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On February 14, 2003, at 2053 central standard time, a Canadair CL-65, N653BR, operated by Atlantic Coast Airline (ACA), flight 7675, sustained minor damage when the nose gear collapsed during landing rollout. The Title 14 CFR Part 121 domestic passenger flight departed the Chicago O'Hare Airport (ORD) at 2026 and landed on runway 20 (7,000 feet by 100 feet, concrete) at the Central Illinois Regional Airport (BMI), Bloomington, Illinois. The captain, first officer (FO), flight attendant, and 26 passengers were not injured. An emergency evacuation was not required. Instrument meteorological conditions prevailed and the flight was on an IFR flight plan.
The flight to BMI was the second, and final, flight of the day for the flight crew. On the first flight of the day they had departed from Lexington, Kentucky, at 1808, and arrived at ORD at 1911. During the flight to BMI, the captain was the pilot flying the airplane and the FO was the pilot not flying.
The cockpit voice recorder (CVR) transcript indicated that ACA flight 7675 (Blue Ridge 675) departed from ORD Runway 9L at approximately 2026, and was cleared to climb to flight level 200 (20,000 feet).
At 2033, the FO listened to Automated Terminal Information Services (ATIS) information Delta (D). ATIS information D contained the following:
"Bloomington tower information Delta, time zero one four five Zulu. Wind zero six zero at one four; visibility one, one half miles; light snow; ceiling two hundred overcast; temperature zero; dewpoint zero; altimeter two niner niner zero. Airfield advisories all runways and taxiways and ramp areas, loose wet snow less than one quarter of an inch with MU ratings above four zero. Advise on initial contact, you have information Delta."
At 2036, the captain stated, "Ehh, there you go ... ninety-two, left and center."
At 2036:26, Chicago Center cleared Blue Ridge 675 direct to BMI and to descend at pilot's discretion to 10,000 feet.
Between 2038:00-2038:39, the FO provided the captain the ATIS brief and set approach speeds. He stated, "ILS is two zero. Here's your ATIS. It's um, zero six zero at fourteen, one and a half, light snow, two hundred over, zero and zero." ... "We got the visibility for it ... ninety on the meters. ILS twenty is in use." ... "There's loose wet snow on taxiways ... but its MU is greater than four." ... "Approach is forty, REF is thirty-five, go-around N1 is off the box, V2's one forty one, VT's sixty-eight. They are set ... my flow's complete."
Between 2038:41-2039:16, the captain gave the Approach Brief. He stated, "All right. ILS two zero. It's in the box. One ninety-eight inbound, top's at twenty four forty eight, bottom's at we're gonna call it ten eighty here." ... "Bottom at uh, ten eighty, airport at eight seventy one, MSA twenty eight hundred. Looks like there's some big MALSR lights on the runway." ... "We will put in on runway twenty, take it probably down to Golf and come back. Let's make sure we don't turn on that little stub down there." ... "And Golf will take us right across the other runway to the ramp."
At 2039, the flight was cleared to descend to 6,000 feet.
At 2041, the FO contacted the company's operations personnel at BMI to inform them that the airplane was 13 minutes from BMI and was inbound for landing. The operation's personnel responded, "All right, good luck in landing. We'll hopefully see you in 15." ... "Uhh. Northwest just did a missed approach because of the snow, so good luck."
At 2042, the FO reported the information received from BMI operations to the captain by stating, "Yeah, he goes, 'I hope you make it in. Northwest just went missed.'"
At 2042:44, the captain asked, "What are they calling the weather?"
The FO responded, "Two hundred over ... but you got plenty of vis."
The captain asked, "Oh, they're calling it two hundred over?"
The FO responded, "Yeah, it's two hundred over, but a mile and a half, so we should be fine."
At 2048, Peoria Approach Control cleared Blue Ridge 675 for the BMI ILS Runway 20 approach.
At 2049, flight 7675 contacted the BMI tower.
At 2050, BMI tower reported, "Blue Ridge 675, reference runway 20, I have had my snow removal been able to plow down the centerline of the, of the field, and I did have a Saab aircraft report braking action uh ... fair to poor." The tower subsequently cleared Blue Ridge 675 to land on runway 20.
