United 93 received 18 ACARS uplinks after alleged 10:03 crash – CONFIRMED


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United 93 received 18 ACARS uplinks after alleged 10:03 crash – CONFIRMED

This article by esteemed 9/11 researcher, "Woody Box" is long and detailed, but it's well worth reading! It may take a few reads to get through. It did for me. I'll provide a summary of key points.

The Warren Stutt ARINC file (of unconfirmed authenticity) indicates that United 93 received 18 ACARS uplinks from United Airlines dispatch after 10:03, its official crash time. However, the aircraft did not acknowledge these additional uplinks. Warren Stutt seems to believe that every received uplink is inevitably acknowledged by the aircraft, so if a message is not acknowledged, it has not been received. However, the real story is more complicated. A plane may receive an uplink, while ground control doesn't receive the acknowledging downlink. Woody Box's article discusses this point.

Crucial to our argument is that a crashed plane cannot perform link tests (or "handshakes") with a ground station. The ARINC 618 air-to-ground protocol is written for manufacturers of avionics equipment, and generally describes the downlink routines for ACARS messages. But it is emphasized several times that the same rules also apply to uplinks. So it's safe to say that uplinks have such a preceding link test too. Because, as "Woody Box" states:
Each Telex transmission (like ACARS is based on) is initiated by a so-called handshake: a synchronization process between sender and receiver to enable and optimize the transmission of the actual message. This requires an exchange of data between sender and receiver before dispatching the message.
Obviously, a crashed plane can't exchange data with another party. This seems implied in the Boeing Avionics manual:
Upon receiving a message, the DSP (ground system) "handshakes" with the aircraft Communications Management function according to the ACARS air-ground protocol.
The significance of the 18 uplinks appearing after 10:03 is that, as Woody Box states:
[a] sent ULBLK (uplink) implies a successful handshake; a successful handshake implies a good VHF connection; a good VHF connection implies that the plane is within line-of sight or at least almost line-of sight of the ground station; and a line-of-sight condition implies that the plane is airborne (exception: the plane is grounded at the airport where the sender is located – but this was not the case for United 93 at 10:11).
Pages 22–26 and Section 5.3 of the ARINC 618 air-to-ground protocols – explained in detail by Woody Box in the above linked article – provides first hand evidence that uplinks are only sent when the preceding handshake is successful, which proves that United 93 received the last 18 uplinks which were sent after 10:03.

Conversely, a dispatch message which is rejected by ARINC CPS (IPCUL 231 or otherwise), logically is not received by the aircraft. David Knerr, manager of dispatch automation at United Airlines, also revealed in his FBI interview that he knew that all ACARS uplinks sent from airline dispatch were automatically received by the aircraft – hence his proposal that United 93 was flying at a low altitude after 10:03. Notably, he chooses 10:12 as the moment when United 93 stopped receiving messages, and not any point before that. This implies that messages sent between 10:03 a.m. and 10:12 a.m. were received by United 93.

Knerr is also corroborated by Michael J. Winter, the United Airlines dispatcher who clearly stated to the FBI that dispatch messages #20 - #24 – sent after 10:12 a.m. and which appear after message #0708 in Ed Ballinger's incomplete desk logs on page 53 – were rejected by ARINC CPS, which means the aircraft indeed did not receive that latter set of messages.

Here's an example of a rejected dispatch message, which failed to be delivered to United 93:


In text:
***UA93 EWRSFO***
Source: Team 7 Box 13 UAL ACARS p. 55

You'll notice that someone wrote "?" beside it, which signifies the strangeness. 1114 is 9:14 a.m (EDT) in Zulu format.

No content, no second Zulu time stamp, no technical acknowledgement. The second Zulu time stamp, at United Airlines, is the time the aircraft received the message, as stated by experienced United dispatcher Ed Ballinger. Message #20 has none of these hallmarks, indicating that it failed to deliver to the addressed aircraft.

Ballinger's desk logs – which include dispatches to all aircraft under his responsibility – are not the sanitized version from ARINC that Winter reviewed in his FBI interview wrt United 93, which is why the number sequencing for messages differs between the Michael J. Winter interview and Ed Ballinger's logs.

