The definition and purpose of CRM, the cognitive vs interpersonal skill distinction, why CRM applies even to single-pilot operations, the link to the Tenerife disaster (1977), and the ICAO Standard compliance requirement.
1.1 Definition of CRM
Definition — CRM
CRM is the effective use of all available resources for flight crew personnel to assure a safe and efficient operation, reducing error, avoiding stress, and increasing efficiency.
CRM is concerned not with technical knowledge and stick-and-rudder skills, but with the cognitive and interpersonal skills needed to manage a flight within an organized aviation system.
Skill Type
Definition (per source)
Cognitive skills
Mental processes used for gaining and maintaining situational awareness, for solving problems and for taking decisions.
Interpersonal skills
Communications and a range of behavioural activities associated with teamwork.
⚠️ Exam Tip — Overlap Rule
These skill areas often overlap with each other AND with the required technical skills. CRM is not confined to multi-crew aircraft — it also relates to single-pilot operations, which invariably interface with other aircraft and ground support agencies.
1.2 Applicability of CRM — Human Factors Framework
CRM is an application of Human Factors (HF) to the flight crew domain. The term "Human Factors" includes CRM along with other aspects of human performance.
Working Definition
CRM is the utilization of all resources available to the crew to manage human error.
The objective of CRM training is to contribute to incident and accident prevention.
CRM is one practical application of Human Factors training — concerned with supporting crew responses to threats and errors that manifest in the operating environment.
✓ SOP — Training Weight
The requirement to develop human-performance knowledge and skills among flight crew members and other operational personnel has the same weight as that related to systems, normal, abnormal, and emergency procedures. Most operators comply mainly through CRM Training and LOFT.
1.3 Historical Origin — The Tenerife Catalyst
It took one of history's worst crashes — the Tenerife disaster of 1977 — to raise CRM from a mostly unpracticed principle to a full-fledged program. It became apparent that pilots needed to learn more about how best to manage all the resources available to them in the cockpit, including:
Other crew members
Procedures
The machine interface
Themselves
1.4 Regulatory Status
🚫 ICAO Compliance Warning
CRM is now considered essential training for most aviation professionals who make an operational contribution — including air traffic controllers and engineers. Non-compliance with the requirement to provide human-performance training would mean non-compliance with an ICAO international Standard.
flowchart LR
A[Aviation System] --> B[Human Factors HF]
B --> C[CRM Training]
B --> D[Other HF Aspects]
C --> E[Error Avoidance]
C --> F[Threat Management]
C --> G[Error Management]
C --> H[Undesired A/C State Mgmt]
E --> I((Accident/Incident Prevention))
F --> I
G --> I
H --> I
style I fill:#e8f5e9,stroke:#2e7d32,stroke-width:3px
style B fill:#e8f1fb,stroke:#2c5aa0,stroke-width:2px
style C fill:#fff8e1,stroke:#f57c00,stroke-width:2px
📌 Quick Revision Summary — Section 1
CRM = Effective use of ALL resources → reduce error, avoid stress, increase efficiency.
Focus on cognitive + interpersonal skills, not stick-and-rudder.
Applies to single-pilot operations too.
Driver event: Tenerife 1977.
Mandatory for compliance with an ICAO Standard.
Aim: contribute to incident and accident prevention.
2. A Conceptual Model of Human Factors — The ICAO SHEL Model
📘 What this section covers
The SHEL model's origin (Edwards, 1972), its ICAO basis (Doc 9859, Circular 216-AN31), the four components (S–H–E–L), the four interfaces, why Liveware is the hub, and why mismatches matter.
2.1 Purpose of the SHEL Model
The SHEL model is a conceptual model of Human Factors that:
Clarifies the scope of aviation human factors.
Assists in understanding the relationships between the flying subsystem (system resources/environment) and the human subsystem.
Provides a conceptual framework illustrating the various constituents and their interfaces — the points of interaction.
Design of flight decks, physical structure of the aircraft, presentation of instruments, positioning and operating sense of controls, machinery, equipment, etc.
E
Environment
Both internal and external to the workplace.
L
Liveware (1st)
Man — the most critical, valuable and flexible component of the system.
Crew co-ordination, briefings, communication (incl. noise interference), worker-management
L–E
Humans & Operating Environment
Weather, time of day, circadian rhythm/jet lag, illumination, vibration, aerodrome facilities
2.5 Liveware as the Hub — Why the Match Matters
🎯 Core SHEL Principle
The Liveware (human element) is the HUB of the SHEL model. The remaining components must be adapted and matched to this central component.
