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911blogger.com does not seek to push any specific 'theories' about 9/11, but rather seeks to cover 9/11 related 'alternative' news. As such all readers should do their own research and develop their own opinions on the news and information covered.

Aidan Monaghan's blog

17,000+ New Pages Of NIST WTC Investigative Records

On April 3, 2012, the National Institute of Standards and Technology (NIST) released an additional 17,000+ pages of World Trade Center (WTC) records obtained by them from the Port Authority of New York and New Jersey, the New York City Department of Buildings and Turner Construction. The latest records are part of an ongoing NIST WTC records release. NIST has since advised that more records will follow.

(Download files here)

http://archive.org/details/NIST_FOIA_12-014_7_8_Interim_Responses

http://911datasets.org/images/NIST_FOIA_12-014_7_8_Interim_Responses_Rel...

New NIST WTC Investigation FOIA Records For WTC 7 OEM “Bunker” & Confidential NYC DoB Collapse Assessment

On March 20, 2012, the National Institute of Standards and Technology (NIST) provided via reply to a Freedom of Information Act (FOIA) request, detailed records describing construction plans for the New York City Office of Emergency Management (OEM) “bunker”, as well as a confidential post-collapse World Trade Center (WTC) assessment by the New York City Department of Buildings.

(Download files here)

http://www.mediafire.com/?1l8ykl42ntrf9

Leading Military Nano-Thermite Developer: No Records Describing Its Nano-Thermite Uses

Within a March 16, 2012 Freedom of Information Act (FOIA) reply, the Indian Head division (IHD) of the Naval Surface Warfare Center (NSWC) advised that it possesses no records describing uses of its nano-thermite products, despite IHDNSWC being described as the leading developer of nano-thermite circa 2008[1] and being "the only reliable source of aluminum nanopowders in the United States” circa September 11, 2001.[2] In 2009, the discovery of nano-sized thermitic material within World Trade Center dust samples was reported.[3]

New NIST FOIA WTC Schematic Drawings

The National Institute of Standards and Technology (NIST) advised via a February 2, 2012 Freedom of Information Act (FOIA) reply that NIST will begin releasing all records in their possession obtained from the Port Authority of New York/New Jersey, Turner Construction and the New York City Department of Buildings used during their investigation of the collapses of World Trade Center (WTC) buildings 1, 2 and 7. The records of most interest obtained thus far consist of various schematic drawings of WTC 1 and 2.

Download NIST WTC files:

http://www.mediafire.com/?eojy14zrdu6h5

Implications of September 11 Flight Transponder Signal Losses

Since September 11, 2001, it has generally been accepted by the media and the 9/11 Commission itself, that the loss of Secondary Surveillance Radar (SSR) information for three of the four September 11 flights was caused by accused hijackers who allegedly seized control of the aircraft flight decks and manually turned off each plane’s Mode S (Mode Select) transponder, for the purpose of evading detection and interception by U.S. air defense systems. However, this conclusion appears to be based only on circumstantial information - the simple loss of SSR flight data to Air Traffic Control (ATC) – and seems unsupported by conclusive information. Moreover, ATC was nevertheless still able to tag and track three flight’s primary radar returns and estimate their location, direction, ground speed and even altitude changes.

Perhaps the most significant consequence of lost September 11 flight SSR data to ATC was a circumstantial impression of accused hijacker flight deck takeovers. As can be shown, aircraft Mode S transponder SSR information can be caused to vanish from ATC radar displays by other documented means. Coincidentally or not, the only September 11 flight with a continuously operative transponder (United 175), was also the only flight with a transponder able to warn away the only other flights in serious danger of colliding with a September 11 flight, thus facilitating it's subsequent impact with World Trade Center 2 (WTC 2).

Plaintiff’s Reply Brief Before U.S. 9th Circuit Court of Appeals for FBI 9/11 Records

On December 12, 2011, the appellant’s reply brief was entered before the U.S. 9th Circuit Court of Appeals in the matter of Monaghan v. Department of Justice, dismissed earlier this year by the U.S. District Court of Nevada. This action seeks the release of numerous FBI records regarding the terrorist attacks of September 11, 2001, including the actual audio recording obtained from the cockpit-voice-recorder for United Airlines Flight 93, plus Pentagon and Shanksville, PA crash scene evidence collection records.

Much thanks to those who have generously donated to this effort.

