Country

Crash of a Mitsubishi MU-2B-60 in Wawa

Date & Time: Nov 27, 2023 at 0739 LT
Type of aircraft:
Operator:
Registration:
C-GYUA
Flight Type:
Survivors:
Yes
Schedule:
Thunder Bay – Wawa – Sault Sainte Marie
MSN:
1553
YOM:
1982
Flight number:
THU890
Location:
Country:
Crew on board:
2
Crew fatalities:
Pax on board:
1
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
2058
Captain / Total hours on type:
184.00
Copilot / Total flying hours:
1984
Copilot / Total hours on type:
44
Circumstances:
The crew was preparing for instrument flight rules (IFR) flight THU890 from Thunder Bay Airport (CYQT), Ontario, to Sault Ste. Marie Airport (CYAM), Ontario. The flight included a stop at Wawa Aerodrome (CYXZ), Ontario, to pick up a patient for a medical transfer to CYAM. As part of the pre-flight preparations, one of the flight crew members contacted CYXZ at 0549 to check the runway conditions and spoke with an aerodrome employee who was on duty for after-hour inquiries. During the call, the flight crew member learned of ongoing light snowfall and understood that the runway would be plowed by about 0730. At approximately 0653, during the hours of darkness, the aircraft departed CYQT for CYXZ with 2 flight crew members and a paramedic on board. The cruise portion of the flight was uneventful. The flight crew maintained radio contact with air traffic control (ATC) and received clearance for the approach to CYXZ. At about 0726, ATC instructed the flight crew to switch to the Wawa aerodrome traffic frequency (ATF). Between 0715 and 0730, aerodrome staff, including the employee to whom the flight crew member had spoken and a trainee, arrived at CYXZ. An ambulance carrying the patient who would be transferred also arrived at the aerodrome in that time. It had snowed overnight, and aerodrome staff were aware of the potential arrival of flight THU890, but had not yet plowed the runway. The staff began their morning duties, which included preparing the snow removal vehicles to clear the runway. There was no radio communication between aerodrome staff and the occurrence flight crew. The approach to CYXZ occurred during civil twilight,Footnote3 before sunrise. The flight crew activated the runway lights using the aircraft radio control of aerodrome lighting system and performed the RNAV (GNSS) [area navigation (global navigation satellite system)] approach to Runway 03. They visually spotted the runway when they were about 10 nautical miles away on final approach. As the aircraft approached the runway, the flight crew had a clear view of the runway lights and saw that the runway was covered in snow. The aircraft touched down on Runway 03 at 0739, and shortly after, it suddenly began sliding to the right. The flight crew attempted to correct this using rudder pedals, as well as differential propeller and power control, but were unsuccessful. The aircraft rotated almost 180° before sliding off the runway’s right side. The aircraft continued sliding sideways off the runway while facing the opposite direction of landing and came to rest on its left side in a drainage ditch, about 78 feet from the runway’s edge. The aircraft was extensively damaged; the right engine propeller blades penetrated the cabin before the engines were shut down. After the engines were shut down, the occupants began evacuating. The right emergency exit was damaged and would not open, so they egressed through the aircraft’s main door, which was located at the rear, on left side of the aircraft. A significant fuel leak was noted. The occupants walked the short distance to the runway, where the snow was between 6 to 8 inches deep on the runway surface. The flight crew called 911 and the London Flight Information Centre (FIC) to report the accident. The aerodrome staff observed the aircraft land and slide off the runway. They drove the snow removal vehicle down the runway, plowing snow along the way. They stopped to check on the occupants and then continued down the remaining runway length before turning around at the end and continuing to plow snow back toward the terminal building. Another vehicle transported the aircraft occupants to the terminal building, where they were assessed by emergency medical services and then transported to the local hospital for examination. There were only minor injuries.
Probable cause:
The investigation was unable to determine the aircraft’s exact touchdown point because the runway was plowed immediately after the occurrence. However, based on the available data, it was estimated that the aircraft touched down between 1000 feet and 1400 feet beyond the runway threshold, and began to slide to the right shorty after. The aircraft continued sliding to the right and rotated nearly 180° while on the runway surface. The aircraft then exited the side of the runway at an angle of about 45° to the runway edge. Shortly after the occurrence, Thunder Airlines Limited issued an operations bulletin to all flight crews, indicating that no flight crew shall depart until there is confirmation of suitable runway conditions (maximum ½ inch wet snow or 2 inches dry snow) from reliable sources on the ground. In addition, the bulletin states that if the communicated information includes a plan to clear the runway, confirmation of a cleared runway must be obtained before landing. The bulletin will be incorporated in the Thunder Airlines Limited standard operating procedures in the next revision.
Final Report:

Crash of a Mitsubishi MU-2B-60 Marquise in Hattiesburg: 4 killed

Date & Time: May 4, 2021 at 2301 LT
Type of aircraft:
Operator:
Registration:
N322TA
Flight Type:
Survivors:
No
Site:
Schedule:
Wichita Falls – Hattiesburg
MSN:
760
YOM:
1980
Crew on board:
1
Crew fatalities:
Pax on board:
2
Pax fatalities:
Other fatalities:
Total fatalities:
4
Captain / Total flying hours:
7834
Captain / Total hours on type:
500.00
Aircraft flight hours:
7610
Circumstances:
The pilot was flying a non precision approach in instrument meteorological conditions at night. While flying the procedure turn for the approach, the airplane’s speed decayed toward the stall speed before the airplane accelerated back to the standard approach speed. During the descent from the final approach fix, the airplane’s descent stopped for about 30 seconds and then the airplane descended at a rate of about 1,300 ft per minute. The airplane decelerated and continued to descend until the airspeed was about 85 knots (about 7 knots above the calculated stall speed for flaps 20°) and the altitude was 500 ft mean sea level. The last recorded data point showed the airplane about 460 ft mean sea level and 750 ft from the accident site. The airplane impacted a private residence, and a postcrash fire ensued and destroyed the airplane. Impact signatures were consistent with a low-energy impact. Examination of the airframe and engines did not detect any preimpact anomalies that would have precluded normal operations. Signatures on the engines and propellers were consistent with both engines providing power at impact. A review of the pilot’s toxicological information found that the level of eszopiclone in his specimens was subtherapeutic and thus not likely a factor in the accident. The circumstances of the accident are consistent with an inadvertent aerodynamic stall from which the pilot was unable to recover.
Probable cause:
The pilot’s failure to maintain control of the airplane during the night instrument approach which resulted in an inadvertent aerodynamic stall from which the pilot was unable to recover.
Final Report:

Crash of a Mitsubishi MU-2B-60 Marquise in Sioux Falls: 1 killed

Date & Time: Jun 7, 2020 at 0415 LT
Type of aircraft:
Operator:
Registration:
N44MX
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Everett – Huron - Kokomo
MSN:
1526
YOM:
1981
Flight number:
MDS44
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
22000
Captain / Total hours on type:
10900.00
Aircraft flight hours:
12104
Circumstances:
The pilot departed on a cross country flight in a turbine-powered, multiengine airplane at night and in visual meteorological conditions. Recovered GPS data revealed that as the airplane accelerated down the runway, it drifted to the right of the runway centerline. A video recording showed that shortly after takeoff, the airplane rolled right, the nose dropped, and the airplane impacted the ground. It came to rest on its left side with both wings separated and the fuselage was highly fragmented forward of the main landing gear. A post-accident examination of the airframe and engines found no mechanical malfunctions or anomalies that would have precluded normal operation. A witness that spoke to the pilot shortly before the accident flight stated that the pilot exhibited difficulty in completing some paperwork; however, no medical reasoning for this difficulty could be determined based upon the available evidence. The investigation determined that at the time of the accident the pilot had been on duty for about 19 hours and 20 minutes, which was contrary to duty and rest regulations. At his estimated arrival time into the destination, the pilot would have accumulated about 20 hours and 54 minutes of duty time. The investigation was unable to determine if the pilot took advantage of the opportunity for rest that existed during the day, and therefore could not determine if fatigue contributed to the accident. Investigators were unable to determine the reason for the loss of control on takeoff with the available information.
Probable cause:
The pilot’s failure to maintain control of the airplane during takeoff for reasons that could not be determined.
Final Report:

