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TCAS RA question

Cptnchia

Dissatisfied Customer
#81
hopefully when ADSB gets RA it knows that im flying a little cessna and not a jet and therefore cannot do insane climbs. I can do RA escape descents as long as I dont get too fast but for climbs it would be constrained.
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.
 

Cptnchia

Dissatisfied Customer
#83
well you want to get out the red and into the green band when it says CLIMB CLIMB NOW
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.
 

A1TAPE

Active Member
#84
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.
 

BobDDuck

Island Bus Driver
#89
So it reports when someone overshoots the RA band and pulls a hoover
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.
 

NovemberEcho

Dergs favorite member
#90
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.
 

Roger Roger

Paid to sleep, fly for fun
#91
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.
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.
 

BobDDuck

Island Bus Driver
#92
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.
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.
 

BobDDuck

Island Bus Driver
#93
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.
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.
 

Attachments

A1TAPE

Active Member
#94
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.
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.
 

Roger Roger

Paid to sleep, fly for fun
#95
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.
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.
 

digduggy

Well-Known Member
#96
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
 

NovemberEcho

Dergs favorite member
#97
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
I didn't do it. A plane I was working did it.
 

Cptnchia

Dissatisfied Customer
#98
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
A perfect example of s pilot over amping and pulling too hard.