(Open entry to view court filing)

DoJ Reply Brief With 9th Circuit Court Of Appeals For 9/11 Records Case

On November, 7 2011, the U.S. Department of Justice entered its reply to the plaintiff’s opening brief, before the U.S. 9th Circuit Court of Appeals in the matter of Monaghan v. Department of Justice, dismissed earlier this year by the U.S. District Court of Nevada. This action seeks the release of numerous FBI records regarding the terrorist attacks of September 11, 2001, including the actual audio recording obtained from the cockpit-voice-recorder for United Airlines Flight 93, plus Pentagon and Shanksville, PA crash scene evidence collection records.

Much thanks to those who have generously donated to this effort.

(Open entry to view brief)

NYC Department of Buildings: World Trade Center Buildings 1, 2 and 7 Deemed “Sensitive Buildings”, Plans Exempt From Disclosure

Within a September 13, 2011 FOI response from the New City Department of Buildings (DoB), it is noted that World Trade Center Buildings 1, 2 and 7 have been deemed sensitive buildings and thus, plans for these buildings have been exempted from disclosure by statute because "if disclosed, the documents requested would endanger the life or safety of any person."

The DoB reply also affirms a previous finding that no elevator records whatsoever were located regarding the extensive elevator modernization within WTC buildings 1 and 2, one of the largest ever.[1] Additionally, the DoB reply advises that the Port Authority of NY/NJ are not under the jurisdiction of the NYC DoB and that records for major pre-9/11 renovations may not have been submitted to the DoB.

The Port Authority of NY/NJ have previously advised within FOI records that records for major pre-9/11 renovations within WTC buildings 1 and 2 were destroyed on September 11, 2001.[2]

Plaintiff’s Opening Brief Before U.S. 9th Circuit Court of Appeals for FBI 9/11 Records

On September 6, 2011, the appellant’s opening brief was entered before the U.S. 9th Circuit Court of Appeals in the matter of Monaghan v. Department of Justice, dismissed earlier this year by the U.S. District Court of Nevada. This action seeks the release of numerous FBI records regarding the terrorist attacks of September 11, 2001, including the actual audio recording obtained from the cockpit-voice-recorder for United Airlines Flight 93, plus Pentagon and Shanksville, PA crash scene evidence collection records.

Much thanks to those who have generously donated to this effort.

DOWNLOAD BRIEF:

http://www.mediafire.com/?qii6jsth7u2s52c

U.S Secret Service: No USSS Records of Reported 2008 Obama/Clinton Bilderberg Attendance

The United States Secret Service (USSS) has reported within an August 5, 2011 Freedom of Information Act (FOIA) request that a search of USSS files produced no records of the reported Bilderberg meeting in Chantilly, VA on June 5-8, 2008 at the Westfields Marriott[1] and no records of the attendance of then U.S. Senators Barack Obama and Hillary Clinton. Obama and Clinton were both assigned USSS protection in 2007.[2][3]

Reported USSS keyword search results:

• Bilderberg - no hits
• Westfield - 1 hit but not relevant
• Chantilly, VA - 3 hits but not relevant
• June 5-8, 2008 - several hits, some of which the message and attachments would not open; others were not relevant
• Hillary Clinton - 205 hits but none were relevant
• Barack Obama June 2008 - several hits, some of which the message or attachments would not open; others were not relevant
• Marriott June 5-8, 2008 - 7465 hits based on the dates rather than "Marriott" and none were relevant

NOTE: some of the hits for Senator Barack Obama showed he was scheduled to be in Virginia during the identified timeframe, but specific locations did not match the request.

NYC Dept. of Buildings: Portions of WTC 7 Emergency Command Center “Plans” Withheld, Release Would “Endanger ... Life or Safety”

The New York City Department of Buildings (DoB) has reported within a May 4, 2011 Freedom of Information (FOI) response, that portions of requested DoB records pertaining to the former NYC Office of Emergency Management command center located within the former World Trade Center building 7 are exempt from release.

“Your request will be granted in part and denied in part. Under FOIL the Department will release copies of all documents we have pertaining to the above referenced address but we will not release copies of plans. We are withholding the plans under §87(2)(t) of the Public Officer's Law on the grounds that, if disclosed, the documents requested would endanger the life or safety of any person.”

To date, no reportedly releasable records have been received.

