NYC07LA018

While level at 3,000 feet above mean sea level and receiving radar vectors for an instrument approach, the pilots received a traffic advisory (TA) from the airplane's Traffic Alert and Collision Avoidance System (TCAS). The co-pilot was flying the airplane when the TA was issued, and began a visual scan for the traffic. The pilot-in-command then "yanked the controls" out of the copilot's hands, and began a banking left turn. Moments later, the TCAS issued a resolution advisory (RA) commanding a climb, so the pilot increased the airplane's pitch attitude, and climbed approximately 800 feet while simultaneously rolling wings level. Neither pilot made visual contact with the airplane for which the RA was issued. During the maneuver, the flight attendant broke her left leg. The airplane, which triggered the TA passed within 0.75 nautical miles laterally, and 100 feet vertically of the accident airplane. While air traffic control did not consider the airplane to be on a collision course, they did notify the accident crew of the airplane's position. The accident airplane's flight data recorder indicated a maximum angle of attack of 15.6 degrees, a maximum bank of 32 degrees, and an altitude increase to 3,778 feet in 16 seconds. The entire maneuver lasted 40 seconds, rate of climb peaked at 2,628.75 feet per minute, and maximum acceleration reached 2.3 Gs. According to the operator a typical RA response consisted of a maneuver requiring a G-force of +/- .25g and when using the information from the TCAS traffic advisory display the flight crew should commence a visual search for the intruder and if, and only if, the intruder is visually acquired, maneuver the aircraft to maintain separation. They also warned their flight crews that maneuvers based solely on TCAS traffic advisories (TA), without visual acquisition of the intruder were not recommended, and that, "certain vertical speeds were not safe" and that the flight crew should monitor their vertical speed indicator (VSI) and keep the VSI pointer out of the "red prohibited area." The guidance provided also advised to "be prepared to maneuver," should an RA sound 10 to 15 seconds later and that the pilot flying should maneuver the airplane "promptly and smoothly" in response to an RA.

History of flight

On October 31, 2006, at 1709 eastern standard time, a Bombardier CL-600-2B16, N322FX, owned by 10 individuals, and managed by Bombardier Aerospace Corporation, doing business as Bombardier Business Jet Solutions, also known as Bombardier Flexjet, was not damaged when it maneuvered to avoid another airplane while on an approach to Teterboro Airport (TEB), Teterboro, New Jersey. The two certificated airline transport pilots were not injured, and the flight attendant was seriously injured. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the flight that originated at Dulles International Airport (IAD), Dulles, Virginia. The positioning flight was conducted under 14 Code of Federal Regulations Part 91.

According to a Federal Aviation Administration (FAA) inspector, the accident airplane was inbound to TEB proceeding direct WANES intersection for the Omni-directional Radio Range/Distance Measuring Equipment A approach. The airplane was flying level at 3,000 feet above mean sea level, when the pilots received a traffic advisory (TA) from the airplane's Traffic Alert and Collision Avoidance System (TCAS). The copilot was flying the airplane when the TA was issued, and began a visual scan for the traffic. The pilot-in-command then "yanked the controls" out of the copilot's hands, and began a banking left turn. Moments later, the TCAS issued a resolution advisory (RA) commanding a climb, the pilot increased the airplane's pitch attitude, and the airplane climbed approximately 800 feet while simultaneously rolling wings level. Neither pilot made visual contact with the airplane for which the RA was issued.

During the maneuver, the flight attendant's tibia and fibula were fractured just above her right ankle. The airplane subsequently landed without further incident, and the flight attendant was transported to a hospital for treatment.

Personnel information

According to FAA records, the captain held an airline transport pilot certificate with multiple ratings including airplane multi-engine land, and type ratings for the CE500, CL600, CL604, IAJET, L-1329, LR60, and LR-JET. According to records provided by the program manager, the pilot had a total flight time of 16,400 hours, with 2,000 hours in the CL-600. His most recent FAA first-class medical certificate was issued on June 14, 2006.

According to FAA records, the first officer held an airline transport pilot certificate with multiple ratings including multi-engine land, and type ratings for the A-320, BA3100, CL-65, CL604, and D328-JET. According to records provided by the program manager, she had a total flight time of 8,000 hours, with 336 hours in the CL-600. Her most recent FAA first-class medical certificate was issued on July 6, 2006.

