airfinair
Posts: 563
Joined: Thu Dec 30, 1999 11:36 pm

Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 1:28 pm

A Northwest flight & a UAX flight came "dangerously close at 30,000 feet over Iowa on Tuesday..."

http://www.chicagotribune.com/news/c...,1,6958553.story?coll=chi-news-hed
ORD,MDW,IND,ARB,AMS,AUS,ANQ,DTW,DEN,PHL,PIT,MIA,GPT,SAN,PHX,LAX,SFO,OAK,SEA,LAS,SLC,SMF,ATL,MEM,BOS,MHT,JFK,EWR,LGA,NASâ
 
MKEdude
Posts: 951
Joined: Thu May 05, 2005 9:55 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 1:34 pm

From the article...

"The planes—heading toward each other at about 500 m.p.h.—were less than 2 miles apart with a vertical separation of 900 feet when on-board collision alarms sounded and a controller helped avert a crash, the FAA and air-traffic controllers said."

ATC, the TCAS, the pilots, sounds like everybody did their job.
"You can't be a real country unless you have a beer and an airline." Frank Zappa
 
mpdpilot
Posts: 688
Joined: Fri Jul 28, 2006 6:44 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 1:41 pm

Quoting MKEdude (Reply 1):
ATC, the TCAS, the pilots, sounds like everybody did their job.

arguably ATC didn't do their job, but the system did work and the accident was avoided.

The article says that they got to within 900ft vertically and 1.79mi laterally, and then the article goes on to say that they were as close as 900ft. Which is it.
One mile of highway gets you one mile, one mile of runway gets you anywhere.
 
airfinair
Posts: 563
Joined: Thu Dec 30, 1999 11:36 pm

RE: Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 1:52 pm

I love how the reporter refers to Chicago Center as "air-traffic control serving O'Hare International Airport." Yes, indirectly, just as Chicago Center also indirectly serves LAX, SEA, FLL, and every other airport in the nation.
ORD,MDW,IND,ARB,AMS,AUS,ANQ,DTW,DEN,PHL,PIT,MIA,GPT,SAN,PHX,LAX,SFO,OAK,SEA,LAS,SLC,SMF,ATL,MEM,BOS,MHT,JFK,EWR,LGA,NASâ
 
SPREE34
Posts: 1560
Joined: Tue Jun 29, 2004 6:09 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 9:38 pm

Quoting MPDPilot (Reply 2):
The article says that they got to within 900ft vertically and 1.79mi laterally, and then the article goes on to say that they were as close as 900ft. Which is it.

"Which is it?"
It is both. They were laterally 1.79 miles apart, and 900 feet vertically apart. In other words 1.79 miles to the side and 900 feet above/below each-other.
If they had seen each-other they're perspective would probably have been "over there" vs "up/down there".
I don't understand everything I don't know about this.
 
IAHFLYR
Posts: 3941
Joined: Sat Jun 25, 2005 12:56 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 10:52 pm

Quoting MKEdude (Reply 1):
ATC, the TCAS, the pilots, sounds like everybody did their job.

I disagree with this statement! The controller did NOT have the required 1,000' of vertical separation if the aircraft were within 5 NM of each other so that pretty much says ATC did not do their job.

Since I am not able to reconnect to the link I can' read if TCAS gave any RA or not, I wouldn't think it did since 900' last I knew of didn't provide for an RA, maybe give a TA so then TCAS did it's job.

Back to ATC. If the aircraft were in level at their assigned altitudes then the 900' could have been a Mode C that was 100' off which certainly isn't a near mid air, nor should that have been a controller error.

Now the NATCA folks saying near mid air, some of that just could be attributed to making a stance to the FAA that the new equipment had not been trained on properly as I don't often remember those type of statements being made public with 900' of vertical separation, but ya never know. Just food for thought and see what else might be stirred.
 stirthepot 

Quoting Airfinair (Reply 3):
I love how the reporter refers to Chicago Center as "air-traffic control serving O'Hare International Airport." Yes, indirectly, just as Chicago Center also indirectly serves LAX, SEA, FLL, and every other airport in the nation.

