Army Hazardous Events Scale (Army-HES)

Abstract

The Army Hazardous Events Scale (Army-HES) is a psychometric instrument designed to quantify the frequency of exposure to specific hazardous or near-miss events experienced by U.S. Army Aviators. Developed by Hunter and Stewart, the scale serves as a critical measure in aviation psychology research, particularly in understanding the relationship between pilot attitudes, risk orientation, and exposure to unsafe flight conditions. The Army-HES captures a wide range of potential dangers, from mechanical failures and severe weather encounters to procedural errors and crew resource management breakdowns, providing empirical data on real-world operational risks over a pilot’s career.

Keywords

Aviation Safety, Pilot Error, Near-Miss Events, Risk Perception, Psychological Scale, Army Aviators, Hazardous Events, Crew Resource Management, Flight Safety.

Authors

David R. Hunter, John E. Stewart.

Purpose

The primary purpose of the Army-HES is to empirically assess the extent to which military aviators encounter or commit specific safety-compromising events during their flight careers. This frequency measure is crucial for research exploring the influence of psychological variables—such as locus of control and risk tolerance—on flight safety outcomes. By quantifying exposure to these events, researchers can establish reliable relationships between stable personality characteristics and operational performance.

Furthermore, the scale aims to identify high-frequency hazard areas within Army aviation operations, informing targeted safety training programs and policy adjustments. The detailed nature of the items allows for granular analysis of both technical piloting errors and failures in judgment or crew coordination.

Construct

The Army-HES measures the construct of Operational Hazard Exposure, defined as the cumulative frequency of experiencing potentially dangerous events or critical incidents during flight operations. Unlike scales that measure attitudes or personality traits, the Army-HES focuses on observable behavioral outcomes and environmental encounters that compromise flight safety.

These hazardous events span four main domains: environmental risks (e.g., severe icing, brown-out), mechanical/technical failures, procedural violations (e.g., runway incursions, unauthorized maneuvers), and crew resource management (CRM) failures (e.g., communication breakdowns, pilot incapacitation). A higher score on the Army-HES indicates a greater history of exposure to, or involvement in, critical safety incidents.

Validity

While specific psychometric validation statistics are detailed in the primary technical report (ADA509824), the scale demonstrates strong face and content validity. The items were developed in consultation with experienced military aviators and cover nearly all critical incident types recognized in military and civilian aviation safety documentation, ensuring comprehensive coverage of the domain of hazardous events.

Construct validity is supported by its use alongside established scales measuring related concepts, such as the Army Locus of Control Scale and the Army Safety Attitudes Scale. Research using the Army-HES established its utility in predicting unsafe decision-making and risk orientation among aviators, suggesting criterion validity in relation to real-world performance indicators.

Reliability

Reliability estimates for the Army-HES, including internal consistency (e.g., Cronbach’s alpha) and potentially test-retest reliability, are documented in the associated technical publications from the U.S. Army Research Institute for the Behavioral and Social Sciences. Given its inclusion in major academic research concerning pilot risk and decision-making, the instrument is utilized as a reliable self-report measure of exposure frequency. High reliability is essential for accurately aggregating the diverse range of low-frequency events into a meaningful, composite score of hazard exposure.

Factor Analysis

Although the raw data provided consists of a single list of items, the structure of the scale implies that a factor analysis would likely reveal underlying dimensions of hazardous events. These factors typically separate risks related to external environmental forces (e.g., weather, visibility like white-out), internal aircraft systems (e.g., mechanical failure), and human factors (e.g., procedural violations, CRM issues).

Understanding the factor structure is crucial, as it allows researchers to determine whether certain psychological traits correlate more strongly with specific types of hazards, such as those related to procedural non-compliance versus unavoidable environmental encounters.

Instrument

Test Type: Self-Report Questionnaire (Frequency Measure)

Format: The scale consists of numerous items (over 60 in the full version) answered using a 5-point frequency scale: a. None (0), b. 1 time, c. 2 times, d. 3 times, e. 4 or more times.

Language Available: English

Population Group: Military Aviators

Age Group: Adult

Population Details: Specifically developed for and validated on U.S. Army Aviators, including rotary-wing and fixed-wing pilots involved in operational missions.