🚫 Mismatch = Source of Human Error
In this model the match or mismatch of the blocks (the interface) is just as important as the characteristics of the blocks themselves. A mismatch can be a source of human error leading to an accident or an incident.
Humans suffer considerable performance variation and many limitations — most of which are now predictable. The Liveware must be carefully matched to other components to avoid stress in the system and eventual breakdown.
📌 Quick Revision Summary — Section 2
SHEL = Software, Hardware, Environment, Liveware (+ second Liveware).
Developed by Edwards, 1972; described in ICAO Doc 9859 and Circular 216-AN31.
Four interfaces: L–H, L–S, L–L, L–E.
Liveware is the HUB → all other components must adapt to humans.
Mismatch at any interface = source of human error.
3. Factors Relating to the Individual (Liveware)
📘 What this section covers
The four factor categories that shape pilot performance — Physical, Physiological, Psychological, Psychosocial — and every sub-element listed in the DGCA source. Source notes the physiological and psychosocial factors are more pronounced in effect.
Many factors influence aviation personnel: Physical, Physiological, Psychological, Psychosocial. However, the effect of physiological and psychosocial factors is more pronounced.
flowchart TB
A[Liveware Individual Factors] --> B[1. Physical]
A --> C[2. Physiological]
A --> D[3. Psychological]
A --> E[4. Psychosocial]
B --> B1[Anthropometry & Sensory limits]
C --> C1[Body state: nutrition, fatigue, drugs, illusions]
D --> D1[Mind state: perception, attention, workload, personality]
E --> E1[Social pressures: family, finance, conflict]
style A fill:#e8f1fb,stroke:#2c5aa0,stroke-width:3px
style C fill:#fff8e1,stroke:#f57c00,stroke-width:2px
style E fill:#fff8e1,stroke:#f57c00,stroke-width:2px
Over-the-counter (OTC) medicines from a chemist are NOT permitted for a pilot before flight. Even OTC items from an aircraft first-aid box must NOT be taken to fly. All medication must be prescribed by an aviation medicine specialist, whose advice on fitness to fly is binding.
Under high arousal / cognitive overload, attention does NOT sharpen — there is a real danger of attention becoming narrowed (channelized attention, fixation). Optimum arousal applies to moderate difficulty tasks; for highly difficult cognitive tasks the optimum arousal is lower.
3.4 Psychosocial Factors
Mental pressure
Interpersonal conflict
Personal loss
Financial problems
Significant lifestyle changes
Family pressure
🧠 Memory Aid — "PPPP" of Liveware Factors
Physical → Physiological → Psychological → Psychosocial.
Remember: "Physiological and Psychosocial effects are MORE pronounced."
📌 Quick Revision Summary — Section 3
Four Liveware factor families: Physical, Physiological, Psychological, Psychosocial.
Physiological + Psychosocial effects are most pronounced.
High noise level in a cockpit is treated as a Liveware–Liveware mismatch because it primarily disrupts oral communication between humans. (Noise is listed as the very first item under "Oral communication" in L–L.)
4.2 Liveware–Hardware (Human–Machine) Interface
✓ Landmark Equipment — GPWS
In the 1980s, the Ground Proximity Warning System (GPWS) marked a substantial decrease in hull loss rates. This is a classic L–H interface improvement.
Workspace layout, standardization, communication equipment, eye reference position, seat design, restrictions to movement (congested cockpit), illumination level, motor workload, information displays, visibility restrictions, alerting and warnings, personal equipment interference (comfort), data link, operation of instruments ("finger trouble").
⚠️ Exam Tip — "Congested cockpit restricting movement"
This is a Liveware–Hardware mismatch (workspace/physical layout). Do not confuse it with Environment (which would be heat/cold/glare etc.).
4.3 Liveware–Software (Human–System) Interface
Sub-Element
Items
Written Information
Manuals, checklists, publications, regulations, maps and charts, NOTAMs, standard operating procedures, signage, directives.
Qualification in position, qualification in management, certification, medical certificate, licence/rating, non-compliance, infraction history.
⚠️ Exam Tip — "Error in checklist"
A checklist is part of Software. Therefore an error in a checklist is a Liveware–Software mismatch. Inefficient warning logic / symbology is also classified under L–S because warning systems are software-driven.
The PIC's authority recalibration, the three foundations of CRM success, the four determinants of an effective CRM programme, and the four formal aims of CRM training.
Both tradition and regulation give full authority to the Pilot-in-Command, who must understand and accept that questions and observations are NOT a threat to his final authority.
🚫 The "Old Days" Failure Mode
The role of the First Officer in the old days was to obey the captain's "gear up and shut up" commands without question. The role of the cabin crew was to bring coffee and meals to the flight deck. No one dared contravene the captain's dictates, even to provide essential safety information. Predictable result: lots of unwanted accidents and many lost lives.