NYC Dept. of Buildings: No Records for Pre-9/11 WTC Elevator Rebuild, One of the “Largest, Most Sophisticated” Ever

The New York City Department of Buildings (DoB) has reported within a June 6, 2011 Freedom of Information (FOI) response, that no records could be located regarding the following request for information pertaining to the massive elevator modernization project underway at World Trade Center buildings 1 and 2 until the very morning of September 11, 2001, one of the largest ever [1]. The DoB governs elevator construction and use within New York City.

An April 15, 2011 FOI appeal request sought:

“Permits or certifications provided by the NYC Department of Buildings regarding elevator modernization/renovation work performed at the former World Trade Center buildings 1 and 2 during the 1990s and 2000s."

The DoB’s June 6, 2011 FOI answer reads as follows:

“BIS shows no elevator records for the time period in question.”

The DoB’s Building Information System (BIS) “is the Department of Buildings’ main database. The database was put into production in 1984 and supports Department functions with respect to: ... Application Processing (application submission ...)” [2]

The DoB’s description of its role regarding elevator installation and use within New York City: “The Department of Buildings' Elevator Division oversees the use and operation of New York City's elevators”. [3] Such duties include the receipt and issuance of construction applications and permits: “Applications and Permits; New Installations or Major Upgrades; File an Elevator Application (EA) to install a new device or perform a substantial upgrade, alteration, replacement or modernization to an existing device.” [4]

Official GPS Data Reveal Superior Aviation GPS Service Provided To WTC & Pentagon During 9/11 Attacks

As the aircraft attacks of September 11, 2001 unfolded at the World Trade Center (WTC) and Pentagon buildings, maximum and near maximum augmented GPS positioning quality for the entire daylight period was provided to the geographic coordinates for the World Trade Center in New York City and the Pentagon in Arlington, VA. Based on output graphs generated by Trimble’s free and highly regarded downloadable GPS planning software [1], which utilizes GPS “almanac” data transmitted by the GPS constellation on September 11, 2001 and now archived at the website for the United States Coast Guard [2], conditions such as GPS satellite visibility and geometric “dilution of precision” are both shown to be at maximum or within minutes of maximum during the aircraft impacts at the World Trade Center and Pentagon. Such augmented GPS service is now in routine use by the U.S. commercial aviation industry to allow aircraft flight management computers to utilize precise aircraft positional information, accurate to within just several meters. This GPS service was activated on a conditional basis by the FAA just one year before the September 11, 2001 attacks [3]. This service provided virtual aerial guidance corridors only 243 feet wide and a 95% confidence that an aircraft's true position will fall within any such designed corridor. The augmented GPS service was also utilized to precisely survey the Ground Zero site immediately after September 11, 2001. [4] Such corridors can be navigated entirely by autopilot and flight management systems scheduled in 1996 and 1998 to be contained by United and American airlines Boeing 757 and 767 aircraft like those used during the terrorist attacks of September 11, 2001.

Port Authority of NY/NJ FOI Records For Pre-9/11 WTC Elevator Modernization Project

Linked below are Freedom of Information records of the Port Authority of New York and New Jersey regarding pre-9/11 elevator modernization work within World Trade Center towers 1 and 2, reportedly performed by the ACE Elevator company.

CONTRACT-845-071

http://www.mediafire.com/?2rz3nr3cibogt16

CONTRACT-846-071

http://www.mediafire.com/?qtbu9qnwsrxx5sr

Federal Court Dismisses FOIA Lawsuit for Numerous FBI 9/11 Investigative Records

On March 16, 2011 U.S. District Judge James C. Mahan dismissed a FOIA lawsuit for numerous FBI investigative records pertaining to the terrorist attacks of September 11, 2001. Case No. 2:09-cv-2199-JCM-PAL, Aidan Monaghan v. Department of Justice et al, sought the release of the following F.B.I. records. An appeal to the U.S. 9th Circuit Court of Appeals is likely.

