The Safety Board's full report is available at http://www.ntsb.gov/publictn/A_Acc1.htm. The Aircraft Accident Report number is NTSB/AAR-08-02. Use your browsers 'back' function to return to synopsisReturn to Query Page
On April 12, 2007, about 0043 eastern daylight time, a Bombardier/Canadair Regional Jet (CRJ) CL600-2B19, N8905F, operated as Pinnacle Airlines flight 4712, ran off the departure end of runway 28 after landing at Cherry Capital Airport (TVC), Traverse City, Michigan. There were no injuries among the 49 passengers (including 3 lap-held infants) and 3 crewmembers, and the aircraft was substantially damaged. Weather was reported as snowing. The airplane was being operated under the provisions of 14 Code of Federal Regulations (CFR) Part 121 and had departed from Minneapolis-St. Paul International (Wold-Chamberlain) Airport (MSP), Minneapolis, Minnesota, about 2153 central daylight time (CDT). Instrument meteorological conditions prevailed at the time of the accident flight, which operated on an instrument flight rules (IFR) flight plan.
The accident occurred on the fifth and final scheduled flight segment on the first day of a scheduled 4-day trip for the flight crew. The flight was scheduled to depart MSP about 2030 CDT for a scheduled arrival time at TVC of 2251. However, when the pilots arrived at the gate for the accident flight, the gate agent advised them that the flight release paperwork was not available and that the flight might be cancelled. About 2022 CDT (about 8 minutes before the accident flight was originally scheduled to depart), the Pinnacle dispatcher provided the captain with details, indicating that the flight could not be dispatched to TVC because the forecast winds at TVC resulted in a tailwind component that exceeded the CRJ's 10-knot landing tailwind component limitation. However, about 22 minutes later, the dispatcher advised the captain that the flight could be dispatched because a new forecast predicted a smaller tailwind component for the landing at TVC. Postaccident interviews indicate that Pinnacle's system operations control (SOC) duty manager had reviewed the observed conditions and forecast for TVC (from Northwest Airline's [NWA] meteorology department) and approved the release.
The flight's dispatch documentation, which listed Detroit Metropolitan Wayne County Airport (DTW) as a destination alternate airport, was subsequently issued about 2043 CDT. However, because the flight was delayed, an update of the airplane's flight management system database software was required before the airplane could depart. After installation of this software, the airplane was pushed back from the gate at MSP about 2144 CDT. The pilots taxied the airplane to the runway 30R deice pad, where it was deiced and the departure clearance was issued. About 2153 CDT, an MSP air traffic control tower (ATCT) controller issued a takeoff clearance, and the accident flight departed for TVC.
Postaccident crew interviews and review of the cockpit voice recorder (CVR) transcript indicated that the departure, climb, and en route portion of the flight from MSP to TVC was routine. The captain/check airman was the flying pilot and was overseeing the first officer's initial operating experience (OE); the first officer performed the duties of the monitoring pilot. The CVR recorded several instances during the accident flight in which the pilots indicated that they were tired. For example, the CVR recorded the following statements on the captain's channel: 1) about 2332:12, "yeah, just tired. Too late for this...;" 2) about 2341:53, "aw I'm tired dude, just (expletive) worn out;" and 3) about 0018:43 "...a wet dog ready to go to sleep tonight dude." Additionally, about 0020:41, the CVR recorded the first officer stating, "jeez, I'm tired." Further, several yawns were recorded on the captain's channel (about 2340:00, 0001:06, 0004:00, and 0009:47).
Because the TVC ATCT had closed at 2200 the night of the accident (consistent with its normal operations), the captain briefed the first officer regarding landing at TVC at night, after the tower closed, in snowy windy weather conditions. Records indicate that the Pinnacle dispatch personnel who were providing flight-following services for the accident flight occasionally provided the pilots with updated TVC weather information during earlier portions of the flight. Specifically, the aircraft communications addressing and reporting system (ACARS) log showed that about 2354, dispatch personnel sent weather updates to the accident airplane indicating IFR conditions with restricted visibility in light snow. After reviewing the weather information (about 2357), the captain made a public address statement advising the passengers that the winds at TVC were "dying down significantly...so it looks like we're gonna have no problems gettin' in this evening."