🎯 Fundamental CRM Concept
No single human being has the full picture, and every single person has something useful to contribute to developing it. Working with other people to assemble a complete picture is absolutely necessary to take advantage of all available information needed for safe operation.
5.2 Three Foundations of Continued CRM Success
flowchart LR
A[Strategic Action for CRM Success] --> F1[Foundation 1 Errors are NORMAL]
A --> F2[Foundation 2 NON-PUNITIVE response]
A --> F3[Foundation 3 Equip crews with countermeasures]
F1 --> R[Continued CRM Success]
F2 --> R
F3 --> R
style A fill:#e8f1fb,stroke:#2c5aa0,stroke-width:3px
style R fill:#e8f5e9,stroke:#2e7d32,stroke-width:3px
Operational error passes through the complete human and technology operational process. CRM aims to present errors as normal occurrences and to develop strategies for managing them.
A non-punitive response to operational error sets the best foundation to identify conditions that breed errors within an organization.
Airlines that tolerate operational error and implement non-punitive policies are likely to better equip flight crews with appropriate countermeasures to deal with operational errors.
5.3 Four Determinants of an Effective CRM Programme
Determinant
Source Description
a) Operational Relevance
Deliberate avoidance of classroom games, non-operational activities, and personality assessment.
b) Use of Own Experience
Utilization of own incidents and accidents that reflect the typical safety issues of the airline — the airline is determined to learn from its own errors.
c) Threat Assessment
Crews allowed to assess threats and their management. Open discussion of threats within the airline and how these are detected, addressed and mitigated.
d) Error Management
Examination of both effective and ineffective error countermeasures — thus maximizing learning.
5.4 Four Aims of CRM Training
✓ Formal Aims (verbatim from source — CPL/ATPL exam direct quote)
CRM training has clear aims in terms of specific skills to develop for the purpose of:
Error avoidance
Threat management
Error management
Undesired aircraft state management
⚠️ Exam Trap — Wrong combinations
Beware options like "system management" or "environment management" — these are NOT among the four aims. The correct list always ends with "undesired aircraft state management".
📌 Quick Revision Summary — Section 5
PIC's authority is final, but questions/observations are not a threat to it.
3 Foundations: Errors normal · Non-punitive · Equip crews.
The 15 specific CRM skill competencies that govern the scope of CRM training, including the important concept of the Trans-Cockpit Authority Gradient (TCAG).
Skill
Competency Description (source-aligned)
1. Leadership / Command
Uses appropriate authority to ensure focus on task and crew member concerns. Supports others in completing tasks.
2. Decision Making
Detects deviation from desired state, assesses the problem, generates alternatives, identifies risks, selects best course of action; subsequently reviews chosen course for learning.
3. Communication
Clear and effective language; plans stated, ambiguities resolved; demonstrated in interactive briefings and debriefings.
4. Situation Awareness
Comprehends present system & environmental conditions; anticipates future changes; projects changes as the flight progresses.
Prioritizes and delegates; keeps everyone "in the loop"; continuously monitors flight progress.
7. Vigilance
Consciously avoids complacency; watches over system/environment changes; informs other crew members of potential threats and errors.
8. Automation Management
Uses automation to assist in managing flight, especially in high workload. Tracks mode changes; "keeps ahead of the curve".
9. Human Performance
Aware of personal and human limitations; recognizes stress loads; assertive when approaching limitations.
10. Trans-Cockpit Authority Gradient (TCAG)
The authority relationship between captain and first officer. Steep with domineering captain + unassertive F/O; shallow with two captains; desired = balanced gradient where captain's authority is recognized but good relationships and synergy retained.
11. Briefings
Sets open and interactive communication; checks understanding by soliciting questions/comments; focuses on operational issues.
12. Setting Bottom Lines
Aware of crew actions and potential breaches of minima; verbalizes concerns when risks increase vulnerability to error.
13. Contingency Management
Constant awareness of changes; assesses threats and plans for contingent actions.
14. Evaluation of Plans
Examines course of action; solicits input to analyse how threats/errors were managed.
15. Assertiveness
Queries others in ambiguous situations; constructively asserts views; contributes to overall team effectiveness.
A gradient where the captain's authority is recognized, but good relationships and synergistic working are retained. This requires a balance of task-oriented and relationship-oriented behaviors, the amount of which depends on the crew-members and the situation.