(1) Records describing aircraft wreckage collection for American Airlines flight 77 and United Airlines flight 93 destroyed on September 11, 2001 in Arlington, VA and Shanksville, PA.; (2) Records describing the make and model of Flight Management Computers (FMCs) or Flight Management System (FMS) and Multi-Mode Receivers (MMR) contained by American Airlines flight 11, United Airlines flight 175, American Airlines flight 77 and United Airlines flight 93.; (3) Records containing inventory control serial numbers for Flight Data Recorders and Cockpit Voice Recorders for American Airlines flight 77 and United Airlines flight 93.; (4) Records regarding 'ACARS' (Aircraft Communications Addressing and Reporting System) communications generated by and transmitted to the four aircraft in question on September 11, 2001.; (5) Records regarding any FBI opinions disseminated by USA Today, describing explosive devices as a suspected cause of the destructions of the World Trade Center buildings in New York city, NY on September 11, 2001.; (6) Records regarding the FBI's collection and/or identification of human remains aboard American Airlines flight 77 recovered from the Pentagon building in Arlington, VA and United Airlines flight 93 recovered from Shanksville, PA following the terrorist attacks of September 11, 2001.; (7) An audio copy of the Cockpit Voice Recorder recording obtained from the Cockpit Voice Recorder recovered from the crash scene of United Airlines flight 93 in Shanksville, PA.; (8) Records pertaining to or establishing in-flight phone calls reportedly placed on September 11, 2001, by passengers on-board American Airlines flight 11, United Airlines flight 175, American Airlines flight 77 and United Airlines flight 93, all hijacked during the terrorist attacks of September 11, 2001.

AIDAN MONAGHAN,
Plaintiff,

v.

DEPARTMENT OF JUSTICE, et al.,
Defendants.

Technology for Autopilot Override of Pilot Control of Boeing Aircraft Developed Circa 2001

The development of the capability of an aircraft Flight Management Computer (FMC) to take control of an aircraft away from a pilot and turn over control to its autopilot system, including apparently Boeing 757's, was underway circa September 11, 2001. The development of a collision avoidance, control override capability utilizing a Boeing 757 is documented as early as 1999. Boeing 757s and 767s containing common avionics, were used during the 9/11 attacks.

"Ultimately, if required, the system could initiate an automatically flown evasive maneuver. Validation flights were completed at the NASA Wallops Flight Facility and in-flight demonstrations of the system were completed at Minneapolis-St. Paul International Airport in November 1999 for FAA officials and other Government and industry representatives. The NASA B-757 ARIES and a Honeywell Gulfstream IV (G-IV) were used in the flight test effort."[1]

NYC Department of Buildings: No Copies of City Issued Permits for Construction Within WTC 7 Found For Years 1999, 2000 and 2001

A Freedom of Information reply from the New York City Department of Buildings reports that copies of city permits for routine or major construction work within World Trade Center building 7 during the years 1999, 2000 and 2001 could not be located. Records for the “ALT 2” category were requested.

“DOB divides construction work into two main categories: New Buildings (NB) and Alterations (ALT). Alterations are further divided into three types—ALT1s, ALT2s and ALT3s—depending upon the scope of work. An ALT1 is a major alteration in which the use or occupancy of an existing property changes. An ALT2 is an alteration in which the use or occupancy of a facility does not change, but includes multiple work types, i.e., plumbing and construction. ALT1s and ALT2s must be filed by a registered architect or licensed engineer."

http://www.nyc.gov/html/dob/downloads/pdf/consbroch.pdf

Large Airliner Crashes Don’t Necessarily Generate Recordable Seismic Data

Freedom of Information Act data from the U.S. Geological Survey for seismic data generated by the crash of U.S. Air Flight 427 in southwestern Pennsylvania on September 8, 1994 suggests that even when a Boeing 737, a smaller but comparable aircraft to the Boeing 757, nose dives into the ground at 300 miles per hour [1], it will not necessarily generate recordable seismic data. Southwestern Pennsylvania is also the same general location of the crash of United Airlines Flight 93, which also reportedly nose dived into the ground at over 500 miles per hour on September 11, 2001. UA 93’s impact apparently did generate weak seismic signals. The reported crash of American Airlines Flight 77 also on September 11, 2001, a Boeing 757, apparently did not generate a discernable seismic signal.

Department of Defense: Images of Pentagon Crash Scene Before And During 9/11 Unavailable; Controlled By FBI

The following is a Freedom of Information Act reply from the U.S. Department of Defense for any unreleased video and images of the crash scene before and during the impact of American Airlines flight 77 at the Pentagon building on September 11, 2001.

###

From: "Jensen, Alfred CTR WHS/ESD/MCNEIL TECH, INC"
Date: September 24, 2010 10:21:34 AM PDT
To: XXXXXXXXXXXXXXX@yahoo.com
Subject: FW: Freedom of Information Act Request

Mr. Monaghan,

This is in response to your Freedom of Information Act request as stated below.

