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Military Human Factors
Military Human Factors - 2
May 2018
Contents A-10 C Lapse in Flight Discipline ........................................................................................................................ 3 Introduction ................................................................................................................................................... 3 Source ........................................................................................................................................................ 3 General data .............................................................................................................................................. 3 Accident brief description ......................................................................................................................... 4 Cause and contributing factors ................................................................................................................. 4 Planned mission......................................................................................................................................... 4 Accident detailed description ........................................................................................................................ 5 Cause and contributing factors ................................................................................................................. 5 Accident sequence..................................................................................................................................... 5 Mishap pilot ............................................................................................................................................... 8 Human factors analysis.................................................................................................................................. 9 1
Risk Assessment - During Operation ................................................................................................. 9
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Violation - Lack of Discipline .............................................................................................................. 9
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Channelized Attention ..................................................................................................................... 10
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Complacency ................................................................................................................................... 10
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Challenge and Reply ........................................................................................................................ 10
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Military Human Factors - 2
May 2018
A-10 C Lapse in Flight Discipline
Source: U.S. AIB Report.
Introduction Source United States Air Force Aircraft Accident Investigation Board (USAF AIB). Final report 052213_A-10C_Whiteman.
General data Date: 22nd May 2013. Aircraft: A-10C T/N 79-0164. Location: Stockton Lake, Missouri.
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Accident brief description
Planned mission
The United States Air Force Aircraft Accident Investigation Board (AIB) describe in their final report that:
According to the accident report, the mishap flight (MF) was planned, briefed and flown as a local two-ship low-altitude surface attack tactics mission. The planned flow of the mission was to depart Whiteman AFB under visual flight rules, complete air-to-air refueling in the Truman A and B Military Operating Areas (MOA), conduct low altitude tactical navigation (LATN) training in the LATN East area at 300 feet above ground level (AGL), execute simulated Maverick attacks in the Truman C MOA, and return to Whiteman AFB.
On 22 May 2013 at approximately 1548 central daylight time, the mishap aircraft (MA), an A-10C, tail number (T/N) 79-0164, assigned to the 442nd Fighter Wing, Whiteman Air Force Base (AFB), Missouri, impacted two cables during a low altitude training mission over Stockton Lake, Missouri, approximately 70 miles south of Whiteman AFB. Neither the mishap pilot (MP) nor any civilians near the mishap site were injured. The MA sustained extensive damage to the right horizontal stabilizer, vertical tail and rudder; the left wingtip; and weapons and suspension equipment mounted under the left wing.
Cause and contributing factors The board president found clear and convincing evidence that the cause of the mishap was the MP's poor judgment and lapse in flight discipline resulting in violation of flight rules and operating procedures relating to minimum altitudes. Additionally, the board president found by a preponderance of the evidence that the following factors substantially contributed to the mishap: (1) The MP channelized his attention on the boat and did not see the cables he ultimately impacted; (2) The MP's complacency led to lack of response to altitude advisories; and (3) The MFL did not confirm that the MP saw the cables nor direct the MP to climb in the absence of that confirmation, contrary to widely utilized techniques.
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Accident detailed description The MF departed the Truman MOA and flew south toward Stockton Lake to conduct LATN. As the flight flew over the southeast branch of the lake, the MP descended below the approved minimum altitude of 300 feet AGL and maneuvered toward a boat that was traveling southeast on the lake. According to the AIB report the MF lead (MFL) advice to the MP that he was approaching to the power lines that cross the lake: The MF lead (MFL) called on the radio that the flight was approaching power lines that cross the lake. The MP acknowledged the call but did not call “contact” on the obstruction as he continued his descent. At approximately 140 feet AGL, the MA impacted two protective cables that run above the power lines crossing the lake. The MP called “knock-it-off” and began a climb as the MFL rejoined with the MP. The MP stated to the MFL that he "hit those power lines". The MFL examined the visible damage to the MA. The flight coordinated and completed checklist procedures for structural damage, controllability, and hydraulic failure, as the right hydraulic system eventually failed due to a cut hydraulic line in the leading edge of the right horizontal stabilizer. The flight coordinated the recovery plan with the supervisor of flying and declared an emergency with Whiteman AFB tower. The MP safely recovered the MA out of a straight-in approach. The MP shut down at the end of runway after landing, and the MA was towed to the parking ramp.