📌 Quick Revision Summary — Section 6
15 CRM skills to remember: Leadership · Decision Making · Communication · Situation Awareness · Team Building · Workload Management · Vigilance · Automation Management · Human Performance · TCAG · Briefings · Setting Bottom Lines · Contingency Management · Evaluation of Plans · Assertiveness.
7. Threat and Error Management (TEM) — Threats
📘 What this section covers
The TEM concept (CRM = manage resources; TEM = manage threats), the foundational acceptance that threats and errors will occur, the formal definition of a threat, and the six types of threats per the DGCA source.
7.1 TEM Concept
Definition — TEM
CRM is about managing resources; TEM is about managing threats. Safe flight operations require the recognition of threats and the appropriate use of error-management countermeasures to avoid, trap and mitigate the effects of human error.
The fundamental purpose of CRM training is to improve flight safety through the effective use of error-management strategies in individual as well as systemic areas of influence. Hence, it is only reasonable to refocus CRM as Threat and Error Management (TEM) training.
✓ Practical Summation of TEM
TEM is the practice of thinking ahead in order to predict and avoid errors and operational threats, and to manage any that occur. A foundation of TEM is the acceptance that threats will occur, and errors will be made. Hence TEM is NOT an attempt to eliminate threats and errors but is concerned with the management of them.
7.2 Definition of a Threat
Definition — Threat
Threats are external events, outside the influence of the crew, that require crew management. They increase the complexity of the operational environment and have the potential to foster flight crew errors.
Examples of real-life threats include bad weather, time pressures to meet departure/arrival slots, delays, and (more recently) security events.
7.3 The Six Types of Threats
#
Type
Examples (source-verbatim)
1
Environmental
Adverse weather, terrain, airport conditions, heavy traffic/TCAS events, unfamiliar airports.
2
ATC
Command events/errors, language difficulties, similar call signs.
8. Error Management — The Five Categories of Errors
📘 What this section covers
The definition of operational error, the five formal error categories under TEM, and what happens when errors go unmanaged — the Undesired Aircraft State.
8.1 Definition
Definition — Operational Error
Within the TEM concept, flight crew operational error is defined as an action or inaction by the crew that leads to deviations from organizational or flight crew intentions or expectations. Operational errors may or may not lead to adverse outcomes.
8.2 The Five Error Categories
#
Category
Source-Verbatim Definition
a
Intentional Non-compliance Error
Willful deviation from regulations and/or operator procedures.
b
Procedural Error
Deviation in the execution of regulations and/or operator procedures. The intention is correct, but the execution is flawed. Includes errors where the crew forgot to do something.
c
Communication Error
Miscommunication, misinterpretation or failure to communicate pertinent information within the flight crew, or between the flight crew and an external agent (e.g., ATC or ground operations).
d
Proficiency Error
Lack of knowledge or psycho-motor ("stick and rudder") skills.
e
Operational Decision Error
A decision-making error not standardized by regulations or operator procedures that, as such, unnecessarily compromises safety.
8.3 The Three Conditions That Define an Operational Decision Error
⚠️ Decision Error — At Least ONE Condition Must Exist
The crew had more conservative options within operational reason and decided NOT to take them.
The decision was NOT verbalized and therefore not shared between crew members.
The crew had time but did not use it effectively to evaluate the decision.
Source example: A crew's decision to fly through known windshear on an approach instead of going around.
8.4 The Undesired Aircraft State (UAS)
🚫 Consequence of Unmanaged Errors
If the crew is unable to avoid, trap or mitigate the error (i.e., unmanaged errors), the consequential outcome may lead to an Undesired Aircraft State. Typical situations:
Incorrect aircraft configurations
Unstable approaches
Vertical, lateral or speed deviations
flowchart LR
T[THREAT External]:::red --> M{Crew Manages Threat?}
M -- Yes --> S[Safe Flight]:::green
M -- No --> E[ERROR]:::red
E --> EM{Crew Manages Error? avoid/trap/mitigate}
EM -- Yes --> S
EM -- No --> UAS[UNDESIRED AIRCRAFT STATE]:::red
UAS --> R{Recovery?}
R -- Yes --> S
R -- No --> ACC[Incident / Accident]:::red
classDef red fill:#fdecea,stroke:#c0392b,stroke-width:2px
classDef green fill:#e8f5e9,stroke:#2e7d32,stroke-width:2px
The definition of LOFT, the source of scenarios, and the critical distinction that LOFT is NOT a check-ride but a validation of training programmes.
9.1 Definition
Definition — LOFT
Line-Oriented Flight Training refers to non-jeopardy, facilitated aircrew training which involves a full mission simulation of situations representative of line operations. LOFT places special emphasis on situations involving communications, management, and leadership.
