Aviation Accident Summaries

Aviation Accident Summary DEN01FA094

STEAMBOAT SPNGS, CO, USA

Aircraft #1

N948FE

Cessna 208B

Analysis

The pilot obtained a weather briefing, filed an IFR flight plan, and departed on a non-scheduled domestic cargo flight, carrying 270 pounds of freight. The flight proceeded uneventfully until it was established on the VOR/DME-C approach. Radar data indicates that after turning inbound towards the VORTAC from the DME arc, the airplane began its descent from 10,600 feet to the VOR crossing altitude of 9,200 feet. Enlargement of the radar track showed the airplane correcting slightly to the left as it proceeded inbound to the VORTAC at 9,400 feet. Shortly thereafter, aircraft track and altitude deviated 0.75 miles northwest and 9,700 feet, 0.5 miles southeast and 9,600 feet, and 0.5 miles northwest and 9,400 feet before disappearing from radar. Witnesses said the weather at the time of the accident was 600 foot overcast, 1.5 miles visibility in "misting" rain that became "almost slushy on the ground," and a temperature of 36 degrees Fahrenheit. One weather study indicated "an icing potential greater than 50% and visible moisture" in the accident area. Another report said "icing conditions were likely present in the area of the accident." The airplane was equipped and certified for flight into known icing conditions. The wreckage was found in a closely area. There was no evidence of pre-impact airframe, engine, or propeller malfunction/failure. The pilot was properly certificated, but his flight time in aircraft make/model was only 38 hours. He had previously recorded 16 icing encounters, totaling 11.2 hours in actual meteorological conditions. He recorded no ice encounters and only 1.0 hour of simulated (hooded) instrument time in the Cessna 208. Microscopic examination of annunciator light bulbs revealed the GENERATOR OFF light was illuminated. This condition indicates a generator disconnection due to a line surge, tripped circuit breaker, or inadvertent switch operation. The operator's chief pilot agreed, noting that one of the items on the Before Landing Checklist requires the IGNITION SWITCH be placed in the ON position. The START SWITCH is located next to the IGNITION SWITCH. Inadvertently moving the START SWITCH to the ON position would cause the generator to disconnect and the GENERATOR OFF annunciator light to illuminate. He said this would be distracting to the pilot.

