National Transportation Safety Board
Aviation Accident Preliminary Report
New Orleans, LA
Date & Time:
08/09/2010, 1134 CDT
EMBRAER ERJ 170 100 SE
1 Serious, 73 None
Flight Conducted Under:
Part 121: Air Carrier - Scheduled
On August 9, 2010, about 1134 central daylight time, a Shuttle America Embraer 170, N856RW, flight # 7630 (TCF7630), was at a cruise altitude of 29,000 feet when they received a Traffic Alert and Collision Avoidance System (TCAS) resolution advisory (RA) to climb. Flight data indicates that within seconds, the flight crew disconnected the autopilot and climbed to 29,600 feet consistent with the TCAS alert. There were 2 pilots, 2 flight attendants and 70 passengers on board the Shuttle America flight. One passenger received a serious injury during the evasive maneuver. The commercial passenger flight was over the state of Mississippi when the TCAS RA occurred. The flight originated from the Chicago O'Hare International Airport (ORD), Chicago, Illinois, and was enroute to Louis Armstrong New Orleans International Airport (MSY), New Orleans, Louisiana. The flight was operating under the provisions of 14 Code of Federal Regulations Part 121 on an Instrument Flight Rules (IFR) flight plan.
Radar data indicates that a U.S. Air Force Northrop Corporation T-38 Talon, call sign FAST13, was on a cross country instrument training flight at 28,000 feet and deviated to 28,600 feet for approximately 30 seconds as it was converging on Shuttle America flight 7630. The military flight was operating under the provisions of 14 Code of Federal Regulations Part 91 on an IFR flight plan from Campbell Army Airfield (HOP), Fort Campbell/Hopkinsville, Kentucky, to Chennault International Airport (CWF), Lake Charles, Louisiana. There were two crewmembers aboard the military airplane. This airplane was not equipped with a TCAS.
At 1053, an aviation routine weather report (METAR) at MSY reported winds 330 degrees at 11 knots, visibility 10 statute miles, scattered clouds at 2,000 feet, broken clouds at 25,000 feet, temperature 33 degrees Celsius, dew point 26 degrees Celsius, and an altimeter setting of 29.97 inches of Mercury.
History of Flight
TCF7630, with four crewmember and 70 passengers, departed Chicago O'Hare International Airport (ORD), Chicago, Illinois at 10:02 on August 9, 2010 for a regularly scheduled 14 CFR part 121 instrument flight rules (IFR) flight to the Louis Armstrong International Airport (MSY), New Orleans, Louisiana.
FAST13, with a crew of two, departed Campbell Army Airfield (HOP), Fort Campbell/Hopkinsville, Kentucky at 1042 on August 9, 2010 for an instrument training flight. FAST13 was on an IFR flight plan to Chennault International Airport (CWF), Lake Charles Louisiana.
At 1134:17, TCF7630 was southbound at flight level (FL) 290 and FAST13 was southwest bound at FL280. The aircraft were on a converging course.
The Citronelle, Alabama Air Route Surveillance raw radar data indicates that at 1134:27 FAST 13 began a brief climb to FL286 before returning to FL280 at 1134:57. During this 30 second period, TCF7630 and FAST 13 courses converged momentarily before diverging after the aircraft passed each other. During FAST13's ascent to FL286, TCF7630 received a Traffic Alert and Collision Avoidance System (TCAS) warning resolution advisory (RA). The TCAS RA, of which pilots are required to comply with, directed the pilot to climb. The pilot of TCF7630 complied with the TCAS RA and immediately climbed to FL296 before returning to the previously assigned altitude of FL290 once the conflict was clear.
During the maneuver in response to the TCAS, a passenger in the aft lavatory of TCF7630, was injured and had suffered a compound fracture of his leg. The flight attendants and two passengers that were medical doctors on board provided basic first aid to the injured passenger until TCF7630 landed at MSY where medical personnel met the aircraft and transported the injured patient to the hospital.
Review of the air traffic control replay via SATORI of the event revealed that the altitude change by FAST13 was not displayed on the ATC radar nor observed by the air traffic controller. ATC was made aware of the TCAS event by TCF7630.
Radar presentation update rates are based on the revolutions per minute of the radar system providing the radar data. In the case the Houston Air Route Traffic Control Center (ARTCC), the air traffic control facility providing ATC service to TCF7630 and FAST13, the radar source data was provided by ARSR commonly referred to as long range radar. ARSR antennae rotate at 5 revolutions per minute (RPM) and provide primary radar returns on targets out to 200 miles. At 5 RPM, the radar data update rate, as observed by an air traffic controller, is 12 seconds.
The radar system employed by ATC has a predictive capability to provide for a continuous presentation of target data. The predictive capability of the radar will continue to present to predicted path of a radar track based on previous radar history. When a radar target is no longer sensed by the radar system the target will continue to be presented on the radar scope until a pre-determined amount of time has elapsed. This predictive capability allows for variations and occasional disruptions in the radar return generated by radar targets while still providing for continuous tracking data to be displayed on the radar indicator.
The TCAS unit, an Aviation Communication and Surveillance Systems (ACSS) TCAS2000 computer, part number 7517900-55007, serial number 20008946, was removed from the Shuttle America airplane and sent to the manufacturer's (ACSS) facility in Phoenix, Arizona. The contents of the memory of the TCAS2000 computer were successfully downloaded. Examination of the information confirmed that the incident TCAS encounter was recorded.
During normal operation, the ACSS TCAS2000 unit tracks and records data that describes the history of intruder aircraft that result in traffic advisories (TAs) and/or RAs. The TCAS2000 stores event history data in Electrically Erasable Programmable Read-Only Memory (EEPROM) for later retrieval and analysis.
The event data that is recorded details the behavior of the responsible intruder(s) and "own" airplane throughout the event. The track data is periodically sampled and recorded to provide a record of the behavior of the intruder(s) prior to causing a TA and/or RA until the advisory is concluded.
The downloaded data indicated that Shuttle America's flight 7630 TCAS computer annunciated a CLIMB RA shortly after the intruder airplane (FAST13) climbed through 28,000 feet altitude. No TA was calculated prior to the CLIMB RA. The CLIMB RA was annunciated for about 6 seconds until Shuttle America flight 7630 initiated a climb departing from 29,000 feet and the intruder arrested its climb at about 28,600 feet altitude. The CLIMB RA was weakened to a TA after the Shuttle America climb maneuver.
Aircraft and Owner/Operator Information
ERJ 170 100 SE 100SE
SHUTTLE AMERICA CORP
Operating Certificate(s) Held:
Flag carrier (121)
Operator Does Business As:
Operator Designator Code:
Meteorological Information and Flight Plan
Conditions at Accident Site:
Condition of Light:
Observation Facility, Elevation:
Distance from Accident Site:
100 Nautical Miles
Lowest Cloud Condition:
Wind Speed/Gusts, Direction:
11 knots / , 330°
Type of Flight Plan Filed:
CHICAGO, IL (ORD)
NEW ORLEANS, LA (MSY)
Wreckage and Impact Information
1 Serious, 69 None
1 Serious, 73 None
Investigator In Charge (IIC):
Effie Lorenda Ward
Additional Participating Persons:
The NTSB traveled to the scene of this accident.