Posted on 12/02/2009 4:21:26 PM PST by george76
Passenger Jets Were 200 Vertical Feet Apart.
the FAA is investigating a Nov. 23rd incident where two passenger jets nearly collided in the airspace over Colorado.
the two planes merged on Air Traffic Control radar at the same altitude and in the same moment.
"They were within a blink of an eye of colliding," and "It was the ugliest thing I've ever seen in all my years."
The incident is classified as an "operational error" ...a mistake made by an air traffic controller.
Several planes were en route to Denver on an arrival path from the northeast, called "Sayge Six."
Sayge is described ...as a "highway in the sky" with traffic only allowed to travel in one direction, toward DIA, at 19,000 feet and 250 knots for jets.
The Sayge marker is about 47 miles northeast of DIA, and is an air traffic control handoff point between Longmont Center and DIA Approach Control.
alarms sounded in at least one of the cockpits telling the pilots to take evasive action.
One plane dove while the other was ordered to pull up, and the two missed by about 200 vertical feet.... The source could not confirm the horizontal separation of the two planes because the radar images briefly merged into a single image.
(Excerpt) Read more at thedenverchannel.com ...
TCAS sure came in handy!!
http://www.ll.mit.edu/publications/journal/pdf/vol16_no2/16_2_04Kuchar.pdf
**IF** they truly were on a collision course, then ‘Bitchin’ Betty’ was yelling at the flight crews.
If ya wanna understand why these two planes probably would NOT have collided, go here and read: http://aerowinx.com/html/tcas.html
I’ve flown that arrival before many times and it is a very congested one, this isn’t the first time for a reported near miss on that arrival either.
It was much worse when the USAF had one of their training routes overlaid with the arrival a few years back.
But in their defense, the TR was there long before the DIA arrival was...
Thanks for the post. There’s alot missing from the aticle. Pilots (especially air carriers) do not normally reverse course to proceed to a fix w/o further clearance or holding instructions. Sounds kinda like the center lost track of this fellow after automated handoff.
Does not seem like a good idea ?
Republic Flight 1539 had already passed the Sayge marker and then the pilots turned about 180 degrees toward the Sayge marker and were traveling in the wrong direction on the “highway,”
That’s part of the missing story. Air Carrier pilots do not like to deviate from their flight plan/clearance. It costs them money (fuel) and time. A pilot that was already established (vectored to join) the enbound radial would put up a severe fuss over the loss of time/money that a 180 would have posed. All I can really say is that TCAS saves yet another one.
On a return trip from Los Angeles to San Jose (my first time flying) This happened to me. Our plane had just reached flying altitude and the fasten seat belt sign had gone off and the stewardess started serving coffee. All of a sudden we dropped so far I almost hit the ceiling. I looked out the window and saw a fighter jet go over top of us.
It scared me so much I don't fly.
AVIATION PING
“I looked out the window and saw a fighter jet go over top of us.”
Damned airline pilots! How dare they threaten our military.
Everyone knows our military jocks would never bust an altitude. ;-)
This is a file that shows the approach in question:
http://naco.faa.gov/d-tpp/0912/09077SAYGE.PDF
You can see SAYGE on the left side of the chart. At that point, traffic on the arrival is inbound toward the Denver area heading roughly southwest (218 degrees) at FL190 (19,000 feet) and 250 knots.
If the Republic flight was past or south of SAYGE and a controller didn’t realize it and told him to “proceed direct SAYGE,” then yeah, he’d be flying right back into the arrival at the same altitude, assuming he’d been cleared down to FL190 and not told to go lower. That’s a serious mistake.
BTW, pilots do have the right to refuse ATC instructions. The pilot-in-command, like a ship captain, has the ultimate responsibility for the safety of his own flight and is allowed to tell a controller that he can’t do something. But it’s exceedingly rare to do it...and the assumption, valid 99.999% of the time, is that the controller has a better overall picture of the airspace than the pilot does, so the controller’s instructions are the correct ones. In this case, it sounds like the pilot was trying to tell the guy that going back to SAYGE made no sense but the controller insisted.
}:-)4
“If the Republic flight was past or south of SAYGE and a controller didn’t realize it and told him to “proceed direct SAYGE,” then yeah, he’d be flying right back into the arrival at the same altitude, assuming he’d been cleared down to FL190 and not told to go lower. That’s a serious mistake.”
Might be a mistake. Might not. When the blue juice hits N1 at ATC you could very well be sent back to a previous fix. In itself, such an amendment is neither illegal or inappropriate. It doesn’t happen often, but when it happens you don’t decide to have a “conference” with the controller. If things went south up ahead, he doesn’t have time to give you an extended briefing on the freq outside of a confirmation (but you know all of this).
The point is, the flight deck crew is not omniscient re. the ATC side of things. You have to assume that the controller knows what they’re about (which is obviously not always the case). The only thing that keeps you safe is an educated sense of paranoia (sometimes).
As bad as it was, the article fails to state, that although the vertical clearance was 200 feet, the closest these planes were when they past each other horizontally was a little over 2 miles.
the two planes radar images briefly merged into a single image.
I have refused a vector by ATC when I thought it was wrong and it was wrong. I was being vectored into a thunderstorm. ATC then gave me another vector to fly.
Thanks
Please dont tempt the kitties.
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