NTSB narrows its focus on Montrose Challenger crash

 - September 22, 2006, 5:48 AM
“Chunks of slush” slid off the taxiing Bombardier Challenger 600 just before
it crashed on takeoff from Montrose Regional Airport in Montrose, Colo., on Nov. 28, 2004, reported NBC Sports chairman Dick Ebersol, who survived the crash of the Air Castle chartered jet.

The NTSB has released a series of factual documents on the accident that killed Ebersol’s 14-year-old son, Teddy, and injured his other son, 21-year-old Charley. The ATP-rated pilot and a flight attendant were killed and the copilot and another passenger seriously injured. Ebersol’s wife, actress Susan Saint James, had disembarked at Montrose.

The Challenger had arrived at Montrose at about 9 a.m. from Van Nuys, Calif. It sat on the FBO ramp for approximately 50 minutes before taxiing to Runway 31 for takeoff on an IFR flight plan to South Bend, Ind. The crew did not have the jet de-iced.

It was snowing at the time of the crash and visibility was low. Both runways were being plowed. Ebersol told the NTSB that as the airplane was taxiing out there was an inch of slush on the runway, and slush slid off the top of the jet and across its windows. He told investigators that when the airplane was 20 to 50 feet in the air the left wingtip hit the ground and dirt came through the windshield. He described the bank angle as “greater than 7 o’clock.”

A witness said the initial ground roll was uneventful and he lost sight of the airplane in the snow and low visibility. Another witness saw the airplane yaw to the right, with the tail almost perpendicular to the runway. It hit the ground to the right of the runway and slid approximately 1,400 feet, through the perimeter fence, across a road and through another fence.

Charley Ebersol, who was severely injured, pulled his father from the airplane before it exploded, but his brother could not be found until later.

The Weather
A low-pressure system was centered over central Colorado with an occluded front extending from the low to southeastern Colorado, where the occlusion front split into a cold front that stretched southwest into New Mexico, then Mexico.

The accident site was on the cold-air side of the occluded front. Just before the accident, the weather report at Montrose was wind calm, visibility 1.25 sm in light snow and mist, a few clouds at 500 feet, overcast at 900, temperature was -1 degree C (30 degrees F) and dew point -2 degrees C (28 degrees F).

At Montrose, the Challenger’s cockpit voice recorder (CVR) captured ground-based reports of snow-removal progress on Runway 31. At 9:42, the Challenger captain asked, “How do you see the wings?” and the copilot responded, “Good.” The captain said, “Looks clear to me,” then asked for a “performance takeoff.”

Fifty-three seconds later, the copilot called, “Rotate,” then asked, “Do you want the gear up?” The CVR recorded a sound “similar to the aircraft pusher wailer,” followed by an electronic voice calling, “Bank angle” and “500 feet.” The CVR recording ended five seconds later at 9:58:46 a.m.

Warnings and ADs
On Dec. 27, 2004, just after the accident, the NTSB issued a special alert about the Challenger 600 series, warning that “research has shown that small amounts of ice accumulation on the upper surface of a wing can result in aerodynamic degradation as severe as that caused by much larger (and more visible) ice accumulations.”

The warning also noted that fine particles of frost or ice, the size of a grain of table salt and distributed as sparsely as one per square centimeter over a wing’s upper surface can degrade lift enough to prevent an airplane from taking off.

The Board emphasized that “pilots should be aware that no amount of snow, ice or frost accumulation on the wing upper surface can be considered safe for takeoff.”
On February 17 last year the FAA issued an airworthiness directive for all U.S.-registered Bombardier Challenger 600s, 601s and 604s and Canadair Regional Jets, requiring the revision of airplane flight manuals to include a new cold-weather operations limitation.

The AD reiterated the NTSB warning and required, in addition to a visual check, a tactile check of the leading edge and forward and rear upper surface of the wing to determine that the wing is free from frost, ice, snow or slush when the outside air temperature is 41 degrees F or less; or it cannot be determined that the wing fuel temperature is above 32 degrees F and if there is visible moisture (rain, drizzle, sleet, snow, fog and so on); or water is present on the wing; or the difference between the dew point and the outside air temperature is 5 degrees F or less; or the atmospheric conditions have been conducive to frost formation.

Another Black Mark for the Charter Industry
The Challenger was owned by Hop-A-Jet of Fort Lauderdale, Fla., and leased to Air Castle Worldwide Executive Jet Charter, which placed the airplane on its Part 135 certificate. Wyvern Consulting had conducted an audit of Air Castle in April 2004 and suspended the firm from “recommended” status after an accident at Fort Lauderdale Executive Airport in June that year.

In February Wyvern reported that the qualifications of the captain who subsequently flew the Montrose charter did not meet the Wyvern standard as pilot-in-command because of his lack, at that time, of 300 hours current pilot time in the previous year and 75 hours in the previous 90 days. Air Castle did not submit the accident copilot’s qualifications.

Key Air, based at Waterbury-Oxford Airport in Oxford, Conn., was originally chartered for the flight but did not have an airplane available, so it sold the charter to Hop-a-Jet and Air Castle.

The NTSB is still investigating the Montrose accident. The Board posted an interim factual report on its Web site a few days after the document release. It has not yet released a final report.