Dulles, VA, USA
N650RW
Embraer 170
As the airplane approached the destination airport in level flight at 3,000 feet, air traffic control issued a traffic advisory and a turn away from approaching traffic, which was 500 feet below. About the same time, the airplane's traffic collision avoidance system (TCAS) alerted the crew to the traffic, and issued a resolution advisory (RA) to climb the airplane. The first officer climbed the airplane to 3,500 feet, and then descended the airplane back to 3,000 feet once the RA was complied with. During the climb and subsequent descent maneuver, a cabin attendant sustained a serious injury. Data downloaded from the flight data recorder (FDR) revealed that the flight crew responded with a pitch-up attitude of 14 degrees, with a sustained g-load of 2 g's. According to Federal Aviation Administration (FAA) Advisory Circular 120-55b, the recommended initial response was no greater than 7 degrees vertical pitch, with a resultant g-load of approximately 0.35 g's. It further advised, "The [pilot not flying] should advise the [pilot flying] on the progress of achieving the vertical rates commanded by TCAS." The manufacturer's airplane operator's manual stated that compliance with pitch guidance provided on the primary flight display should require no more than a 0.75g to 1.25g maneuver (+-0.25g).
On October 3, 2005, at 1100 eastern daylight time, an Embraer 170-100 SE, N650RW, operated by Shuttle America as United Express flight 7627, was undamaged while climbing to avoid traffic near Washington Dulles International Airport (IAD), Dulles, Virginia. The certificated airline transport pilot, commercial pilot, a cabin attendant, and 70 passengers were not injured. One cabin attendant was seriously injured. Visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan was filed for the flight that originated from Montreal Dorval International Airport (YUL), Montreal, Canada. The scheduled passenger flight was conducted under the provisions of 14 Code of Federal Regulations Part 121. In written statements, the flight crew explained that as they approached the airport, on the downwind leg of the traffic pattern at 3,000 feet, the airplane's traffic collision avoidance system (TCAS) provided a resolution advisory (RA), which advised the crew to initiate a climb. The first officer climbed the airplane to 3,500 feet, and "once the RA was complied with," descended back to 3,000 feet. Air traffic control (ATC) radar and communication data depicted the accident airplane on a southerly track at 3,000 feet, and another airplane converging head-on from the south, at 2,500 feet. The controller instructed the accident airplane to turn to a southwesterly heading, and the airplane assumed a divergent, southwesterly track for about 10 seconds, before a climb to 3,500 feet was initiated. After the airplane descended to 3,000 feet, a cabin attendant advised the flight crew that the other cabin attendant was injured. After consulting with the cabin crew, the flight crew elected to continue the flight to Dulles Airport, and medical personnel met the airplane at the gate. According to the director of safety for the operator, company management did not immediately know the exact details of the event, and the airplane was placed back into service. Consequently, cockpit voice recorder data for the accident flight was lost. Company personnel, however, did download the flight data recorder (FDR), and the data was forwarded to the National Transportation Safety Board laboratory in Washington, D.C., for analysis. Examination of FDR data revealed that the climb initiated by the crew resulted in a pitch-up attitude of 14 degrees, and the peak g-forces sustained were 2 g's. According to Federal Aviation Administration (FAA) Advisory Circular 120-55B, response to an RA required an initial pitch adjustment based on airspeed, in order to achieve a vertical rate of 1,500 feet per minute. Then, "refer to the vertical speed indicator (VSI) and make all necessary pitch adjustments to place the VSI in the green arc." The maximum suggested pitch adjustment, based on speeds below 200 knots indicated airspeed, was 5 to 7 degrees. It further advised, "The [pilot not flying] should advise the [pilot flying] on the progress of achieving the vertical rates commanded by TCAS." According to the Airplane Operations Manual (AOM), the Primary Flight Display (PFD) provided pitch guidance to the crew to recommend or prohibit maneuvers that prevented hazardous encounters. The "avoidance zone" was depicted by a red trapezoid, and the "fly-to-zone" was depicted by a green rectangle. According to one note, "If needed, promptly and smoothly adjust the airplane's pitch into the green rectangle (if displayed), and fly out of the red trapezoidal shaped avoidance zone(s). This should require no more than 0.75g to 1.25g maneuver (+-0.25g)." According to the operator's director of safety, "The ERJ-170 is a fully automated aircraft that provides flight director guidance for the pilot experiencing an RA and presenting him/her with a picture on the primary flight display showing a red area and a green area. The pilot procedure is to fly the aircraft out of the red area and into the green area which is considered to be the safe zone." According to the manufacturer's AOM, the maximum allowable g-load on the airframe was 2.5 g's in a flaps-up configuration, and 2.0 g's with flaps deployed. The captain held an airline transport pilot certificate with a rating for airplane multi-engine land. His most recent Federal Aviation Administration (FAA) first class medical certificate was issued April 14, 2005. The captain reported 2,000 total hours of flight experience, 173 hours of which were in make and model. The first officer held a commercial pilot certificate with ratings for airplane multi-engine land. His most recent FAA first class medical certificate was issued on October 6, 2004. The first officer reported 5,300 total hours of flight experience, 453 hours of which were in make and model. At 1051, the weather reported at Dulles Airport included a broken ceiling at 20,000 feet, with 8 miles of visibility. The temperature was 21 degrees Celsius and the dew point was 12 degrees Celsius.
The flight crew's excessive maneuver in response to a traffic alert during the landing approach.
Source: NTSB Aviation Accident Database
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