Factual Information

HISTORY OF FLIGHT On May 5, 2001, at 0856 mountain daylight time, a Cessna 208B, N948FE, owned by Federal Express Corporation of Memphis, Tennessee, and operated by Corporate Air, Inc., of Billings, Montana, as Airspur Flight 8810 (CPT8810), was destroyed when it collided with mountainous terrain approximately 3 miles south of Steamboat Springs, Colorado. The airline transport pilot, the sole occupant aboard, was fatally injured. Day instrument meteorological conditions prevailed, and an IFR (instrument flight rules) flight plan had been filed for the on-demand cargo flight being operated under Title 14 CFR (Code of Federal Regulations) Part 135. The flight originated in Casper, Wyoming, at 0744, and was en route to Steamboat Springs. According to Federal Aviation Administration (FAA) documents, the pilot telephoned the Casper Automated Flight Service Station (AFSS) at 0433 on the morning of May 5, and requested weather reports for stations in northwestern Colorado. He was given an "abbreviated weather briefing," that included current weather observations for Casper, Rawlins, and Rock Springs, Wyoming, and Hayden, Craig, and Aspen, Colorado; current AIRMETs (Aeronautical Meteorology) that forecast occasional moderate rime and mixed icing in clouds and precipitation from 8,000 to 20,000 feet above mean sea level (msl), mountain obscurement in all quadrants, and occasional moderate turbulence above 18,000 feet; terminal forecasts for Casper, Rock Springs, and Rawlins; and winds aloft forecast for Crazy Woman and Medicine Bow, Wyoming, at 12,000 and 18,000 feet. The briefing was terminated at 0441. According to the load manifest, the 270 pounds cargo aboard Airspur Flight 8810 consisted of "class 2.2 non-flammable" refrigerated gas and "class 1.4 explosive" (blasting caps). At 0736, the pilot contacted Casper ground control and was issued an IFR clearance to Steamboat Springs "via V26 Cherokee (CKW VORTAC, Very High Frequency Omnidirectional Radio Range-Tactical Air Navigation)," and taxi clearance to runway 3. At 0742, the pilot was cleared for takeoff, and at 0744, he contacted Casper departure control. He was issued radar vectors to join V [victor (low altitude) airway] 26 and clearance to climb to 13,000 feet. At 0758, the pilot contacted Denver ARTCC (Air Route Traffic Control Center). All aircraft on that frequency were advised of a hazardous weather AIRMET for areas west of the Mississippi, and were advised to contact Flight Watch or FSS for more information. At 0832, the pilot requested the VOR/DME-C (Very High Frequency Omnidirectional Radio Range/Distance Measuring Equipment) instrument approach to the Steamboat Springs Airport runway 32. The flight was cleared for the approach via the BQZ (Robert VORTAC) 280 degrees radial 9 DME fix. At 0839, the pilot was advised that radar services were terminated and frequency change was approved. The pilot's acknowledgement of the clearance was the last radio contact with the flight. At 0923, after the pilot failed to report being on the ground at Steamboat Springs, Sundance Aviation (BNC) flight 498 was asked to monitor for an ELT (emergency locator transmitter) signal and to attempt contact with Airspur 8810. The Sundance pilot reported receiving no ELT signals and his attempt to contact Airspur 8810 was unsuccessful. FAA issued an ALNOT (Alert Notice) at 1034. According to a statement submitted by another Corporate Air pilot, he was notified at his home approximately 0945 that the airplane was missing. He called corporate headquarters and learned the last radio contact with the flight was when it was 19 miles north of the airport and had been cleared for an instrument approach. He drove to the airport, arriving there approximately 1215, and found that the Routt County Search and Rescue (SAR) had been activated and was preparing to initiate a ground search. He and one of his flight students took off in the latter's Cessna 170 airplane approximately 1245 and begin an aerial search. Approximately 1255, they located the wreckage of N948FE on the side of Emerald Mountain, in a steep drainage, about 0.5 mile south of the Robert VORTAC. The accident occurred during the hours of daylight at a location of 40 degrees, 27.389' north latitude, and 106 degrees, 52.670' west longitude. PERSONNEL INFORMATION The 44-year-old pilot possessed an airline transport pilot certificate with an airplane multiengine land rating, and commercial privileges in airplanes, single-engine land, dated May 29, 1998. His first class airman medical certificate, dated June 5, 2000, contained no restrictions or limitations. His last proficiency check, administered by Corporate Air and dated June 5, 2000, constituted his initial checkout in the Cessna 208. The pilot's most recent logbook (number 4), containing some incomplete entries from March 27, 1995, to May 4, 2001 (the day before the accident), indicated the following (all times approximate): Total time 3,041.1 Pilot-in-command 2,887.5 Second-in-command 35.5 Airplane, single-engine 1,834.1 Airplane, multiengine 1,186.2 Airplane, turboprop 117.9 Cessna 208 37.9 Night 327.0 Actual instruments 206.4 Simulated instruments 96.0 Flight simulator 20.8 Items found amongst the pilot's personal papers were an FAA Pilot Proficiency Award Program Phase VII card, and a U.S. Department of Agriculture/Department of Interior Airplane Pilot Qualification card, endorsed for multiengine airplane with copilot, and single pilot with autopilot, and special mission endorsements for the Cessna 310, 340, 402, and 421 airplanes. The latter was issued by Lynch Flying Service, Billings, Montana, when the pilot was employed there. According to the logbook, between 1999 and 2001, the pilot logged 16 icing encounters that totaled 11.2 hours in actual instrument meteorological conditions, to wit: 04/29/99 Cessna 402C, N5774C HLN/HLN 0.2 "Flight cancelled. Icing during climb. Unable to get 80(00). Returned to Helena." 