For certification purposes, the 707-100 and -200, the 707-300 and -400, and the 720/720B are all different aircraft. They are just derived from each other The C135 is Boeing model 717. The RC135 is 739. Starting in 1956, Boeing initiated studies on a short haul airliner designated the 707-020, with a suffix of -1 through -10. The -5 through -8 were twin engined aircraft seating 74 pax (no pax capacity were stated for the -7 and -8). The other 6 were had 4 engines seating 85-87 pax. In July, 1957, announced plans for the 717, a 4 engined aircraft seating 88 to 130 pax. In November 1957, announced plans to go ahead with the aircraft, now redisgnated the 720. SO, why the 720? William "Pat" Patterson, United's president, was impressed with the 707's performance but he felt the aircraft was too narrow. Boeing had told him the aircraft could be made longer but not wider. However, it was later determined the 707 could be widen. Patterson liked the 717 but was concerned his airline's image might suffer after going back to Boeing after ordering the DC-8. He wanted a different designation to that it wouldn't appear he was having second thoughts on the DC-8. He urged Boeing to change the designation and Boeing wanted a launch customer for the 717 so they agreed to the change. Patterson also didn't like the sound of "Seven One Seven" or "Seven Seventeen." Other airlines went along with the change of designation. All airlines except for 3 carried "Boeing 720" fuselage titles on their aircraft. The exceptions were American, TWA, and Aer Lingus. American referred to the 720 as "707 Jet Flagship" and the 720B as the "707 Astrojet." TWA leased four 720B's carried "SuperJet" titles (no "720" designation"). Aer Lingus carried only "Boeing" on the aircraft with no aircraft model shown. Sources: Great Airliners Volume 7: Boeing 720 by Jon Proctor (Word Transport Press) The Boeing 707, 720 and C-135 by Tony Pither (Air Britain) I look forward to meeting with you to discuss my qualifications for this position. David R http://home.comcast.net/~damiross/books.html -----Original Message----- From: The Airline List [mailto:AIRLINE@xxxxxxxxxxxxxxxxx]On Behalf Of Alireza Alivandivafa Sent: Friday, January 28, 2005 14:54 To: AIRLINE@xxxxxxxxxxxxxxxxx Subject: Re: Its Offical "787" In a message dated 1/28/2005 3:19:12 PM Central Standard Time, damiross3@xxxxxxxxxxx writes: Not quite true. There was the 720. And the succession shown above is not correct. The 717 came last. The first 717 was actually a military version of the 707. Also, if I'm not mistaken, the 767 saw service before the 757. The 720 was a version of the 707, just shortened. It actually had another name that was 707-XXX but 720 was the one used. The 717 was indeed the internal Boeing name for the KC-135 but they swapped over to using the military designation (remember, the KC-135 is narrower than the 707). The 767 did see service before the 757, but the 757 was designed first -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.8.1 - Release Date: 1/27/2005