In short — LOFT means realistic, real-time, full-mission training.
9.2 Scenario Sources
LOFT scenarios may be developed from many sources, but accident and incident reports provide a realistic and appropriate starting point.
9.3 LOFT is NOT a Check-Ride
🚫 Critical Limitation — Non-Jeopardy
LOFT should NOT be used as a method of checking the performance of individuals. Instead, it is a validation of training programmes and operational procedures.
✓ Post-LOFT SOP
An individual or crew needing additional training after a LOFT session shall be afforded that opportunity immediately, with no stigma or recrimination.
flowchart LR
A[Accident/Incident Reports] --> S[LOFT Scenario Design]
S --> F[Full Mission Simulation]
F --> T[Crew Training Non-jeopardy]
T --> E{Additional Training Needed?}
E -- Yes --> P[Provide Immediately No stigma]
E -- No --> V[Validates Training & SOPs]
P --> V
style F fill:#e8f1fb,stroke:#2c5aa0
style V fill:#e8f5e9,stroke:#2e7d32,stroke-width:3px
NOT a check on individuals — it validates training and procedures.
Additional training after LOFT = immediate, no stigma.
📝 Practice Questions & Detailed Answers
How to use this section: Attempt each question first by covering the answer panel. Read your option, then reveal. Even if correct, read the explanation and distractor analysis — exam tricks live in the wrong options. Cross-reference back to the relevant study section using the anchor links.
Total: 21 MCQs · Source: DGCA Human Factors (Chapter 24) Question Bank
Q1.Human errors:
Are now considered as being inherent to the cognitive function of human and can be totally eliminated by CRM training.
Are now considered as being inherent to the cognitive function of human and are generally inescapable.
Are likely to be eliminated in the near future by higher degree of automation.
✓ Correct Answer: (B) Are now considered as being inherent to the cognitive function of human and are generally inescapable.
(A) — CRM does NOT "totally eliminate" errors. This contradicts the foundational TEM premise.
(C) — Automation has historically relocated errors, not eliminated them (see Q16). New automation creates new types of error.
Instructor's Note: Any option containing the words "eliminated", "totally", or "completely removed" alongside human error is almost always a distractor. Bank this rule.
Q2.The error in checklist is related to an interface mismatch between:
Liveware – Liveware.
Liveware – Software.
Liveware – Environment.
✓ Correct Answer: (B) Liveware – Software.
Explanation: Checklists are explicitly listed under the Liveware–Software interface as part of "Written Information" (along with manuals, NOTAMs, SOPs, charts). Therefore an error in a checklist is a human–software mismatch. See Section 4.3 — L–S Written Information.
Why the other options are wrong:
(A) — L–L is about humans interacting with humans (communication, briefings); a paper/electronic checklist is not a human.
(C) — Environment relates to weather, glare, vibration, ambient noise, time of day — not procedures or documentation.
(A) — Includes "system management" which is NOT one of the four aims.
(B) — Includes "environment management" which is NOT among the four aims.
Instructor's Note: Memorize the EXACT four: Error Avoidance → Threat Mgmt → Error Mgmt → Undesired Aircraft State Mgmt. The pattern goes from prevention → reaction → recovery.
Q4.A congested cockpit restricting movement is an interface mismatch between:
Liveware – Software.
Liveware – Environment.
Liveware – Hardware.
✓ Correct Answer: (C) Liveware – Hardware.
Explanation: A congested cockpit is a workspace / physical design issue. The source explicitly lists "workspace layout" and "restrictions to movement" under Liveware–Hardware. See Section 4.2 — L–H Workspace.
Why the other options are wrong:
(A) — Software involves documents and procedures, not physical space.
(B) — Environment refers to ambient conditions (heat, humidity, glare, vibration), not the cockpit's internal physical layout.
Instructor's Note: A useful tag: "Physically touchable" + "machine/airframe-related" = L–H. Cockpit layout, controls, displays, seats — all L–H.
Q5.High noise level in a cockpit is a mismatch between:
Liveware – Liveware.
Liveware – Environment.
Liveware – Hardware.
✓ Correct Answer: (A) Liveware – Liveware.
Explanation: This is a classic DGCA trap. Although noise originates from the environment/machine, the mismatch it causes is at the human-to-human communication interface. The source lists "Noise interference" as the very first item under L–L Oral Communication. High cockpit noise degrades inter-crew communication — that's the operational mismatch. See Section 4.1 — L–L Oral Communication.
Why the other options are wrong:
(B) — A tempting choice since noise is an "environmental" stressor, but the operational impact (and the source's classification) is on inter-human communication.