At 2051, while on the approach to runway 20 with the landing ckecklist complete, the captain said, "Forty-five knots of wind." The FO responded, "I see that. Quartering, uh."
Approximately 500 feet above ground level (agl), the FO reported seeing "lights."
At 2052:12, the airplane's Ground Proximity Warning System (GPWS) stated, "Minimums."
At 2052:13, BMI tower reported, "Windcheck. Zero eight zero at one five."
At 2052:25, the CVR transcript indicated, "Sound similar to touchdown."
At 2052:26, the CVR transcript indicated, "End of recording."
In a written statement, the captain reported, "We broke out of the overcast at approximately 300' AGL, lights and runway in sight. Touched down in the touchdown zone and approximately a few seconds later as we were rolling across the stub end of RWY 11-29 and E taxiway, I heard and felt a bang and the nosegear collapsed. We received a "nosegear disagree" aural warning as we continued the rollout. As the flying pilot I maintained directional control of the aircraft using rudder, differential braking and thrust reversers and brought the aircraft to a stop a few feet to the right of the centerline with about 1500' of runway remaining. Per company procedures we ran the QRC (Quick Reference Checklist) for a shutdown/evacuation."
The captain reported that because the weather was so extremely cold, snowy, and windy on the runway, he stopped the emergency evacuation and kept the passengers on board the airplane until buses arrived to take the passengers to the terminal. The captain reported, "After the passengers were deplaned I obtained a ride with airport personnel in a pickup truck to the touchdown zone and observed snowbanks and FOD (large ice and snow chunks) in the touchdown zone. I inquired of the driver about this and he said they were just presently plowing RWY 11-29. I returned to the aircraft, completed the QRC shutdown and the crew was transported to the terminal."
During an interview, the captain reported the ridges of snow and ice on the runway were located between Echo taxiway and the intersection of runway 02/20 and runway 11/29.
The captain was an airline transport rated pilot with single-engine land, multi-engine land, glider, and instrument airplane ratings. He was a certified flight instructor in single engine land airplanes, multi-engine land airplanes, gliders, and an instrument airplane instructor. He held a First Class medical certificate. He had a total of 4,550 flight hours with 2,140 hours in make and model. He flew 255 hours in the last 90 days. He had been employed by ACA for approximately five years.
The FO was an airline transport rated pilot with single-engine and multi-engine land ratings. He was a certified flight instructor in single-engine land airplanes, multi-engine land airplanes, and as an airplane instrument instructor. He held a First Class medical certificate. He had a total of 3,337 flight hours with 1,269 hours in make and model. He flew 174 hours in the last 90 days. He had been employed by ACA for approximately two years.
The airplane was a twin-engine Canadair CL-65, serial number 7438, with a maximum takeoff weight of 53,000 pounds. The engines were General Electric CF-34-3B1 engines that delivered 8,729 pounds of thrust. The airplane was on a Continuous Airworthiness maintenance program. The last service check was conducted on February 11, 2003. The airplane had a total time of 5,962 hours.
The airplane is equipped with an electronic flight instrument system (EFIS). Two primary flight displays (PFD) and two multifunction displays (MFD) receive altitude, heading, airspeed and attitude data from the respective on-side sensors.
According to the aircraft manufacturer, the MFD wind speed and wind direction data is updated at 2 Hz. The wind data is recorded on the Flight Data Recorder (FDR) once every 4 seconds. The wind data is calculated in the aircraft's Flight Management System (FMS). The accuracy is a function of the errors associated with the mode of navigation, heading and airspeed. At 200 kts true airspeed (TAS), the windspeed accuracy would not be better than + / - 10 kts.
Surface weather observations at BMI are made by personnel from the Midwest Air Traffic Control (ATC) and by personnel of the Mobile Weather Team. The Midwest ATC weather observations are taken in the BMI tower, and the Mobile Weather Team weather observation location is in the BMI main terminal building. Midwest ATC makes the weather observations whenever the tower is in operation. The BMI Mobile Weather Team makes the weather observations between the hours of 2230 to 0530 local time, when the BMI tower is not in operation.
