Saturday, November 24, 2012

List of United 93 Airfone calls

The above list is an excerpt of a  9/11 Commission paper on the GTE airfone calls. For a better view click  here.

Airfone is a terrestric system. The calling passenger is connected to the recipient via a net of ground stations (RBS=radio base station) scattered over the country. They connect the caller with the dialed number via landline. If the plane moves from one RBS area to the next, a handoff takes place, similar to cell calls. So in general, the position of a plane can be determined by the RBS with a decent uncertainty, just like VHF ACARS messages. Because the net of RBS is more wide-meshed than the net of ARINC RGS, the uncertainty is even bigger. Nevertheless, the list delivers valuable position information.

For each call, the list denotes (among other things)

- the name of the caller, 
- the seat where the call was placed from
- the begin of the call
- the duration of the connecting process
- the duration of the actual call
- the RBS at the begin of the call
- the RBS at the end of the call
- the number of handoffs during the call

The meaning of the columns (first row) is explained here:

For instance the last column - SCP duration,  "Switch Control Processor" - indicates the time (in seconds) the call was connected to the dialed number. For United 93, only four RBS were involved, and each of them has an ID number: Columbus (59 - "Colombus" with a typo), Fort Wayne (26), Belleville near Detroit (91) and Coraopolis near Pittsburgh (65).

The list makes it possible to determine the time and RBS when the call was commenced as well as the time and RBS when it was disconnected.

     Caller         Seat      Begin of Call         End of Call         # Handoffs

                             Time       RBS        Time    RBS     

Thomas Burnett     24ABC   9:30:32  Fort Wayne   9:31:19  Columbus     *

Flight Attendant   34ABC   9:32:39  Fort Wayne   9:34:17  Fort Wayne 

Flight Attendant   34ABC   9:31:14  Columbus     9:31:34  Columbus

Flight Attendant   33DEF   9:35:40  Detroit      9:41:45  Fort Wayne   *

Flight Attendant   34ABC   9:35:48  Detroit      9:37:32  Detroit

Flight Attendant   33ABC   9:35:58  Detroit      9:37:42  Detroit

Mark Bingham       25DEF   9:36:10  Detroit      9:36:51  Detroit

Mark Bingham       25DEF   9:37:03  Detroit      9:40:05  Fort Wayne   *

Jeremy Glick       27DEF   9:37:41  Detroit     11:44:00  Pittsburgh   ********

Thomas Burnett     25ABC   9:37:53  Detroit      9:39:19  Detroit

Lauren Grandcolas  23DEF   9:39:21  Detroit      9:40:21  Detroit

Lauren Grandcolas  23DEF   9:40:42  Detroit      9:41:04  Detroit 

Mark Bingham       25DEF   9:41:20  Detroit      9:41:36  Detroit

Lauren Grandcolas  23DEF   9:41:34  Columbus     9:41:52  Columbus

Mark Bingham       25DEF   9:41:53  Detroit      9:42:29  Detroit

Lauren Grandcolas  23DEF   9:42:03  Columbus     9:42:19  Columbus   

Joseph de Luca     26DEF   9:42:13  Columbus     9:42:47  Columbus

Lauren Grandcolas  23DEF   9:42:25  Columbus     9:42:41  Columbus

Todd Beamer        32DEF   9:42:44  Detroit      9:42:48  Detroit

Todd Beamer        32DEF   9:42:44  Detroit      9:43:29  Detroit 

Lauren Grandcolas  23DEF   9:42:45  Columbus     9:43:02  Columbus

Joseph de Luca     26DEF   9:43:03  Columbus     9:45:28  Columbus 

Lauren Grandcolas  23DEF   9:43:24  Columbus     9:43:31  Columbus

Lauren Grandcolas  23DEF   9:43:44  Columbus     9:44:16  Columbus  

Todd Beamer        32DEF   9:43:46  Detroit      9:43:49  Detroit

Todd Beamer        32DEF   9:43:48  Detroit     10:50:20  Detroit      ******

Thomas Burnett     25ABC   9:44:23  Columbus     9:45:37  Columbus

Waleska Martinez   34ABC   9:45:37  Columbus     9:47:55  Columbus

Linda Gronlund     26DEF   9:46:05  Columbus     9:47:44  Columbus

Ceecee Lyles       32ABC   9:47:57  Columbus     9:49:28  Columbus

Joseph de Luca     26DEF   9:48:48  Columbus     9:48:57  Columbus

Marion Britton     33ABC   9:49:12  Columbus     9:53:01  Pittsburgh   ***

Sandra Bradshaw    33DEF   9:49:30  Columbus     9:49:45  Columbus

Sandra Bradshaw    33DEF   9:50:04  Columbus     9:58:27  Pittsburgh   ***

Honor Wainio       33ABC   9:53:43  Pittsburgh   9:58:23  Pittsburgh

Here is a map of all RBS in 2006 (Source).

It is unclear whether all of these RBS were operative in 2001. According to this source f.i., the Cleveland RBS was not operative in 1991. This might explain why Cleveland doesn't appear on the airfone call list. The list will certainly shed a better light on the story of the "heroes of United 93". More research is forthcoming.