05/12/99 Cessna 402C, N6839Y HLN/BIL 0.5 "Booted three times." 06/30/99 Cessna 402C, N5774C HLN/BIL 0.7 "11-13 degrees, +RA (heavy rain), moderate IC (icing) [up to] 15,000 ft. Heavy IMC. 10/02/99 Cessna 402B, N69316 BIL/COD/BIL 1.2 "IMC, 1,000 ft. overcast, 1/2 sm, 1 in. ice accumulation." 01/11/00 Cessna 402C, N5774C COD/WRL 0.2 "Moderate ice at 9,300 ft." 01/27/00 Cessna 402C, N5774C COD/BIL 0.3 "Clear ice @ Pyror int." 3/28/00 Cessna 402C, N5774C COD/BIL 0.4 "IMC@POY, tra(ce) ic(e)." 09/19/00 Cessna 340A, N2703U M46/BIL 0.5 "Ic(e) at 8(000 ft.)" 09/21/00 Cessna 414A, N9187S BIL/WRL 0.9 "Moderate ice." 10/04/00 Cessna 402B, N69316 GTF/BIL 1.5 "2 in. (accumulation) ice." 10/11/00 Cessna 414A, N9781S BIL/GTF 0.7 "5 layers 16(00) [down to] 12(00) ov(er)c(ast), moderate ic(e)." 11/11/00 Cessna 340A, N2703U S59/MSO 0.9 "3/8-in. ice." 12/04/00 Beech 100A, N9002N BTM/BIL 0.8 "Ice 3/4-1.0 in. A/S (airspeed) 140 (knots). Boot 5-6 times." 01/05/01 Cessna 414A, N5690C BIL/FCA 1.3 "Heavy ice." 01/15/01 Beech C90, N552R G2V/BIL 0.4 "Lt. rime (ice during) climb, tops 8,000 ft." 02/09/01 Cessna 414A, N5690C BIL/SDY 0.7 "Rime to clear ice." Between March 28 to May 4, 2001, when the pilot was flying the Cessna 208 exclusively, he recorded no ice encounters and only 1.0 hour of simulated (hooded) instrument time. AIRCRAFT INFORMATION N948FE, a Cessna 208B (s/n 208B0052), was manufactured by the Cessna Aircraft Company in 1987. It was equipped with a Pratt & Whitney PT6A-114A engine (s/n 17079), rated at 675 shaft horsepower, and a Hartzell 3-blade composite, constant-speed, full feathering and reversible hydraulically actuated propeller (m/n HC-B3MN-3). According to the accident report submitted by Corporate Air, the airplane was maintained under an approved inspection program (AAIP). The airframe was last inspected on December 29, 2000. As of the date of the accident, the airframe had accrued 8,690.6 hours and 196.4 hours since the last inspection, and the engine had accumulated 9,557.0 hours since new, 5,895 hours since major overhaul, and 187 hours since last inspection. An entry in the "Aircraft Flight Records" made prior to the accident flight indicated the airframe had accrued 8,887.0 total hours and 8,527 total landings. According to the Federal Aviation Administration, the Cessna 208 is certified for flight into known icing conditions when properly equipped. N948FE was equipped with leading edge deicing boots on the wings and on the horizontal and vertical stabilizers, and windshield anti-ice. A deice system had been installed on the external cargo pod and landing gear fairings on January 12, 1993. METEOROLOGICAL INFORMATION According to ground witnesses, Steamboat Springs' weather at the time of the accident was 600 foot overcast skies, 1.5 miles visibility in misting rain and a temperature of 36 degrees Fahrenheit. A Superior Aviation pilot landed a Swearingen Metroliner at Yampa Valley Airport, Hayden, Colorado (located approximately 21 miles west of Steamboat Springs). He was in the vicinity of the accident site approximately 0815. He reported picking up a "dusting" of ice on departure from Denver, but did not accumulate any ice on approach to Hayden, nor did he hear of any reports of icing conditions in the area. He and his copilot had heard the radio communications from the pilot of Airspur 8810, and were "puzzled" why he requested the VOR/DME-C approach because the Hayden AWOS (automated weather observation station) was reporting "a ceiling (800 feet) lower than the MDA (minimum descent altitude, 1,262 feet). The pilot of BNC 498 was also in the vicinity shortly after the accident. He said he did not encounter any ice during his approach to Hayden. He described the weather conditions as a 2,000 to 3,000-foot thick overcast layer of clouds and improving. Ground witnesses and SAR personnel said that weather conditions at the time of the accident were "poor." The overcast ceiling was approximately 500 to 600 feet, temperature was approximately 40 degrees F., and visibility was 1-1/2 miles in "misting" or light rain that became "almost slushy on the ground." NTSB's Operational Factors Division in Washington, DC, conducted a weather study. According to the meteorologist's factual report, there was "an icing potential greater than 50% and visible moisture" in the Steamboat Springs area. WeatherData, Inc., of Wichita, Kansas, conducted another weather study at the request of the Cessna Aircraft Company. According to WeatherData's report, "Icing conditions were likely present in the area of the accident." AIDS TO NAVIGATION There were no reported difficulties with the various navigational radio aids. COMMUNICATIONS There were no reported difficulties with radio communications. AERODROME INFORMATION Steamboat Springs/Bob Adams Field (SBS) is located 3 miles northwest of the city at an elevation of 6,878 feet msl. It is served by one runway, 14-32, that is 4,452 feet long and 100 feet wide. The runway is made of grooved asphalt with a porous friction coarse overlay. Runway lighting is pilot-controlled with low, medium, and