Monday, September 8, 2003
NTSB Explores Second Fatal Crash of Beechcraft 1900D This Year
Similarities Examined Between Colgan Air and Air Midwest Crashes
Investigators probing the fatal crash of a Colgan Air Beechcraft 1900D Aug. 26 in the waters off Hyannis, Mass., are exploring possible ties to a similar incident, the fatal crash of an Air Midwest Beechcraft 1900D in Charlotte, N.C., in January.
Both planes had trouble shortly after takeoff, and both had maintenance performed on the tail sections days before the crashes.
"It's very early to start drawing conclusions, but some of the investigators we sent up to Hyannis are knowledgeable about the Charlotte accident, and so they are certainly alert to anything that relates to both of them," Paul Schlamm of the National Transportation Safety Board (NTSB) told CRAN. "But they have not drawn any conclusions yet."
Investigators have not uncovered any fleet-wide problems as a result of the accidents, Schlamm said, and a federal order to inspect and possibly repair the entire fleet of Beechcraft 1900Ds is not anticipated. But a Federal Aviation Administration official who has the authority to issue such an order was among the authorities inspecting the wreckage and records at Barnstable Municipal Airport.
Within five seconds after liftoff from Barnstable, the pilot and co-pilot of Colgan Air flight 9446 reported troubles controlling the pitch of the aircraft. Pilot Scott Knabe radioed he was having a problem with a "runaway trim" and was cleared to return to the airport for an emergency landing.
After being airborne for about two minutes, the aircraft plunged nose-first into Nantucket Sound. NTSB investigators said the flight data and cockpit voice recorders (FDR/CVR) indicated the crew lost control in the last 10 seconds of the flight, as the aircraft fell steeply and accelerated.
The FDR/CVR revealed that as the pilots were attempting to return to the airport, the plane nosed down at a 30-degree angle and reached an air speed of 285 miles per hour before crashing into the water, Schlamm said. Nearly 90 percent of the aircraft has been recovered.
The aircraft was headed to Albany, N.Y., on a repositioning flight, where it was to pick up passengers. Knabe and First Officer Steven Dean were the only ones on board and were killed.
The plane's two elevator trim actuators and its forward elevator trim cable were replaced the night before the crash and investigators were focusing on the tail section of plane. The elevator controls the pitch of the aircraft while trim tabs maintain the plane's equilibrium.
Schlamm told CRAN that investigators brought a portion of the elevator trim system to the NTSB's laboratory in Washington for examination. "They will be doing that over the coming weeks," he said. "Aside from that, they'll continue to go over maintenance records and other data they've collected."
The remainder of the aircraft has been turned over to Colgan Air's insurance company, he added, and the NTSB has completed its on-site investigation.
Investigators said the pilot was not specific about the control issue -- whether he could ascend or decend -- adding that they would not concentrate solely on the trim mechanism. Investigators will also look at the weather, the weight of the plane, the engine and electrical system performance.
Mary Colgan Finnigan, a vice president at Colgan Air, said the company was devastated by the accident, the first fatal crash in the company's 32-year history. The family-run operation, which operates as a US Airways Express code-share partner, prides itself on its close-knit relationship with its employees. Colgan Air employs 550 people, including more than 200 pilots.
Finnigan confirmed that Colgan Air maintenance personnel worked on the trim mechanism of the crash aircraft at Colgan's Hyannis repair facility the night before the fatal flight. Colgan Air's founder and chairman, Charles Colgan, told CRAN in June that the airline started doing all of its own heavy maintenance in a cost-cutting move. "We used to farm all that out before," he said (CRAN, June 9). Colgan and his family this year won CRAN's Airline Executive of the Year award.
Schlamm said federal investigators interviewed four Colgan mechanics and their interviews will be publicized as the investigation proceeds. In about a week, the NTSB will publish on its Web site a preliminary report that contains very basic information about the accident. In about six months, NTSB will issue a detailed report setting out all the factual information it has gathered in the investigation. At this time, NTSB also will open a public docket, making for public inspection supporting documentation, transcripts of interviews, readouts of the flight data recorder, and a transcript of the voice recorder, he said. Shortly thereafter, NTSB will issue a final report with a determination of cause.
If during the course of the investigation the FAA determines an airworthiness directive must be issued, it can do so at any time. It does not require a directive from or concurrence by the NTSB, Schlamm said.
