Hi N320AW (is this a tail number or ??),

Ummm, where to start- the link was to a 23-PAGE thread over at P4T. I used some reasonably accurate approximation methods based upon latitude/longitude and the ~12 second radar "sweep" time interval to estimate the "average" velocity between radar data returns.

Aside from the 888 knots (1022 mph) velocity anomaly at 08:55:47 EDT for UA175 at 28400 feet Mode C altitude (derived DIRECTLY from the USAF 84 RADES .XLS data file), I found an average (arithmetic mean) velocity for the UA175 flight of 391 kts (453 mph). Incidentally, the "high" velocities started well before the alleged hijack time:

"The 9/11 Commission concludes that Flight 175 is then hijacked within the next four minutes (see (Between 8:42 a.m. and 8:46 a.m.) September 11, 2001). [9/11 Commission, 7/24/2004, pp. 7]"

http://www.cooperativeresearch.org/t...e_911_timeline

Disregarding the one radar "anomaly", I found a 2nd highest velocity of 546 kts (628 mph) at 08:53:47 EDT. The V_mo/M_mo for a Boeing 767 is listed at 360 knots / 0.86 mach.
http://rgl.faa.gov/Regulatory_and_Gu...C?OpenDocument

Another problem is that the USAF 84 RADES cover letter submitted to the FBI 13 September 2001 lists flight UA175 as a Boeing 757, not a B767. Incidentally, the same cover letter lists UA93 (Pennsylvania) as a Boeing 747...

FWIW, the V_mo/M_mo for a B757 is only slightly lower at 350 kts / 0.86 mach.
http://www.757.org.uk/limits/lim1.html

http://rgl.faa.gov/Regulatory_and_Gu...B?OpenDocument

According to Joseph Keith, the ex-Boeing engineer in the above video, the turbofan engines are capable of 330 mph at 700 feet AGL, but the airframe is only capable of 220 mph before it "begins to shake itself apart" according to the video.

FEMA, Kean/Hamilton, NIST, and others all put the impact velocity with WTC2 South above 500 mph from what I recall. Several of the 2+2's here are coming up 9 it would seem...