Introduction
On October 25, 2011, a King Air A100 crashed on final approach into Eveleth, Minnesota claiming the lives of the pilot and co-pilot as well as all six passengers. The flight was intended to fly U.S. Senator Paul Wellstone and five members of his campaign staff to Eveleth, Minnesota, but unfortunately, the flight was never completed.
Accident History and Relevant Information
There were numerous human factors that contributed to the crash of King Air A100 N41BE, starting with the Captain. A company copilot expressed that three days before the fatal flight, the Captain flew with him in another King Air. After takeoff, the captain attempted to engage the yaw damper switch, but instead activated the autopilot. This caused the plane to dangerously pitch forward, but the copilot was able to deactivate the autopilot and correct the flight path. On the return flight to STP, the copilot noted that the Captain continuously used the wrong call sign for his aircraft until he was corrected by ATC.
The NTSB was not able to determine who was flying the aircraft during the crash because the Captain reportedly often let the First Officer fly during most phases of flight. Aviation Charter’s Multiengine Turbopropeller Maneuvers Guide describes the standards that the pilots must meet. Because the cause of the accident was determined to be a stall, whichever pilot was in control did not meet these standards.
The cloud ceiling at the time of the accident was 700 AGL, and moderate mixed icing was reported from 11,000 to 8,000 feet MSL, as well as light rime icing below 8,000 feet. Multiple pilot reports confirmed icing at various level of flight in the area, and the airport manager verified the ceilings soon after the crash.
Several company pilots also expressed concern for the First Officers ability to land the airplane without assistance. A few pilots commented on his forgetfulness regarding keeping his hand on the throttle at all times during the approach phase of flight.
Analysis
Pilot in Command
In the previous days leading to the accident, the pilot in command (PIC) began making fairly simple skill-based errors. One example was on a flight three days before the incident in another king air, shortly after takeoff the pilot flipped the switch to engage the autopilot but actually activated the yaw damper. Activating the autopilot caused the plane to pitch forward, the copilot was able to disengage the autopilot and correct the flight path. The copilot had to explain to the PIC what he did wrong and the PIC responded with, “Oh, that could have been really bad”. The situation came to be being an issue with negative transfer, but because it wasn’t anything new about the plane there was no reason the PIC would flip the wrong switch.
On the return leg of the previous flight the copilot noted that the PIC was constantly using the wrong call sign. The PIC would identify himself as “Citation 6356K” instead of the correct call sign, which was “King Air 6356K”. After a while of making the same mistake ATC finally corrected the PIC by saying, “You wouldn’t happen to be a King Air today would you?”. After that, the PIC apologized and the flight continued without issue. This again sounds like negative transfer, but because the pilot had already flown a previous leg in the same plane without misidentifying the plane, this was again, another skill-based error.
Even though both of the situations could be passed off as simple mental lapses, there is a high possibility that the root of the cause is deeper. Someone who becomes complacent and relaxed at the controls could make simple mental slips like flipping the wrong switch or using the wrong call sign. Due to the PIC’s recent skill based errors, one could conclude that the PIC committed a skill-based error that could have aided in causing the incident.
Weather
Based on investigation, the pilot asked the Princeton Automated Flight Service Station (AFSS) about any weather disturbance at around 7:16 a.m. on that fateful day, and the specialist told him that there was icing conditions present on the entire route at that time. Despite this condition, the pilot didn’t express any plan of canceling the flight. When asked by the campaign scheduler what he intended to do if icing became a problem, the pilot responded that the carrier had deicing equipment, and that he would turn the airplane towards warmer air to get rid of the ice or divert to DLH if necessary. He also reassured her that he’s an experienced pilot who knew what to do in case of an emergency. Despite the almost freezing condition, the pilot pushed through with the flight. At 10:18 a.m., the radar indicated that the airplane started turning left while maintaining 3,500 feet above, but afterwards, it overshot the targeted approach course and extended its travel for almost 1 mile distance from the course. Soon, it impacted the ground at a distance of 1.8 miles from the targeted runway 27 approach. The wreckage was discovered at an elevation of about 1,361feet.
Although he held a multi-engine airline transport pilot (ATP) certificate, he had received a notice of disapproval from the FAA in April 1989 due to unsatisfactory performance in professional fields like area arrivals, judgment, normal/abnormal procedures, and instrument landing system.
The pilot’s decisional error led to the tragedy of the airplane he was carrying. This is based on the wrong decisions that he had taken in pursuing the flight despite the prevailing bad weather conditions at that time. By choosing to fly into poor weather the pilot increased the safety risks of the flight that ultimately proved to be fatal. Therefore with these facts on hand, there’s no doubt that the pilot has committed decisional errors in flying the chartered plane.
Power Management
The lack of skill based knowledge regarding power management is what was thought by NTSB to have caused this accident. Lack of power management caused the aircraft to reach a critically low airspeed and develop into a stall. When the copilot was descending with instruction from DLH Air Traffic Control, the power management should have been a main priority in holding a standard rate descent. The copilot reached 1800 ft. with a CAS of 76 knots where the error of power management was most crucial. The copilot was known for not keeping his hand on the throttle during approaches causing an error chain to develop before the final accident. The copilot was most likely distracted due to the work load caused by the missed approach and bad weather, which was drawing his attention even more away from a common mistake he already was known to make. The chain of events leading to the low airspeed and poor power management attributed to the inability to detect the stall and use proper power management to recover from it. In turn, if the copilot’s work load was less intensive, and the situation around him was less distracting, power management before the stall would have prevented this accident.
Stall Recovery
Because the Pilot in Command often allowed the First Officer to conduct flights as if they were single pilot operations, the NTSB was not able to determine who was in control of the airplane when it stalled. This aside, whichever pilot was at the flight controls should have identified and correctly recovered from the stall that occurred do to the critically low airspeed. This is a skill based error because each pilot had adequate training. Aviation Charter required all pilots to meet the standards listed in their Multiengine Turbopropeller Maneuvers Guide. This guide requires that pilots be knowledgeable in different factors that affect stall speed, able to immediately initiate recovery at the onset of the stall, and recover within an acceptable altitude. In the accident scenario, neither pilot demonstrated these abilities.
At first this seems like a very obvious mistake to make, but there are several factors to keep in mind before quickly passing judgment. During the final portion of flight, including the phases before and during the approach, the workload on the flight deck was very high. The pilot in control overshot the approach and was dealing with very poor weather conditions, including icing. These distractions most likely contributed to the lack of situational awareness and inability to identify and recover from the fatal stall. Another factor that could pertain to the error was the possibility of the first officer being at the flight controls without much oversight from the captain. The first officer had a small reputation for forgetting to keep a hand on the throttle during approaches to landings, and several pilots expressed concern about the copilots inability to land the aircraft without assistance from the captain. Whichever pilot was flying the aircraft at the time of the stall should have been able to recover the plane. This skill based error occurred at the end of a long line of errors and was the final piece that caused the crash.
Conclusion
The National Transport Safety Board found that there were numerous human factors that contributed to the crash of King Air A100 N41BE, starting with the Captain. A co-pilot had related how they had escaped an accident three days ago with the same pilot. Some pilots also commented also commented on the forgetfulness of the pilot, a factor that could have also contributed to the accidents. The management also contributed to the accident because first officers did not have the experience to fly alone. Investigators determined that the cause of the accident was the failure by the crew to maintain adequate airspeed, which led to an aerodynamic stall from which they did not recover. The main human factors that contributed to the accident included, proficiency of the flight crew, inadequate crew resource management training, Aviation Charter operational issues, surveillance, and the need for awareness on low-airspeed.