Two of the four investigators who are working on the Colgan Air accident investigation also worked on the crash of the Air Midwest Beechcraft 1900D in Charlotte, N.C., in January. In that case, a Beechcraft 1900D operated by Air Midwest under the US Airways Express banner crashed into a hanger shortly after takeoff from Charlotte-Douglas International Airport, killing all 21 people aboard (CRAN, June 30, and June 2). In a preliminary report after that crash, the NTSB found that an incorrect cable adjustment hindered the pilots from controlling the pitch of the aircraft.
The crash spurred the FAA to issue an emergency airworthiness directive on elevator rigging and to order operators of aircraft carrying up to 19 passengers to validate passenger and baggage weights. Maintenance work had been performed on the airplane's elevator control system two days before the crash.
"Examination of the elevator control cables revealed that the turnbuckle on the 'down' elevator cable was offset to nearly full extension and the turnbuckle on the 'up' elevator cable was near the fully retracted position, a difference of 1.8 inches," according to NTSB's report on the accident. "The turnbuckles are used to set cable tension and are typically adjusted to about the same length."
Unconfirmed reports indicated that the contract technician who performed the work was doing so for the first time on this particular model of airplane. The crash occurred on the ninth flight two days later. The preliminary evidence suggested that the cables might have been adjusted such that there was tension in the "take up" direction (i.e., back- stick or rearward movement of the control column), but possibly a lack of tension in the "stick forward" direction. For reasons of passenger comfort, pilots achieve descent attitudes airborne by reducing power (the nose drops naturally) and nose-down trimming; full stick forward is only checked on the ground (i.e., not under air loads).
In the case of this particular aircraft, the rigging was such that the pitch control position sensor showed a 10� nose-down shift. In other words, a yoke or stick forward control input would have hit the stops sooner. This likely would not have been noticed during the flights between the maintenance action and the accident when the airplane was more lightly loaded.
Because the Air Midwest aircraft was heavily laden during the accident flight, the pilot likely would have needed full back column for rotation. It is possible that at full up elevator deflection a cable may have come off a pulley and jammed, leaving the elevator itself in the near full nose-up position.
At a press conference NTSB member John Goglia expressed his "personal opinion" that the yoke likely was "stuck" at the near full back position on rotation.
A pulley-jumped cable-jam would have caused the yoke to seize in the rearward position and the aircraft would continue to pitch up, which it did to the point of stall at about 52� above the horizontal.
The FAA issued an emergency airworthiness directive Jan. 27 requiring Beech 1900, 1900C and 1900D operators to conduct control column sweeps and other rigging checks by Jan. 31 (AD No. 2003-03-18): "If maintenance procedures are not properly followed ... it may appear to the crew that they have full elevator control column movement," the AD said. It went on to caution, "However, the elevator may not have full travel. Such restricted travel may remain undetected until the airplane is operated in a loading condition that requires full elevator authority to control the pitch."
Regarding the weight issue, preliminary accounts indicate that the airplane was within 100 pounds of its 17,000- lb. maximum takeoff weight and within 1 percent of its rearward center of gravity. However, the weight is based on FAA average weights applied to passengers and baggage. (Cont. on next page)
On the same day the emergency AD was issued, the FAA ordered operators to conduct spot checks for purposes of validating average passenger and bag weights used in determining payload weight in 10-19 seat passenger aircraft.
With no passengers on board, weight was likely not a factor in the Colgan Air crash. With NTSB investigators studying a portion of the aircraft's trim mechanism at its headquarters laboratory in Washington, preliminary indications are that they believe a maintenance error occurred.
Following the Charlotte crash, the FAA ordered all Beechcraft 1900 owners to implement new maintenance procedures when working on the elevators.
The Jan. 27 airworthiness directive also mandated that two mechanics must work on the elevators each time repairs are made to the parts. When working on trim mechanisms, one maintenance worker must sit in the cockpit and operate the controls to make sure the elevators work properly. Another must look at the tail of the aircraft to see how far the elevators move up and down
Updated maintenance manuals containing the new maintenance procedures were distributed to all owners of Beechcrafts this past spring, said Tim Travis of Raytheon Aircraft, the company that builds the Beech 1900s.