Aircraft information

According to the operator, in addition to TCAS, the airplane was equipped with both a cockpit voice recorder (CVR) and flight data recorder (FDR). The airplane's most recent continuous airworthiness inspection was completed on September 22, 2006, and at that time it had accumulated 7,118 total hours of operation.

Postaccident functional checks of both the TCAS and pitot static system by maintenance personnel revealed no defects.

Meteorological information

The reported weather at TEB, at 1651, included: winds from 220 degrees at 6 knots, visibility 10 miles, skies clear, temperature 19 degrees Celsius, dew point 8 degrees Celsius, and an altimeter setting of 29.86 inches of mercury.

According to United States Naval Observatory data for TEB, sunset occurred at 1654, and the end of civil twilight was at 1722.

Tests and research

Air Traffic Control Data

Air traffic control (ATC) data provided by the FAA revealed that the traffic, which triggered the TA was a radar target later identified as a Cessna 172. The Cessna was operating under visual flight rules, transmitting a squawk code of 1200, and the pilot was not in voice communication with any air traffic control facility.

At 17:05:26, it appeared on radar about a 1/2 mile southwest of Essex County Airport (CDW), Caldwell, New Jersey. It was at 1,100 feet, on a southwesterly track. The airplane then began a climbing right turn to a 279-degree track. At 17:06:32, the Cessna climbed to 2,500 feet, and then at 17:07:46 began another climb, from 2,500 feet to 2,700 feet.

At 17:08:54, ATC issued traffic information to the accident crew, advising them of traffic at their 2 o'clock position, 1 mile northwest bound, at 2,800 feet unverified.

The accident airplane and the Cessna passed within 0.75 nautical miles laterally, and 100 feet vertically of each other. According to the ATC quality assurance support manager, the Cessna was "not considered on a collision course" with the accident airplane.

CVR and FDR Information

The CVR and FDR from the accident airplane were downloaded. The CVR recording had been recorded over and contained no data from the accident flight. The FDR, however, contained recorded data from the accident flight, which was forwarded to the airplane manufacturer for review.

According to the manufacturer, on the accident flight, the FDR data indicated that prior to the TCAS event, at 17:09:00 the airplane was flying with autopilot engaged at a recorded altitude of 3,034 feet, a speed of 243.75 knots, and a heading of 074 degrees magnetic.

At 17:09:16, the airplane began a left wing down turn with a slight increase in altitude. Three seconds later, the autopilot was disengaged and the bank began to steepen. The airplane's angle of attack then increased from 3.4 degrees nose up to 15.6 degrees in 6 seconds, and the altitude increased from 3,077 feet to 3,778 feet in 16 seconds. The bank angle reached a maximum of 26.9 degrees left wing down.

The airplane then began to roll to the right, and at 17:09:33, the airplane rolled through wings level until reaching a right wing down bank angle of 32 degrees. At 17:09:40, the airspeed began to increase as the airplane continued to turn to the right, and pitch attitude and altitude both began to decrease. At 17:09:56, the autopilot was re-engaged and the airplane returned to a stable flight condition.

The entire maneuver lasted 40 seconds. The rate of climb peaked at 2,628.75 feet per minute, and maximum acceleration reached 2.3 Gs.

Additional information

TCAS Training

A review of training materials provided to flightcrews by the operator revealed that guidance was given to the "pilot flying," which stated, "Using the information from the TCAS traffic advisory display, or navigation display, commence a visual search for the intruder. If, and only if, the intruder is visually acquired, maneuver the aircraft to maintain separation."

A warning stated that, "Maneuvers based SOLELY on TCAS traffic advisories (TA), without visual acquisition of intruder ARE NOT RECOMMENDED." Guidance regarding vertical speed and use of the vertical speed indicator (VSI) also stated that, "Certain Vertical Speeds are not safe....Monitor VSI and keep the VSI pointer out of RED PROHIBITED area."

Flight Operations Manual

A review of the operator's flight operations manual (FOM) revealed that under normal conditions, a TA would precede an RA by 15 seconds. It further advised that the flight crew should attempt to gain visual contact with the intruder, and "be prepared to maneuver," should an RA sound 10 to 15 seconds later.

It also stated that the RA information was incorporated into the VSI by "illuminating" red and green light bands around the dial. "Fly-to" and "fly-away-from" commands were displayed coinciding with the "required vertical rate," and that the pilot flying should maneuver the airplane "promptly and smoothly" in response to an RA.

The FOM stated that a typical TCAS maneuver required a G-force of +/- .25g.

Flight Attendant Guidance

According to the flight attendant, at the time of the acci