On January 28, 2002, Michael J. Winter was interviewed at United Airlines UAL, World Headquarters, 1200 E. Algonquin Road, Elk Grove Village, IL. The interviewing Agent indentified himself to Mr. Winter and told him, the interview concerned UAL flight 93 on September 11, 2001 and the communications between UAL flight 93 and the flight dispatchers. Mr. Winter voluntarily provided the following information regarding these communications.
In reviewing the Sanitized Time and Text of ACARS messages as provided by the FBI, Mr. Winter said Meassage #1 was from the aircraft to UAL Dispatch. Message #2 was to the aircraft from UAL Dispatch at John F. Kennedy International Airport, New York, NY and Message #3 was to the aircraft from UAL flight dispatcher ED BALLINGER. Message #4 was from the aircraft to UAL flight dispatcher ED BALLINGER. Message #5, listed as unreadable, was engine data advisory information. Message #6 was from UAL flight dispatcher A.D. "Sandy " ROGERS to the aircraft and Message #7 was from UAL flight dispatcher ROBERT BRITTAIN to the aircraft.Message #8 was to the aircraft from BALLINGER and Message #9, listed as unreadable, was the engine data advisory information. Message #10 was from UAL flight Dispatcher CHAD McCURDY to the aircraft. Except for Message #13, which was to the aircraft from UAL SAn Francisco Maintenance, DAVID PRICE, all of the other messages listed were from UAL flight dispatcher BALLINGER.
Mr. Winter explained the Aircraft Condition and Reporting System ACARS uses radio ground stations RGS at various locations throughout the United States for communication. The messages from the aircraft utilize the RGS ina downlink operating system. A central router determines the strongest signal received from the aircraft and routes the signal/message to UAL flight dispatch.
Message #1 was routed from the aircraft through the RGS near Pittsburgh, PA PIT as designated in the line "DT DDL PIT...". Message #2, to the aircraft, was also routed through the RGS near Pittsburgh, A and was directed to the ACARS printer on the aircraft. The routing to the printer is designated by the letters "AGM" following "Smi=AGM" and "STX=AGM.."
Message #3 was a message to the aircraft from Chicago Dispatch CHIDD listed as a Command Respoinse MD type message. The CMD message, designated in the line "Smi=CMD Agy/Num=65535", was sent to the ACARS screen and utilized the RGS near Pittsburgh, PA. In this type of message, the flight dispatcher can also activate an audible signal to alert the flight crew of the sent message but this was not done.
Message #4 was sent from the aircraft to UAL flight dispatch using the RGS near Pittsburgh, PA. The designation "C4" appears just before the sentence "EWRSFO..." indicating the message was sent from the aircraft.
Message #5 was an engine data message which was sent automatically to UAL Chicago dispatch and a UAL maintenance computer. The information in the message as N41.20 W080.5" was the latitude and longitude of the aircraft when the date was sent.
Message #6 was a message to the aircraft from CHIDD using a RGS near Akron/Canton, OH CAK and was sent to the ACARS screen. The designation for Akron/Canton, OH CAK appears in the line beginning "AN N591UA/GL CAK..."
Message #7 was sent to the aircraft from CHIDD using a RGS near Akron/Canton, OH. The message was sent to the ACARS screen and was a CMD type message.
Message #8 was sent to the aircraft from CHIDD using the RGS near Akron/Canton, OH. The message ws a CMD message and also activated the audible signal. The audible signal designated as "BEL" in the line "QUCHIAKUA-1-BL>UA 93".
Message #9 was an engine data message. The latitude and longitude was also listed in the message as "N41.31 W081.06".
Message #10 was sent to the aircraft from CHIDD and was sent to the ACARS screen omly. The RGS in this instance was near Cleveand, OH CLE from the line "AN N591UA/GL CLE...".
Messages #11 and #12 were sent to the aircraft from CHIDD using the RGS near Cleveland, OH. These messages also activated the audible signal in the aircraft.
Message #13 was sent to the aircraft from UAL San Francisco, CA line maintenance to the ACARS screen and also activated the audible signal. The RGS for this message was near Toledo, OH as designated "TOL" in the oine "AN N591UA/GL TOL...".
Messages #14 and #15 were sent to the aircraft from CHIDD using the RGS near Toledo, OH. The messages were sent to the ACARS printer.
Messages #16 and #17 were sent to the aircraft from CHIDD using the RGS near Ft. Wayne, IN, FWA as designated in the line "AN N591UA/GL FWA...". The messages were sent to the ACARS printer.
Messages #18 and #19 were sent to the aircraft from CHIDD using the RGS near Champaign, IL CMI as designated in the line "AN N591UA/GL CMI...". Both messages were sent to the printer and Message #19 also activated an audible signal in the aircraft.
Messages #20 to #24 were sent to the aircraft from CHIDD. However, all of the messages were rejected indicating the aircraft did not receive them.
Also present during part of this interview was David Knerr, Manager Flight Dispatch Automation, UAL WHQ.