High Or Low? Pilots Disagree On Right Approach, Part 3

The Sierra West Dassault Falcon 20, registered as N283SA, was manufactured in 1967 and last inspected 12 days before the October 2021 crash in Thomson, Georgia. Both engines had recently been removed for maintenance and had only operated for 12 hours before the accident. At its estimated landing weight of 20,280 lb., the appropriate reference speed for landing at Thomson-McDuffie County Airport (HQU) was 113 kts. The minimum field length required was 3,975 ft.

According to the Fan Jet Falcon 20 Aircraft Operating Manual, the speed brakes had two positions—retracted (IN) and extended (EXT). An Airplane Flight Manual (AFM) limitation specified that speed brakes cannot be extended when flaps are deployed on approach, except when anti-ice is in use. In that event, they must be retracted no later than 500 ft. above the ground. The temperature at Thompson at 0530 was 20 deg. C, so icing was not a factor on the approach.

The NTSB performance engineer used ADS-B data from the FAA to plot the jet’s trajectory. Her report showed graphically how the Falcon 20 swung wide left of the localizer, then turned back to intercept it. The airspeed gradually decreased from 168 kts at CEDAR to 137 kts at 400 ft AGL. She calculated the stall speed in the final configuration to be 89 kts at flaps 40, and even with partial flaps and deployed speed brakes, that would not cause the stall warning to sound. Most likely, the warning sounded because the pilots pulled back abruptly on the controls just before collision with the trees.

A performance graphic integrated the captain’s comments with the jet’s final trajectory. In the last two minutes of flight, the captain made eight comments but did not attempt to take control to correct the errant flight path.

The 73-year-old captain lived in Arizona, 447 highway miles from El Paso. His wife said in an interview that he was accustomed to driving that route, and he had done so on Saturday, Sept. 26. He stayed at a company-provided hotel near the El Paso airport. He told her he did not expect to fly on the night of Oct. 4, due to maintenance issues with the jet. He texted her later during the flight, saying the crew was flying through thunderstorms and icing. She said he had a very good relationship with the first officer (FO) and was glad he was assigned to fly with him.

The captain had 11,955 hr. and an ATP certificate with type ratings for the Boeing 737, British Aerospace Jetstream 3100, DC-3, DC-8, and Embraer EMB-110 as well as the DA-20. He also had a glider rating. His last first class medical exam was on Jan. 5, 2021. He had worked for Ameristar Jetcharter before working for Sierra West. He had several training deficiencies in recent years, including check ride failures in 2017, 2019 and 2021. He had trouble with steep turns, circling approaches, and landings.

The FO was 63, had 4,748 hr. and held a commercial certificate with type ratings on the DA-20, Learjet 60, LR-JET series, and Swearingen SA-227. His most recent second-class medical certificate was issued on March 10, 2021. He had trouble with unusual attitudes on a 2019 check ride and was graded “SIC only” on a 2020 check ride. Company officials said he lacked the necessary performance, airmanship, and aeronautical decision making to be promoted to captain.

In an interview, a long-time friend of the first officer said she had talked and texted with him the night of the accident. She said he was accustomed to asking her, “please pray for me,” and he texted this to her while he was in storms during the accident flight.

While the night flight was inherently more fatiguing than a comparable daytime flight, neither pilot said anything about being tired. The flight times and duty day were well within the limitations set by 14 CFR 135.267. That rule requires that each pilot must have had at least 10 consecutive hours of sleep opportunity and less than 14 hr. of on-call duty or 10 hr. of flight time.

Conclusions and Comments
Among the many errors the Falcon 20 crew made during the last 40 minutes of flight, the most egregious was deploying the speed brakes when the gear and flaps were already extended and the power was at idle. This was prohibited by the AFM and created an unrecoverable high drag condition.

The NTSB said as much. The primary probable cause was “the flight crew’s continuation of an unstable dark night visual approach and the captain’s instruction to use air brakes during the approach contrary to jet’s operating limitations, which resulted in a descent below the glide path and a collision with terrain.”

The captain was subject to further criticism. “Contributing to the accident was the captain’s poor crew resource management (CRM) and failure to take over pilot flying responsibilities after the first officer repeatedly demonstrated deficiencies in flying the airplane.” The captain’s refusal to take control and either stabilize the approach or divert to a more manageable airport is inexplicable.

Finally, the NTSB put in a word for safety management systems (SMS). “(Contributing) was the operator’s lack of a safety management system and flight data monitoring program to proactively identify procedural non-compliance and unstable approaches.” The Sierra West director of operations said that an SMS program was under development.

The behavior of this crew brought to mind the guidance in AC120-51E, “Crew Resource Management.” It says “SOPs (standard operating procedures) define the shared mental model upon which good crew performance depends. Too often, well-established SOPs have been unconsciously ignored by pilots and others; in other cases, they have been consciously ignored.” The Sierra West pilots ignored checklists, briefings, callouts, instrument procedures and stabilized approach criteria. To them, SOPs didn’t exist.

The advisory circular also says: “CRM training should instruct crew members how to behave in ways that foster crew effectiveness.” Sierra West Flight 887 might well become one of the best examples of what happens when CRM training doesn’t work.

High Or Low? Pilots Disagree On Right Approach, Part 1: https://aviationweek.com/business-aviation/safety-ops-regulation/high-o…

High Or Low? Pilots Disagree On Right Approach, Part 2: https://aviationweek.com/business-aviation/high-or-low-pilots-disagree-…