The Colgan maintenance crew in Hyannis had the updated manual, NTSB investigators said, but they were not sure if the crew followed this directive. The maintenance manual on the Beech 1900Ds states that inspections should occur on the elevator trim actuators and the forward elevator trim cable every 1,200 hours of flying time, Travis said.
The aircraft involved in Colgan Air crash was built in 1993 and was acquired by Colgan from Raytheon Aircraft in January, according to US Airways. The plane had been flown a total of 16,503 hours, 1,219 of them by Colgan.
Travis said the Beech 1900 has a proven record since it was first introduced in 1982.
"Through the millions of flight hours around the world that this aircraft has flown, the 1900 is a proven and reliable aircraft," Travis told CRAN. "Third party groups would tell you the same thing."
In all, Raytheon built 696 C and D versions of the 1900. The main difference between the two is that the D model features a taller cabin to allow passengers to stand up fully. Raytheon built 439 1900Ds starting in 1991, and 257 1900Cs from 1982 to 1991.
Raytheon stopped producing the Beechcraft 1900D last year and the number in operation has recently declined. In 1999, there were 230 1900D airplanes in operation while last year there were 154, according to Regional Airline Association figures.
If the FAA does issue an airworthiness directive or announce new maintenance requirements for the Beech 1900 model, several domestic U.S. regional airlines would be impacted, Air Midwest in particular, which operates 42 Beech 1900s. Please see table below.
>>Contact: Paul Schlamm, NTSB, 202-314-6100; Tim Travis, Raytheon, 316-676-8674.<<
Allocation of Beechcraft 1900s by Carrier (as of Dec. 31, 2002)
|Arizona Express Airlines||
|Eagle Canyon Airlines||
|Frontier Flying Service||
|Great Lakes Aviation||
|Gulfstream International Airlines||
|Hageland Aviation Services||
|Total Beechcraft 1900s in service||
|Source: AvStat Associates via the Regional Airline Association|
10677 Aviation Lane
- Chairman - Charles Colgan
- President - Michael Colgan
- VP- Finance - Patti Barth-Carlo
- VP-Maintenance - David Fitzpatrick
- VP-Admin. - Mary Colgan Finnigan
- VP-Operations - Donnie Nunn
Fleet: 16 Beech 1900s, 7 Saab 340Bs
- RPMs (000) - 95,383
- ASMs (000) - 221,491
- Passengers Carried - 449,485
Colgan Air Pilots Were Experienced
Colgan Air issued the following statement after the crash of a Beechcraft 1900D shortly after takeoff from Hyannis, Mass. The accident killed Capt. Scott Knabe of Cincinnati, Ohio, and First Officer Steven Dean of Euless, Texas. There were no passengers aboard the aircraft.
"We at Colgan are devastated and saddened by the loss of Scott and Steve, two well-respected and well-liked crewmembers. On behalf of everyone at our company, I wish to express our deepest personal sympathy to their families and friends. All are in our prayers," said Colgan President Mike Colgan. "We do not know why this accident occurred, nor will we speculate about the cause, which is under investigation by the National Transportation Safety Board. Colgan is cooperating fully with the NTSB."
Knabe, 39, was hired as a first officer at Colgan in 2001 and upgraded to captain in January. He was based at Hyannis and had 2,886 hours of flying time, 1,358 of them in the Beech 1900. He earned an accounting degree from Ohio State, held an airframe and power plant license and performed aerial surveys before joining Colgan.
Dean, 38, was hired by Colgan in 2002 and also was based in Hyannis. He had 2,500 total hours of flying time with 682 in the Beech 1900. Before joining Colgan he was a flight instructor on single-engine aircraft, a pilot for a Dallas company and a flight simulator instructor.
The crash aircraft, tail number N240CJ, was on a repositioning flight from Hyannis to Albany, N.Y.
It was manufactured in 1993 and acquired by Colgan in January from Raytheon Aircraft, the manufacturer. The aircraft has logged 16,503 hours, 1,219 of them by Colgan.
The Beech 1900D was first certified for service by the Federal Aviation Administration in 1991. Raytheon Aircraft reports that 439 units have been built and that the aircraft model has over 1 million flight hours in service around the world.
Colgan Air is based in Manassas, Va., and has been in the airline business for 27 years (CRAN, June 9).
Source: Colgan Air