Crash of a Mitsubishi MU-2B-40 Solitaire in Ainsworth: 1 killed

Date & Time: Sep 23, 2017 at 1028 LT
Type of aircraft:
Registration:
N73MA
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Ainsworth – Bottineau
MSN:
414
YOM:
1980
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
3775
Captain / Total hours on type:
2850.00
Aircraft flight hours:
5383
Circumstances:
The instrument-rated private pilot departed on a cross-country flight in instrument meteorological conditions (IMC) with an overcast cloud layer at 500 ft above ground level (agl)
and visibility restricted to 1 ¾ miles in mist, without receiving an instrument clearance or opening his filed instrument flight rules flight plan. There was an outage of the ground communications system at the airport and there was no evidence that the pilot attempted to open his flight plan via his cellular telephone. In addition, there was a low-level outage of the radar services in the vicinity of the accident site and investigators were unable to determine the airplane's route of flight before impact. The airport manager observed the accident airplane depart from runway 35 and enter the clouds. Witnesses located to the north of the accident site did not see the airplane but reported hearing an airplane depart about the time of the accident. One witness reported hearing a lowflying airplane and commented that the engines sounded as if they were operating at full power. The witness heard a thud as he was walking into his home but attributed it to a thunderstorm in the area. The airplane impacted a field about 3.5 miles to the northeast of the departure end of the runway and off the track for the intended route of flight. The airplane was massively fragmented during the impact and debris was scattered for about 300 ft. The damage to the airplane and ground scars at the accident site were consistent with the airplane impacting in a left wing low, nose low attitude with relatively high energy. A postaccident examination of the engines and propeller assemblies did not reveal any preimpact anomalies that would have precluded normal operation. Signatures were consistent with both engines producing power and both propellers developing thrust at the time of impact. While the massive fragmentation precluded functional testing of the equipment, there was no damage or failure that suggested preimpact anomalies with the airframe or flight controls.Several days before the accident flight, the pilot encountered a "transient flag" on the air data attitude heading reference system. The pilot reported the flag to both the co-owner of the airplane and an avionics shop; however, exact details of the flag are not known. The unit was destroyed by impact forces and could not be functionally tested. If the flag affecting the display of attitude information had occurred with the unit after takeoff, the instrument panel had adequate stand-by instrumentation from which the pilot could have continued the flight. It is not known if this unit failed during the takeoff and investigators were unable to determine what role, if any, this transient issue may have played in the accident. Based upon the reported weather conditions, the location of the wreckage, and the attitude of the airplane at the time of impact with the ground, it is likely that the pilot experienced spatial disorientation shortly after takeoff which resulted in a loss of control and descent into terrain.
Probable cause:
The pilot's loss of airplane control due to spatial disorientation.
Final Report:

Crash of a Mitsubishi MU-2B-26A Marquise near San Fernando: 3 killed

Date & Time: Jul 24, 2017 at 1430 LT
Type of aircraft:
Operator:
Registration:
LV-MCV
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
San Fernando – Las Lomitas
MSN:
361
YOM:
1977
Country:
Crew on board:
1
Crew fatalities:
Pax on board:
2
Pax fatalities:
Other fatalities:
Total fatalities:
3
Captain / Total flying hours:
682
Captain / Total hours on type:
58.00
Aircraft flight hours:
5804
Aircraft flight cycles:
4670
Circumstances:
Shortly after takeoff from San Fernando Airport in Buenos Aires, while in initial climb, the pilot was contacted by ATC about an apparent transponder issue. The crew did not respond when, few seconds later, the twin engine airplane entered an uncontrolled descent and crashed in a marshy area located in the delta of Paraná de la Palmas. The wreckage was found on August 19 about 17 km north of San Fernando Airport. The aircraft disintegrated on impact and all three occupants were killed.
Crew:
Matías Ronzano,
Passengers:
Emanuel Vega,
Matías Aristi.
Probable cause:
Loss of control during climb due to the combination of the following factors:
- The particular characteristics of the aircraft;
- The attention required by the transponder as it is not displayed by air traffic control;
- The detour of the planned flight at the request of the inspection department of air traffic;
- Aircraft trajectory management with autopilot switched off;
- The pilot's limited experience in instrument flight conditions. In addition, the absence of additional instruction in the aircraft type (due to the lack of specific regulations) can be considered a contributing factor, according to the probable scenario described above. In addition, the research identified the following elements with potential impact in operational safety:
- Absence of the TAWS system on the aircraft in non-conformity with the established RAAC 91;
- Lack of effective means to enable the flight plan office to quickly determine whether an aircraft has operating restrictions;
- Shortcomings in the training of staff in the units ATS and SAR in search and rescue.
Final Report:

