ANC02LA002

The captain and first officer were conducting a localizer DME back course approach to runway 36 in a twin-engine turboprop airplane during a night cargo flight under IFR conditions. The minimum visibility for the approach was one mile, and the minimum descent altitude (MDA) was 460 feet msl (338 feet agl). Prior to leaving their cruise altitude, the first officer listened to the ATIS information which included an altimeter setting of 29.30 inHg. No other altimeter information was received until the crew reported they were inbound on the approach. At that time, tower personnel told the crew that the visibility was one mile in light snow, the wind was from 040 degrees at 22 knots, and the altimeter setting was 29.22 inHg. The crew did not reset the airplane altimeters from 29.30 to 29.22. At the final approach fix (5 miles from the runway), the captain began a descent to the MDA. Thirty-six seconds before impact, the first officer cautioned the captain about the airplane's high airspeed. Due to strong crosswinds, the captain disconnected the autopilot 22 seconds before impact. He said he pushed the altitude hold feature on the flight director at the MDA. Eighteen seconds before impact, the airplane leveled off about 471 feet indicated altitude, but then descended again 9 seconds later. The descent continued until the airplane collided with the ground, 3.5 miles from the runway. The crew said that neither the airport, or the snow-covered terrain, was observed before impact. The crew reported that the landing lights were off. The airplane was not equipped with a ground proximity warning system.

History of flight

On October 16, 2001, at 2129 Alaska daylight time, an Embraer 120ER airplane, N120AX, sustained substantial damage after colliding with terrain during an approach to land, about 3.5 miles south of the Bethel Airport, Bethel, Alaska. The airplane was being operated as an instrument flight rules (IFR) nonscheduled domestic cargo flight under Title 14, CFR Part 135, when the accident occurred. The airplane was operated as Flight 24, by Alaska Central Express Inc., Anchorage, Alaska. The captain and first officer received minor injuries. Dark night instrument meteorological conditions prevailed, and an IFR flight plan was filed from Anchorage to Bethel. The flight originated at the Ted Stevens Anchorage International Airport, Anchorage, at 1949.

The director of operations for the operator reported the captain was conducting his third trip of the day to Bethel. The accident flight was the first officer's second flight of the day to Bethel. The first two flights to Bethel landed in visual flight rules (VFR) conditions.

The following narrative is derived from crew statements, information recorded on the airplane's cockpit voice recorder (CVR), air traffic control communications, and data recorded on the airplane's solid state flight data recorder (SSFDR).

After departure from Anchorage on the accident flight, the crew proceeded toward Bethel. The captain reported that he initially planned a VFR arrival, but as the flight neared King Salmon, Alaska, the weather conditions became IFR. Prior to leaving their cruise altitude, the first officer listened to the recorded automatic terminal information service (ATIS) broadcast at 2104, recorded by the Bethel air traffic control tower (ATCT) controller. ATIS information "Charlie," recorded at 2053, stated: "Bethel tower information 'charlie', 0353 Zulu. Wind, 040 at 20, gust 28. Visibility 10. Ceiling 9,000 overcast. Temperature minus 4. Dew point minus 8. Altimeter 29.30. Visual approach runway 36 in use. Notice to airman, runway 18 locator middle marker out of service. Runway 36 localizer back course unusable seven-tenths DME inbound. Advise on initial contact you have information Charlie."

At 2111, the crew set 29.30 on the airplane altimeters. They were cleared by Anchorage Air Route Traffic Control Center (ARTCC) to descend and maintain 3,000 feet, and to report Bethel Airport in sight. The crew responded by reporting the airport was in sight. Anchorage ARTCC then reported that the visibility at the airport was rapidly dropping, and the crew could expect the localizer approach. At that point, the crew said they were about 28 miles northeast of the Bethel VOR.

At 2114, the captain briefed the first officer on the anticipated localizer approach. He included information about the airport NOTAM by stating: "...this is what cracks me up. Missed approach is .5 DME, but the DME's unusable with the .7 inbound." The first officer responded by stating: "...see we gotta do it at .7.... legally." The captain replied: "...legally. Jee, like that's gonna happen."