Cause and contributing factors The AIB determined the probable cause of the accident was: “… the MP's poor judgment and lapse in flight discipline resulting in violation of flight rules
and operating procedures relating to minimum altitudes.” The board president found that the following factors substantially contributed to the accident: (1) the MP channelized his attention on the boat and did not see the cables he ultimately impacted; (2) the MP's complacency led to lack of response to altitude advisories; and (3) the MFL did not confirm that the MP saw the cables nor direct the MP to climb in the absence of that confirmation, contrary to widely utilized techniques.” The AIB explains that the mishap mission was planned as a local two-ship low altitude surface attack tactics (SAT) continuation training (CT) mission. The purpose of the mission was to improve the proficiency of the Mishap Flight Lead (MFL) and MP in air-to-air refueling (AAR), low altitude operations down to 300 feet above ground level (AGL), and Maverick air-to-surface missile employment. No special emphasis was placed on training rules or operating procedures that applied to low altitude operations and obstacle avoidance because the MFL had selected a route that avoided obstacles that would be a factor to the flight at 300 feet.
Accident sequence During the briefing, MP did not say anything about his intention to flight above the boat: According to the MFL, the MP was attentive and focused in the briefing and did not indicate any lack of understanding of the overall mission plan prior to stepping to the aircraft. The flight proceeded to the southeastern branch of Stockton Lake in southwest Missouri.
Military Human Factors - 2
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Before flying over the lake, the flight was flowing as planned:
these indications and continued to turn and descend toward two boats he saw on the water.
Approximately 7 minutes prior to the mishap, the flight was established at 300 feet AGL. From that time to the mishap, the flight flew over mildly rolling terrain before reaching the lake shoreline. En route to the lake, the MFL made a radio call identifying a tower 2 miles southeast of the formation, which the MP acknowledged by calling “contact”, indicating he saw the tower the MFL had called out.
The MP continued the flight in spite of the warnings of the MFL. The MFL made a radio call that the flight was approaching power lines that cross the lake, to which the MP responded “2”, indicating he heard the MFL's radio call but not necessarily that he had the obstruction in sight, contrary to the MFL's assumption. The MFL did not confirm that the MP had the cables in sight when the MP responded “2”, which is the normal technique of every other pilot interviewed.
This is the normal procedure, to answer to the radio call saying “contact” when the pilot sees the object above terrain.
Six seconds later, the MP flew at 130 feet above the water nearly directly over the first boat traveling northwest on the lake.
The MA started to descend to the lake, in spite of multiples alert from the aircraft alerting system the MP followed with his intention to fly over the boat, as describe in the final report:
The MP climbed slightly and acquired the second boat traveling southeast on the lake toward him. The MP maneuvered his aircraft in a shallow, left-turning descent to point in the direction of the boat.
The MP experienced 52 audible "ALTITUDE, ALTITUDE" alerts from the aircraft voice messaging system over those 7 minutes, indicating his altitude was below the 300 feet AGL advisory altitude he had set. Throughout this sequence, his altitude indicated as low as 120 feet AGL. The MP did not appear to react to any of those alerts by maneuvering the aircraft vertically to correct the deviation or stop the altitude advisories.
At 140 feet AGL, 3° of descent, approximately 10° left bank, heading 283°, and 299 knots indicated airspeed (KIAS), the MA impacted and severed two cables that spanned the lake.
The attitude of the MP was not appropriate: The MP was also whistling in the intercom throughout this sequence. As the flight reached the southeast corner of the lake, the MP executed a turn from south to west utilizing approximately 80° right bank and the nose dropped to 6° of dive. The predictive ground collision avoidance system (PGCAS) generated a "PULL UP, PULL UP" audio warning and a "break X" in the HUD. The PGCAS warning is designed to alert the pilot that the aircraft will descend to less than 90 feet AGL on its current trajectory unless an aggressive, wings-level climb is initiated. The MP did not appear to react to
Source: U.S. AIB Report. Severed cable at mishap site.
