Dallas, TX, USA
N648AE
Embraer EMB-145LR
The 4,274-hour airline transport pilot lost control of the airplane while landing on a 7,752-foot long, by 150-foot wide runway, with a prevailing crosswind. The airplane drifted off the right side of runway 31R. A review of the flight data (FDR) and cockpit voice recorders (CVR), revealed that for the first ten seconds after touchdown the number 3 brake received more brake pressure than the number 1 brake. Also, for the four seconds that thrust reversers were utilized, the number 2 engine was brought to a higher N1 than the number 1 engine. Just prior to touching down, the tower reported winds from 250 degrees at 27 knots, with gusts to 38 knots. The operator used tabular data in determining crosswind component without having to utilize a graph. Utilizing the graph, the crosswind component was approximately 33 knots. According to the Airplane Flight Manual, the maximum demonstrated crosswind for the airplane is 30 knots.
HISTORY OF FLIGHT On February 24, 2007, about 1255 central standard time, a twin-fan jet Embraer EMB-145LR airplane, N648AE, operated by American Eagle as Flight 3400, sustained minor damage when it departed the right side of runway 31R during the landing roll at the Dallas Love Field (DAL), near Dallas, Texas. There were no reported injuries to the 3 crewmembers and the 23 passengers. Visual meteorological conditions prevailed for the scheduled revenue domestic flight that departed from the San Antonio International Airport (SAT), near San Antonio, Texas, at 1216 CST. Flight 3400 was conducted under an instrument flight rules (IFR) flight plan under 14 Code of Federal Regulations Part 121. The 4,274-hour airline transport pilot (ATP), reported that after the airplane touched down on the 7,752-foot long, by 150-foot wide runway, and lowered the nose "the airplane started to move to the right." The captain stated that he was unable to maintain directional control of the airplane and the airplane departed the right side of the runway. The airplane came to rest in a grassy area between taxiways Alpha 2 and Alpha 3. The airplane's flight data recorder (FDR) and cockpit voice recorder (CVR) were sent to the NTSB's Vehicle Recorder Division in Washington D.C. for analysis. According to the FDR, at 8 seconds prior to touchdown the rudder pedals command right rudder deflection. The airplane turns from a 300 degrees magnetic heading to 310 degrees. The ailerons are deflected to the maximum input for a left turn. The ailerons remained fully deflected until approximately 12 seconds after touchdown. The main gear touchdown was recorded on the FDR at 12:54:42 and confirmed by sound on the CVR. Indicated airspeed and ground speed both read 119 knots, magnetic heading was 308 degrees, the localizer deviation was less than 1/4 dot, and ground spoilers deployed. However, during the landing, brake pressures increased to different maximum values. Brake #1 increased to only 586 psi, while Brake #3 increased to 1176 psi. Four seconds after touchdown, the rudder is deflected to maximum left rudder. The captain is recorded on the CVR commenting about "full deflection." The airplane's heading turns from 308 degrees towards the final heading of 333 degrees at a rate of approximately 2 degrees per second. Ten seconds after touchdown, a single chime is recorded on the CVR. Thrust reversers are fully deployed. Engine #1 increases to 68% N1 and Engine #2 increases to 75% N1. Brake #1 increases to 800-1000 psi and Brake #3 decreases to 350-460 psi. Four seconds later, the thrust reversers are disengaged and N1 decreases to 35%. Fifteen seconds after touchdown a single chime is again recorded on the CVR. Eighteen seconds after touchdown, a loud "impact" noise is recorded on the CVR. The sound of the airplane coming to rest is heard approximately 5 seconds later. DAMAGE TO AIRPLANE An inspection of the airplane revealed two dents to the underside of the fuselage. Additionally, both landing gear doors for the nose landing gear were found damaged. METEOROLOGICAL INFORMATION At 1253, the automated weather observing system at DAL, reported the wind from 250 degrees at 26 knots, gusting to 36 knots, 10 statute miles visibility, scattered clouds at 10,000 feet, temperature 69 degrees Fahrenheit, dew point 14 degrees Fahrenheit, and an altimeter setting of 29.55 inches of Mercury. ADDITIONAL INFORMATION American Eagle provided data in a tabular form to assist in determining wind without having to utilize a graph. The table is arranged in increments of 5 knots and 10 degrees angle of deviation. On final, tower reported winds 250 degrees at 27 knots gusting to 38 knots. Using sixty degrees of deviation at 35 knots equates to 30 knots of crosswind, and 40 knots equates to 35 knots of crosswind. Utilizing the graph, the crosswind component is approximately 33 knots. A review of the Aircraft Operating Manual reveals that the maximum demonstrated crosswind component for the Embraer 145 is 30 knots, but the manual states that "[t]his value is not considered to be limiting." American Eagle's Flight Manual informs crews that crosswind gust velocities and direction are advisory only, but should be given consideration as such when weighing the operational acceptability of a cross wind situation. The maximum acceptable crosswind component, including gusts for a dry runway is stated as Max Demonstrated. In the limitation section of the Flight Manual the Max Demonstrated is defined as 30 knots. The Aural Warning System (AWS) emits a chime to warn crews of malfunctions. A single chime is a representative of a malfunction or failure. This chime plays every 5 seconds unless the malfunction is removed, cancelled or replaced by a higher priority aural warning.
The pilot's failure to maintain directional control of the airplane while landing with a crosswind. A contributing factor was the prevailing crosswind.
Source: NTSB Aviation Accident Database
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