The wind sensor used by the BMI tower is located about 2,000 feet west-northwest of runway 29 at a height of about 22 feet agl. The wind sensor used by the BMI Mobile Weather Team is located on top of the BMI main terminal building at a height of about 25 feet above the terminal roof. It is located about 3,600 feet west-northwest of the wind sensor used by the BMI tower.
At 1945, the recorded wind information obtained from the BMI Mobile Weather Team indicated average winds of 030 degrees at 24 knots. The wind information reported on the Surface Weather Observations form for the BMI tower indicated a wind of 060 degrees at 14 knots.
At 2045, the BMI Mobile Weather Team wind information indicated an average wind of 040 degrees at 25 knots. At 2045, the BMI tower reported wind from the Surface Weather Observations form of 060 degrees at 12 knots. A peak wind from the BMI Mobile Weather Team wind data of 36 knots was noted at 2048.
A review of wind information from Peoria and Springfield, Illinois, indicated winds consistent with the BMI Mobile Weather Team wind data. In addition, the wind report from the Flight Data Recorder (FDR) of N653BR indicated a wind near the approach end of runway 20 of about 075 degrees at 40 knots. (The National Transportation Safety Board's [NTSB] Meteorology Report is in the docket material associated with this case.)
The surface weather observations for BMI between the times of 1945 on February 14 to 0053 on February 15 are listed below:
METAR KBMI 141945 06014KT 1 1/2SM -SN OVC002 00/00 A2990
METAR KBMI 142145 06014KT 1SM -SN OVC002 00/00 A2991
METAR KBMI 142353 05028G32KT 1 1/2SM -SN BR BKN002 OVC010 M01/M01 A2994 RMK PKW ND 05034/30
METAR KBMI 150053 06028G33KT 21/4SM -SN BR BKN006 OVC010 M01/M01 A2994 RMK PK WND 0540/19
The flight crew for Blue Ridge 675 received their ACA dispatch release and weather briefing for the flight from ORD to BMI at 1856 on February 14, 2004. The surface weather observations provided to the pilots in the weather briefing were the following:
At 1645, the surface observation at BMI was: Winds 080 degrees at 12 knots, 3 statute miles (sm) visibility, light rain and mist, overcast 1,000 feet above ground level (agl), temperature 1 degree C, dew point zero degree C, altimeter 29.85 inches of mercury.
At 1745, the surface observation at BMI was: Winds 070 degrees at 10 knots, 3 sm visibility, light rain and mist, overcast 1,000 feet agl, temperature 1 degree C, dew point 0 degree C, altimeter 29.85 inches of mercury.
The ACA weather briefing RAMTAF (terminal area forecast weather) provided to the pilots the following forecast weather information:
Forecast weather for BMI for 1600 was: Winds 130 degrees at 10 knots, 4 sm visibility, light freezing rain and mist, overcast 1,500 feet agl; temporarily from 1600 to 2200 feet agl, 2 sm visibility, light freezing rain, light ice pellets, mist, overcast 600 feet agl.
Forecast weather for BMI for 2200 was: Winds 130 degrees at 10 knots, 3 sm visibility, light freezing rain, light ice pellets, mist, overcast 600 feet agl; temporarily from 2200 to 0400 feet agl, 1 sm visibility, light freezing rain, light ice pellets, light snow, mist, overcast 300 feet agl.
The BMI ATC tower reported that a power failure occurred at approximately 2034:30, prior to the arrival of Blue Ridge 675. The control tower facility temporarily lost electrical power that deactivated the control tower tape recorder, and the ATC tower controller was unable to reset the tape recorder prior to Blue Ridge 675's arrival. Therefore, no ATC transcript exists of the communications between BMI tower and Blue Ridge 675.
The communications between BMI tower/ground control and snow removal equipment were recorded between 2017 - 2029. (The BMI ATCT transcript is in the docket material associated with this case.)