In the appendix of his article, Woody Box proposes a plausible solution for the failed acknowledgement of the 18 uplinks which appear in the Stutt ARINC file after 10:03. In short, it's likely due to the plain CSMA algorithm which was in use on September 11th, and the "hidden transmitter" problem which corrupts the subsequent downlinks from the aircraft. He speculates that N591UA was flying at a low altitude, hence the hidden transmitters in its flight path. I speculate further that it was preparing to land, as IPCUL 231 NO STATION TO are reported after 10:14 a.m. Woody Box states that "IPCUL 231" was reported because the output buffer was empty.

Yet, I do think his analysis of the ACARS data flow's partly incorrect. IPCUL 231 is an immediate rejection (i.e. failed hand-shake), not IPCUL 311. The fact that it appeared so soon after the last 311 error (see message No. 20) seems to me that the plane was no longer airborne, otherwise the hand-shake would succeed (unless it were out of radio contact in-air, in which case a new station would've been selected.) He even states himself that 311 is only sent after 9 unacknowledged uplinks.

Woody Box provides an example of American 11 receiving UBLKs while idling at the airport, so it's possible that United 93 had landed somewhere by 10:12 and the pilot pulled the circuit breaker shortly after. That's how I would explain the "IPCUL 231" errors, anyhow.

When paired with this article from another researcher, which examines the ACARS uplink sent to United 175 at 9:51, it's in my view among the best evidence that 9/11 was indeed a false flag, and indirect evidence that drones were used in the attacks. My thinking goes like this:

Planes still airborne past their supposed crash times → Flights were duplicated → The buildings were not struck by the original flights→ only a State has the resources to co-ordinate an operation with that implied level of complexity and complicity (elements within NORAD, the Joint Chiefs of Staff, the national security state in general...etc.) → 9/11 was a false flag.

The last sent message to United 93 indicates that it was in the vicinity of Champaign, Illinois at 10:11 a.m. (ground station CMI):

https://kapitalgate.files.wordpress.com ... df#page=53

Champaign, Illinois is over 400 miles away from Shanksville, Pennsylvania, and the 10:11 a.m. message was received by the aircraft as confirmed by Michael J. Winter and David Knerr. ACARS has a theoretical 200 mile range at FL 290 in ideal conditions, and in real world conditions the reliable range is often half that, to no more than 150 nautical miles considering terrain contours, signal power level decay over distance, etc.

(Reference: "VHF propagation from aircraft at 130 MHz", by Dennis Cimino, US Navy Combat Systems Technician. This additional commentary below was posted by Sergio, which I presume is partly an e-mail excerpt from Cimino):
Addendum: The truth is that the transmission lines and, in fact, the essential grounding terminations on most airliners are degraded over time, which in fact increases the insertion losses between the antenna and the rack on the plane by (using signal generators and power meters) as much as 6 dB more than normal. That's why ARINC specifically states "up to 200 nautical miles" at FL 290 (29,000 feet) as maximum range.

What happens in reality is that, due to overall crappy maintenance and corrosion on aircraft skins, with the bonding so questionable for the transmission line shield integrity at the antenna connector being so generally not optimal, it's a stretch to really get that 200 miles very often except with very new aircraft or exceptionally well maintained airplanes. Cyclical maintenance schedules do not even touch routine corrosion prevention on these antenna grounding plates unless the plane is removed from service and then completely overhauled. Bottom line: a range of 180 nautical miles at best.

But now let's take a closer look at the quote that JREF people use to “prove” that VHF ACARS has a range of 250 nautical miles. The title of the document is “Signal-In-Space Minimum Aviation System Performance Standards (MASPS) For Advanced VHF Digital Data Communications Including Compatibility With Digital Voice Techniques”. I will now quote the complete paragraph as it is (pp. 48–49):
The propagation characteristics of the VHF band restrict transmission and reception to essentially line-of-sight conditions. The maximum line of-sight range for an enroute aircraft at an altitude of 30,000 feet is about 250 nautical miles. The radio range decreases at lower altitudes to astrictly localized coverage when the aircraft is on the ground. The normal index of refraction of the atmosphere is greater than unity, which extends the possible range of VHF transmissions most of the time.

However, the refractivity varies widely, resulting in a significantly lower reliability of extended-range communications. The VHF radio channel is subject to slow and fast fading due to time varying multipath, obstruction of the radio line of sight, and changes in atmospheric conditions. The predominantly line-of-sight nature of VHF radio limits its use for air-ground and ground-air communications to airspace that can be served by land-based stations. Thus, coverage is limited to reasonably accessible over-land areas. Air-to-air communication is possible in any airspace, subject to the constraints of line-of-sight, transmitter effective radiated power, and receiver subsystem sensitivity.
The first part not marked in bold is the part that supporters of the official story of 9/11, selectively quote. The second part marked in bold is what he knowingly omitted. And why did he omit it? Because, if read in its entirety, the above paragraph clearly proves the contrary of what intended by the poster. While 250 nm is to be considered as the max. technical line of-sight range at an altitude of 30,000 ft, in reality ground-air communications are limited by physical constraints such as "transmitter effective radiated power, and receiver subsystem sensitivity".