Oh lets tell the media that, and then toss in that a flight from EWR-FLL is served by Chicago Center, hell they control the entire world, and then toss in the question, why do we have other centers around the U.S., isn't that a waste of funds??? What a great way to spool up the brain surgeons in the govt.

Guess I am being a bit crazed today!
 biggrin 
Any views shared are strictly my own and do not a represent those of any former employer.
 
VEEREF
Posts: 560
Joined: Wed Jun 09, 2004 12:55 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 11:14 pm

900ft?
Whoop de doo, that happens every day here in the US with RVSM. Quite often I've had aircraft 900 ft above pass directly overhead. We'll get a traffic alert from the TCAS but as long as it doesn't get any closer that's the end of it.
Also wondering how is it a controllers fault if an aircraft is 100 ft off it's altitude? It's not like he assigned it that way.

Must have been a slow news day.

[Edited 2007-01-19 15:18:35]
Airplanes are cool. Aviation sucks.
 
lowrider
Posts: 2542
Joined: Wed Jun 30, 2004 3:09 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Fri Jan 19, 2007 11:32 pm

Quoting VEEREF (Reply 6):
Whoop de doo, that happens every day here in the US with RVSM. Quite often I've had aircraft 900 ft above pass directly overhead. We'll get a traffic alert from the TCAS but as long as it doesn't get any closer that's the end of it.
Also wondering how is it a controllers fault if an aircraft is 100 ft off it's altitude? It's not like he assigned it that way.

Agreed, the fact that they were seperated by 1.79 miles laterally takes a little more wind out of the sails. In some parts of the country they call that excessive seperation.
Proud OOTSK member
 
ATCGOD
Posts: 517
Joined: Wed Aug 30, 2006 3:24 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:04 am

Quoting IAHFLYR (Reply 5):
I disagree with this statement! The controller did NOT have the required 1,000' of vertical separation if the aircraft were within 5 NM of each other so that pretty much says ATC did not do their job.

Well, it could be a transponder error, or autopilot error. I highly doubt this was a case where the controller assigned an altitude that wasn't in 1000' increments. This sounds like an equipment error...happens all the time.
 
IAHFLYR
Posts: 3941
Joined: Sat Jun 25, 2005 12:56 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:08 am

Quoting ATCGOD (Reply 8):
Well, it could be a transponder error, or autopilot error. I highly doubt this was a case where the controller assigned an altitude that wasn't in 1000' increments. This sounds like an equipment error...happens all the time.

Correct and I mentioned that later in my post.
Any views shared are strictly my own and do not a represent those of any former employer.
 
VEEREF
Posts: 560
Joined: Wed Jun 09, 2004 12:55 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:10 am

What's really fun is being the meat in an "RVSM sandwich" where two aircraft are coming directly at you, one 1000ft above and one 1000ft below. And as often as not, one will read 900 instead of 1000 on TCAS. Any number of reasons for that as stated above.
Airplanes are cool. Aviation sucks.
 
ATCGOD
Posts: 517
Joined: Wed Aug 30, 2006 3:24 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:22 am

Quoting IAHFLYR (Reply 9):
Correct and I mentioned that later in my post.

It's all good.  Wink
 
IAHFLYR
Posts: 3941
Joined: Sat Jun 25, 2005 12:56 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:27 am

Quoting ATCGOD (Reply 11):
It's all good.


Agreed  highfive 
Any views shared are strictly my own and do not a represent those of any former employer.
 
flyboy7974
Posts: 1210
Joined: Sat Jan 18, 2003 4:35 pm

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:35 am

wait a second, just woke up, but, am I reading this correctly, and then doing the math in my head that I am reading 1.79 miles, that equals, um, how many feet, alot!

and then 900 feet seperation, um again, wait what? the airspace system is set up on the basics of 500 feet intervals seperating by direction and flight plan aircraft from each other based upon vfr vs. ifr flightplans. now, yes, yes i know that we are talking about commercial aircraft flying at 30,000 feet which then all a/c are on ifr flight plans, but, come on now, get real. this clip sounds like a filler, and please people, research this and you'll find that this happens countless times everyday, a/c passing like this happens all the time everyday, it's just an uneducated newsperson got a hold of something and has now fulfilled the commitment of the media, to blow it ouf of proportion. how many times on trip reports here or other aviation sites have we seen pictures of a/c holding into LHR and a/c are stacked and circling at 1000 ft intervals, or pictures of a/c approaching airports and seperation is less than 1000 feet, come on, people, don't encourage media that can be as stupid as this person was in reporting this, god, and the chicagotribune printed this, digging deep, digging so very deep, i now place them as low if not lower than the national enquirer, chicagotribune now equates to bottomfeeders
 