Additional Declassified U.S. Secret Service Records Describe Unidentified Aircraft Circling Washington, D.C. On 9/11

The following is a two page U.S. Secret Service Executive Summary included within a April 23, 2010 Freedom of Information Act release, describing the activities of President George W. Bush, Vice President Dick Cheney, families of the president and vice-president, threats against Air Force One and activity within the Presidential Emergency Operations Center on September 11, 2001. The Executive Summary report describes Secret Service reports of an unidentified aircraft circling Washington, D.C. and the activity of other noteworthy Secret Service protectees on September 11, 2001.

DOWNLOAD & READ DECLASSIFIED DOCUMENTS [pdf]:

http://www.mediafire.com/?7xie8kdglcdf468

Previously published documents [pdf]:

http://www.mediafire.com/?vydb4nxdmyy

Declassified 9/11 U.S. Secret Service FOIA Records Describing Activity of President Bush & VP Cheney

The following are declassified United States Secret Service records obtained on April 23, 2010 via a Freedom of Information Act (FOIA) request, describing the activities of President George W. Bush, Vice President Dick Cheney, families of the president and vice-president, threats against Air Force One and activity within the Presidential Emergency Operations Center on September 11, 2001.

Download the PDF file via the following link:

http://www.mediafire.com/?vydb4nxdmyy

Discussion: Vector And Turn Analysis Of Observed And Measured Flight Paths Of 9/11 WTC Aircraft

Abstract

Video footage depicts United Airlines Flight 175 (UA 175) impacting World Trade Center tower 2 (WTC 2) on September 11, 2001 in New York City via a trajectory comprised of two separate banked turns. The second turn was apparently not required to generate impact. The first turn, which maintains a constant angle of bank (AoB), is evident at 1.2 miles before impact.[1] Although human control of UA 175’s observed maneuvers cannot be ruled out, the precise coordination of variables such as the selections of a correct bank angle and turn start time for the first turn apparently pose challenges to the unaided human control hypothesis. The observed turn stability favors the use of autopilot operation, either functioning in a conventional course control mode or in Control Wheel Steering (CWS) mode. The probability that either of these two control systems were used is discussed. Flight deck images of United and American airlines 757s and 767s suggest that such CWS functions may have been disabled circa 2001. Constant radius turns utilizing plotted waypoints during commercial aviation operations are routinely supported by augmented GPS navigation service and related commercial Flight Management Systems (FMS) available circa 2001.[2] As will be demonstrated, the implementation of UA 175’s observed 1.2 mile constant radius arc, seconds earlier or later than observed, would apparently result in UA 175 missing WTC 2. Estimates of the likely effect of crosswinds on the approach to WTC 2 are also provided. It is noted that a projected impact via the first observed banked turn would have occurred under crosswind conditions capable of generating between 122 and 134 approximate total feet of lateral displacement from the calculated final position of the aircraft if not affected by such crosswinds. Aircraft distances and other calculations are based on reported aircraft speed for UA 175 of 799 feet per second at impact and measured times to impact [3]. The observed speeds of both attack aircraft were extreme by comparison to the typical speeds of similarly descending aircraft. While creating significantly less response time for possible human hijacker pilot course corrections during final target approaches that would demand superior control surface operation, a general vector analysis considering the final course and speed for each aircraft suggests that the unusually high speeds observed would generate greater accuracy of the aircraft while enroute to their targets, as a result of smaller course deflection angles and ground track displacements, created by existing and potential crosswinds.

AFIP FOIA Appeal: 9/11 Investigation Still Open; Pentagon & Shanksville Hijacker Records Exempt From Disclosure

The following is a February 4, 2010 Freedom of Information Act (FOIA) appeal reply from the U.S.Armed Forces Institute of Pathology regarding a request for records that confirm the recovery and identification of terrorists accused of hijacking American Airlines flight 77 and United Airlines flight 93 on September 11, 2001. Such records are reportedly exempt from disclosure under exemption (b)(7)(a) which prohibits disclosure of information which would interfere with an on-going law enforcement investigation and exemption (b)7(c), which also provides protection for law enforcement information the disclosure of which could reasonably be expected to result in an unwarranted invasion of personal privacy of individuals in being associated with criminal activities, including investigators.

According to the AFIP, the FBI considers the investigation into the terrorist attacks of September 11, 2001 as still open.

Additional information:

http://www.911blogger.com/node/22200

KLAV 1230AM Radio Las Vegas Covers 9/11 FOIA Research

On Friday January 8, 2009 KLAV 1230AM radio Las Vegas, hosted a one hour segment devoted to the topic of 9/11 FOIA research and other areas of 9/11 research.

