Wind speed in fatal plane crash exceeded plane’s landing capability
Pilot, warned of wind shear, reported 30-knot tailwind just minutes before accident
The cockpit voice recorder recovered from the 2014 plane crash at the Aspen-Pitkin County Airport that killed a co-pilot revealed a jocular, expletive-filled atmosphere in the minutes leading up to the accident.
About 12 minutes before the 12:22 p.m. crash on Jan. 5, 2014, one of three pilots aboard (two were in control, one was a passenger) said, “Yes, we have a 30-knot tailwind, dude,” according to the transcript of the recorder released Wednesday by the National Transportation Safety Board.
The private Bombardier Challenger is rated for only 10-knot winds upon landings and takeoffs, the NTSB factual report says.
The Mexican pilots, flying from Tucson, Ariz., had only limited experience with the twin-engine corporate jet, and the third pilot “was invited to join on the trip to ‘provide any recommendations’ because of the special conditions” at Sardy Field, the report says.
Aspen’s airport is considered by many pilots to be one of the nation’s most challenging, with special training required for commercial crews.
The recorder transcript, translated from Spanish, shows the pilots laughing about 19 miles from the runway, with one suggesting they should have gotten “dirty,” lingo for extending landing gear and flaps to slow the plane’s speed.
“[Expletive] mm, hmm,” another pilot responded (who is speaking is not clear from the transcript).
“We should be dirtying up the darn plane, dude,” the first pilot said.
At one point, the air-traffic controller told the plane: “You copied our divert” to the Rifle airport and then asks the crew to stand by for clearance to that airport. The crew did not respond, according to the transcript.
It was lightly snowing in Aspen at the time, and crews had cleared the tarmac of snow not long before the plane’s approach. The plane, 4 miles from Aspen, was directed to proceed directly to Sardy Field.
The first pilot apparently told another person in the cockpit to thank the tower for the right to land “because I see that another [expletive] is going to Rifle, dude. Then who knows what … is down there.”
A pilot in another plane told the tower minutes before the crash that they had experienced a wind gust of 20 knots, leading the air-traffic controller to alert the Bombardier Challenger crew to “use caution for low-level windshear.”
The aircraft missed its first approach — with one pilot reporting 33 knots of tailwind — and circled around. Upon its second attempt, the plane touched down and bounced off the tarmac as the crew apparently again attempted to abort the landing. The plane, lacking enough power for the second takeoff, smashed into the runway nose-down and burst into flames.
Co-pilot Sergio Carranza Brabata, 54, was killed in the crash. Pilot Moises Carranza Brabata, the brother of the man killed, and Miguel Henriquez, were seriously injured. A quick response from airport safety crews was credited with saving their lives.
NTSB investigators haven’t been able to document why the crew continued into Aspen despite the high winds, nor whether the pilots were under a time crunch to land here, said spokesman Peter Knudson.
“We’re data driven, and we openly go where the facts take us,” he said. “That doesn’t mean there wasn’t time pressure on the pilots.”
Such potential contributing factors and other analysis could be revealed in NTSB’s probable-cause report, which is to be released in the coming weeks. But for now, “we’ve reached no conclusions,” Knudson said.
Marie Moler, an NTSB airplane performance specialist, wrote that the weather at the time “was near or in exceedance of the aircraft’s maximum tailwind and crosswind component for landing.” She added that the plane’s speed after it touched down and tried to ascend again was “15 percent to 45 percent lower than the specified takeoff power for the airplane weight and atmospheric conditions.”
The findings were in line with the NTSB’s initial investigation that suspected wind gusts as the cause.
Mike Boyd, an aviation expert and principal of Boyd Group International, said Thursday that he wasn’t surprised by the report.
The wind meant the plane was “going so fast you can’t slow down,” he said. “You can add another 25 knots to your landing speed, [meaning] you’re going 30 mph faster than you should be going.”
Boyd said he believed the pilots simply made a mistake.
“As long as you have humans in the cockpit” this can happen, he said.