AlexPorter
Posts: 1655
Joined: Mon Jan 16, 2006 11:10 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:48 am

The one thing that's goofy here with 900' is that according to the article, both flights were eastbound, which means they should have been 2000' feet apart, not just 1000'. This happened near Dubuque, and NW was going to Detroit while UAx was going to Chicago. But otherwise, 900' and 1.79 miles is not a big deal at all. Strange that it happened when both were heading east.
Last Flight: SCX701 MSP-PHX B738 8Jan2008
 
planespotting
Posts: 3026
Joined: Sat Apr 17, 2004 4:54 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:53 am

Quoting ATCGOD (Reply 8):
This sounds like an equipment error...happens all the time.

That was my first thought as well -- it would be fairly easy for an autopilot or a transponder to get it wrong -- calibration errors do happen, and in those cases it isn't necessarily the pilots fault. But, since they were both heading east, it means that one of those planes had to have been at the wrong altitude, seeing as east-bound aircraft fly at odd-thousands (29,000, 31,000, etc...), so if both planes were flying east in level flight 1,000 feet apart, that seems like an odd circumstance.

Quoting AlexPorter (Reply 14):
But otherwise, 900' and 1.79 miles is not a big deal at all. Strange that it happened when both were heading east.

Yeah! really strange, unless one of the aircraft was descending...
Do you like movies about gladiators?
 
IAHFLYR
Posts: 3941
Joined: Sat Jun 25, 2005 12:56 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:55 am

Quoting Flyboy7974 (Reply 13):
wait a second, just woke up, but, am I reading this correctly, and then doing the math in my head that I am reading 1.79 miles, that equals, um, how many feet, alot!

Nah, you're still snoring!  Smile

Aircraft in a holding pattern and someone taking a picture out a window going into LHR doesn't mean they are 1,000' vertically separated, one could be descending to a lower alttidue so you could be 1,400' above that aircraft or more, and your 500' comparison is not for aircraft above 17,999' MSL, so what is your actual point as I think I am now sleeping?
Any views shared are strictly my own and do not a represent those of any former employer.
 
loggat
Posts: 426
Joined: Sat Feb 12, 2000 11:34 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:56 am

Quoting AlexPorter (Reply 14):
both flights were eastbound

Not quite, the article says that Northwest was going DTW-DEN (west), and the UAX was going from Lincoln to ORD (east). 30,000 is a westbound altitude, but for operational necessity, can be used in any direction.
There are 3 types of people in this world, those that can count, and those that can't.
 
IAHFLYR
Posts: 3941
Joined: Sat Jun 25, 2005 12:56 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 1:04 am

.

Quoting Loggat (Reply 17):
but for operational necessity, can be used in any direction


So true....

Consider that they may have actually been on crossing routes with someone wanting higher or someone wanting lower with the interm altitude issued until clear of the traffic......not that someone was at the wrong altitude. As shown above "operational necessity" and certainly not set in stone.
Any views shared are strictly my own and do not a represent those of any former employer.
 
Thrust
Posts: 2584
Joined: Wed Sep 17, 2003 12:17 pm

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 3:59 am

It kind of surprises me that TCAS didn't warn them of the danger before that. Unless it malfunctioned it kind of surpises that experienced pilots like that allowed such a thing to come that close to happening.
Fly one thing; Fly it well
 
allstarflyer
Posts: 3264
Joined: Mon Jan 10, 2005 7:32 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 4:10 am

Quoting MKEdude (Reply 1):
ATC, the TCAS, the pilots, sounds like everybody did their job.

I'd say so.

Quoting VEEREF (Reply 6):
Whoop de doo, that happens every day here in the US with RVSM.

 checkmark 

Quoting ATCGOD (Reply 8):
Well, it could be a transponder error, or autopilot error.