Test Methodology: Respondents are asked to reflect on their entire flying career and report the frequency with which they have encountered each specific hazardous event listed in the scale.

Keywords

Aviation Psychology, Military Research, Flight Safety Measurement, Pilot Decision Making, Human Factors, DTIC, Hazard Exposure, Risk Orientation.

Authors

Author ORCID Identifier: Not provided.

Affiliation Email addresses: [email protected]

Correspondence Address: Not provided.

Permissions & Fee and Test Year

Test Year: 2009

Permissions and Fee: The scale was developed under the United States Army Research Institute for the Behavioral and Social Sciences (ARI). The instrument is generally considered part of the public domain for research purposes, although proper citation is required. The original technical report detailing the scale and its application, titled “Locus of Control, Risk Orientation, and Decision Making Among U.S. Army Aviators,” can be accessed via the Defense Technical Information Center (DTIC). The instrument itself is available for download here: www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA509824.

Reference’s

Hunter, D. R., & Stewart, J. E. (2009). Locus of Control, Risk Orientation, and Decision Making Among U.S. Army Aviators. United States Army Research Institute for the Behavioral and Social Sciences.

Hunter, D.R. (2006). Risk perception among general aviation pilots. International Journal of Aviation Psychology, 16, 135-144.

Hunter, D.R. (2004). Measurement of hazardous attitudes among pilots. International Journal of Aviation Psychology, 15, 23-43.

Hunter, D. R. (2002). Risk perception and risk tolerance in aircraft pilots (Report DOT/FAA/AM–02/17). Washington, DC: Federal Aviation Administration.

Hunter, D. R. (2002). Development of an aviation safety locus of control scale. Aviation, Space, and Environmental Medicine, 73, 1184-1188.

Hunter, D.R. (1995). Airman research questionnaire: Methodology and overall results. DOT/FAA/AM-95/27. Washington, DC: Federal Aviation Administration.

Items of the Army Hazardous Events Scale (Army- HES)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

• Run so low on fuel that you were seriously concerned about making it to an airfield/heliport or refueling point before you ran out?*
• Made a precautionary or forced landing at an airfield/heliport other than your original destination? *
• Made a precautionary or forced landing away from an airfield/heliport? *
• Been forced to perform an abrupt maneuver to avoid an obstacle? *
• Become so disoriented that you had to land or call ATC for assistance in determining your location?
• Had a mechanical failure that jeopardized the safety of your flight? *
• Had an engine quit because of fuel starvation, either because you ran out of fuel or because of an improper pump or fuel tank selection?
• Flown into areas of instrument meteorological conditions, when you were not on an instrument flight plan? *
• Turned back or diverted to another airport because of bad weather while on a VFR flight? *
• Experienced icing so severe that you had to divert or change altitude?
• Noticed that you were significantly undershooting your approach to landing?
• Attempted to hover in ground effect and discovered you had insufficient power? *
• Experienced vertigo so severe that you had to pass control of the aircraft to the other pilot? *

• Taken off when you knew you were over the maximum gross weight limit for the conditions?
• Had a crewmember become ill or incapacitated during flight, to the extent that they could not fully perform their duties? *
• Penetrated a gun-target line without clearance?
• Lost visual contact with the ground because of dust or snow while landing or taking off (brown-out)? *
• Descended below the MDA while on an instrument approach without having the airfield in sight?
• Descended more than two dots below the glideslope while on an ILS approach?
• Drifted more than two dots to the left or right of course while inside the outer marker on an ILS approach? *
• Failed to complete the before-landing checklist while landing at an airfield/heliport?
• Experienced an in-flight fire or smoke in the cabin?
• Failed to follow ATC/tower instructions?
• Taken off without clearance from a controlled airfield/heliport?
• Entered or crossed an active runway without clearance?
• Had cargo shift while in-flight?
• Landed without clearance at a controlled airfield/heliport?
• Experienced an electrical failure during night flight?
• Lost one or more of your primary flight instruments (gyro failure, altimeter failure, etc.) during instrument flight? *
• Experienced wake turbulence from other aircraft that resulted in near loss-of-control?
• Lost cyclic authority while hovering (lateral load exceeded)?
• Lost anti-torque authority while hovering?