Commercial air carrier service is provided to BMI, and as such, BMI is governed by 14 CFR Part 139. As a result of the incident that occurred to Blue Ridge 675, an Airport/Safety Inspector from the Certification Office of the Federal Aviation Administration's (FAA) Central Region conducted a separate investigation into the circumstances on the incident. When the FAA had completed its investigation, it issued BMI a Warning Letter, EIR #2003GL800031. It stated, "The Federal Aviation Administration is unable to conclude definitively whether or not unsafe conditions were present on Runway 2/20 at the time of landing for Blue Ridge #675 on February 14, 2003. During the investigation, we did however discover that the Central Illinois Regional Airport had violated 14 CFR Part 139 under numerous subparts of the regulation the evening of February 14, 2003." The findings of the investigation included:
1. The BMI certification manual "did not identify the maintenance personnel who were responsible for issuing Notice to Airmen Reports (NOTAMS) and airport condition reports on the evening of February 14, 2003."
2. BMI failed to comply with the provisions concerning "Snow and Ice Control" measures as outlined in the certification manual. The report stated, "BMI did not conduct or provide friction measurement reports between the hours of 7:00 p.m. and 10:00 p.m. when airport conditions were rapidly changing with significant snowfall accumulations and snow removal equipment was actively operating on Runway 2/20."
3. BMI had only one individual on the airport that was available and authorized to conduct airfield condition reports, issue NOTAMS and conduct friction measurement reports. However, that person (snow crew leader) was also tasked with other collateral duties that prevented him from providing a runway condition report on Runway 2/20 after snow removal operations.
The FAA made the following recommendations to BMI:
1. BMI close all runways during snow removal activities to ensure that "safe conditions are present for air carrier operations."
2. Discontinue the practice of "allowing air carrier aircraft to operate on air carrier runways that are not plowed full length and width. While the regulation does not prohibit the practice of opening runways that have been partially plowed (providing a NOTAM is in place), the airport operator must ensure that snow is positioned off movement area surfaces."
3. Opening runway 11/29 following the Blue Ridge #675 incident resulted in the potential contamination of evidence at the intersection of Runway 11/29 and Runway 2/20. The report stated, "At a very minimum, a thorough inspection of Runway 2/20 should have been conducted and properly documented prior to initiating snow removal activities into the intersection of Runway 2/20."
4. On the evening of February 14, 2003, the personnel inside the snow removal vehicles were making runway condition assessments by looking out their side view mirrors. Instead, personnel need to "follow up behind all snow removal equipment to accurately and carefully assess runway conditions following any given snow removal event."
The FAA's Warning Letter stated, "It is apparent from the events of that evening, BMI was caught off guard and ill prepared to deal with the extreme weather conditions. The situation made apparent the lack of adequate training, staffing and management oversight required to handle emergencies. We expect future compliance with the regulations." (The FAA's complete investigation of BMI is in the docket of this case.)
The CVR was a solid-state based recorder that contained approximately 30 minutes of audio. The CVR group convened at the Vehicle Recorder Division of the NTSB on June 18, 2003. A full transcript the recording is in the docket of this case.
The digital FDR was read out by the NTSB Vehicle Recorders Division. The FDR data indicated that the aircraft touched down on a heading of 190 degrees at 124 knots with 0.4 degrees of nose up pitch. The data indicate the nose was pitching nose down at the time of touchdown. According to the Flight Data Study, the data indicated that the airplane touched down near the runway intersection, approximately 2,900 +/- 250 feet (2,650 feet to 3,150 feet) from the approach end of Runway 20. The recorded ground speed was approximately 13 knots greater than the recorded computed airspeed. All 3 landing gear Weight-on-Wheels (WOW) switches changed from Air to Ground within 0.25 seconds of each other. The left main WOW changed first, then the right main WOW 0.25 seconds later, and then the nose gear WOW 0.25 seconds after that. The data indicated that the lateral acceleration parameter showed "a -0.2 G load the same time as the nose gear gets WOW. Negative lateral load is acceleration to the left side of the aircraft and indicates that the nose of the aircraft was crabbed to the left of the aircraft's flight path as the aircraft touched down. Approximately 1.75 seconds later the nose gear WOW switches to Air again." The vertical acceleration parameter did not show a significant load at touchdown. However, the accelerometer is located near the center of gravity of the aircraft.