(C) — Hardware would apply only if the question was about cockpit design causing noise, not the noise itself.
Instructor's Note: The DGCA rule of thumb: noise affecting comms → L–L. This is one of the most frequently misanswered questions in the bank — note it.
Q6.Inefficient warning system in the cockpit is a mismatch between:
Liveware – Liveware.
Liveware – Environment.
Liveware – Software.
✓ Correct Answer: (C) Liveware – Software.
Explanation: A "warning system" — its logic, symbology, alerting cues, and procedures — is fundamentally a software concept (computer programs, symbology, procedural alerts), all of which are listed under Liveware–Software. While the physical chime or light is hardware, the warning system as a whole (the question's phrasing) is classified as L–S. See Section 4.3 — L–S Computers / Automation / Written Information.
Why the other options are wrong:
(A) — Warning systems do not involve human-to-human interface.
(B) — Environment is about external/ambient conditions, not engineered alerts.
Instructor's Note: Treat warning systems, automation logic, EICAS/ECAM alerts, FMS messages, and computer prompts as L–S. The physical button/light hardware is L–H, but the alerting system is L–S.
Q7.A disturbance of the biological rhythm is a mismatch between:
Liveware – Hardware.
Liveware – Software.
Liveware – Environment.
✓ Correct Answer: (C) Liveware – Environment.
Explanation: Circadian dysrhythmia (jet lag) is caused by time-zone changes in the external environment. The body's biological rhythm is desynchronized from the new local time — a clear human-vs-environment mismatch. See Section 3.2 — Sleep / Circadian Dysrhythmia and Section 4.4 — L–E Time of Day.
Why the other options are wrong:
(A) — Hardware has nothing to do with body clock disruption.
(B) — Procedures/manuals cannot cause biological-rhythm disturbance.
Instructor's Note: Jet lag = environment-induced. Treat time of day, day/night, time-zone effects consistently as L–E.
Q8.The main consideration in modern airline operations should be:
Efficient utilisation of resources.
Maximum utilisation of resources.
Safety.
✓ Correct Answer: (C) Safety.
Explanation: Safety is the cardinal principle of aviation. Efficiency and resource utilisation matter, but never above safety. The entire CRM/TEM/LOFT framework exists to contribute to incident and accident prevention (see Section 1.2). Safety is the overarching objective.
Why the other options are wrong:
(A) — Efficient utilisation matters but is subordinate to safety.
(B) — "Maximum" utilisation can even push against safety margins (e.g., rostering crews to fatigue limits).
Instructor's Note: "Safety first" is non-negotiable in any DGCA exam — if Safety appears as an option in a question about priorities, it is almost always correct.
Q9.The elements of the SHEL model are:
Software, hardware, electronics, and livewire.
Shareware, hardware, education, and limitations.
Software, hardware, environment, and livewire.
✓ Correct Answer: (C) Software, hardware, environment, and livewire.
Explanation: S–H–E–L stands for Software, Hardware, Environment, Liveware. Note: option (C) uses the variant spelling "livewire" exactly as printed in the source question bank — the intended term is "Liveware". This is the only option that has all four correct categories. See Section 2.3 — The Four SHEL Components.
(B) — Three wrong terms: Shareware, Education, Limitations are not in SHEL.
Instructor's Note: The official DGCA source spells it "Liveware". The Q-bank's "livewire" is a printing variant, not a real change in meaning. Both refer to the human element.
Q10.Which is true regarding the interaction between various elements of the SHEL model?
All components of the SHEL model are equally important, as conflict and error can arise from the various mismatches.
The hardware is the hub for interactions between the different components of the system, hence other components should be matched to design most suitable hardware.
The liveware is the hub of the SHEL model; therefore, the nonhuman components should be adapted and matched to this central component.
✓ Correct Answer: (C) The liveware is the hub of the SHEL model; therefore, the nonhuman components should be adapted and matched to this central component.
Explanation: The source explicitly states: "The liveware (human element) is the hub of the SHEL model. The remaining components must be adapted and matched to this central component." See Section 2.5 — Liveware as the Hub.
Why the other options are wrong:
(A) — Misleading: while mismatches matter, components are NOT equally important — Liveware is the hub.
(B) — Wrong: Hardware is NOT the hub. Designing other components to suit hardware reverses the Human Factors principle.
Instructor's Note: "Liveware is the hub" is a single-sentence answer to many SHEL questions. Bank it.
Q11.CRM and LOFT training are designed to improve:
The quality number of individuals performance.
Individual performance in adverse conditions.
The quality of crew performance.
✓ Correct Answer: (C) The quality of crew performance.
