airtraffic

Author Topic: Need Some Expertise  (Read 4011 times)

Offline josmul123

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Need Some Expertise
« on: March 11, 2012, 12:57:22 PM »
I had a particularly rough flight on March 9th on AA398. The whole flight was turbulent, but at about 8:05AM CST, the plane started going down fast. Extremely fast. I'm trying to determine why.

I found this:
http://flightaware.com/live/flight/AAL398/history/20120309/1200Z/KORD/KLGA/tracklog - You can see the descent there. A bit early and a bit steep.

The pilot didn't mention anything, even after we leveled off. I figured the ATC logs might have more information, but I'm confused as to which ones to listen to.
So far, I've tried KLGA Tower and the KLGA NY Approach archives for 14:00 UTC, and I can't find any reference to that flight.

Can anyone point me in the right direction? Any help would be appreciated.



Offline josmul123

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Re: Need Some Expertise
« Reply #1 on: March 11, 2012, 05:36:26 PM »
So my first problem was that the times on flightaware are all eastern. So 1400 UTC/8:05AM CDT wasn't right. However, I don't hear anything in the 1500 UTC logs either.


I looked at history for that flight, and a LOT of them have those sudden descents previously. Perhaps it's just the approach.

Offline JetScan1

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Re: Need Some Expertise
« Reply #2 on: March 11, 2012, 09:53:48 PM »
8:05 EST = 13:05 UTC (on the 9th), at that point the flight would have been working New York Center Milton Sector (frequency 128.57), AFAIK that sector is not covered by any radios on LiveATC.

On that arrival (MILTON FOUR) there is a restriction to cross MARRC at FL180 (18000 feet) or the lowest usable flight level, if ATC gave the descent clearance a little late it might have required a more aggressive descent profile to make the restriction, or maybe ATC required an expedited descent for traffic ? 3200 feet per minute is not that unusual. 

http://aeronav.faa.gov/d-tpp/1203/00289MILTON.PDF

Offline sykocus

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Re: Need Some Expertise
« Reply #3 on: March 11, 2012, 10:44:34 PM »
I don't think you'll find anything profound. Being a passenger gives you a very limited perspective on what is going on with the plane. You'll even notice that shortly after you started descent your ground speed started to slow even though it probably "felt" like you were going faster.

Here are several flights which exceeded 3,000 fpm in descent.
http://flightaware.com/live/flight/UAL7/history/20120311/0815Z/RJAA/PGUM/tracklog
http://flightaware.com/live/flight/UAL166/history/20120310/0240Z/RJFF/PGUM/tracklog
http://flightaware.com/live/flight/UAL874/history/20120310/1155Z/RJAA/PGUM/tracklog