Agreed, and, in my limited time in the cockpit (being a dispatcher), I'd say it's autopilot. It's like, sometimes, the altimeter has a little variance on it - for example, when flying IND-BOS at 37000', the altimeter might read 36,900' or 36,800' - just something I've noticed from time to time.

Quoting ATCGOD (Reply 8):
This sounds like an equipment error...happens all the time.

Agreed, like said.

Besides, ATC will usually give a traffic alert, and then, if it's close, TCAS goes off and that annoying (but definitely necessary) alert "TRAFFIC, TRAFFIC" sounds and then pilots are scouring the area where (usually) ATC has already said to watch. Just leaving O'Hare itself, I've seen more than 1 traffic alert on the same flight - the example in this thread may not have been too close to O'Hare, but this stuff just happens.

-R
Living the American Dream
 
Cubsrule
Posts: 11368
Joined: Sat May 15, 2004 12:13 pm

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 4:12 am

Quoting Airfinair (Reply 3):
I love how the reporter refers to Chicago Center as "air-traffic control serving O'Hare International Airport."

The Tribune has actually corrected this now.
I can't decide whether I miss the tulip or the bowling shoe more
 
redcordes
Posts: 244
Joined: Wed Jan 18, 2006 6:28 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 4:15 am

Read some of these quotes from the article and think about union-management politics. Heck, 900' vert. separations must happen fairly frequently for brief periods--that's only a 50' error in each altimeter/piloting. I'll bet the union isn't happy with the new system and chose to blow the whistle and go public with it. I wonder who contacted the Chicago Tribune with the story? I doubt the FAA reported this minor incident themselves with such sensational language. Also, since the investigation has just begun, it seems surprising that the responsible party has already been determined:

"The FAA attributed the incident... to an error by a veteran air-traffic controller"

"Union officials said the Traffic Management Advisor tool is riddled with bugs and has caused problems at other airports, including in Dallas and Houston."

"He said the system is especially prone to problems when heavy streams of airplanes are headed to multiple runways at O'Hare."

"The controllers union said the controller responsible for the planes and an assistant became distracted by a new technology that was being tested."
"The only source of knowledge is experience." A. Einstein "Science w/o religion is lame. Religion w/o science is blind."
 
planespotting
Posts: 3026
Joined: Sat Apr 17, 2004 4:54 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 5:31 am

Quoting Cubsrule (Reply 21):
The Tribune has actually corrected this now.

Yeah -- their transportation reporter, John Hilkevitch, is usually pretty good when writing about aviation. He's not perfect, but as we all know, it'd be pretty hard to satisfy all the media-naysayers on this board, as well as those on here who demand 110% perfection and airline-pilot technical knowledge when writing anything remotely related to aviation.
Do you like movies about gladiators?
 
dw747400
Posts: 1091
Joined: Wed Aug 15, 2001 8:24 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 6:28 am

Quoting Redcordes (Reply 22):
Heck, 900' vert. separations must happen fairly frequently for brief periods--that's only a 50' error in each altimeter/piloting.

Keep in mind that all RVSM aircraft are flying on autopilot, and all altimeters should be set to 29.92. Thus, pilot error in terms of flying the aircraft or setting the altimeter, though still possible, are unlikely.

I'm thinking one aircraft must have been cleared to climb or descend in a manner that would conflict with the other. Normally 900 feet would not be significant; as many members have said numerous factors could cause such deviation. If a controller ordered one jet to climb or descend into another's airspace, that is much different.
CFI--Certfied Freakin Idiot
 
5mileBob
Posts: 103
Joined: Wed Aug 16, 2006 9:45 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 8:04 am

Hi folks - Didn't read the article, nor all of the responses, but for what it is worth: the ATC computer system will show an aircraft level at it's assigned altitude (Mode C) when the aircraft is within 299 feet of that altitude. Also, aircraft can be within feet of each other latterally, as long as they are at different altitudes. If at the same altitude, 5 miles is the minimum lateral separation in the en-route environment.
Still looks like a Ramp Rat
 
brilondon
Posts: 3010
Joined: Sun Aug 21, 2005 6:56 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 8:18 am

Quoting Airfinair (Reply 3):
I love how the reporter refers to Chicago Center as "air-traffic control serving O'Hare International Airport." Yes, indirectly, just as Chicago Center also indirectly serves LAX, SEA, FLL, and every other airport in the nation.