Crash of a Mitsubishi MU-2B-40 Solitaire off Eleuthera Island: 4 killed

Date & Time: May 15, 2017 at 1329 LT
Type of aircraft:
Registration:
N220N
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Aguadilla – Space Coast
MSN:
450
YOM:
1981
Country:
Crew on board:
1
Crew fatalities:
Pax on board:
3
Pax fatalities:
Other fatalities:
Total fatalities:
4
Captain / Total flying hours:
1483
Captain / Total hours on type:
100.00
Aircraft flight hours:
4634
Circumstances:
The commercial pilot and three passengers were making a personal cross-country flight over ocean waters in the MU-2B airplane. During cruise flight at flight level (FL) 240, the airplane maintained the same relative heading, airspeed, and altitude for about 2.5 hours before radar contact was lost. While the airplane was in flight, a significant meteorological information notice was issued that warned of frequent thunderstorms with tops to FL440 in the accident area at the accident time. Satellite imagery showed cloud tops in the area were up to FL400. Moderate or greater icing conditions and super cooled large drops (SLD) were likely near or over the accident area at the accident time. Although the wreckage was not located for examination, the loss of the airplane's radar target followed by the identification of debris and a fuel sheen on the water below the last radar target location suggests that the airplane entered an uncontrolled descent after encountering adverse weather and impacted the water. Before beginning training in the airplane about 4 months before the accident, the pilot had 21 hours of multi engine experience accumulated during sporadic flights over 9 years. Per a special federal aviation regulation, a pilot must complete specific ground and flight training and log a minimum of 100 flight hours as pilot-in-command (PIC) in multi engine airplanes before acting as PIC of a MU-2B airplane. Once the pilot began training in the airplane, he appeared to attempt to reach the 100-hour threshold quickly, flying about 50 hours in 1 month. These 50 hours included about 40 hours of long, cross-country flights that the flight instructor who was flying with the pilot described as "familiarization flights" for the pilot and "demonstration flights" for the airplane's owner. The pilot successfully completed the training required for the MU-2B, and at the time of the accident, he had accumulated an estimated 120 hours of multi engine flight experience of which 100 hours were in the MU-2B. Although an MU-2B instructor described the pilot as a good, attentive student, it cannot be determined if his training was ingrained enough for him to effectively apply it in an operational environment without an instructor present. Although available evidence about the pilot's activities suggested he may not have obtained adequate restorative sleep during the night before the accident, there was insufficient evidence to determine the extent to which fatigue played a role in his decision making or the sequence of events.The pilot's last known weather briefing occurred about 8 hours before the airplane departed, and it is not known if the pilot obtained any updated weather information before or during the flight. Sufficient weather information (including a hazardous weather advisory provided by an air traffic control broadcast message about 25 minutes before the accident) was available for the pilot to expect convective activity and the potential for icing along the accident flight's route; however, there is no evidence from the airplane's radar track or the pilot's communications with air traffic controllers that he recognized or attempted to avoid the convective conditions or exit icing conditions.
Probable cause:
The pilot's intentional flight into an area of known icing and convective thunderstorm activity, which resulted in a loss of control of the airplane.
Final Report:

Crash of a Mitsubishi MU-2B-60 Marquise in Le Havre-aux-Maisons: 7 killed

Date & Time: Mar 29, 2016 at 1230 LT
Type of aircraft:
Operator:
Registration:
N246W
Survivors:
No
Schedule:
Montreal - Le Havre-aux-Maisons
MSN:
1552
YOM:
1982
Country:
Crew on board:
1
Crew fatalities:
Pax on board:
6
Pax fatalities:
Other fatalities:
Total fatalities:
7
Captain / Total flying hours:
2500
Captain / Total hours on type:
125.00
Aircraft flight hours:
11758
Circumstances:
The twin engine aircraft left Montreal-Saint-Hubert Airport at 0930LT for a two hours flight to Le Havre-aux-Maisons, on Magdalen Islands. Upon arrival, weather conditions were marginal with low ceiling, visibility up to two miles, rain and wind gusting to 30 knots. During the final approach to Runway 07, when the aircraft was 1.4 nautical miles west-southwest of the airport, it deviated south of the approach path. At approximately 1230 Atlantic Daylight Time, aircraft control was lost, resulting in the aircraft striking the ground in a near-level attitude. The aircraft was destroyed and all seven occupants were killed, among them Jean Lapierre, political commentator and former Liberal federal cabinet minister of Transport. All passengers were flying to Magdalen Islands to the funeral of Lapierre's father, who died last Friday. The captain, Pascal Gosselin, was the founder and owner of Aéro Teknic.
Crew:
Pascal Gosselin, pilot.
Passengers:
Fabrice Labourel, acting as a copilot,
Jean Lapierre,
Nicole Beaulieu, Jean Lapierre's wife,
Martine Lapierre, Jean Lapierre's sister,
Marc Lapierre, Jean Lapierre's brother,
Louis Lapierre, Jean Lapierre's brother.
Probable cause:
Findings as to causes and contributing factors:
1. The pilot’s inability to effectively manage the aircraft’s energy condition led to an unstable approach.
2. The pilot “got behind” the aircraft by allowing events to control his actions, and cognitive biases led him to continue the unstable approach.
3. A loss of control occurred when the pilot rapidly added full power at low airspeed while at low altitude, which caused a power-induced upset and resulted in the aircraft rolling sharply to the right and descending rapidly.
4. It is likely that the pilot was not prepared for the resulting power-induced upset and, although he managed to level the wings, the aircraft was too low to recover before striking the ground.
5. The pilot’s high workload and reduced time available resulted in a task-saturated condition, which decreased his situational awareness and impaired his decision making.
6. It is unlikely that the pilot’s flight skills and procedures were sufficiently practised to ensure his proficiency as the pilot-in-command for single-pilot operation on the MU2B for the conditions experienced during the occurrence flight.

Findings as to risk:
1. If the weight of an aircraft exceeds the certified maximum take-off weight, there is a risk of aircraft performance being degraded, which may jeopardize the safety of the flight.
2. If pilots engage in non-essential communication during critical phases of flight, there is an increased risk that they will be distracted, which reduces the time available to complete cockpit activities and increases their workload.
3. If flight, cockpit, or image/video data recordings are not available to an investigation, the identification and communication of safety deficiencies to advance transportation safety may be precluded.
4. If pilots do not recognize that changing circumstances require a new plan, then plan continuation bias may lead them to continue with their original plan even though it may not be safe to do so.
5. If pilots do not apply stable-approach criteria, there is a risk that they will continue an unstable approach to a landing, which can lead to an approach-and-landing accident.
6. If pilots are not prepared to conduct a go-around on every approach, they risk not responding appropriately to situations that require one.
7. If a flight plan does not contain search-and-rescue supplementary information, and if that information is not transmitted or readily available, there is a risk that first responders will not have the information they need to respond adequately.

Other findings:
1. Transport Canada does not monitor or track the number of days foreign-registered aircraft are in Canada during a given 12-month period.
2. Turbulence and icing were not considered factors in this occurrence.
3. Transport Canada considers that the discretionary installation of an angle-of-attack system on normal-category, type-certificated, Canadian-registered aircraft is a major modification that requires a supplemental type certificate approval.
4. Although the aircraft was not in compliance with Airworthiness Directive 2006-17-05 at the time of the occurrence, there was no indication that it was operating outside of the directive’s specifications.
5. Although not required by regulation, the installation and use of a lightweight flight recording system during the occurrence flight, as well as the successful retrieval of its data during the investigation, permitted a greater understanding of this accident.
Final Report:

Crash of a Mitsubishi MU-2B-25 Marquise in Owasso: 1 killed

Date & Time: Nov 10, 2013 at 1546 LT
Type of aircraft:
Operator:
Registration:
N856JT
Flight Type:
Survivors:
No
Schedule:
Salina - Tulsa
MSN:
306
YOM:
1974
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
2874
Captain / Total hours on type:
12.00
Aircraft flight hours:
6581
Circumstances:
Radar and air traffic control communications indicated that the Mitsubishi MU-2B-25 was operating normally and flew a nominal flightpath from takeoff through the beginning of the approach until the airplane overshot the extended centerline of the landing runway, tracking to the east and left of course by about 0.2 nautical mile then briefly tracking back toward the centerline. The airplane then entered a 360-degree turn to the left, east of the centerline and at an altitude far below what would be expected for a nominal flightpath and intentional maneuvering flight given the airplane's distance from the airport, which was about 5 miles. As the airplane was in its sustained left turn tracking away from the airport, the controller queried the pilot, who stated that he had a "control problem" and subsequently stated he had a "left engine shutdown." This was the last communication received from the pilot. Witnesses saw the airplane spiral toward the ground and disappear from view. Examination of the wreckage revealed that the landing gear was in the extended position, the flaps were extended 20 degrees, and the left engine propeller blades were in the feathered position. Examination of the left engine showed the fuel shutoff valve was in the closed position, consistent with the engine being in an inoperative condition. As examined, the airplane was not configured in accordance with the airplane flight manual engine shutdown and single-engine landing procedures, which state that the airplane should remain in a clean configuration with flaps set to 5 degrees at the beginning of the final approach descent and the landing gear retracted until landing is assured. Thermal damage to the cockpit instrumentation precluded determining the preimpact position of fuel control and engine switches. The investigation found that the airplane was properly certified, equipped, and maintained in accordance with federal regulations and that the recovered airplane components showed no evidence of any preimpact structural, engine, or system failures. The investigation also determined that the pilot was properly certificated and qualified in accordance with applicable federal regulations, including Special Federal Aviation Regulation (SFAR) No. 108, which is required for MU-2B pilots and adequate for the operation of MU-2B series airplanes. The pilot had recently completed the SFAR No. 108 training in Kansas and was returning to Tulsa. At the time of the accident, he had about 12 hours total time in the airplane make and model, and the flight was the first time he operated the airplane as a solo pilot. The investigation found no evidence indicating any preexisting medical or behavioral conditions that might have adversely affected the pilot's performance on the day of the accident. Based on aircraft performance calculations, the airplane should have been flyable in a one engine-inoperative condition; the day visual meteorological conditions at the time of the accident do not support a loss of control due to spatial disorientation. Therefore, the available evidence indicates that the pilot did not appropriately manage a one-engine-inoperative condition, leading to a loss of control from which he did not recover. The airplane was not equipped, and was not required to be equipped, with any type of crash resistant recorder. Although radar data and air traffic control voice communications were available during the investigation to determine the airplane's altitude and flight path and estimate its motions (pitch, bank, yaw attitudes), the exact movements and trim state of the airplane are unknown, and other details of the airplane's performance (such as power settings) can only be estimated. In addition, because the airplane was not equipped with any type of recording device, the pilot's control and system inputs and other actions are unknown. The lack of available data significantly increased the difficulty of determining the specific causes that led to this accident, and it was not possible to determine the reasons for the left engine shutdown or evaluate the pilot's recognition of and response to an engine problem. Recorded video images from the accident flight would possibly have shown where the pilot's attention was directed during the reported problems, his interaction with the airplane controls and systems, and the status of many cockpit switches and instruments. Recorded flight data would have provided information about the engines' operating parameters and the airplane's motions. Previous NTSB recommendations have addressed the need for recording information on airplane types such as the one involved in this accident. Recorders can help investigators identify safety issues that might otherwise be undetectable, which is critical to the prevention of future accidents.
Probable cause:
The pilot's loss of airplane control during a known one-engine-inoperative condition. The reasons for the loss of control and engine shutdown could not be determined because the airplane was not equipped with a crash-resistant recorder and postaccident examination and testing did not reveal evidence of any malfunction that would have precluded normal operation.
Final Report: