How 9/11 cell phone calls were made

I think these phone company records provide evidence of how cell phone calls were made from 9/11 planes.

These are calls that went through the "Claircom box" on AA77, the plane that hit the Pentagon. This is the box that handles seatback phones, but calls did not originate from seatback handsets. It appears they came from something plugged into external port #4 of the Claircom box.

My hypothesis is someone put a picocell (cell phone base station) on the plane and plugged it into Claircom box in order to get a connection to ground stations. The implications are:

.. Someone other than hijackers was involved. The Claircom box was not accessible from the passenger compartment. The picocell must have been installed days beforehand.

.. Cell phone calls were legit. The calls seen here were operator assisted, but calls from United planes, which used a different seatback phone system, might have passed through normally so as to show the caller's cell phone's number on the recipient's CallerID.

I believe calls did not come from seatback phones because HandsetID shows ffff, computer code for -1, meaning unknown. I believe they came from port #4 because Originating # shows 9045550004. The 555 in the middle (NXX) indicates is not a working telephone number, but rather for internal use. Area code (NPA) 904 is in Jacksonville FL. They had to put some three digit number to fill the space. Perhaps software was developed in JAX. The last four digits (NNNN) contain the useful information. I think 0004 means external port #4.

Background: Claircom was an AT&T subsidiary that developed and initially operated the seatback phone system, marketing name Air One, on American Airlines. They sold it to Iridium in 1999. Iridium is known for its network of 66 low-orbit communication satellites, but the Claircom system did not talk through satellites. It used ground stations designed for airplane communication. Iridium's US operation center is in Tempe AZ, which is in Mountain Standard Time. That explains why timestamps on the records show 7x am, two hours earlier than they occurred in Eastern Standard Time.

American Airlines was in the process of uninstalling the Claircom system from its planes, but had not yet uninstalled it from this particular plane. The existence of these records proves that. There is a switch in the cockpit enabling the pilot to turn off seatback phones. It is likely that switch turns off the front end seatback phone controller while leaving the Claircom back end running, to avoid an annoying startup delay when phones are switched on.

United Airlines was using a system with marketing name Airphone, developed and operated by Verizon (formerly GTE). It would be interesting to see whether records from Airphone boxes also show calls coming through an external port rather than a seatback handset. If one showed a cell phone number as Originating #, the cat would be out of the bag for sure.

Picocells were available long before 2001. They were used in airport terminals, office buildings, hotels, etc. To use them on airplanes, the hard part is developing a back end that can talk to the ground. It requires an antenna outside the plane. On a plane already equipped with a seatback phone system, a picocell can simply use it as its back end. Seatback phone controllers have external ports in case the airline wants to add a feature such as WiFi.

I am a software developer who worked at AT&T, Sprint, and Amdocs.