At 2116, about 12 miles northeast of the Bethel VOR, the crew was cleared to contact the Bethel ATCT. The crew was subsequently cleared for the localizer DME back course approach to runway 36. The first officer reported that as the airplane crossed over the Bethel VOR, outbound, he again checked the Bethel ATIS, but the recording was silent. The first officer said he thought the ATIS was being updated. According to the FAA, the ATIS information was turned off at 2113 to update the information, but the weather conditions were changing rapidly. An updated ATIS information "Delta" was not recorded before the accident.

At 2119, the first officer told the captain that the airplane altitude was captured at 3,000 feet (msl), and then proceeded to set 2,500 feet (msl) in the altitude alerter window. At 2120 the altitude annunciator of "Altitude Alert" is heard on the CVR. The crew identified the localizer heading and altitude requirements for the approach, confirming at 2123, that at NAPAC intersection, the airplane could descend to 1,800 feet (msl). At 2123, the "Altitude Alert" annunciator sounded. Also at 2123, the first officer commented to the captain: "It's the first time I've shot a back course in this. Pretty cool."

At 2124, the crew reported to the Bethel tower that they completed the procedure turn and were inbound on the localizer. The Bethel tower controller acknowledged by stating: "Ace Air 24, report NAPAC, and uh, visibility has dropped down to about a mile, with uh, light snow and the ceiling 1,200 broken. Altimeter 29.22. Wind 040 at 22." The crew responded to the radio transmission by stating: "24 thanks a lot. We'll call you NAPAC inbound."

At 2125, the captain told the first officer he was at 1,800 feet (msl) and requested what was next (on the approach). The first officer replied at 2126: "460 (feet msl) at NAPAC." The captain said, "Okay, I'll put 400 in here."

At 2128, the crew configured the airplane for landing by putting the landing gear down, and positioning the flaps to 25 degrees. The crew then reported to the Bethel tower they were at NAPAC. The tower controller replied, "Ace Air 24, not in sight, runway 36, cleared to land." The first officer told the captain, "good to 460 (feet msl)." At NAPAC intersection, with the airplane at 1,800 feet msl, the captain said he began a 1,000 fpm descent for the minimum descent altitude of 460 feet msl.

About 2128:58, recorded data from the SSFDR indicated the airplane pitched nosed down about 5.5 degrees, and the airplane began descending.

At 2129:19, the first officer cautioned the captain by stating: "careful on the speeds. We got flaps 25." About 2129:27, SSFDR data indicated the airplane was 8.3 degrees nose down, and the airspeed reached 172.4 knots, (the operator reported that the maximum airspeed at 25 degrees of flaps is 150 knots).

The captain reported that during the approach, strong wind conditions kept pushing the airplane left of the localizer centerline. The autopilot was engaged during the approach, but due to the strong winds, the autopilot was having difficulty maintaining the centerline. About 700 to 800 feet msl, the captain said he disconnected the autopilot and hand-flew the airplane.

At 2129:26, the "Altitude Alert" annunciator sounded, and at 2129:33, the sound of three chimes (similar to the autopilot disconnect signal) was heard on the CVR, followed at 2129:35 by an audio annunciator of "autopilot."

The captain said that upon reaching 460 feet (msl), he pushed altitude hold on the flight director, and noticed the airplane was slightly left of the localizer centerline.

Recorded data on the SSFDR indicated the airplane began to level off about 2129:36, about 471 feet msl (indicated altitude with an altimeter setting of 29.30 inHg). About 2129:45, SSFDR data indicated the airplane began another descent that continued until the data ended.

Sounds of impact were heard at 2129:54, and the CVR recording ended at 2129:56. The crew reported that neither the airport, or the snow-covered terrain, were observed before impact. The crew reported that the landing lights were off.

The airplane collided with the ground on the 186 degree radial of the Bethel VOR, 3.5 miles from the threshold of runway 36. The crew said that after ground contact, an orange flash was seen in the right engine. The airplane's engine fire extinguishers were pulled by the crew. The airplane sustained damage to the fuselage, wings, and engines. After the collision, the first officer reported seeing 390 feet (msl) displayed on his altimeter.

Aircraft information

Although not required for cargo operations, the airplane was equipped with a cockpit voice recorder and a solid state flight data recorder. The recorder equipment was not removed when the airplane was converted from com