Explanation: Both CRM and LOFT target crew (collective) performance, not individuals. LOFT specifically is described as a validation of training programmes and procedures, NOT a check on individuals. See Section 1 and Section 9.
(B) — Again focused on individuals and limited to "adverse conditions" only; CRM applies always.
Instructor's Note: Remember: CRM = "Crew" Resource Management. The word crew is built into the acronym. The answer in any "what does CRM improve?" question will involve crew, not individuals.
Q12.Four important disciplines from which information is drawn in understanding human performance and behavior are:
Psychology, engineering, physiology, and anthropometry.
Sociology, mathematics, biology and industrial design.
Physics, biochemistry, physiology, and anthropometry.
✓ Correct Answer: (A) Psychology, engineering, physiology, and anthropometry.
Explanation: The four disciplines underpinning Human Factors are: Psychology (mind, behaviour), Engineering (machines, systems), Physiology (body function), and Anthropometry (body measurements — reach, fit, size). These provide a complete coverage of mind + body + machine + fit. Anthropometric attributes (height, weight, reach, etc.) are explicitly listed in Section 3.1 — Physical Factors.
Why the other options are wrong:
(B) — Sociology and mathematics are not core HF disciplines in the SHEL framework.
(C) — Physics and biochemistry are too narrow/specific; psychology is missing entirely.
Q13.Pilots have now become responsible for the management of hardware and software interfaces, through which they are required to direct the operation of the aircraft. These technological advances have:
Significantly eliminated human errors.
Given rise to new forms of error.
Are aimed to eliminate pilots from the cockpit.
✓ Correct Answer: (B) Given rise to new forms of error.
Explanation: Automation and advanced cockpit interfaces have relocated errors rather than eliminated them, introducing new categories such as mode confusion, automation surprises, and over-reliance on FMS. The source's automation discussion under L–S highlights operator workload, monitoring task, task saturation, situational awareness and skill maintenance as new concerns. See Section 4.3 — L–S Automation.
Why the other options are wrong:
(A) — Same trap as Q1: nothing "eliminates" human error.
(C) — Aviation does NOT aim to eliminate pilots; automation assists them.
Instructor's Note: Pair this with Q16 (automation relocates and adds workload). The pattern is consistent: more automation → different errors, not fewer.
Q14.About what proportion of civil air accidents result from inadequate human performance?
89%
73%
57%
✓ Correct Answer: (B)73%
Explanation: The widely accepted figure cited in DGCA Human Factors material and reflected in this Q-bank is approximately 73% of civil air accidents attributable to inadequate human performance. This is the reason CRM/TEM training carries the same regulatory weight as systems and emergency procedure training (see Section 1.2).
Why the other options are wrong:
(A) 89% — Overstated; not the DGCA figure for this question.
(C) 57% — Understated.
Instructor's Note: Lock this number — 73%. It is one of the few numerical figures asked directly in DGCA Human Factors exams.
Q15.What is meant by the trans authority gradient?
It is the authority exercised by the captain over all flight operations.
It is the authority relationship between captain and other crew members.
It is the authority relationship between captain and first officer.
✓ Correct Answer: (C) It is the authority relationship between captain and first officer.
Explanation: The source defines Trans-Cockpit Authority Gradient (TCAG) precisely as "the authority relationship between captain and first officer" — not all crew, not unilateral captain authority. The gradient may be steep, shallow, or balanced (desired). See Section 6.1 — TCAG.
Why the other options are wrong:
(A) — Describes captain's general command authority, not the gradient.
(B) — "Other crew members" is too broad; TCAG is specifically captain ↔ first officer.
Instructor's Note: Bookmark this exact phrasing — "between captain and first officer" — it's a direct DGCA quotation.
Q16.Introducing Automation in a cockpit:
Always reduces potential for human error and workload.
Generally relocates potential for error and increases workload.
Eliminates human error but workload increases.
✓ Correct Answer: (B) Generally relocates potential for error and increases workload.
Explanation: Automation does NOT eliminate errors — it shifts them to new domains (mode confusion, monitoring failures, complacency). It also increases certain workloads: monitoring tasks, mode awareness, data entry, programming, and managing automation itself. This matches the L–S Automation source items: operator workload, monitoring task, task saturation, situational awareness, skill maintenance. See Section 4.3 — L–S Automation.
Why the other options are wrong:
(A) — "Always" is wrong; automation reduces some workloads but adds others.
(C) — "Eliminates" is wrong (same trap as Q1, Q13).
Instructor's Note: Mantra — "Automation relocates error, it does not eliminate it." Pair with Q13.
Q17.High Arousal Overload results in:
A real danger of attention becoming narrowed.