NTSB docket items: http://dms.ntsb.gov
NTSB Identification: CEN14FA099
14 CFR Part 91: General Aviation
Accident occurred Sunday, January 05, 2014 in Aspen, CO
Aircraft: CANADAIR LTD CL 600 2B16, registration: N115WF
Injuries: 1 Fatal, 2 Serious.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The following is an INTERIM FACTUAL SUMMARY of this accident investigation. A final report that includes all pertinent facts, conditions, and circumstances of the accident will be issued upon completion, along with the Safety Board's analysis and probable cause of the accident:
HISTORY OF FLIGHT
On January 5, 2014, at 1222 mountain standard time, a Bombardier CL-600-2B16, N115WF, impacted the runway while attempting to land on Runway 15 at Aspen-Pitkin County Airport/Sardy Field (KASE), Aspen, Colorado. There were two crewmembers and a passenger onboard. One crewmember was fatally injured; the other crewmember and passenger received serious injuries. The airplane was destroyed. The airplane was registered to the Bank of Utah Trustee and operated by Vineland Corporation Company, Panama, South America under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the flight, which operated on an instrument flight rules flight plan. The flight originated from Tucson International Airport (KTUS), Tucson, Arizona, at 1004.
According to preliminary information from the Federal Aviation Administration, the flight was in radio contact with ASE air traffic control (ATC). At 1210, the crew utilized the localizer DME-E approach into KASE. ASE ATC reported winds as 290º at 19 knots (kts), with winds gusting to 25 kts to the crew before landing. The crew executed a missed approach, and then requested to be vectored for a second attempt. On the second landing attempt N115WF briefly touched down on the runway, then bounced into the air and descended rapidly impacting with the ground at midfield. No further communications were received by ASE ATC from the accident airplane.
Video of the runway showed the accident aircraft landing at KASE. The sequence of events in the video was: the aircraft above the runway in a slightly nose down configuration, a flash of light indicating a runway strike, the aircraft in the air above the runway and nose down, and then the aircraft impacting the runway nose down and being engulfed in light. Approximately four seconds elapse between the runway strike and the final impact.
The pilot, age 52, held a valid FAA Temporary Airman Certificate issued on November 9, 2013. The temporary commercial pilot certificate held ratings for airplane single-engine land, multi-engine land rating, type-rating for CL-600, and instrument airplane. The certificate was subject to a limitation for English proficiency. Upon FAA review of the pilot's temporary certificate after the accident, it was determined that the limitation of pilot-in-command for the CL-600 should have been included on the temporary certificate, however, the limitation had been overlooked by the designated pilot examiner. The pilot was issued a first-class airman medical certificate on August 27, 2013, with the limitation: must have available glasses for near vision and was valid at the time of the accident.
On November 9, 2013, the pilot completed training for the CL601 type rating at Simuflight in Dallas, Texas. According to the training records, the pilot received a "satisfactory" rating at the completion of the training. The pilot stated he did not have any troubles during his flight training other than with management of the FMS system. His flight experience in the CL601 at the time of the accident consisted of a ferry flight from Dallas, Texas to Toluca, Mexico; and a flight from Toluca, Mexico to Eagle County Airport, Colorado and back to Toluca, Mexico. He stated his total flight time in the CL601 was 12 to 14 hours, including his flight training at Simuflight. He explained he accrued 8,000 hours flying the Airbus 318, 319 and 320 prior to flying the CL601, with about 17,000 hours of total flight time. The Airbus time reported was completed during flight time accrued on his Mexican Flight Certificate and did not transfer to his FAA issued certificate.
The co-pilot, age 54, held a valid FAA Temporary Airman Certificate issued on November 14, 2013. The temporary commercial pilot certificate held ratings for airplane single-engine land, multi-engine land rating, a type rating for CL-600, and instrument airplane. The certificate was subject to Pilot-in-Command limitation for the CL-600 and a limitation for English proficiency. A limited First Class Medical Certificate was issued on December 13, 2012 with the limitation: must have available glasses for near vision. A limited first class medical is valid for 6 months from the time of issuance, the medical would then loose the first class medical privileges and assume the second class medical certificate. The second class would assume the privileges of a third class one year after date of issuance. At the time of the accident, one year and one month after the time of issuance, the co-pilot's medical certificate would have been equivalent to a third class medical. The pilot reported on his most recent medical certificate application that he had accumulated 20,398 total flight hours, with 31 hours in the previous 6 months. The co-pilot's logbook was not located during the investigation. The flight time reported during the co-pilots medical certification was accrued on his Mexican Flight Certificate and did not transfer to his FAA issued certificate.