Aidan Monaghan's Blog

http://www.911blogger.com/blog/2074

Part 1:

U.S. Secret Service: 9/11 White House Visitor Logs Unavailable; Part Of National Archives

The following is a Freedom of Information Act (FOIA) reply from the U.S. Secret Service regarding a request for records of White House worker and visitor logs for September 11, 2001 and September 12, 2001. The Secret Service alleges that such records are not agency records and are now under the control of the National Archives and Records Administration (NARA).

AFIP: Records Confirming Collection And Identification Of 9/11 Hijacker Remains Exempt From Disclosure

The following is a Freedom of Information Act (FOIA) reply from the U.S.Armed Forces Institute of Pathology regarding a request for records that confirm the collection and identification of terrorists accused of hijacking American Airlines flight 77 and United Airlines flight 93 on September 11, 2001. Such records are reportedly exempt from disclosure under exemption (b)(7)(a) which prohibits disclosure of information which would interfere with an on-going law enforcement investigation and exemption (b)7(c), which also provides protection for law enforcement information the disclosure of which could reasonably be expected to result in an unwarranted invasion of personal privacy of individuals in being associated with criminal activities, including investigators.

Port Authority Of NY/NJ: No Records Of Contracts For All Major WTC Renovations Recommended By Year 2000 Property Assessment

The following is a November 25, 2009 Port Authority of New York and New Jersey Freedom of Information (FOI) reply to a request for copies of all contracts regarding renovation work within the World Trade Center towers recommended by the December, 2000 Merrit & Harris Inc. World Trade Center (WTC) property assessment entitled "Due Diligence Physical Condition Survey - World Trade Center". Such work included major renovations upon the core support columns contained within WTC towers 1 and 2 to be completed within one year of the December, 2000 report date, that included rust treatment and asbestos abatement. Records requested previously regarding major renovation work performed by known WTC contractors (Turner Construction) until the morning of September 11, 2001, were reportedly destroyed during the terrorist attacks. Turner Construction managed the controlled demolition of the Seattle Kingdome in 2000.

Department Of Energy FOIA Records For Nano-Explosive Materials Development Circa 2001

The following are Freedom of Information Act (FOIA) records provided by the U.S. Department of Energy (DoE) pertaining to nano-sized energetic materials research and development circa 2001. Along with various divisions of the U.S. Department of Defense, the DoE also developed nano-sized explosive materials circa 2001, similar to nano-sized explosive materials discovered in the dust created by the World Trade Center tower collapses on September 11, 2001 and reported by the 2009 study entitled Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe.

http://www.bentham-open.org/pages/content.php?TOCPJ/2009/00000002/000000...

Additional Port Authority Of NY/NJ WTC Property Assessment FOI Records

The following are additional Port Authority of New York & New Jersey World Trade Center property assessment Freedom of Information (FOI) records from the December 2000 Merritt & Harris Inc. report entitled "Due Diligence Physical Condition Survey World Trade Center", which contained recommendations for immediate major renovations throughout the World Trade Center complex during the year prior to the terrorist attacks of September 11, 2001.

Previously released portions included those recommending immediate renovations upon major steel support columns located within the elevator shafts of WTC towers 1 and 2 just prior to September 11, 2001.

Reports include focus on the WTC Retail Mall, WTC Subgrade, WTC Central Plant, WTC 4, and WTC 5.

Leading GPS Software Suggests Superior Augmented GPS Service At WTC During 9/11 Attacks

As the aircraft attacks of September 11, 2001 unfolded at the World Trade Center, virtually maximum augmented GPS positioning quality for the entire daylight period was provided to the geographic coordinates for the World Trade Center.

GPS position quality is strongly affected by the number of GPS satellites visible to a GPS receiver and the orbital geometry of GPS satellites with respect to a GPS receiver. Augmented GPS signal receivers and Flight Management Systems that utilize augmented GPS signals for navigation and positioning purposes were scheduled to be contained by American and United airlines Boeing 757s and 767s by 2000.

"Factors that can degrade the GPS signal and thus affect accuracy include the following: Number of satellites visible - The more satellites a GPS receiver can "see," the better the accuracy; Satellite geometry/shading - This refers to the relative position of the satellites at any given time. Ideal satellite geometry exists when the satellites are located at wide angles relative to each other. Poor geometry results when the satellites are located in a line or in a tight grouping."[1]