against another aircraft with Mode S. Theoretically, you can still operate without this coordination but the alerts may not be as efficient. In the real world, you can't operate TCAS II without a mode S transponder. The way many systems are configured, they won't activate without the Transponder system enabled in A/C mode. It also relies on other aircraft to have a mode S or mode A/C transponder to detect traffic. TCAS cannot "see" aircraft that are not equipped with transponders.

TCAS I which only gives TAs does not need a transponder on board to work, but again it can't detect aircraft not equipped with a mode S or mode A/C transponder.

I'm not a pilot but I often participate in system certification flight tests. The one and only RA I have ever witnessed was during EGPWS testing in Arizona adjacent to an MOA. Just as we heard the warning, two "warthogs" flew by us. I was sort of surprised that a military aircraft would be equipped with a transponder compatable with TCAS.


User currently offlineRick767 From United Kingdom, joined Jan 2000, 2662 posts, RR: 51
Reply 12, posted (12 years 5 months 1 week 2 days 7 hours ago) and read 1995 times:

Essential,

Yes, a 767-300(ER).



I used to love the smell of Jet-A in the morning...
User currently offlineEssentialPowr From United States of America, joined Sep 2000, 1820 posts, RR: 2
Reply 13, posted (12 years 5 months 1 week 2 days 3 hours ago) and read 1981 times:

I get it now. Could Comair's Aviation Academy in any way be a factor for some of your RAs???

cheers-


User currently offlineBjones From United States of America, joined Feb 2002, 123 posts, RR: 0
Reply 14, posted (12 years 5 months 1 week 1 day 16 hours ago) and read 1964 times:

With TCAS II you don't need the other aircraft to have Mode S for an RA to occur. Mode S is only required for their to be coordination between RAs so that both aircraft will get different commands on their TCAS. Any aircraft using mode C can result in an RA for you.

Regarding US military aircraft all of them have mode C and some do have mode S although I doubt the A-10s you saw did.


Top Of Page
Forum Index

Reply To This Topic Resolution Advisory?
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
What's A Break In Action Advisory? posted Mon Feb 10 2003 05:21:53 by Pilottim747
Resolution Advisory? posted Wed Jun 12 2002 19:56:34 by Frequentflyer5
Weather Advisory posted Mon May 13 2002 01:10:45 by Pilottim747

Sponsor Message:
Printer friendly format