As part of the Flight Data Study, the FDR data from the 10 previous landings made in N653BR was compared with the incident flight. The comparison of FDR data indicated the incident landing was not consistent with the 10 previous landings. The report stated the following:
"The heading at touchdown for the previous 10 landings was in the range of 0-2 degrees of deviation from the runway heading verses 8-9 degrees for the incident landing. The pitch at touchdown for the previous 10 landings was in the 2-4 degree range, with the exception of one landing where it was about 1 degree, verses 0.4 degrees at touchdown on the incident flight." ... "The time between main landing gear and nose landing gear compression on the 10 previous landings fell in the range of 2-8 seconds verses the 0.5 seconds of the incident landing." ... "Additionally, the incident landing showed lateral and longitudinal decelerations greater than those on any of the previous 10 landings." (The NTSB Flight Data Study is in the docket material associated with this case.)
WRECKAGE AND IMPACT DAMAGE
An on-site inspection of the airplane was conducted by a Federal Aviation Administration airworthiness inspector, representatives from the aircraft manufacturer, and representatives from the airplane operator. The on-site inspection of the airplane revealed that the nose gear drag brace had broken and the nose gear collapsed rearward. The nose wheel and tire remained intact and were jammed under the airplane as it skidded to a stop. The nose gear wheel well received minor damage.
The on-site inspection revealed there was no apparent damage to the main landing gear. No damage was noted on the landing gear doors or the hydraulic line attached to the main landing gear. There was no damage to the flaps that were positioned at Flaps - 45. No damage to the main landing gear wheels or tires. The dust cap on the left main landing gear was damaged and there was minor damage to the right main landing gear brush retaining ring. When the main landing gear were inspected by the landing gear manufacturer, they reported, "During the disassembly process, although no dimensions were recorded and no NDT [Non-Destructive Testing] was performed, there was no reported signs of any abnormal damage."
TESTS AND RESEARCH
The broken parts of the upper drag brace link were sent to the Bombardier Aerospace Materials Laboratory for a metallurgical inspection. A representative of Canada's Transportation Safety Board provided oversight of the inspection process.
The Bombardier Aerospace Materials Laboratory report stated the following:
1. Fractographic and metallographic examination confirmed that the drag brace failed due to the application of an overload.
2. Based on the orientation, type and extent of the cracks and fractures, it is conceivable to believe that the overload was applied from the "LEFT" side of the component. The force appeared to have an asymmetrical "lifting" effect on the pintle pin area, resulting in excessive bending stresses that exceeded the UTS [ultimate tensile strength] of the material.
3. Metallographic examination did not reveal any materials defects.
The Bombardier Aerospace Materials Laboratory Report No. 2003LAB03947 is in the docket material associated with this case.
The nose landing gear was examined by the landing gear manufacturer, Messier-Dowty, with a representative of Canada's Transportation Safety Board providing oversight. The Messier-Dowty inspection report, number DS-820, stated the following:
"The drag brace, distorted retract actuator, deformed retract actuator pin and bent shock strut piston is evidence of the excessive impact loading applied to the nose gear."
Messier-Dowty conducted an analysis of the nose landing gear fracture. The purpose of the analysis was to determine plausible loading conditions under which the nose landing gear upper drag brace could fracture causing the nose landing gear to collapse. The Messier-Dowty investigation report, number SF-808, stated the following:
"Since side load is not a contributing factor to the fracture of the Drag Brace, the generation of the load required to fracture the Drag Brace at the calculated incident VAT [Vertical Axle Travel] of 4.9 inches is best supported by a drag load generated by hitting an obstacle." It further stated, "The occurrence of this case is clearly outside the design parameters for the nose landing gear."
The aircraft manufacturer, Bombardier Aerospace, calculated the actual stopping distance for the aircraft had the nose landing gear not collapsed. The calculation was based on the following airport and aircraft conditions:
Aircraft Weight: 42,000 lbs
Airport: Bloomington, Illinois, field elevation 871 feet msl
Tailwind: 10 knots, (factored tailwind was 15 knots and was used to determine landing distance in the Airplane's Flight Manual).
Touchdown speed: Actual - 124 KCAS, from FDR.
Runway Surface: Loose snow, 0.125 inch depth.
Reversers: 2 - maximum reverse down to 60 knots.