The pilot-rated passenger, age 52, held a valid FAA, foreign-based commercial pilot certificate with an airplane single-engine land and airplane multi-engine land rating. No type rating for the CL601 was included on the FAA issued commercial certificate. The certificate was issued and only valid when accompanied by his Mexican Pilot License. Additionally, the FAA certificate was not valid for the carriage of persons or property for compensation or hire, or for agricultural aircraft operations. A First Class Medical Certificate was issued to him on December 9, 2013, with the limitation: must have available glasses for near vision. According to the Pilot, the passenger was a friend of his and the co-Pilot's. The passenger was an experienced pilot on the CL601 and was invited to join on the trip to "provide any recommendations" because of the special conditions at ASE. The passenger was sitting in the flight deck jumpseat position.
The accident airplane, a twin-engine corporate jet (serial number 5153), was manufactured in 1994. It was powered by two General Electric, CF34-3A1 turbofan engines rated at 9,000 pound-foot of thrust. The airplane had an occupancy of 12 passengers and two crewmembers, with an additional jumpseat for a cabin crewmember.
According to the information provided by the pilot on the NTSB Pilot/Operator Aircraft Accident/Incident Report, the most recent annual inspection was completed on December 18, 2013, with an airframe total time of 6,750 hours.
According to the Canadair Challenger Airplane Flight Manual (AFM), Section 3(f) Tailwind Conditions under Operating Laminations states:
The maximum tailwind component approved for take-off and landing is 10 kts.
The National Weather Service (NWS) Grand Junction (GJT) Weather Forecast Office was responsible for issuing the terminal area forecast (TAF) for the Aspen area. At 0500 MST, the NWS's upper air sounding depicted a shallow surface based temperature inversion with light winds below 300 feet (ft), and northwesterly winds above the altitude with little variation in direction with increasing wind speeds. The mean wind was from 324° at 39 kts. The wind and temperature profile supported a light to moderate mountain wave formation with respect to updrafts, downdrafts, and turbulence potential.
The observations for ASE indicated IFR conditions with light snow in the morning with VFR conditions prevailing at the time of the accident. Immediately prior to the aircraft's arrival in the area the wind speeds began to increase with gusts to 28 kts. The gusty winds only lasted a short period between 1853Z and 2253Z where northwesterly wind gusts of 25 kts or more were reported. The wind event was not noted in the NWS TAF for Aspen issued at the time of departure from PHX, no winds over 10 kts were predicted for the estimated time of arrival. However, the NWS TAF for Eagle (EGE) current at the time of departure had expected westerly winds of 14 kts gusting to 21 kts during the same period.
The airport had a federally installed and maintained Automated Surface Observation System (ASOS) located east of the touchdown zone of runway 15. At 1153 MST, the ASE automated ASOS reported the following weather conditions:
Wind from 310° true at 9 kts gusting to 28 kts, wind variable from 270° to 360, visibility 9 miles in haze, a few clouds at 3,500 ft agl, ceiling broken at 4,600 ft, overcast at 5,000 ft, temperature -11° C, dew point temperature -20° C, altimeter 30.07 inches of mercury (Hg). Remarks: automated surface observation system, peak wind from 320° at 28 kts occurred at 1150 MST, sea level pressure 1024.3-hPa, temperature -11.1° C, dew point -12.0° C.
At 1220, the approximate time of the accident, the ASE ASOS reported the following weather conditions:
Wind from 320 at 14 kts gusting to 25 kts, wind variable from 280 to 360, visibility 10 miles in haze, scattered clouds at 4,700 ft above ground level, ceiling broken at 6,000 ft, temperature -12 degrees (deg) Celsius (C), dew point temperature -21 deg C, altimeter 30.07 inches of mercury. The remarks indicated a peak wind from 320 at 26 kts occurred at 1204.
The ASE ASOS one-minute data (2-minute average wind issued every minute) during the second approach were:
TIME WIND GUST CROSS TAILWIND
1918Z 333° 15KT 345° 20KT 5KT 19KT
1919Z 323° 15KT 339° 22KT 0KT 22KT
1920Z 324° 14KT 324° 25KT 7KT 24KT
1921Z 333° 15KT 338° 22KT 1KT 22KT
1922Z 333° 14KT 328° 17KT 3KT 17KT Accident
An urgent pilot report over Aspen at 1205 MST from a Lear jet 35 flightcrew reported low-level wind shear with a 10 knot loss of airspeed on a 2 mile final to runway 15.
