NORAD’s MISSION AND INTERCEPT PROCEEDURES
North America is surrounded by an area called the
Air Defense Identification Zone (ADIZ), which is jointly administered by the United States (US) and Canada. This area, which is almost exclusively over water, serves as a national defence boundary for air traffic, as a sort of "buffer zone". Any aircraft that wishes to fly in or through the boundary must file either a
Defence Visual Flight Rules (DVFR) flight plan or an
Instrument Flight Rules (IFR) flight plan before crossing the ADIZ. The pilot must have a transponder and a two-way radio while approaching and crossing the ADIZ. In the US, the
Federal Aviation Authority (FAA) handles these requests; Transport Canada handles Canadian requests. Any aircraft flying in these zones without authorization may be identified as a threat and treated as enemy military aircraft.
The
continguous US ADIZ is defined by Federal Aviation Regulation
Part 99 section 43:
Sec. 99.43
Continguous U.S. ADIZ.
The area bounded by a line from 43°15'N, 65°55'W; 44°21'N; 67°16'W; 43°10'N; 69°40'W; 41°05'N; 69°40'W; 40°32'N; 72°15'W; 39°55'N; 73°00'W; 39°38'N; 73°00'W; 39°36'N; 73°40'W; 37°00'N; 75°30'W; 36°10'N; 75°10'W; 35°10'N; 75°10'W; 32°00'N; 80°30'W; 30°30'N; 81°00'W; 26°40'N; 79°40'W; 25°00'N; 80°05'W; 24°25'N; 81°15'W; 24°20'N; 81°45'W; 24°30'N; 82°06'W; 24°41'N; 82°06'W; 24°43'N; 82°00'W; 25°00'N; 81°30'W; 25°10'N; 81°23'W; 25°35'N; 81°30'W; 26°15'N 82°20'W; 27°50'N; 83°05'W; 28°55'N; 83°30'W; 29°42'N; 84°00'W; 29°20'N; 85°00'W; 30°00'N; 87°10'W; 30°00'N; 88°30'W; 28°45'N; 88°55'W; 28°45'N; 90°00'W; 29°25'N; 94°00'W; 28°20'N; 96°00'W; 27°30'N; 97°00'W; 26°00'N; 97°00'W; 25°58'N; 97°07'W; westward along the U.S./Mexico border to 32°32'03"N, 117°07'25"W; 32°30'N; 117°25'W; 32°35'N; 118°30'W; 33°05'N; 119°45'W; 33°55'N; 120°40'W; 34°50'N; 121°10'W; 38°50'N; 124°00'W; 40°00'N; 124°35'W; 40°25'N; 124°40'W; 42°50'N; 124°50'W; 46°15'N; 124°30'W; 48°30'N; 125°00'W; 48°20'N; 128°00'W; 48°20'N; 132°00'W; 37°42'N; 130°40'W; 29°00'N; 124°00'W; 30°45'N; 120°50'W; 32°00'N; 118°24'W; 32°30'N; 117°20'W; 32°32'03"N; 117°07'25"W; eastward along the U.S./Mexico border to 25°58'N, 97°07'W; 26°00'N; 97°00'W; 26°00'N; 95°00'W; 26°30'N; 95°00'W; then via 26°30'N; parallel to 26°30'N; 84°00'W; 24°00'N; 83°00'W; then Via 24°00'N; parallel to 24°00'N; 79°25'W; 25°40'N; 79°25'W; 27°30'N; 78°50'W; 30°45'N; 74°00'W; 39°30'N; 63°45'W; 43°00'N; 65°48'W; to point of beginning.
The
North American Aerospace Defense Command (NORAD) is responsible for the intercept of aircraft inside the ADIZ. However, as it is the FAA and Transport Canada that handle the ADIZ clearances, a request for intercept from one of these agencies precedes any action by NORAD against civilian aircraft. NORAD do not, and never have, directly monitored air traffic inside the ADIZ themselves.
NORAD areas of responsibility are divided into three regions – Alaska, Continental USA (CONUS), and Canada. Each region is further divided into Air Defense Sectors, with a number of fighter interceptor aircraft always on alert for rapid deployment.
At the height of the Cold War fighters were located at over 100 alert sites across the NORAD Continental United States Region, however after the fall of the Soviet Union there was not considered to be a significant threat, and the number of alert bases was slashed repeatedly. In February 1993 the Chairman of the Joint Chiefs of Staff recommended that the dedicated alert stations be entirely eliminated.
In February 1993, the Chairman of the Joint Chiefs of Staff recommended that (1) the continental air defense mission be performed by dual tasking existing active and reserve general-purpose fighter and training squadrons in the Air Force, the Navy, and the Marine Corps and (2) the number of Air National Guard units dedicated to this mission be sharply reduced or eliminated.
In a 3 May 1994 Report to Congressional Committees entitled
Continental Air Defense – A Dedicated Force Is No Longer Needed it was announced that NORAD would reduce the continental US force to 28 aircraft located in 14 alert stations, on 5 minute response time, 24 hours a day:
NORAD plans to reduce the number of alert sites in the continental United States to 14 and provide 28 aircraft for the day-to-day peacetime air sovereignty mission. Each alert site will have two fighters, and their crews will be on 24-hour duty and ready to scramble within 5 minutes.