• Attempted to hover out of ground effect, and discovered you had insufficient power? *
• Noticed that you were drifting significantly to one side during your approach to landing?
• Discovered live ordnance left on board after a flight?
• Grazed trees (or other objects) while flying low-level?
• Struck an object with the main rotor while hovering?
• Experienced a near mid-air collision? *
• Experienced a near collision while taxiing or hovering?
• Nearly collided with the ground or some object while flying? *
• Had your aircraft slide after landing on a slope or smooth rocks? *
• Unexpectedly had your aircraft tip significantly after landing on a slope?
• Experienced a hard landing?
• Executed a go-around after encountering brown-out or white-out conditions during the last portion of your approach to landing? *
• Made a zero-visibility take-off in which you immediately lost visual contact with the ground while pulling pitch because of brown-out or white-out? *
• Came close to hitting terrain or some other obstacle after inadvertently entering instrument meteorological conditions?
• Narrowly avoided a wire-strike? *
• Followed an instruction meant for another aircraft because of confusion over call signs?
• Became so fatigued while flying that you had difficulty remaining alert and performing your duties? *
• Were asked by a ranking passenger to perform an action that you believed was contrary to the safety of flight? *
• Became so ill during a flight that you could not perform your duties?
• Struck a large bird while in flight? *

• Experienced much worse weather reroute or at your destination than was forecast? *
• Made a significant navigation error that could have taken you into rising terrain, an enemy controlled area, or otherwise seriously jeopardized the aircraft/mission?
• Experienced a failure of your night vision device during a critical phase of flight (for example, while on approach to an LZ or while maneuvering low-level)? *
• Had a significant dispute with the other pilot regarding what course of action should be taken? *
• Found that you and the other pilot had a very different mental picture of what was going on in or around the aircraft (for example, your position relative to friendly and enemy forces, the location of the next navigation fix)? *
• Flown with a pilot, outside of a training situation, who did not seem to have the skills needed to fly the aircraft and accomplish your mission? *
• Encountered turbulence so severe that you had significant difficulty maintaining control of the aircraft?
• Discovered after a flight that some important part of the aircraft had been damaged without your being aware of it?
• Had a weapon accidentally discharge in your aircraft?
• Had the other pilot perform some action that was completely unexpected and might have jeopardized the safety of your flight? *
• Been forced to perform a go-around because of dust/brownout in the landing area?
• Experienced a wire strike?
• Had a radio communications failure that jeopardized the safety of your flight? *
• Discovered during a flight that you did not have the correct frequencies and/or call signs required for communication with ground personnel? *
• Lost communications with another member of the crew during some critical phase of flight? *
• Realized afterward that you had followed the wrong procedure for an emergency or near emergency situation?
• Discovered that neither you nor the other pilot had the controls?
• Misinterpreted some statement or request by the other pilot or a crewmember leading to an unsafe condition? *
• Exceeded the airspeed, power, or RPM limitations of your aircraft?
• Had the other pilot misunderstand some statement or request that you made, leading to an unsafe condition? *
• Noticed that the other pilot or a crewmember was doing something wrong, but did not correct them?

• Experienced a lightning strike on the aircraft during flight?
• Discovered during a flight that you did not have the correct maps for your route and/or destination?
• Experienced a smoke or fire indicator that was not a false alarm?
• Allowed a non-rated person to fly the aircraft?
• Had a hard landing resulting in a maintenance inspection before flight could continue?
• Taken off without checking the weather and/or NOTAMS?
• Discovered that a cowling or hatch was not secured prior to flight?
• Inadvertently moved the control (cyclic, collective, or control wheel) when you were not the pilot flying the aircraft? *
• Had a flight control bind or stick?
• Performed more than two unsuccessful approaches to landing at the same location during a single mission?
• Performed unauthorized aerobatics, return to target maneuvers, or buzzed ground vehicles? *
• Made a serious error in reading or interpreting an instrument, but later realized your mistake?
• Performed a terrain (low-level) flight without having documented all the hazards on your maps? *