An attention becoming sharpest.
An optimum arousal for more difficult or intellectually (cognitive) tasks.
✓ Correct Answer: (A) A real danger of attention becoming narrowed.
Explanation: Under high arousal/overload, attention narrows (channelization, fixation) — the opposite of "sharpening". This is consistent with the Yerkes-Dodson inverted-U: high arousal degrades performance on cognitively demanding tasks. The source lists "channelized attention" and "fixation" as failure modes under Section 3.3 — Attention.
Why the other options are wrong:
(B) — Attention does NOT become "sharpest" under overload — it narrows.
(C) — Difficult cognitive tasks have a lower optimum arousal, not higher.
Instructor's Note: The classic exam phrase to recognise: "channelized attention" or "tunnel vision under stress" → both indicate the narrowing referenced in option (A).
Q18.A pilot suffering from a mild headache before flight can:
Take Over The Counter medicines from the chemist and fly.
Take Over The Counter medicines from the first aid box in the aircraft and fly.
Should take medicines prescribed by an aviation medicine specialist and take his advise for flying.
✓ Correct Answer: (C) Should take medicines prescribed by an aviation medicine specialist and take his advice for flying.
Explanation: OTC medicines can have side effects (drowsiness, blurred vision, impaired reaction time) that compromise flight safety. A pilot must consult an aviation medicine specialist, who can prescribe an appropriate medication AND determine whether the pilot is fit to fly. The headache itself may also be a symptom requiring grounding. See Section 3.2 — Drugs / Health.
Why the other options are wrong:
(A) — Self-medication with chemist-bought OTC is prohibited.
(B) — The aircraft's first-aid box is for passenger/emergency use, not pilot self-medication; also fails the specialist-prescription requirement.
Instructor's Note: Golden rule — "Pilot + medication" answer is ALWAYS: consult Aviation Medicine Specialist. No DGCA exam question on this topic deviates from this.
Q19.Categories of errors defined by TEM are:
Intentional non-compliance error, Procedural error, Communication error, Proficiency error and Operational decision error.
Intentional non-compliance error, Procedural error, Communication error, Proficiency error and vigilance error.
Instrument error, Procedural error, Communication error, Proficiency error and vigilance error.
Explanation: TEM defines exactly five error categories per the source: Intentional Non-compliance · Procedural · Communication · Proficiency · Operational Decision. See Section 8.2 — Five Error Categories.
Why the other options are wrong:
(B) — "Vigilance error" is NOT a TEM category. Vigilance is a CRM skill (see Section 6), not an error category.
(C) — "Instrument error" is also not a TEM error category.
Instructor's Note: Mnemonic — "I PCPO": Intentional non-compliance, Procedural, Communication, Proficiency, Operational decision. Drill this once and you own every TEM error question.
Q20.Operational Threats outside the control of flight crew are:
Adverse weather, Terrain, Airport conditions, Heavy traffic/TCAS events, Unfamiliar airports etc.
Time pressure, Irregular operations, Flight diversions, Missed approaches etc.
Aircraft malfunctions, Automation events etc.
✓ Correct Answer: (B) Time pressure, Irregular operations, Flight diversions, Missed approaches etc.
Explanation: The question specifically asks about the "Operational" category of threats. Per the source's Threat Type #5 (Operational), examples are exactly: Time pressure, Irregular operations, Flight diversions, Missed approaches. See Section 7.3 — Threat Type 5: Operational.
Why the other options are wrong:
(A) — These are Environmental threats (Type 1), not Operational.
(C) — These are Aircraft threats (Type 3), not Operational.
Instructor's Note: Read the question's key adjective. "Operational" threats = the schedule/ops world (time, diversions, missed approaches). "Environmental" = weather/terrain. "Aircraft" = malfunctions/automation. Match the category to the listed items.
Q21.What airplane equipment marked a substantial decrease in hull loss rates in the eighties?
Explanation: The source directly states: "In 1980s Ground Proximity Warning System (GPWS) marked a substantial decrease in hull loss rates." GPWS attacked the leading cause of fatal accidents at the time — Controlled Flight Into Terrain (CFIT). See Section 4.2 — L–H GPWS milestone.
Why the other options are wrong:
(B) TCAS — Addresses mid-air collision risk (TA/RA), not CFIT. Came into widespread mandate in the 1990s.
(C) SSR — Secondary Surveillance Radar is a ground-side ATC surveillance technology, not aboard-aircraft hull-loss reduction equipment.
Instructor's Note: Decade-equipment pairing: 1980s → GPWS (anti-CFIT). The DGCA loves direct decade quotes from the chapter — remember this verbatim.