Flight Data Recorder

Left image
Debris, including the Flight Data Recorder lies near the Flight 93 crash site
Credit: Photo Courtesy of Ron Horak

Right image
Circled is the Flight Data Recorder as found near the crash site of Flight 93
Credit: Original photo by Ron Horak, Edited by NPS

 

This is a summary page for the Flight 93 Flight Data Recorder (FDR) which includes a downloadable copy of the Flight Path Study Report from the National Transportation Safety Board (NTSB). For more information about Black Boxes visit the Glossary page.

To learn about the Flight 93 Flight Data Recorder, click the dropdown boxes below.

 

Flight Data Recorder Functions

The Flight Data Recorder (FDR) onboard the aircraft records many different operating conditions of the flight such as altitude, airspeed, heading, fuel usage, autopilot status, and aircraft altitude. It was also capable of recording data from the entire flight, from take-off to crash. With the data retrieved from the Flight Data Recorder, the National Transportation Safety Board (NTSB) can generate an animated video reconstruction of the flight that enables the investigating team to combine the data from the Cockpit Voice Recorder and the Flight Data Recorder to visualize the last moments of the flight before the accident. 

The Flight Data Recorder is made of stainless steel or titanium and made to withstand high impact velocity or a crash impact of 3,400 g-force and temperatures up to 2000 degrees Fahrenheit (1,100 degrees Celsius) for at least 30 minutes. The recorder is wrapped in a thin layer of aluminum and a layer of high temperature insulation.

Recovery of Flight Data Recorder

On Thursday, September 13 at 4:20 am, workers uncovered the Flight Data Recorder from Flight 93 from the crater at a depth of 15 feet. The cylinder-shaped box was photographed as it was uncovered in the crater. FBI agents assumed custody of the box, logged it as evidence and immediately removed it from the site, flying it to the National Transportation Safety Board (NTSB) laboratory in Washington, DC where its contents could be analyzed. 

However, the memory board showed signs of impact damage, thus the Flight Data Recorder was taken from Washington, DC and then to the Honeywell facilities in Redmond, Washington for evaluation and downloading. The data was extracted and electronically transferred to the National Transportation Safety Board (NTSB). 

Releasing Information from the Flight Data Recorder

In February 2012, the NTSB released four reports utilizing data from the Flight 93 Flight Data Recorder: The "Factual Report of Investigation" of the Flight Data Recorder consisting of graphs and tables summarizing the output of the Flight Data Recorder during the entire flight, the "Recorded Radar Study," the "Study of Autopilot, Navigation Equipment, and Fuel Consumption Activity," and the "Flight Path Study." The "Study of Autopilot" report includes graphs illustrating the values of speed, altitudes, headings, and climb/descent rates over the duration of the flight and describes changes in the magnetic heading entered in the Mode Control Panel that indicate that Flight 93 was on a heading for Washington, DC. The report also indicates that the VOR (very high frequency omnirange station) receiver on Flight 93 was set to correspond with the VOR station at Washington Reagan National Airport (DCA), suggesting "that the operators of the airplane had an interest in DCA and may have wanted to use that VOR station of help navigate the airplane towards Washington." Data retrieved from the Flight Data Recorder allowed the NTSB to calculate that Flight 93 had about 37,500 pounds of fuel remaining when it crashed in Pennsylvania.

A summary of the "Flight Path Study" report concludes with the following summary of the flight's final moments of erratic flight:

• At 9:59 the airplane was at 5,000 feet when about 2 minutes of rapid, full left and right control wheel inputs resulted in multiple 30-degree rolls to the left and right. From approximately 10:00 to 10:02 there were four distinct control column inputs that caused the airplane to pitch nose-up (climb) and nose-down (dive) aggressively. During this time the airplane climbed to about 10,000 feet turning to the right. The airplane then pitched nose-down and rolled to the right in response to flight control inputs and impacted the ground at about 490 knots (563 MPH) in a 40-degree nose down, inverted altitude. The time of impact was 10:03:11. 

 

 

Downloadable Flight Path Study from Flight 93 FDR

The "Flight Path Study" shows the flight path of the aircraft and its altitude for the 1 hour and 21-minute duration of the flight and includes a transcript of aircraft-to-ground communications including a summary of the flight's final moments of flight. 

Flight Path Study from United Flight 93 

 

Recovered Flight Data Recorder from Flight 93

Image courtesy of Department of Justice and Federal Bureau of Investigation