high intensity settings. In addition to the VOR/DME-C approach, there are published GPS (Global Positioning System) and RNAV (Area Navigation) instrument approaches available. FLIGHT RECORDERS The airplane was not equipped with a cockpit voice recorder or flight data recorder. It was, however, equipped with a PAR (power analyzer and recorder) computer that records and stores engine operating parameters. The computer was sent to NTSB's vehicle performance laboratory in Washington, DC, for download and readout. The EPROM (erasable programmable read only memory) data retrieved indicated that power was applied to the unit at 0737:02 and removed at 0858:39 on the morning of the accident. At the time of the power loss, the PAR computer recorded normal power parameters and an outside air temperature of +1 degree Celsius. No exceedences were recorded and engine parameters were normal throughout the flight. WRECKAGE AND IMPACT INFORMATION The airplane struck the ground on a magnetic heading of 145 degrees, almost 180 degrees opposite the inbound course to the Robert VORTAC. The angle of terrain impact was approximately 40 degrees as measured by the severed treetops. The elevation at the accident site was 7,864 feet. There was no evidence of an in-flight or post-impact fire. SAR personnel reported "a strong odor of jet fuel" when they arrived on-scene. No airframe ice was noted on-scene. The fuselage sidewalls had been breached and had collapsed. The cargo had shifted to the forward portion of the cabin. A portion of the external cargo pod was located 25 feet downhill from the point of impact. The right wing was separated from the fuselage and located 20 feet south of the main wreckage. The outermost wing panel had also separated from the right wing. The leading edge bore numerous indentations similar to tree strikes. The left wing remained attached to the fuselage but was similarly damaged. Both wing fuel tanks had been compromised. Preimpact position of the fuel selector was inconclusive. The vertical and horizontal tail remained attached to the fuselage. The flap actuator jackscrew was extended 3.25 inches, which, according to the Cessna Aircraft Company, indicated the flaps were extended 10 degrees. According to Corporate Air's chief pilot, company policy requires conducting a zero flap approach if there is any indication of an accumulation of airframe ice. The elevator trim actuator was extended 1.75 inches, which equates to 5 degrees tab up (nose down). Aileron trim measurement was unreliable due to impact damage. Control cable continuity was established to the elevators and rudder from the aft cabin area. Only partial control cable continuity could be established to the ailerons. Wing control cable separations were consistent with tensile overload. The engine remained attached to the fuselage, but the propeller assembly had separated from the engine and one blade had separated from the hub. All of the blades were embedded in the ground about 5 feet from the main wreckage. The pilot's seat was destroyed, but there was evidence to indicate that he had been wearing the 5-point restraint system. Most of the instruments, switches, and controls were destroyed. The pilot's altimeter indicated 9,450 feet and was set to 29.93 inches. The copilot's altimeter indicated 7,800 feet and was set to 29.92 inches. The radar altimeter indicated 120 feet and the bug, which was displaced, was set to 70 feet. The copilot's directional gyro indicated 145 degrees, and the vertical speed registered 2,000 fpm down. The cabin heater was off. Switches controlling the surface, windshield, and propeller deicing were either destroyed, or their positions were inconclusive and unreliable. The power, fuel condition, and propeller levers were in the idle, mid-range, and full forward positions, respectively. MEDICAL AND PATHOLOGICAL INFORMATION On May 8, 2001, an autopsy was performed at the Jefferson County Coroner's Office, Golden, Colorado. The coroner's office and FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma also did toxicological screening. Both toxicological reports (CAMI #200100110001) indicated negative findings for carbon monoxide, hydrogen cyanide, and ethyl alcohol. However, 155.814 (ug/ml, ug/g) Salicylate was detected in blood. According to the toxicologist, Salicylate is found in analgesics and painkilling medications that are derivatives of salicylic acid. The best-known use of Salicylate is in the form of acetylsalicylic acid, or aspirin. TESTS AND RESEARCH Recorded National Track Analysis Program (NTAP) radar data was retrieved from the Denver ARTCC and plotted by Frank M. McDermott, Ltd., of Great Falls, Virginia. According to the data, the track of CPT8810 began at 0744:26, when it was north of Casper at 7,000 feet. It joined V26, climbed to 13,000 feet, and crossed the Cherokee VORTAC at 0817:07. It crossed the Dixon, Wyoming, Airport (9U4), passed just north of Hayden, Colorado, and descended to 10,700 feet as it joined the 9 DME arc (10,600 feet minimum arc altitude). At 0951:38, the target turn

Probable Cause and Findings

an inadvertent stall during an instrument approach, which resulted in a loss of control. Contributing factors were the pilot's attention being diverted by an abnormal indication, conditions conducive to airframe icing, and the pilot's lack of total experience in the type of operation (icing conditions) in aircraft make/model.

 

Source: NTSB Aviation Accident Database

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