Oystein,
We are off on the wrong foot completely. I haven't got the foggiest idea what point you're trying to make. In connection with 'assumption' you appear to assume a meaning concerning something I may have posted, but you mix what I posted with what the video claims.
You have on occasion used the process of "checking for accuracy of understanding" and I think it would behoove you to do so in this instance. What are you claiming I said and how does it relate to the claims in the video? Please source the time segment of the video and let's see if we can figure this out and get it right.
OK?
*sigh*
Alright.
Let's review
your post # 2931:
Bill,
As I indicated, the Flight 175 simulation of 4min40sec of the supposed Flight 175 flight path, based on using a Boeing simulator and the known data is an excellent piece of data.
...
The simulation, based on the NTSB flight path and other data confirms the flight path and rate of descent is impossible and the data do not correlate with what is seen in the alleged Flight 175 crash videos.
...
1--0:00-0:22--
Claims "pilots dispute" whether a Boeing 767 could descend 20,000ft in 4min4sec
2--0:22-0:37-- Flight simulation needed. Claims using Boeing 747 simulation to detail Boeing 767 flight is valid.
3--0:44-0:52--"Official story" of Flight 175 from National Security Archives is referenced as a data point.
4--0:52-0:59 Claims to use NTSB "Flight Path Study" that was based on "is this exercise or is this real world" data about which we do not know whether it is the one or the other.
5--1:00-1:28 References use of radar data from NTSB study in the reconstruction and explains the use of the flight path data points A to G.
6--1:29 - 1:35 The scene now changes to that of an aircraft Simulator with the claim that Flight 175 is at 31,000ft.
7--1:36-1:44 The white triangle on the simulator is said to represent the plane and the points of reference from the NTSB radar data.
8--1:44- 2:10 The radar points are coordinated with the simulator and it is explained how it is that the tracking can be done with accuracy.
9--2:10-2:30
The NTSB data is then used to plot a chart of the descent, including rate, speed and so on over the course of the last 4min40sec. of the supposed flight.
That concludes the first segment of the video. The next is entitiled Reconstruction and begins at about the 2:30mark.
I snipped some paragraphs which are superfluous in the debate about the (im)possibility of descent rate. I colored those phrases in COLOR="Teal" whci I want to concentrate on. Particularly the claim that "
"pilots dispute" whether a Boeing 767 could descend 20,000ft in 4min4sec".
Actually you made some minor mistakes in that phrase, namely:
- 4min40sec instead of 4min4sec
- descent of more than 20,000 feet between point G and the end of the chart. Point G is at 24,600ft according to the video, and the end of the chart is at 2000ft. So that's 22,600 ft descent
Now what "impossible" rate of descent are we talking about?
Let's look at some screenshots from the video:
2:12 - jst showing that they put 5 lines of data to the right of the chart - can't read it in that shot. They then zoom in. Point of this screen grab is: 5 data points, no more
2:26: Shows that point G is at 24,600 feet and 0:00 minutes (beginning of minute 1):
2:30: Shows descent rates increasing to a maximun (5th data point) of 6300 ft/min
They run the simualtion then.
At 5:30, when increasing descent rate from 3100 to 5000 ft/min, they say the craft immediately "overspeeds", which means "going into the valley of death". Ok, that is their claim. They make it appear
as if the descent rate is responsible for the increase of speed to overspeed.
At 6:30, with descent rate now increased to 6000ft/min, and
throttle at 46%, altutude around 12,000 feet, the airspeed is now increased beyond 400 KIAS. Video goes on to
claim that now the airframe is at danger of disintegrating and would break at 12,000 feet.
Remember
your claim after watching the video:
"pilots dispute" whether a Boeing 767 could descend 20,000ft in 4min4sec (actually, 22,600 feet in 4min40sec). That's on average 4842 ft/min, and a maximum of 6300 ft/min - according to the video. Video claims such a descent rate would increase speed to a point where plane would break and crash.
Are you following thus far?
The document "Type Acceptance Report 767" (New Zealand) that I presented tells a different story:
It recommends a descent rate of more then 8500ft/sec above 17,000 feet, and 7000 ft/sec above 10,000 feet in case of an emeregancy (loss of oxygene).
Evidently, the claim made in the video that a descent rate of 6000ft/min at 12,000 feet would put the plane at high risk of disintegrating is thus refuted. A 767 can safely descent at higher rates and not overspeed dabgerously.