# NTSB NYC04LA174: Bombardier CL-600, N995CA, Snow Hill, VA, July 21, 2004 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: July 21, 2004, 08:15 local (12:15 UTC) - Place: Snow Hill, VA - Coordinates: 38.056388, -75.46389 - Nearby events: https://openairdocs.org/map.md?lat=38.0564&lon=-75.4639&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 4 uninjured - Status: Completed, report March 28, 2006 - Report: Approved by Office Director - Parties: FAA/FSDO - NTSB case key (mKey): 59797 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC04LA174 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59797/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=59797 - Page: https://openairdocs.org/ntsb/NYC04LA174 ## Probable cause The pilot's excessive maneuvering in response to a TCAS alert, which resulted in a serious injury to the flight attendant. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, maneuvering - collision avoidance system - activated - maneuver - excessive, pilot in command (cause) ## Analysis The flight crew received a traffic advisory (TA) alert from the Traffic Alert and Collision Avoidance System (TCAS), followed shortly by an aural resolution advisory (RA) warning to "CLIMB, CLIMB." The first officer (FO) then disconnected the autopilot and initiated a climb, at a rate of ascent of 1,500 feet per minute. The captain then announced he was taking the controls and proceeded to pitch the airplane at a greater angle. As the airplane ascended, the flight attendant fell to the floor and broke her ankle. Once the TCAS announced, "clear of conflict," the captain leveled the airplane at 30,000 feet. He then returned the controls to the FO, and the airplane was descended back to an assigned altitude of FL 290. A review of radar data and air traffic control information, revealed that the accident airplane was climbing at a rate of 2,500 feet per minute and an airspeed of 483 knots. The airplane which caused the traffic alert for the accident airplane was an MD-80, which was climbing at 2,000 feet per minute, and an airspeed of 433 knots. The closest proximity between the two aircraft was 1.54 nautical miles, and 1,500 feet. According to the operator's Flight Standards Manual, "the correct response to a corrective RA is to fly from the red zone into the green zone. This maneuver requires a response within 5 seconds of the advisory using approximately a 0.25g maneuver". A performance review of the radar data revealed the flight crew's maneuver in response to the TCAS alert included a 1,000-foot climb, followed immediately by a descent back to the airplane’s assigned altitude. The maneuver described by the radar data could be performed using an initial 1.15 G pull-up to start the climb, followed by a 0.05 push-over to arrest the climb and start the descent, followed by a 1.4 G pull-up to level the airplane at the assigned altitude. In this sequence, the time between the 0.05 G push-over and the 1.4 G level-off was about 5 seconds. ## Factual narrative On July 21, 2004, at 0815 eastern daylight time, a Bombardier CL-600, N995CA, operated by Comair Airlines Inc., as flight 5645, was not damaged during a climb to avoid traffic near Snow Hill, Virginia. The two certificated airline transport pilots, and two non-revenue passengers were not injured. One flight attendant was seriously inured. Visual meteorological conditions prevailed for the flight that departed from the Charleston International Airport (CHS), Charleston, South Carolina, destined for the John F. Kennedy International Airport (JFK), New York, New York. An instrument flight rules flight plan was filed for the scheduled passenger flight conducted under 14 CFR Part 121. According to the first officer (FO), while in cruise flight at flight level (FL) 290, the crew received an audible traffic advisory (TA) alert from the traffic collision avoidance system (TCAS). The multi-functional display depicted an aircraft at the 12-to 1-o'clock position, about 2,000 feet below, and climbing about 500 feet per minute. As the conflicting aircraft reached approximately 1,400 feet below the CL-600, the first officer visually observed the airplane, announced "traffic in sight, " and alerted the captain to the traffic. At the same time as the captain instructed the FO to climb, the crew received an aural resolution advisory (RA) warning to "CLIMB, CLIMB" from the TCAS. The FO then disconnected the autopilot and initiated a climb, while advancing the thrust levers. The captain continued his instruction to climb and the vertical speed indicator displayed a rate of ascent of 1,500 feet per minute. The captain then announced he was taking the controls and proceeded to pitch the airplane at a greater angle. Once the TCAS announced, "clear of conflict," the captain leveled the airplane at 30,000 feet. He then returned the controls to the FO, and the airplane was descended back to FL 290. After the airplane was level, the captain was informed that the