All of this is clearly described in the document quoted, but obviously the poster removed this essential information from his original quote because the resulting meaning would be completely different than the intended. As a matter of fact, the document quoted by the guy completely confirms (one more time) why ARINC only guarantees deliveries "up to 200 nm", whereas "up to 200 nm" is to be interpreted in its simple, literal meaning and not as a distance that one can personally adapt based on circumstances or can fit into a theory that has been already and conclusively proven as wrong for many other reasons.

Finally, if the poster insists that the VHF range can jump up to 265 nm when an aircraft is flying at FL 350 using an online calculator as best evidence for this claim, then I inform him that United 93 dropped a DLBLK block containing "ORDA6" in the "BepStnName =" at 9:40 EDT, while the distance from the Chicago airport was 278.46 nautical miles. Also, in the second DLBLK block within the same message there is a reference to IADC6. Dulles airport at 9:40 EDT was 238.05 nautical miles from United 93!

Anyway, if the poster on UM is really confident about the theory he's claiming, then I challenge him to contact an ARINC professional and present it. I challenge him to prove that an aircraft could not see a station at only 7 miles at 9:35 EDT or two stations at only 20 miles at 9:40 EDT, but was able to see stations at 238.05 nautical miles and 278.46 nautical miles as "RGS with the strongest signal". Until then I will keep on thinking that his claim is completely unfounded.
This suggests that United 93 was much closer to Champaign, Illinois than it was to Shanksville, Pennsylvania at the time it received the 10:11 message. ARINC CPS, which handles the message routing to and from aircraft and their company, selects the best station based on the strongest relative signal. It is therefore implausible that United 93 was anywhere near Shanksville when it received the 10:11 message.

United 93's official take off time was 8:42 a.m., according to Newark Tower transcripts.

But according to the Bureau of Transportation Statistics departures data, it's 8:28 a.m. (wheels-off time):


The wheels-off time is recorded automatically by a sensor in the aircraft which senses when contact to the ground is lost. This information is forwarded by the airline to the Bureau of Transport Statistics on a regular basis via ACARS. No human failure is apparently possible with this data point. The consistency of the gate departure time (8:01) across sources suggests the data herein is valid.

I also read a Washington Post article back in September, which said that United 93 was 25 minutes delayed with a take-off time of 8:26. I know the author had to be referring to the wheels-off time from the Bureau of Transport Statistics departures data. He probably meant to write 8:28.

However, when I checked the article again a couple of hours later, the take-off time was deleted. The statement that the flight was 25 minutes delayed was kept, however. I know I saw 8:26 mentioned, because I immediately went to search the official take-off time of United 93, except I fat-fingered it and searched YouTube instead of Wikipedia.

The official story drawn from the 9/11 Commission and ground control transcripts, is that United 93 had a 40 minute take-off delay. Yet, the author of this article (which was undoubtedly fact-checked) insists on a delay of 25 minutes after multiple revisions. The article also says it was last edited September 9th, but I saw the deletion on the 11th.


This is the article I read: https://www.washingtonpost.com/outlook/ ... utType=amp

The 8:26 time I saw, although in error, checks out. The gate departure time of 8:01 (gate push back) + 25 minutes = 8:26. So the author must've looked at the Bureau of Transport Statistics departure data, but misremembered the wheels-off time of 8:28. Yet, as we saw, the official wheels-off time is 8:42.

The evidence is clear. United 93 was duplicated at the airport, hence the two different take-off times. Secondly, it was still airborne well after its official crash time. The duplicate "United 93" isn't necessarily the plane which crashed in Shanksville, however. This is a topic I can discuss for another time.

Here are supplemental articles to the one I posted above:
These are all very well researched articles, using authoritative sources like the 9/11 Commission, FBI interviews, the Boeing avionics manual, etc.


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Awesome stuff here. Very damning evidence, and very detailed. The ACARS data is the most important data point there is in my opinion. I believe the flights were either duplicated on the ground or shortly after takeoff as well. Looking forward to more posts like this !