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The MP called “knock-it-off” on the radio and the MFL rejoined with the MP. The MP stated on the radio that he “hit those power lines”. The MFL did a visual check of the MA, and noted that the Maverick air-to-ground and Air Intercept Missile9 (AIM-9) air-to-air missiles were damaged, as well as the suspension equipment under the left wing and the left wing tip. The Bomb Dummy Unit-33 (BDU-33) on the center station of the left Triple Ejection Rack (TER) was twisted, but all training munitions were still on the MA. On the right side of the MA, the MFL noted there was damage to the leading edge of the right horizontal stabilizer and base of the right vertical stabilizer.
no control of the slats, speed brakes, and airrefueling door. The MP had control of the MA to land safely back at Whiteman AFB. Due to the break in the hydraulic line, the right system was depleted of fluid, and the MP completed the hydraulic system failure checklist. The MA had normal braking available because the left hydraulic system was intact. The MP pulled the emergency brake handle in accordance with the controllability check checklist to provide a minimum of five brake applications. The brake system did not sustain any damage and operated normally on recovery of the aircraft.
Source: U.S. AIB Report. MA with visible damage to rudder cap and horizontal stabilizer. Source: U.S. AIB Report. Damage to BDU-33, TGM-65 Maverick, AIM-9, DRA.
Despite the visible damage, the MP maintained control of the MA and returned to base with no further events. He also observed the MA was leaking some unknown fluid. The flight turned toward Whiteman AFB and coordinated their recovery plan with the Supervisor of Flying (SOF). The MP completed the structural damage and controllability checklists. The MA has a left and right hydraulic system for primary and back-up control. The left system was intact. However, the cable struck the leading edge of the right horizontal stabilizer, removing a portion of the leading edge, and damaging the right system hydraulic line to the right rudder. The break in the line compromised the right hydraulic system to the point that the MP attempted to isolate it to prevent total hydraulic failure. With the right system failure, the MP had
Source: U.S. AIB Report. Damage to right vertical and horizontal stabilizer and right rudder cap. The MP coordinated for an emergency landing on Runway 01 at Whiteman AFB, he flew
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Mishap pilot
an uneventful straight-in approach, taxied clear of the runway, and shut the aircraft down after post flight end of runway and engine shutdown procedures were completed.
The AIB describe in their final report about the MP lifestyle: The MP was not available for questioning. Therefore, the AIB was only able to use information gathered from interviews of other squadron members. None of the witnesses interviewed disclosed information indicating that the MP had demonstrated any behavior, stress, distraction or unusual habits in the days leading up to the mishap that would have contributed to the mishap. There is no evidence that any behavior, stress, distractions or unusual habits displayed by the MFL contributed to the mishap. Neither witness testimonies nor the 72-hour history of the MFL revealed evidence of abnormal behaviors that contributed to the mishap.
Source: U.S. AIB Report. Severed/damaged hydraulic, electrical (lighting), avionics, and manual flight control lines.
Source: U.S. AIB Report. Damage to right rudder bottom cap and hinge.
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Human factors analysis The investigation of human factors was carried out using the AFI 91-204, Attachment 5, Department of Defense Human Factors Analysis and Classification System (DOD HFACS). Two human factors were identified as causal to this mishap: risk assessment-during operation and lack of discipline. Three factors were identified as substantially contributing: channelized attention, complacency, and challenge and reply. Applying this method the Human Factors applicable in this accident are the following.
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Risk Assessment - During Operation
Risk Assessment - During Operation is a factor when the individual fails to adequately evaluate the risks associated with a particular course of action and this faulty evaluation leads to inappropriate decision and subsequent unsafe situation. This failure occurs in real-time when formal risk-assessment procedures are not possible.
after the mishap that he "hit those power lines," indicate he was aware that the cables were in the vicinity and were a factor to the MF. He did not call "contact" as he had done previously during the LATN. The lack of a "contact" call indicated he did not see the cables. Failure to appropriately address the risk the cables posed to the flight and the people on the boat led to an inappropriate decision to continue his maneuver to make a low altitude pass over the boat. This created an unsafe situation and was causal to the mishap.