flight attendant was hurt. The flight continued to JFK, where the flight crew requested that paramedics meet the flight to assess the flight attendant's injury. According to the flight attendant, she was performing a walk-through of the cabin, when she "felt pressure on herself, " and fell to the floor. Two jumpseating passengers in the cabin assisted her to a seat, and retrieved ice for her ankle. After landing, she was transported to an urgent care facility, and diagnosed with a broken ankle. A review of radar data and air traffic control information provided by the Federal Aviation Administration (FAA), revealed that the Comair flight was climbing at a rate of 2,500 feet per minute and an airspeed of 483 knots. The airplane which caused the traffic alert for the Comair crew was an MD-80, which was climbing at 2,000 feet per minute, and an airspeed of 433 knots. The closest proximity between the two aircraft was 1.54 nautical miles and 1,500 feet. According to the Comair CL-600 Flight Standards Manual, "the correct response to a corrective RA is to fly from the red zone into the green zone. This maneuver requires a response within 5 seconds of the advisory using approximately a 0.25g maneuver. Listed below [is one] possible corrective RA aural warning: - 'CLIMB, CLIMB,' - Climb at the rate shown on the VSI, normally 1,500 FPM." A performance review of the radar data revealed the flight crew response to the TCAS alert included a 1000-foot climb, followed immediately by a descent back to the airplane’s assigned altitude. The entire maneuver lasted about a minute and a half. While the nature of the radar data that tracked the flight did not allow the load factors in the cabin to be computed with certainty, the maneuver described by the radar data could be performed using an initial 1.15 G pull-up to start the climb, followed by a 0.05 push-over to arrest the climb and start the descent, followed by a 1.4 G pull-up to level the airplane at the assigned altitude. In this sequence, the time between the 0.05 G push-over and the 1.4 G level-off was about 5 seconds. According to Comair training documents, flight crews receive initial TCAS training, during simulator LOFTs. During recurrent training, TCAS training/demonstrations may be built into specific LOFT scenarios. ## Aircraft - Registration: [N995CA](https://openairdocs.org/deregistered/N995CA-2012-11-08), registration cancelled 2012-11-08, S/N 7229, built 1998 (OpenAirDocs) - Reported make and model: Bombardier CL-600 - Registry model: [Canadair CL-600-2B19](https://openairdocs.org/model/canadair-cl-600-2b19) (registry code 1900309) (OpenAirDocs) - Registry engine: [GE CF34 series](https://openairdocs.org/engine/ge-cf34-series) (registry code 30015, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 7229 - Airframe hours: 15817 - Engines: General Electric CF34-3A1 9220 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Registered owner: Comair Inc - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, July 1, 2004 - Departed: CHS, CHARLESTON, SC - Destination: JFK, NEW YORK, NY - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: none; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review July 1, 2004; seat: left; flight hours: 6,530 total, 4,570 in this make and model, 197 in the last 90 days - Co-pilot; age 27; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review October 1, 2003; seat: right; flight hours: 2,213 total, 1,179 in this make and model, 953 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 5 knots - Visibility: 4 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 68 °F - Altimeter: 30.00 inHg - Observed at: WAL, 7 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20040721017019A](https://openairdocs.org/incident/20040721017019A), Jul 21, 2004: Cndair CL6002B19, Snowhill, MD. (-23) While cruising at flight level 290, a TCAS ra was observed by flight crew. First officer (fo) was pilot flying. Fo disconnected autopilot and initiated… ## Docket (5 files) The files NTSB released with the investigation on January 11, 2006, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=59797. 1.1 MB in all. - Radar Data (item 1, PPT, 681 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40241906&FileExtension=ppt&FileName=Radar%20Data-Master - Performance Plots (item 2, .PDF, 15 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40241910&FileExtension=.PDF&FileName=Performance%20Plots-Master.PDF - Comair Flight Standards Manual (excerpt) (item 3, .PDF, 27 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40242592&FileExtension=.PDF&FileName=Comair%20Flight%20Standards%20Manual%20(excerpt)-Master.PDF - Crew Statements (item 4, .PDF, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40418103&FileExtension=.PDF&FileName=Crew%20Statements-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 5, .PDF, 209 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40418104&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.