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 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.