Lake County Airport (LXV), Leadville located 25 miles east of Aspen reported IFR conditions in light to heavy snow with west-northwesterly winds gusting to 31 kts at the time of the accident.
Copper Mountain (CUU) 36 miles east of Aspen reported westerly winds at 20 kts gusts to 46 kts during the period.
For further information, see the Meteorology Group Chairman's Factual Report within the public docket for this accident.
Aspen-Pitkin County/Sardy Field is a certificated Part 139 airport. It is a towered airport operating in Class-D airspace. The airport is equipped with one runway; runway 15/33 is 8,006 ft in length and 100-ft wide. The reported field elevation of the airport is 7,838 ft mean sea level. An aircraft rescue and firefighting station is located on the airfield and responded to the accident.
WRECKAGE AND IMPACT INFORMATION
The airplane was found inverted with fire damage on the fuselage and wings. The inside of the cockpit and cabin did not have evidence of fire. The aircraft under belly from the air driven generator to the underside of the inboard right wing had marking consistent with ground scraping. The right upper cockpit structure was partially collapsed and structurally breached. The right wing was folded at approximately 1/3 of the wingspan from fuselage. The left wing was bent downward (relative to aircraft reference) outboard of the outboard flap. The upper section of the vertical stabilizer, including the horizontal stabilizer, was missing from the main hull.
Both main landing gear were found in the extended position and connected only by their side stay actuators. Examination of the left and right main landing gear attachment points on the wing spars and trunions showed the pivot bushings intact and in their bore holes. The right main landing gear door link was still attached. Both main landing gear attachment fittings were found structurally intact. The nose landing gear wheel well structure was deflected upwards but did not contact any flight control beam assemblies under the cockpit floor. The nose landing gear was found folded approximately 70 deg aft and 30 deg to the left. The right axle for the nose landing gear was severed and the right nose wheel tire was missing. The left nose wheel was missing a portion of the inboard hub rim. The nose landing gear lower oleo strut had markings consistent with ground scraping on the axle jack point. A portion of the nose landing gear axle fracture surface had markings consistent with ground scraping.
The flaps were found in a deployed position. The right inboard and outboard flaps were disconnected from the wing. The left inboard flap inboard and outboard actuator screws were severed. The left outboard flap was attached to the wing by both actuators and hinges. The outboard flap screw actuator was measured from the gearbox housing aft surface (just forward of the dog stop ring) to the face surface of the ball screw assembly and found a distance of 5 ¾ inches. The exposed threads were counted and found 26 threads indicting a flap position of 45deg.
The horizontal stabilizer trim actuator jack screw was examined and found intact. Measurements taken from the gear box upper surface to the upper gimbal lower surface gave a distance of 4.85inches, indicting a trim setting of 4.85 (trim indicator is from 0-9, 0 is full nose-down and 9 is full nose-up). The left electrical connector for the horizontal stabilizer trim noise suppressor was found pulled from its connection.
The left and right main Angle of Attack (AOA) vanes were found intact with no visible damage. Both vanes moved normally when a finger force was applied. The right aux AOA vane had no visible damage, however, it did not move when a finger force was applied.
The left side engine, S/N 807029, outer cowling did not appear to sustain any impact damage. The outside of the engine cowl, the fan inlet and the fan blades exhibited smoke sooting. The cowls and core cowls were able to open normally. The engine under the cowls was free of soot and appeared normal. The main fuel control lever/linkage feedback match marks were aligned consistent with an engine that was in the "off" position. No other anomalies were noted while the engine was still mounted to the aircraft. After the engine was removed from the aircraft, it was placed on the ground and further inspection was conducted. During engine removal all engine to pylon connections were visually inspected and appeared normal. The fan blades did not sustain any visible damage. The inner surface of the fan inlet appeared bubbled and heat distressed from 0-90 deg aft looking forward (ALF). The fan was free to turn by hand with no abnormal sounds noted. There were scrapes on the outside of the fan case from 270-0 deg ALF. Visual inspection of all under cowl areas indicated all hardware was consistent with a normal flight engine. The fan cowls were not removed from the engine. Visual inspection of the tailpipe indicated no anomalies with the low pressure turbine.