By 2001 this had dropped to 14 aircraft at 7 alert bases located on the perimeter of the continental USA, with a 15 minute response time.
At the time of the attacks, only seven locations—around the perimeter of the United States—were engaged in the air defense mission. Each was assigned a pair of Air National Guard fighter aircraft ready to scramble if US airspace were threatened. These alert locations had F-15 or F-16 fighters on the runways, fueled, and ready to take off in fewer than 15 minutes.
The hijackings on September 11 occurred within the
North East Air Defense Sector (NEADS). The NEADS mission normally had four interceptor aircraft on duty at any given time – 2 at
Otis Air National Guard Base (ANGB) in Massachusetts, and 2 at
Langley Air Force Base (AFB), Virginia.
None of the aircraft hijacked on September 11 entered the ADIZ. Prior to September 11, there was no formal system in place for military intercepts of civilian aircraft outside the ADIZ. In the 10 years prior to September 2001 there was only one instance in which military aircraft were involved in an intercept of a civilian aircraft outside the ADIZ.
This was the intercept of Payne Stewart’s Learjet 35, registration N47BA, which lost cabin pressure and flew across several states before crashing on October 25, 1999. According to the
National Transportation Safety Board (NTSB)
report on the incident, communication with the aircraft was lost at 0933 EDT. The Jacksonville Air Radar Traffic Control Centre (ARTCC) directly requested an intercept from the USAF. A test pilot from the 40th Flight Test Squadron at Eglin Air Force Base, Florida, reached the Learjet at 0954 CDT – a full 81 minutes* after initial communication was lost.
(* note change in time zone from Eastern to Central daylight time)
In comparison, for the four aircraft hijacked on September 11 the duration from first sign of distress to flight termination was:
[latex]
\begin{center}
\begin{tabular}{|l|l|l|l|}
\hline
FLIGHT & HIJACKING & CRASH & DURATION \\
\hline
AA11 & 0813 & 0846 & 33 minutes\\
\hline
UA175 & 0847 & 0903 & 16 minutes\\
\hline
AA77 & 0856 & 0937 & 41 minutes\\
\hline
UA93 & 0928 & 1003 & 35 minutes\\
\hline
\end{tabular}
\end{center}
[/latex]
All times are Eastern Daylight Time (EDT)
The intercept of Stewart’s Learjet took twice as long as the longest hijack duration on 9/11 – American Airlines Flight 77. Unlike Stewart’s Learjet, all four aircraft hijacked on September 11 had their transponders turned off. The transponder broadcasts vital information including the flight identification. Only transponder contacts appear on the secondary radar screen.
Without transponder information, aircraft had to be located on the primary radar screen which shows a radar signal from every single aircraft in the air – none of them labelled. In order to identify the hijacked aircraft, Air Traffic Controllers had to first cross-reference all of the aircraft appearing on the secondary radar screen with their correlating reading on the primary screen. AA 77, for example, was only located on the primary radar screen five minutes before it crashed into The Pentagon.
To truly appreciate the enormity of the task before ATC on 9/11,
here is an animation that depicts air traffic across the USA on a typical day.
From the information gathered we can conclude the following facts:
- NORAD's area of responsibility is inside the ADIZ
- The Hijackings occurred outside the ADIZ
- There was no standard procedure for hijackings outside the ADIZ on 9/11
- From 1991 to 2001 only one military intercept occurred over CONUS airspace. It took 81 minutes and the aircraft transponder remained on at all times.
- Incident-specific conditions on 9/11 did not favour a successful intercept, based on previous experience.
In addition, standard FAA procedure for a hijacking is to hand over all details to the FBI; there is no procedure for involving the military in incidents outside the ADIZ. This is primarily because a hijacking inside the USA is a Federal crime rather than a threat to National Security, thus is under the jurisdiction of the FBI. As such there were delays between the first signs of hijacking, and NEADS being notified. This delay is critical. A delay in notification restricts the “window” of time in which NEADS has to execute a successful intercept.
As you can see from the
NORAD timeline, the times from NEADS notification to aircraft destruction are as follows:
[latex]
\begin{center}
\begin{tabular}{|l|l|l|l|l|}
\hline
FLIGHT & HIJACKING & NEADS NOTIFIED & CRASH & INTERCEPT WINDOW\\
\hline
AA11 & 0813 & 0837 & 0846 & +9 minutes\\
\hline
UA175 & 0852 & 0903 & 0903 & 0 minutes\\
\hline
AA77 & 0856 & 0935 & 0937 & +2 minutes\\
\hline
UA93 & 0939 & 1007 & 1003 & -4 minutes\\
\hline
\end{tabular}
\end{center}
[/latex]
All times are Eastern Daylight Time (EDT)
So from the outset a successful intercept by NORAD on 9/11 was to be difficult. Indeed, an intercept of UA175 or UA93 would be quite simply chronologically impossible. The longest window NEADS would get was 9 minutes. How did the wargames factor into this?
MarkyX, I assume you'll want to update your one.