The aircraft manufacturer's report stated, "The certified landing expansion program for the CRJ was used and Vref was adjusted so that a touchdown speed of 124 knots calculated airspeed (KCAS) was obtained. Based on the condition used for this example, the total decelerating distance from touchdown to full stop was 4,337 feet."
BMI airport snow removal personnel had cleared runway 11/29 of snow when that runway was the active runway. BMI tower transcripts indicate that Mesaba flight 3294, a Saab 340 airplane, landed at BMI at 2036. Prior to the Mesaba 3294's arrival, the winds had shifted and the active runway was changed to Runway 20. The snow removal personnel then tried to clear Runway 20 of snow before Mesaba 3294 arrived. The BMI ATC tower/ground transcript indicated that Mesaba 3294 was approximately 5-7 minutes from landing when the snowplows started clearing runway 20. According to one of the operators of a broom truck, 3 snowplows went down Runway 20's centerline ahead of the 2 broom trucks. After that pass, he reported 1/4 inch of snow remained on runway where the broom trucks had passed.
At 2022:20, the BMI tower operator instructed the snowplows and broom trucks to exit Runway 20 for landing traffic. The snow plow leader in snowplow #24 reported to the tower that three snowplows had cleared the center of the runway from Foxtrot taxiway full length to Golf taxiway, and the 2 broom trucks were making one pass on the edge of the runway. The snow crew leader informed the tower that there was a 2 inch ridge of snow about 2 feet left of runway centerline. He reported that 1/2 inch of snow remained where the snowplows had passed. The 3 snowplows cleared the runway at Golf taxiway before Mesaba 3294's arrival.
At 2023:32, the BMI tower operator instructed Mesaba 3294 to go-around due to one of the broom trucks still being on runway. Mesaba 3294 executed the go-around. The broom trucks exited the runway.
During the go-around, Mesaba 3294 declared an emergency due to a loss of de-icing on its number one engine. The BMI tower alerted the airport's emergency personnel and they responded by scrambling the emergency equipment to runway 20 to await Mesaba 3294's arrival. Mesaba 3294 landed without incident and taxied to the terminal.
In a written statement, the captain of Mesaba 3294 reported that a normal landing was made and normal braking was used with "no adverse conditions noticed." He reported seeing a small ridge of snow a few feet off the runway centerline, but it had "no effect on our braking action." He reported that the braking action on the taxiway was poor.
After Mesaba 3294 cleared the runway, the 2 broom trucks were then cleared to continue snow removal operations on Runway 20. A broom truck operator reported that the broom trucks entered Runway 20 at Echo taxiway and plowed down the east side of the runway to the south end of Runway 20. The broom trucks then proceeded on the west side of Runway 20 to the threshold of the runway. Then they proceeded back down the east side of Runway 20 and exited at Golf 1 taxiway since Blue Ridge 675 was inbound for landing. The broom truck operator reported that there was no snow in the intersection of Runway 20.
The broom truck operator reported that after Blue Ridge 675 had landed and Runway 20 was closed, the snow crew leader instructed the broom trucks to immediately start clearing Runway 11/29. The broom truck operator reported the broom trucks entered runway 11/29 at Golf taxiway and started clearing the runways back to the intersection of Runway 11/29 and Runway 2/20. He reported, "We turned around at the threshold of Runway 29, where it made a "T" intersection into the middle of Runway 2/20." The broom trucks made a 180 degree turn to the left onto Runway 2/20, "breaking through the snow berm at the threshold of Runway 11 , past what would be the right (west) side of Runway 20 and pushing the residue back onto Runway 2/20 as we did our 180 degree turn." The broom trucks then proceeded down the right side of Runway 29. The operator reported that it took 5-7 minutes from the time they had been instructed to clear Runway 11/29 to the time it took to get to the intersection of Runway 2/20. He reported that the fire trucks had not arrived yet when the brooms had made their 180 turn in the intersection of Runway 20.