Right side engine, S/N 807136, sustained fire damage from the exterior of the aircraft. The outer cowls showed burn-through from outside to inside in several areas. Melted cowl material had dropped onto the exterior of the engine cases and components. The upper cowl had to be pried and cut with a saw in order to open it. Under the cowls, the engine appeared normal with no indications of an engine fire. The main fuel control linkage feedback match marks were aligned consistent with a shut off engine. No other engine anomalies were noted while still mounted to the aircraft. After the engine was removed from the aircraft, it was placed on the ground and further inspection was conducted. During engine removal all engine to pylon connections were visually inspected and appeared normal. Impact damage to the inner surface of the fan inlet showed deformation from 0-90 deg ALF. The fan did not rotate by hand. Contact was noted between the fan case and fan blades, as well as molten material from the aircraft fire in the area. A handful of blades showed un-blended foreign object debris (FOD) damage; both hard and soft body damage was noted. The un-blended FOD damage consisted of tears, and bent material consistent with multiple foreign objects entering the fan with the engine still producing power. Visual inspection of all under cowl areas indicated all hardware was consistent with a normal flight engine; with the exception of the soot and molten material from the aircraft fire. Fan cowls were not removed from the engine. Visual inspection of the tailpipe indicated no anomalies with the low pressure turbine.
A visual inspection of the cockpit found the following:
- The flap handle was found at 45 deg.
- The engine power levers were found in the shut off position.
- The engine reverse thrust levers was found in the stowed position.
- The landing gear handle was found in the down position.
- The flight spoiler handle was found in the retract position.
- The ground spoiler switch was found in the ON position.
- The right control column was bent to the left by approximately 20 deg.
- The left and right control yokes were deflected to right by approximately 20 deg and
appeared to be synched.
- The pitch and roll disconnect handles were in their normally stowed position.
- The EGPWS PBAs were found in their normal out position.
- The following circuit breakers were found collared in the OUT position on CBP-A: #67 IRU#3 BATT, ENTERTAIN (2 BREAKER), FWD.
- The STALL PROTECTION PUSHER switches for pilot and copilot were in the ON position.
- The Air Driven Generator was found in the deployed position.
MEDICAL AND PATHOLOGICAL INFORMATION
A post mortem examination of the co-pilot was conducted under the authority of Rocky Mountain Forensic Services, PLLC, Loma, Colorado on January 6, 2014. The cause of death for the co-pilot was attributed to multiple injuries.
The Federal Aviation Administration (FAA) Civil Aeromedical Institute performed toxicology examinations for the co-pilot which was negative for carbon monoxide, alcohol and drugs. No toxicology exam was completed for the pilot or pilot-rated passenger.
TESTS AND RESEARCH
An NTSB Vehicle's Performance Specialist completed an Airplane Performance Study using the data from the FDR. For the purposes of the study, the elevation at ASE used was 7837 ft, the landing weight calculated by the crew was 35,881 pounds, and the center of gravity (CG) was 512.6 inches.
During the last six minutes of flight, the aircraft descended from 13,500 ft and slowed from an airspeed of 220 kts. The aircraft's descent angle for the last nautical mile of flight was approximately 4 deg and its airspeed was about 140 kts.
Runway 15 at KASE was on a magnetic heading of 151 deg (160 deg true); it began at an elevation of 7680 ft, and sloped upward at a gradient of 1.9 percent. During the last minute of flight the aircraft track aligned with the runway heading. The winds were variable from 280 deg to 360 deg at 14 kts gusting to 25 kts. A 25 kt gust from 280 deg would be a 21 kt crosswind and a 12 kt tail wind. Winds from 340 deg would be a pure tailwind. The aircraft's maximum tailwind component for takeoff and landing, as reported in the Airplane Flight Manual, was 10 kts. The maximum crosswind component for landing on a dry runway was 24 kts.
