Following is a transcript of the radio communications of American Airlines Flight 11 (AAL11) and United Air Lines Flight 175, which took off from Logan International Airport in Boston and then were crashed into the World Trade Center. The transcripts were obtained by The New York Times.

7:45:48 -- Ground Control 1: American eleven heavy boston ground gate thirty two you're going to wait for a Saab to go by then push back.

7:45:58 -- AAL11: After the Saab cleared to push, and we're gonna need four right today, American eleven heavy.

7:46:09 -- Ground Control 1: American eleven heavy uh understand you need alpha roger. Push back after the Saab is approved.

7:46:15 -- AAL11: O.K. Yeah what I said was we're going to need runway four right today, American eleven heavy.

7:46:21 -- Ground Control 1: American eleven heavy. Roger plan on runway four right.

7:49:20 -- AAL11: American eleven, heavy taxi november.

7:49:23 -- Ground Control 1: O.K. American eleven heavy, just hold right there i'll move you shortly.

7:50:00 -- Ground Control 1: American eleven heavy, you're going to give way to the Dornier and the regional jet on the opposite side. Taxi to the bravo hold point via kilo bravo. Expect runway four right for departure.

7:50:11 -- AAL11: O.K. to the bravo hold point after the regional jet and the Dornier, American eleven heavy.

7:53:23 -- Ground Control 1: And American eleven heavy, I'm gonna have to give you sierra and then alpha to the bravo hold point so just hold short of sierra for now.

7:53:31 -- AAL11: Holding short of sierra American eleven heavy.

7:53:59 -- Ground Control 1: American eleven heavy giving way to that Embraer off your right turn right on sierra alpha kilo one bravo to the bravo hold point for now expect four right.

7:54:09 -- AAL11: O.K. we copy all. Expect four right, American eleven heavy.

7:55:14 -- Ground Control 1: American eleven heavy, taxi to the bravo hold point. Continental's waiting for you. Monitor tower one two eight point eight. Expect runway four right, thanks.

7:55:21 -- AAL11: Twenty-eight eight. We'll expect four right and bravo hold point American eleven heavy.

7:56:27 -- Local Control West: American eleven heavy, Boston Tower. Taxi to runway four right via bravo and monitor the tower one one niner point one.

7:56:34 -- AAL11: Taxi to four right via bravo then nineteen one, American eleven heavy.

7:57:31 -- Local Control East: American eleven heavy, Boston Tower. Good morning, Move right up to hold short of four right after departure maintain three thousand.

7:57:40 -- AAL11: Holding short of four right uh three thousand American eleven heavy.

7:57:57 -- Local Control East: American eleven heavy runway four right taxi into position and hold traffic departing niner.

7:58:04 -- AAL11: Four right position and hold American eleven heavy.

7:59:02 -- Local Control East: American eleven heavy traffic's orbiting north of the field at thirty five hundred feet. Maintain three thousand runway, four right cleared for takeoff.

7:59:11 -- AAL11: Maintain three cleared for takeoff on four right. What are the winds?

7:59:14 -- Local Control East: Wind three three zero at niner.

7:59:16 -- AAL11: Thank you.

8:00:11 -- Local Control East: American eleven heavy, contact departure that traffic's now in your ten o'clock and two miles thirty four hundred feet.

8:00:19 -- AAL11: We have him in sight talk to departure so long American eleven heavy.

8:00:30 -- AAL11: Departure. Good morning, American eleven heavy with you passing through ah two thousand for three thousand.

8:00:36 -- Boston Departure Radar: American eleven heavy, Boston departure radar contact. Good morning. Traffic ten o'clock two miles, maneuvering Cessna Skyland [flying under visual flight rules] at three thousand five hundred.

8:00:43 -- AAL11: We have him in sight American eleven.

8:01:19 -- Boston Departure Radar: American eleven heavy climb and maintain eight thousand.

8:01:21 -- AAL11: Eight thousand American eleven heavy.

8:02:14 -- Boston Departure Radar: American eleven heavy turn right heading one eight zero.

8:02:16 -- AAL11: One eighty American eleven heavy.

8:03:03 -- Boston Departure Radar: American eleven heavy climb and maintain one four thousand.

8:03:06 -- AAL11: One four thousand American eleven heavy.

8:03:34 -- Boston Departure Radar: American eleven heavy turn right heading two two zero.

8:03:37 -- AAL11: Two zero American eleven.

8:04:27 -- Boston Departure Radar: American eleven heavy turn right heading two seven zero contact Boston approach one two seven point two good day.

8:04:32 -- AAL11: Twenty seven two and two seventy American eleven so long.

8:04:48 -- AAL11: American eleven heavy with you passing through one zero thousand for one four thousand.

8:04:52 -- Boston Approach: American eleven heavy Boston approach fly heading two seven zero.

8:04:55 -- AAL11: Two seventy, American eleven.

8:05:14 -- Boston Approach: American eleven heavy, contact Boston center one three three point four two.

8:05:19 -- AAL11: Thirty-three forty-two. So long American eleven.

8:12:21 -- UAL175: Position and hold runway niner United one seventy five heavy.

8:13:26 -- Local Control East: United one seventy-five heavy runway niner cleared for takeoff traffics holding in position on four right.

8:13:32 -- UAL175: Cleared for takeoff runway niner uniteds one seventy five heavy.

8:13:34 -- Local Control East: United one seventy-five heavy contact departure.

8:14:36 -- UAL: Departure Uniteds one seventy-five heavy.

8:14:44 -- UAL175: Approach, United one seventy-five heavy with you out of twelve hundred.

8:14:46 -- Boston Departure Radar: United one seventy-five heavy, Boston departure radar contact. Climb and maintain one four thousand.

8:14:51 -- UAL175: One four thousand, United one seventy-five heavy.

8:15:41 -- Boston Departure Radar: United one seventy-five, heavy turn right heading, two one zero.

8:15:45 -- UAL175: Turn two one zero, United one seventy-five heavy.

8:16:51 -- Boston Departure Radar: United one seventy-five, heavy turn right, heading two seven zero.

8:16:54 -- UAL175: Turn to two seven zero, United one seventy-five.

8:17:09 -- Boston Departure Radar: United one seventy-five heavy, contact Boston approach. One two seven point two good day.

8:17:13 -- UAL175: Two seven point two, United one seventy-five heavy. Good day.

8:17:21 -- UAL175: Boston, good morning. United one seventy-five heavy out of eight thousand.

8:17:24 -- Boston Approach: United one seventy-five heavy, Boston approach. Fly heading two seven zero.

8:17:28 -- UAL175: Two seven zero on the heading, United one seventy-five.

8:19:09 -- Boston Approach: United one seventy-five heavy, contact Boston center one three three point four two.

8:19:13 -- UAL175: Three three four two, United one seventy-five heavy. Good day.