These reporters are not the brightest people in the world. They would know more if they just paid attention and did a little research on the topic at hand and less on the sensationalism of the story, but I guess that goes with trying to compete with all other media outlets in our society.
Rush for ever; Yankees all the way!!
 
travellin'man
Posts: 469
Joined: Sun May 13, 2001 1:55 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 8:26 am

Quoting AlexPorter (Reply 14):
1.79 miles is not a big deal at all.

When you consider that jets fly 6-8 miles per minute, less than 2 miles is about 20 seconds or less. Had they been flying towards each other at similar speeds, it would be half that. It seems like a lot of distance, but really it's not a lot of time.
It is not enough to be rude; one must also be incorrect.
 
IAHFLYR
Posts: 3941
Joined: Sat Jun 25, 2005 12:56 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 9:35 am

Quoting Redcordes (Reply 22):
"Union officials said the Traffic Management Advisor tool is riddled with bugs and has caused problems at other airports, including in Dallas and Houston."

Show me the report of that!!!! I know nothing of it and work in Houston so let the games and bs begin!  Smile
Any views shared are strictly my own and do not a represent those of any former employer.
 
User avatar
zeke
Posts: 9729
Joined: Thu Dec 14, 2006 1:42 pm

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 9:55 am

Quoting VEEREF (Reply 6):
900ft?
Whoop de doo, that happens every day here in the US with RVSM.

My reading of the article is that the United Express aircraft was in a climbing turn, that is the only way the aircraft above will get an RA to climb.

RAs should never be common in any airspace.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
 
YYZatcboy
Posts: 1001
Joined: Fri Apr 22, 2005 2:15 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 10:25 am

Sounds like they were flying past eachother and within the 5 mile boundary one of the Mode C transponders dropped down 100FT. It was likely just a computer Hiccup.
DHC1/3/4 MD11/88 L1011 A319/20/21/30 B727 735/6/7/8/9 762/3 E175/90 CRJ/700/705 CC150. J/S DH8D 736/7/8
 
KDTWflyer
Posts: 786
Joined: Tue Jun 29, 2004 12:51 pm

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 10:45 am

So was this NWA1224 and SKW6834 on 1-16-2007?
NW B744 B742 B753 B752 A333 A332 A320 A319 DC10 DC9 ARJ CRJ S340
 
airfinair
Posts: 563
Joined: Thu Dec 30, 1999 11:36 pm

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 10:57 am

I thought that the most interesting thing about the article is not so much the info in the article itself, but how John Hilkevitch may have received the information in the first place. Was it the FAA or the controllers union that originally contacted him? Or was it a member of one of the flight crew? Or someone else from within the airlines? Surely he didn't hear about it on the street - someone had to have contacted him about it. So who was trying to spin a rather mundane event into something bigger than it was - for some kind of political gain? This article smells fishy. FAA vs. NATCA? My take on the response from the NATCA is a more defensive one than the FAA's (meaning the FAA originally contacted Hilkevitch and he asked the NATCA to respond to their allegations.) Any thoughts?

And that leads to the question of why print the story at all. Was this truely interesting to most laypeople? Or was it shock value? Slow news day? John Hilkevitch is one of my favorite transportation reproters around, and I usually respect his writing a lot. (He had the balls enough to break the story about the UFO at ORD!) But this one smells a bit much of old fish dipped in Jet-A with a slight scent of politics to me.
ORD,MDW,IND,ARB,AMS,AUS,ANQ,DTW,DEN,PHL,PIT,MIA,GPT,SAN,PHX,LAX,SFO,OAK,SEA,LAS,SLC,SMF,ATL,MEM,BOS,MHT,JFK,EWR,LGA,NASâ
 
ikramerica
Posts: 13730
Joined: Mon May 23, 2005 9:33 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 11:42 am

Quoting Travellin'man (Reply 27):
When you consider that jets fly 6-8 miles per minute, less than 2 miles is about 20 seconds or less. Had they been flying towards each other at similar speeds, it would be half that. It seems like a lot of distance, but really it's not a lot of time.

