Tailwind Takeoff, Part 1: Beech 200 Takeoff Excursion
The winds of Unalaska Island and Dutch Harbor, Alaska, are notorious for their strength and changeability, and Unalaska Airport (PADU) has been the site of many wind-related aircraft accidents. One such accident took place there on the morning of Jan. 16, 2020. A medevac Beech King Air 200, registration N547LM, attempted to take off with a tailwind that exceeded what the pilot expected, and it wound up in the frigid waters of Unalaska Bay.
When the NTSB began to examine the facts of the accident, investigators found that in addition to the tailwind takeoff, the airplane was overloaded. Some of the pilots’ statements about the wind and the weight and balance were not consistent with more objective facts that were found.
The FAR Part 135 operator of the flight had a safety management system (SMS) and should have been able to identify the types of shortcuts and mistakes the pilot was making, both on the accident flight and on previous flights. However, the company’s SMS was not up to the task.
The NTSB pointed to the pilot’s decisions and the SMS as causal factors. However, there was one area the investigation did not address. Why did the pilot choose to take off with a tailwind when he could have taxied to the other end of the runway and taken off into the wind? We’ll have a look at one small clue that might have explained why.
On the morning of the accident, the pilot preflighted the airplane in preparation for an 8 o’clock takeoff and found no discrepancies. In the high latitude of Unalaska, it was still dark, and skies remained dark throughout the taxi and takeoff. Sunrise did not occur until 1015 Alaska Standard Time (AKST).
The flight’s destination was Adak, Alaska, located about 387 nm west of Unalaska. After picking up a passenger there, the crew planned to fly to Anchorage. The pilot told investigators he thought there were 450 gal. of jet fuel on board, and that he intended to add fuel after landing at Adak.
There were two medical crewmembers on board—a flight paramedic and a flight nurse. The airplane was configured with a medical bed and associated equipment, as well as a raft, survival gear, some deice fluid, a small ladder and crew bags. The paramedic was seated in an aft-facing seat just behind the pilot, and the nurse was seated in a forward-facing seat in the fourth row.
The pilot told the crewmembers that he intended to make a tailwind takeoff, and that the airplane was capable of handling it.
The airplane was equipped with a cockpit voice recorder (CVR). It recorded engine start at about 0750. Four minutes later, the Dutch Harbor Automated Weather Observation System (AWOS) could be heard. It was “1654 Zulu, winds from 100 deg. at 15 kt. with gusts to 22 kt.; visibility 6 sm with light rain and mist; ceiling of 1,400 ft. overcast; temperature, 4C; dew point, 2C; altimeter, 29.48 in. of mercury.”
After closing doors, turning on lights, and checking with the medical crew, the pilot obtained his IFR clearance from Anchorage Center. He was cleared as filed and cleared to climb and maintain FL260. Just before 0800, he announced on Dutch Harbor traffic frequency that he was taking the active Runway 31 for a southwest departure.
At least two witnesses observed what happened next. An aviation weather observer stationed at the airport saw the airplane go off the end of the runway. She noted that the pilot had not checked the current weather conditions with her. An airport official could see the runway and watched the airplane take off. He saw it get airborne and then descend. He proceeded to the runway end and saw the airplane nose down in the ocean.
In a telephone interview seven days after the accident, the pilot said he believed the wind was 100 deg. at 9 kt. He said the takeoff was normal, with a midfield airspeed crosscheck of 75 kt. He rotated the nose at 90 kt., had a positive rate of climb for a moment, then felt a sinking sensation. The airspeed dropped dramatically, the stall horn came on and he added power. After pitching down to recover from the impending stall, he saw his lights glaring off the water, and he pulled back on the yoke.
The engines were running when they hit the water. The pilot said he cut off the fuel and tried to release his seat belt as water rushed in rapidly. He remembered exiting the airplane after the two medical technicians and entering the inflatable raft. He said a rescue boat arrived within about 30 min.
The pilot also recalled that he was the last pilot to fly the airplane before the accident, having flown it to Unalaska the previous day. He said the airplane had no mechanical malfunctions or problems.
When interviewed, the paramedic in the first row said that during the takeoff he felt it was taking longer than normal to lift off, and when they did, it felt steeper than normal. The nose came back down pretty hard, and the bump shook the airplane. He thought they had driven over something pretty big. He heard the stall warning and then they hit the water.
The raft was located just below the emergency exit. The paramedic remembered that the pilot helped him open the exit, get the raft out, and inflate it, while the other technician retrieved life jackets and handed them forward. He used his cellphone to call his company dispatch and told them they were in the water in a raft. He could see headlights at the end of the runway, and he knew help was on the way.
After being picked up by a rescue boat, the crew was taken ashore and given treatment at a nearby medical clinic. The pilot sustained serious injuries, but the two medical crewmen escaped without injury. The airplane was damaged beyond repair.
The investigation was classified by the NTSB as Class 3, a limited category requiring somewhat greater resources than other limited investigations. Investigators did not visit the accident site and a report on the wreckage was not produced. Staff from the FAA, Aero Air LLC and LifeMed Alaska assisted the NTSB in the investigation.
The CVR was recovered from the airplane and sent to the NTSB’s Vehicle Recorder Division lab in Washington, D.C. When it arrived, it was partially submerged in water. There was some minor water intrusion on the memory chips, but a specialist cleaned them and successfully downloaded the digital audio data. Three of the four channels produced excellent to good quality recordings.
In addition to the accident flight, 20 min. of the previous flight was recorded. It was uneventful. The recorded sounds of the accident flight corresponded closely to what the pilot and crew said in interviews, except for the AWOS. At the end of the recording, the 1,000 Hz tone of the stall warning sounded continuously.
The 41-year-old pilot held an ATP certificate and an instructor rating for both single-engine and multiengine land airplanes. He reported having 6,470 total hours and about 756 hr. in the BE-200. He had flown only 14 hr. in the last 90 days and 6 hr. in the last 30 days. His Class I medical certificate was issued the previous August and had no waivers or limitations.
After attending the flying program at the University of North Dakota in 2009, the pilot had followed the common path of instructing and flying charter and freight in a variety of airplanes. He had spent about two years flying a King Air for a hospital and had served some time as a director of safety for a freight company.
The pilot joined Aero Air in June 2019, about six months before the accident. He had about 630 hr. in the King Air when he started at the company. After initial ground school and flight training with Aero Air, he was assigned to fly the King Air in Alaska. He flew two 15-day on/15-day off rotations in Fairbanks with another company pilot, and was then assigned to the base in Unalaska.
LifeMed Alaska was the public face of the operation. It employed the medical technicians, and its logo and paint scheme were on the aircraft. However, as noted on its website, its aircraft were actually operated by Part 135 entities based in Colorado, Utah and Oregon, as well as in Alaska. The accident airplane was operated by Aero Air of Hillsboro, Oregon.
Aero Air was a diversified company with multiple business areas, including charter, maintenance, firefighting, air ambulance and transplant flight services. It maintained bases at Fairbanks, Anchorage, Dutch Harbor and Kodiak to service the LifeMed business.
Aero Air’s program manager for the LifeMed operation was available to assist pilots with flight planning and go/no-go decisions, but these were pilot responsibilities. Pilots were supposed to accomplish weight and balance and risk assessments for every takeoff. Investigators could not find evidence that either was done on the accident flight.
Aero Air’s director of operations and chief pilot were available to back up the program manager on nights and weekends. Their offices in Oregon were about 1,744 nm from Unalaska as the crow flies, but more like 1,800 nm away following the coastline.
In Part 2, we’ll discuss the NTSB’s investigation and conclusions.