KASE was a high-altitude, terrain-limited airport. The missed approach procedure was to execute a climbing right turn to 14,000 ft on 300 deg. The missed approach point was between 1.4 NM from the threshold to runway 15 (VHF Omni Directional Radio Range (VOR) approach) and 2.6 NM from the threshold (localizer (LOC) approach). The accident aircraft had performed a missed approach before the accident landing. There were three points of high terrain (Aspen Mountain, the location of the I-PKN localizer, and Richmond Hill) beyond the end of runway 15 to clear during an attempted go-around. Of the three, the location of the I-PKN localizer would require the steepest climb gradient from the runway threshold. To clear the I-PKN localizer, an aircraft has 31,000 ft of horizontal distance to climb 3,500 ft to an altitude above 11,188 ft.
The Aircraft Operating Manual (AOM) provided climb data from sea level to various altitudes for different take-off weights for international standard atmospheric conditions (ISA). The temperature on the day of the accident was colder than ISA, so climb performance would have been better than this data indicates, making the following evaluation conservative. Data provided were the altitude gain, time, ground distance, and fuel burn for conditions with both engines operating; no information was provided to indicate the change in climb performance with the anti-icing systems on. Given the information known from the FDR, AOM, and elevations of the airfield and obstacles to clear, it was determined the aircraft should have been able to clear both Aspen Mountain and Richmond Hill. Clearing the I-PKN localizer would require a more optimal climb performance and less than a 25 kts tailwind. However, the climb performance data used was conservative, the atmosphere was cooler, the winds were variable, and anti-ice protection may not have been used. Additionally, the weather (scattered clouds at 4,700 ft above ground level, and a broken ceiling at 6,000 ft) might have allowed the crew to maneuver around the worst case terrain obstacles.
For further information, see the Performance Study Specialist's Report within the public docket for this accident.
Air Traffic Control
The following air traffic control transcription details communications between the accident airplane (N115WF) flight crew and Aspen Airport Traffic Control Tower (ATCT) during the accident approach.
During the missed approach, ATCT began communication with the accident airplane at 1209:31, when the flight crew reported they were "nine miles out." The remainder of the communications during the missed approach are as follows:
1210:04 (ATCT) Wind 290 at 19, 1-minute average wind 320 at 12 gust 25, runway 15 cleared to land.
1210:15 (N115WF) Cleared to land, roger.
1210:38 (ATCT) Falcon just reported a gain of 20 kts, use caution for low level wind shear.
1210:45 (N115WF) Roger
1211:07 (ATCT) winds 310 at 10.
1211:18 (N115WF) Okay. Missed approach. 33 kts of tailwind.
1211:26 (ATCT) Execute publish missed.
1211:30 (N115WF) Okay.
1211:37 (ATCT) Climb and maintain 16,000, expedite your climb, execute published missed. 16,000 on the missed.
1211:45 (N115WF) Executing. Climbing to 16,000.
1212:38 (ATCT) Contact departure 123.8.
1212:50 (N115WF) 123.8.
N115WF contacted Aspen ATCT terminal control (approach) following the missed approach, as follows:
1212:53 (Approach) N115WF aspen departure, say intensions.
1213:03 (N115WF) Okay. We turn back and do another approach. We got a tailwind of 30 kts.
1213:10 (Approach) Roger. Fly heading 310, vector localizer DME echo approach.
1213:16 (N115WF) 310 and vectors again got localizer 15.
1213:42 (Approach) N115WF descend and maintain 13,400.
1213:44 (N115WF) 13,400.
1214:07 (Approach) N115WF fly heading 290.
1214:10 (N115WF) Now heading 290, 115WF.
1215:12 (Approach) N115WF turn right heading 020.
1215:18 (N115WF) 020 on the heading 115WF.
1215:32 (N115WF) Confirm 15WF 020 on the heading.
1215:36 (Approach) N115WF turn right heading 060 now.
1215:40 (N115WF) 060 now.
1216:56 (Approach) N115WF, 4 miles from jargu turn right heading 120 cross jargu at 13,400, cleared localizer DME echo approach.
1217:05 (N115WF) 120 on the heading to intercept localizer DME, 115WF.
1217:10 (Approach) and N115WF that's cleared localizer DME echo approach.
1217:15 (N115WF) localizer DME approach N115WF
1218:01 (Approach) N115WF contact tower.
1218:04 (N115WF) Contact tower.
N115WF contacted Aspen ATCT (local) for the second approach into ASE. This approach was the accident approach, with the follow air traffic communications:
1218:37 (Local) N115WF Aspen tower.