Yes, but the point is, they weren't flying at each other. They only got near each other for a split second, nearly 2 miles apart, with NO CHANCE of hitting each other.

This is a non-event article and sounds very much like a planted article. I would suspect union involvement only because newspapers are also union and there are always reporters who are willing to write an article about anything a union leader tells them to.

So it begs the question about the new system: Does this new system, in any way, lead to a decrease in union employees? Does it mean that the same number of controllers can handle more airspace and thus the FAA need not hire as many new controllers as the union wants? What is the potential motivation for this story by the union leadership? There's usually an angle...
Of all the things to worry about... the Wookie has no pants.
 
alfa75
Posts: 488
Joined: Mon May 16, 2005 11:27 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:40 pm

If this is a little off topic please let me know. But I was just driving home from work wondering why I never see any other planes when I am flying. I've seen a few on approach or take-off but never at altitude. How come?
The best things in life aren't things!
 
allstarflyer
Posts: 3264
Joined: Mon Jan 10, 2005 7:32 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 12:51 pm

Quoting Alfa75 (Reply 34):
But I was just driving home from work wondering why I never see any other planes when I am flying.

Are you the one flying, or just riding along?

Quoting Alfa75 (Reply 34):
I've seen a few on approach or take-off but never at altitude. How come?

Probably because if they're on a jet route along your path, they're either behind you, in front of you or above/below you by 2,000' or more. If they're heading in the opposite direction (on the same jet-route), you may get a glimpse of one flying by out the window - then you'll know when the pilots received a traffic alert from TCAS. The a/c may appear close, but will probably be 1,000' above/below your position and at least 1-2 miles off. And they fly by fast. Otherwise, the only time you should see another a/c near you at altitude is for a flight filed direct, and not along normal jet routes (which is not implausible, since RNAV doesn't require hi-alt VOR's, thus less need in that sense for jet-routes).

-R
Living the American Dream
 
alfa75
Posts: 488
Joined: Mon May 16, 2005 11:27 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 1:06 pm

Quoting Allstarflyer (Reply 35):
Are you the one flying, or just riding along?

Riding along I'm afraid.

Thanks for the explaniation.
The best things in life aren't things!
 
irobertson
Posts: 409
Joined: Thu Apr 13, 2006 11:35 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 1:27 pm

I will agree that 900 feet is certainly a bit close for comfort, but with almost two miles of separation? That wasn't a near hit... (George Carlin homage there  Smile )

Tell me that they were 900 feet from hitting each other, that's a near hit. Certainly on transatlantic flights, I've been two miles off laterally from passing aircraft, judging on the size of contrails out my window and the shaking of wake turbulence...
 
antskip
Posts: 829
Joined: Mon Jan 02, 2006 8:53 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 1:53 pm

Quoting ATCGOD (Reply 11):
It's all good. Wink

So how frequent is it that the "on-board collision alarms" go off on a scheduled service? Sounds to me that many regard the incident as trivial. So is the collision alarm going off and requesting pilots to immediately alter course a trivial event or a serious one? And why does the report say that, in response to the on-board alarm, the controller helped avert a crash? Sounds like the pilots made the decisions in response to the on-board alerts. Wouldn't both pilots immediately obey their collision alarms and change their positions; and only then report the incident to the controller (who would at that point realize their error)? Surely on-board collision alarms take precedence over controller instructions?
 
mrcomet
Posts: 575
Joined: Mon Mar 28, 2005 5:53 am

RE: Near Mid-Air Collision 30,000' Over Iowa

Sat Jan 20, 2007 5:48 pm

Quoting Flyboy7974 (Reply 13):
wait a second, just woke up, but, am I reading this correctly, and then doing the math in my head that I am reading 1.79 miles, that equals, um, how many feet, alot!

Lets see 5480 feet in a mile x 1.79 miles = 9809 feet

The square root of 9809 to the second power plus 900 to the second power =

The planes were 9850 feet apart = almost 10,000 feet apart.

It is comforting to know that authorities consider that a near mid-air collision.
The dude abides

Who is online

Users browsing this forum: AAirbusCA, Baidu [Spider], blooBirdie, Clipper002, DavidByrne, Google Adsense [Bot], JannEejit, rutankrd, SusmithaNaidu, zanl188 and 216 guests