The Blue Ridge 675 CVR transcript indicated that neither the FO nor the Captain questioned whether the reported winds of 060 degrees at 14 knots were within the tail wind limitations of the aircraft. The reported winds were not checked against the Canadair Regional Jet "Wind Component Conversion Chart" that was available to the pilots for determining whether the headwind/tailwind and crosswind components were within limits. The Wind Component Conversion Chart indicates that the tailwind would be 10.5 knots and the crosswind would be 9 knots for winds of 060 degrees at 14 knots. The airplane's tailwind limitation is 10 knots. The FDR data indicated that the airplane landed with a 13 knot tailwind.
During separate interviews with the captain and FO, they were asked to use the Wind Component Conversion Chart and determine the correct tailwind and crosswind components for winds of 060 degrees at 14 knots while landing on runway 20. Neither pilot provided the correct tailwind and crosswind component. The captain indicated the tailwind was 9.5 knots with a 13 knot crosswind. The FO indicated the tailwind was 9.5 knots with a crosswind of about 11.5 knots.
The CVR transcript indicated that at 2052:13, the BMI tower controller reported the winds as 080 degrees at 15 knots when the airplane was at the landing minimums, approximately 20 seconds prior to landing. The Wind Component Conversion Chart indicates that the tailwind would be 7.5 knots and the crosswind component would be 13 knots with winds of 080 degrees at 15 knots.
The CVR transcript indicated that the captain did not brief the missed approach procedures during the Approach Brief as required in the ACA CL-65 Flight Standards Manual (FSM) (revision 5, page 3-4-24), nor did the FO query the Captain concerning the missed approach procedures. The FSM states that during an IFR approach, the flying pilot will brief the pilot not flying on the "Missed approach point and procedure."
According to the ACA FSM (revision 8, page 5-2-1), a runway is contaminated "when 25% of the surface is covered" by standing water, slush, wet snow, dry snow, compacted snow, or wet ice. The ACA FSM defines wet snow as "Snow that will easily stick together and tend to form a snowball if compacted by hand."
The ACA Flight Operations Manual (revision 21, page 8-7-5) states the following concerning landing on contaminated runways:
"1. Landing - contaminated runway
a. The aircraft should be landed in the normal manner, making sure the landing does not take place beyond the normal touchdown point.
b. Each time a landing is to be made on a contaminated runway, particularly when there is the possibility of landing with a tailwind, the flight crew will consider and brief the following:
1) How the weight of their aircraft impacts their performance margins as dictated by Airport Analysis Charts.
2) The type of runway surface and how their aircraft brakes on the surface when it is contaminated.
3) Use of maximum anti-skid breaking and full reverse thrust to aid in stopping the aircraft.
4) When it is evident that brakes will be required to stop, the application should begin immediately.
c. An approach stabilized on profile is critical to safe operations under these circumstances. These considerations should be studied and briefed prior to any contaminated runway landing, the detail of the briefing being dictated by the severity of the situation."
The ACA FSM (revision 8, page 5-6-1) instructions for landing in adverse weather include the following:
"DO NOT try to make up for poor braking conditions by landing short. The desired touchdown point is always 1,000 feet from the approach end of the runway. Fly a stabilized approach and maintain recommended speed for existing conditions. If the approach will result in an unsatisfactory touchdown point, go around."
The FDR data indicated that the airplane touched down near the runway intersection, approximately 2,900 +/- 250 feet (2,650 feet to 3,150 feet) from the approach end of Runway 20. Runway 20 is 7,000 feet long. The desired touchdown point is 1,000 feet from the approach end of the runway, or the first 1/3 of the runway. Runway 20's touchdown zone limit is 2,333 feet from the approach end of the runway.
At the time of the incident on February 14, 2003, ACA was using Airport Analysis charts that were developed and provided by a third party vendor to determine maximum takeoff weight and maximum landing weight performance. The Airport Analysis chart for BMI Runway 20 "Wet Runway Limits" indicated that an aircraft weight of 47,000 pounds or less could land on Runway 20. The ACA FSM, page 6-3-4, "Landing Field Length Requirements" states, "Actual landing distance is 60% of the Landing Field Length assuming a threshold crossing of 50' at Vref and idle thrust, touchdown 1,000' beyond the threshold and maximum braking.
Parties to the investigation included the Federal Aviation Administration, Bombardier Aerospace, Messier-Dowty, Atlantic Coast Airlines, and ALPA.