1219:21 (Local) N115WF Aspen tower.
1219:24 (N115WF) Go ahead.
1219:26 (Local) Runway 15 continue for N115WF.
1219:28 (N115WF) We'll continue the 115WF.
1219:42 (Local) N115WF traffic 12 0'clock, 7 miles turning westbound 9,200 ft.
1219:47 (N115WF) IFR.
1220:08 (Local) N115WF traffic no factor. Disregard, no factor, westbound now.
1220:14 (N115WF) Roger 115WF. In IFR conditions now.
1220:35 (Local) N115WF winds 330 at 16, runway 15 cleared to land. 1-minute average 320 [at] 14 gust 25.
1220:45 (N115WF) Roger, 115WF.
1222:04 (Local) Go around, go around, go around, go around. [The accident occurred here. Emergency services were dispatched and ASE was closed.]
On January 11, 2014, based on the events of the accident, Aspen ATCT changed the Standard Operating Procedures for dissemination of wind information. The one-minute average wind data was established to be the "official winds to be issued" to pilots at ASE. While the local controller provided the 1-minute wind average to the accident flight crew during arrival, the procedure in place at the time of the accident was to provide the most current wind data from the ASOS (a two-minute average wind data). It was up to controller judgment whether updated 1-minute average wind data was also provided to flight crews. Although the ASOS continued to provide pilots with the 2-minute average wind data via radio, the most updated information from the wind data available (the 1-minute average wind data) was required to be provided by ATCT, including the gust information.
Flight Data Recorder
The accident airplane was operating such that it was required to be equipped with an FDR that recorded, at a minimum, 18 parameters, as cited in 14 CFR Part 91.609(c). The NTSB's Vehicle Recorders Lab extracted the data contained on the Loral/Fairchild F1000 (P/N S603-1000-00, S/N 00523) flight data recorder (FDR) installed on the accident airplane.
The FDR recording contained approximately 124 hours of data. The event flight was the last flight of the recording and its duration was approximately 2 hours and 18 minutes. The parameters evaluated for the purpose of this report appeared to be in accordance with the federal FDR carriage requirements, except the flight spoiler parameter. The flight spoiler parameter was installed and appeared not to be working. During the investigation, the FAA was informed of the inoperative flight spoiler parameter.
The FDR data starting at 1208:00 MST showed a pattern consistent with the missed approach. After the missed approach, at 1219:45 MST, approximately 2 minutes and 37 minutes before the end of the FDR recording, the aircraft began its final descent from a pressure altitude of approximately 12,900 ft. At this time, the left and right flaps were at 28 deg, the autopilot was "On", and engine 1 N1 (Eng1 N1) and engine 2 N1 (Eng2 N1) were both decreasing through about 73% revolutions per minute (RPM).
Twenty-four seconds later, at 1220:09 MST, while descending through a pressure altitude of about 12,500 ft, the autopilot transitioned to "Off" and remained "Off" for the rest of the FDR recording. At this time, Eng1 N1 and Eng2 N1 were steady at about 33% RPM.
Thirty-four seconds later at 1220:43 MST, while descending through a pressure altitude of about 11,000 ft, the left and right flaps increased to 44 deg. Twenty-seven seconds later at 1221:10 MST, while descending through a pressure altitude of about 9,150 ft, Eng1 N1 and Eng2 N1 began increasing.
For the next 56 seconds, Eng1 N1 and Eng2 N1 varied between a maximum of about 75% RPM and a minimum of about 42% RPM. Also during this time, the pitch angle varied, peaking at a maximum of 4.3 deg and a minimum of -5.2 deg. At 1222:06 MST, the vertical acceleration peaked at 2.91 g's and pitch angle increased to about 5.6 deg.
For the next 16 seconds, until the end of the FDR recording at 1222:22 MST, the pitch angle increased to about 15.3 deg, decreased to about -13.1 deg, increased to about 24.7 deg and then settled to about 0 deg. Additionally, vertical acceleration decreased to -0.17 g's, peaked at 5.76 g's and then settled at -1.46 g's.
For further information, see the Flight Data Recorder Specialist's Factual Report within the public docket for this accident.
 N1 is the rotational speeds of the engine sections expressed as a percentage of a nominal value.