10:01 a.m.-10:15 a.m. September 11, 2001: Delta 1989 Pilot’s Failure to Use Standard Term in Communications Makes Controllers Suspicious

Air traffic controllers at the Cleveland Terminal Radar Approach Control (TRACON) remain suspicious of Delta Air Lines Flight 1989 as it is coming in to land at Cleveland Hopkins Airport, due to the pilot’s failure to use an important standard term in his communications with them. [Federal Aviation Administration, 9/16/2001] A TRACON is an FAA facility that guides aircraft approaching or departing an airport. Flights coming in to land will subsequently be passed on to the airport’s air traffic control tower once they are within five miles of the airport and below 2,500 feet. [Federal Aviation Administration, 3/24/2006] The Cleveland TRACON is in contact with Delta 1989 as it descends from 9,000 feet down to 3,000 feet. [Federal Aviation Administration, 9/16/2001] Delta 1989, a Boeing 767 out of Boston, is mistakenly suspected of being hijacked (see 9:39 a.m. September 11, 2001 and (Shortly After 9:44 a.m.) September 11, 2001) and has been instructed to land as soon as possible in Cleveland (see (9:42 a.m.) September 11, 2001). [USA Today, 8/13/2002; 9/11 Commission, 7/24/2004, pp. 27-28; Spencer, 2008, pp. 167-168; USA Today, 9/11/2008]
Pilot Does Not Use Term ‘Heavy’ – A detailed timeline provided by the Cleveland Airport control tower shortly after 9/11 will describe, “One anomaly that perpetuated concern by approach controllers in the face of constant information that there was nothing going on with [Delta 1989] was that the pilot never used the HEAVY designator in his communications.” [Federal Aviation Administration, 9/16/2001] The term “heavy” alerts controllers to provide extra spacing behind very large aircraft, which are above a certain weight, because these aircraft generate significant wake turbulence. [USA Today, 6/1/2005; USA Today, 5/22/2006]
Controllers Skeptical of Delta 1989’s Security – While the TRACON controllers use the “heavy” designator, “the pilot [of Delta 1989] did not respond with it.” The control tower’s timeline will state that, while this detail “may seem minor,” it “should not be overlooked. The use of HEAVY in the terminal environment is of the highest importance. Increased separation standards are required, and misapplication of separation standards can be disastrous. For pilots, not referring to a heavy aircraft as HEAVY is tantamount to calling a doctor ‘Mister.’” As a result, “This omission, along with all of the other information flying around, kept everyone alert and skeptical of the security of the flight.” [Federal Aviation Administration, 9/16/2001]