The MP's response to the MFL's radio call identifying the cables, along with the MP's call
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Violation - Lack of Discipline
Violation - Lack of Discipline is a factor when an individual, crew or team intentionally violates procedures or policies without cause or need. These violations are unusual or isolated to specific individuals rather than larger groups. There is no evidence of these violations being condoned by leadership. These violations may also be referred to as "exceptional violations."
procedures. The MP knows the rules and normally adheres to them. In this case, the MP intentionally and unnecessarily maneuvered his aircraft in violation of flight rules and operating procedures contained in AFI 11-202, Volume 3; AFI 11-2A-I0C, Volume 3; and AFI II-2AOAI0V3/442 FW Supplement 1. While it seems to be anomalous for the MP, the lack of discipline demonstrated by his attempt to do a low pass over the boat in violation of these directives created an unsafe situation and was causal to the mishap.
Interviews with eleven 303 FS pilots who know and have flown with the MP indicate that he does not regularly violate flight rules or operating
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Channelized Attention
Channelized Attention is a factor when the individual is focusing all conscious attention on a limited number of environmental cues to the exclusion of others of a subjectively equal or higher or more immediate priority, leading to an unsafe situation. It may be described as a tight focus of attention that leads to the exclusion of comprehensive situational information.
exclude information being made available to him through MFL radio calls and auditory and visual advisories from the aircraft. It also prevented him from considering the highest priority task at the time-gaining visual contact with the cables. By channelizing his attention on the boat in the vicinity of the cables, the MP allowed an unsafe situation to develop, substantially contributing to the mishap.
The MP was clearly focused on flying over the boats on the lake. This focus caused him to
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Complacency
Complacency is a factor when the individual's state of reduced conscious attention due to an attitude of overconfidence, under motivation or the sense that others "have the situation under control" leads to an unsafe situation.
that he was audibly whistling over the intercom throughout that period, demonstrated the MP's overconfidence during low altitude operations and MP demonstrated a high level of comfort flying at low altitude, which I believe resulted in the MP's complacency during low altitude operations. His overconfidence resulted in reduced attention to the threat posed by the cables in the mishap area. This behavior continued up to impact with the cables. Complacency substantially contributed to the mishap.
While it is not unusual to have occasional altitude alerts when operating at low altitude over rolling terrain, the MP experienced 52 altitude alerts and one ground collision warning in the 7 minutes prior to the mishap. The MP's lack of response to these advisories, along with the fact
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Challenge and Reply
Challenge and reply is a factor when communications did not include supportive feedback or acknowledgement to ensure that personnel correctly understand announcements or directives.
obstacle in sight. The MFL said that with a more experienced wingman, like the MP, a response of "2" would be sufficient to indicate that he heard the call identifying the obstacle and had the obstacle in sight. Only a "no joy" call would be definitively interpreted by the MFL that the wingman did not see the obstacle. In that case, the wingman would need amplifying information to locate the obstacle, or a directive call to maneuver to avoid it. In the case of the MF, the MP responded "2" when the MFL called out the cables over the lake, but the MP did not have them in sight, contrary to the MFL's assumption.
Eleven 303 FS pilots were asked to explain the squadron standard for identification and avoidance of obstacles during low altitude operations. All but the MFL adhere to the same technique. The MFL stated that, depending on whom he was flying with, he did not necessarily expect to hear his wingman call "contact" to indicate that the wingman had a declared
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The MFL did not confirm that the MP had the cables in sight when the MP responded "2," which is the normal technique of every other pilot interviewed. A no-notice review of 7 HUD videos conducted by the board during the investigation revealed that in all cases when an obstacle was encountered, communication continued until all flight members called "contact" with the obstruction. That communication is not directed or procedural, nor is it written in the squadron standards.
However, it appears to be the accepted, and perhaps the expected, flow of communications in this situation. Had the MFL utilized this accepted/expected technique, he may have gotten the MP's attention and prevented the impact with the cables. Lack of the accepted/expected challenge and reply technique substantially contributed to the mishap.
LucĂa Ferraz Juan Urrutia Product and Flight Safety
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