About 0010, the pilots listened to the TVC automated surface observation system (ASOS) for updated airport weather information, which indicated, in part, that winds were out of 040º at 7 knots and visibility of 1 1/2 miles in light snow. About 0021, the MSP Air Route Traffic Control Center (ARTCC) controller confirmed that the accident pilots had received the current TVC weather and began to issue radar vectors for the instrument landing system (ILS) approach to runway 28 at TVC. About 0025, the captain sent a message to dispatch indicating that the TVC weather looked good for the approach, citing winds out of 040 degrees at 8 knots. Company dispatch personnel responded, stating, "[w]e show that too, looks like we should be good."
The weather data subsequently recorded by the TVC's ASOS showed that the conditions at TVC began to deteriorate rapidly after 0025, with visibility of 1/2 mile in moderate snow, sky obscured, and vertical visibility of 400 feet. The pilots did not listen to the ASOS again as they continued to follow ATC-provided radar vectors for the ILS approach to TVC; however, they did obtain information regarding runway conditions from TVC airport operations personnel. For example, beginning about 0025, the CVR recorded a radio conversation between the captain and the TVC airport operations supervisor regarding the runway condition and ongoing snow removal operations. The airport operations supervisor indicated that he had "multiple pieces of [snow removal] equipment" on runway 28 and that he was "running numbers for you as we speak." The captain indicated that they would be landing in about 13 minutes.
According to the CVR, about 0026:56, the airport operations supervisor radioed the pilots, advising that the braking action on runway 28 was "40 plus," with "thin wet snow [over] patchy thin ice...give us about [5 to 8] minutes to clear the runway...when you're ready to land." About 0029:10, the CVR recorded the captain stating, "there's snow removal on the field yet they're showing forty or better sounds like a contaminated...runway to me." During the next 4+ minutes, the CVR recorded additional conversation between the pilots, TVC operations, and MSP ARTCC personnel regarding the status of the snow removal equipment on the runway and the timing of the approach. About 0032:16 (about 6 minutes before the captain's estimated arrival time), the airport operations supervisor contacted the pilots to indicate that the last snow plow was off the runway. The captain responded, advising that the accident flight would be turning inbound and requesting additional airport traffic advisories if applicable.
About 0033, the captain advised the MSP ARTCC controller that the TVC runway was clear of snow removal equipment; the controller advised him that it would "be about another...2 minutes 'til I get you out far enough to turn you back onto the ILS." The pilots then discussed the length of the landing runway, and, about 0033:46, the captain stated, "...and at night it'll feel short too...with contaminant...more than likely." About 0034, the airport operations supervisor contacted the accident pilots again regarding their proximity to the airport. The captain replied that they expected an inbound turn clearance from the controller in about 1 minute, and the airport operations supervisor responded, "okay, roger that...it's comin' down pretty good here so ahhh (guess) I'll see you on the ground here." About 1 minute later, the airport operations supervisor queried the pilots about their progress, indicating "it's comin' down pretty good guys, just to give you a heads up." About 7 seconds later (about 0035:42), the controller issued the first of a series of heading changes, vectoring the accident pilots towards the approach to runway 28.
About 0036:19, the captain commented to the first officer, "...says it's comin' down good, which means its snowing...and we probably won't see the runway, so be ready for the missed [approach]." About 1 minute later, the airport operations supervisor contacted the pilots, stating 'I need to know if [you] guys are gonna be landing soon 'cause I gotta...this is fillin' in pretty quick down here...so, ah, how far are you guys out?" The captain replied that they were intercepting the approach course inbound and anticipated landing in "4 1/2, 5 minutes at the most."
According to the CVR, at 0038:03.2, the airport operations supervisor stated, "...I don't know what the ah conditions [are] like...the runway, but I'm gonna call braking action nil now. 'Cause it's fillin' in real hard." However, during that transmission, beginning at 0038:04.3, the controller also contacted the pilots, issuing another heading change for the approach. CVR information and postaccident interviews indicated that the pilots did not recognize or acknowledge the airport operations supervisor's nil braking action report. About 0038:30, the controller cleared the pilots for the ILS runway 28 approach at TVC. Postaccident evaluation of the CVR revealed that the first officer was initially monitoring both the common traffic advisory frequency (CTAF) and MSP ARTCC frequencies but turned down the volume on the CTAF to hear the ATC assignment. The captain acknowledged the approach clearance and the pilots continued toward the airport. About 0039:21, the CVR recorded the captain saying, "I mean, what kind of report's that, it's fillin in? Ya know doesn't tell me good, bad, fair, poor." About 24 seconds later, the controller advised the pilots, "...show you joining the [approach course], radar services terminated, change to advisory frequency approved."
About 0040:46, the CVR recorded the captain advising TVC traffic on the CTAF that the flight was inbound from the final approach fix and about 2 minutes from the airport. The airport operations supervisor responded that all equipment was clear of the runway, adding, "...and again ah brakin' actions probably nil on the runway." About 0040:57, the captain asked, "Are you saying it's nil?" and the airport operations supervisor responded, "....haven't been out there to do a field report and it's been ah 5, 10 minutes, so I don't know what it's doin' now." About 0041:05, the captain replied, "ok," and then said to the first officer, "He's not reporting it nil, he's like he's sayin' it's nil. Heh."
Beginning about 0041:15, the pilots performed the before landing checklist, confirming appropriate landing gear, flap, and thrust reverser settings. About 0041:31, as the airplane descended through about 1,000 feet above ground level (agl) on the approach, the captain asked TVC airport operations "how deep of a [contaminant] would you say it is?" and airport personnel responded, "...I'd say it's probably close to half inch now." The captain responded, "okay, that's not bad, thank you" and explained to the first officer, "We're allowed 3 inches...if it looks ugly when we're comin' in I'll go around...half inch is nothin'." As the approach descent continued, about 0042:05, the captain continued to discuss issues relevant to a possible go around with the first officer. About 0042:42, the captain announced that the runway was in sight and that they would continue to a landing.
At 0042:42.9, about 1 second after the captain saw the runway, the CVR recorded an electronic voice stating, "minimums." The airplane touched down at 0043:03.7. Review of flight data recorder (FDR) data indicated that the accident airplane crossed the approach threshold of runway 28 at an airspeed of about 148 knots and touched down on the runway about 2,400 feet from the threshold at an airspeed of 123 knots. The FDR data showed that the brakes were applied and the spoilers deployed immediately after the airplane touched down and that the thrust reversers were fully deployed within 4 seconds after touchdown. FDR information further showed that the thrust reversers were deployed and stowed twice during the landing roll. The first deployment occurred when the airplane was about 3,000 feet from the departure end of the runway, and the second deployment occurred when the airplane was about 1,100 feet from the departure end of the runway.
The airplane ran off the end of runway 28 at a ground speed of about 47 knots, on a heading of about 254°. It came to a stop on a heading of about 250°, about 100 feet west of the end of the 200-foot-long, 190-foot-wide blast pad pavement located off the end of runway 28.
1.The pilots were properly certificated and qualified under Federal regulations and Pinnacle Airlines training requirements. No evidence indicated any medical conditions that might have adversely affected the pilots' performance during the accident flight.
2.The accident airplane was properly certificated and was equipped and maintained in accordance with industry practices and was within weight and center of gravity limits.
3.The investigation revealed no evidence of any failure or anomaly of the airplane's powerplants, structures, or systems (including the airplane's deceleration devices, such as brakes, antiskid devices, and thrust reversers) that would have affected the airplane's performance during the accident landing.
4.Based on the system designs and runway conditions, it is likely that the airplane's braking and antiskid systems were performing to their maximum effectiveness.
5.Although, at its original departure, time Pinnacle dispatchers could not dispatch the accident flight because of strong winds in the Cherry Capital Airport (TVC) forecast, an amended forecast issued by Northwest Airline's meteorology department (and reflected in a subsequent National Weather Service-issued forecast) predicted more favorable wind conditions (as well as higher ceilings and improved visibility in light snow) at TVC and thus met the required criteria for the flight's dispatch.
6.The services provided by the air traffic control (ATC) system did not affect the outcome of the flight. Information commonly provided by ATC (for example, weather and runway surface condition reports) was available to the flight crew, and its availability was unaffected by the air traffic control tower's closure before the flight's arrival at Cherry Capital Airport.
7.Cherry Capital Airport's snow removal operations and runway surface condition assessment activities were conducted in accordance with the airport's Federal Aviation Administration-approved snow and ice control plan.
8.Considering the severe winter weather and the relatively intact condition of the airplane, the captain's decision to deplane the passengers using Pinnacle's "expeditious deplaning" procedures was appropriate.
9.Although there were no reported injuries resulting from this accident, had a postaccident fire occurred, the delay in aircraft rescue and firefighting response could have adversely affected the safety of passengers after the accident.
10.The forward-looking infrared equipment installed in the aircraft rescue and firefighting (ARFF) vehicle did not help the firefighter locate the accident airplane; however, improved crash detection and location equipment would likely have facilitated a more timely ARFF response.
11.Although there is no reason to believe the pilots' performance was affected by alcohol, the failure of the airline to perform required postaccident alcohol tests prevents a definitive statement on the issue.
12.Even though there was initially some uncertainty as to whether the Cherry Capital Airport runway overrun was an accident or an incident, it would have been prudent for Pinnacle to comply with the drug and alcohol testing regulations as if the overrun were to be classified as an accident.
13.The pilots failed to perform the landing distance assessment that was required by Pinnacle's Operations Specifications; had they done so, using current weather information, the results would have shown that the runway length was inadequate for the contaminated runway conditions described.
14.Because the pilots had ample evidence that wet snow was accumulating rapidly on the runway at Cherry Capital Airport, they should have anticipated a landing on a contaminated runway and performed a landing distance assessment as required by the company's Operations Specifications.
15.Initial training for pilots on the rationale for and criticality of conducting a landing distance assessment before landing on a contaminated runway would reinforce the need to conduct such an assessment.
16.It is likely that neither pilot heard the Cherry Capital Airport operations supervisor's first "nil" braking report because that transmission occurred simultaneously with critical approach instructions issued by the controller.
17.Although Pinnacle procedures prohibit landing when runway braking action is reported as "nil," the Cherry Capital Airport operations supervisor's description of "probably nil" (a term that has no clearly defined meaning with regard to runway braking action) and his subsequent failure to confirm a nil braking report when questioned further by the pilots likely led the pilots to believe that the runway braking action was not actually nil and therefore did not directly prohibit the landing.
18.The accident airplane landed farther down the runway than the 1,500-foot touchdown point assumed by the landing distance calculations; however, even if the airplane had touched down within the 1,500-foot, company-designated standard touchdown zone, it would likely not have stopped before the end of the runway given the accident conditions.
19.The pilots' use of the thrust reversers during the landing roll was not inconsistent with company and manufacturer guidance related to thrust reverser usage in adverse weather conditions and company policies prohibiting thrust reverser use at speeds less than 60 knots except in emergency circumstances.
20.The poor decision-making shown by the accident pilots, including their failure to account for the changing weather and runway conditions during the approach; their failure to perform a landing distance calculation; and their failure to reassess or discontinue the approach accordingly, likely reflected the effects of fatigue.
21.Existing Federal Aviation Administration pilot flight and duty time regulations permitted the long and demanding day experienced by the accident pilots, which resulted in their fatigued condition and degraded pilot decision?making.
22.The additional responsibilities and task demands involved in providing operating experience and performing related check airman functions likely aggravated the effects of fatigue for the captain/check airman.
23.The pilots could have made a more informed landing decision if they had monitored the current (updated every minute) and unambiguous Cherry Capital Airport (TVC) weather information that was continuously available to them through the TVC automated surface observing system broadcast.
24.The Cherry Capital Airport operations supervisor's use of ambiguous and unspecific radio phraseology when providing braking action information likely affected the captain's decision to continue the approach; an unambiguous runway surface condition report would have provided the pilots with more accurate and useful information to factor into their landing decision.
25.Incorporation of minimum safe operating limits for runway surface conditions into an airport's snow and ice control plan would ensure that airport operations personnel prohibit air carrier operations on any runway if, in their estimation, the braking action on that runway is unsafe.