Human Factors and Pilot Performance

1. Human Factors and Pilot Performance Section 3 Information Processing, Decision Making and Memory

2. Human Factors and Pilot Performance 3.1 Information processing. • Information is transmitted through the peripheral nervous system to the brain where it is processed and used as the basis for action. See Thom 6.1 • Brain functions as a single channel decision maker, which it handles one at a time (Thom 6.2) Basis of decision making: Stimulus -e.g. airspeed decreasing in climb. Sensory nerves send a message to the brain Analysis– consequences of airspeed continuing to decrease: plane could stall: Need to correct. Action–lower nose/ reduce angle of attack. Message to muscles (motor nerves) Feedback– check that action was effective (if not, need to do something more) • Same principles apply to all decision making • Note: We can assist the CDM process by arranging things sequentially at the outset e.g. FREDA(CH) checks (see below)

3. Human Factors and Pilot Performance • As well as conscious decision making (thinking) there are mechanisms involving unconscious mental activity that amount to something similar • Motor programmes (skills). Groups of muscles are trained to work automatically e.g. walking, flying. Motor programes usually initated by a CDM decision e.g. child wants to see whats on a table. Deliberate decisions trigger a motor programme • Reflexes. Similar to motor programmes but much quicker . Sensory and motor nerves close together, automatic response (without thinking). E.g. Touching a hot surface. • Conditioned reflexes – trained reflex – train to do something without thinking e.g. FREDA checks. Can get things wrong – always monitor e.g. carb heat/mixture control • Autonomic activities (breathing, heartbeat, digestion) carry on completely automatically. Separate nervous system (autonomic) • See Thom6.3, 6.4

4. Human Factors and Pilot Performance Sensing and Perception • Sense organs (sensory perceptors) are groups of specialised cells that detect changes and feed that information to the brain where it is interpreted. e.g. taste buds (chemical), rods and cones (light), vestibular apparatus (balance). • Have a threshold below which change not detected - stimulus too faint • The time information is stored may vary: • Visual – about 1 sec • Sounds – about 5 secs • Perception is the interpretation of sensory images by the brain. e.g. an ATC message • may be affected by experience. e.g. approaching controlled airfield expect ATC msg “report on finals” BUT if different message sent, may be missed because of the expectation to “report on finals” e.g. “left orbit on base” • Known as mindset. • Sensory confusion – when msg from one sensor does not match msg from another. e.g. Leans

5. Human Factors and Pilot Performance Attention and motivation • Attention is selection of stimuli you think are most important (selective attention). • Divided attention (time sharing) is what we need to do most of the time when flying – regularly checking everything that’s going on. E.g. position checks with ground features, FREDA checks, ATC traffic, weather checks, other aircraft. • Stress and over-concentration on one task can diminish perception e.g. in an emergency or too great a workload. Moderate arousal good Thom 6.6 Action and Feedback • Checking that an action is having the desired affect e.g.use of rudder on take off, • Coordination of rudder and ailerons in crosswind

6. Human Factors and Pilot Performance Response time. • Critically important. EFTO – 300 ft – less than 30 secs to respond. • More time (a little!!) when landing – go-around decision point. • More time when touring – low fuel. • More time = more options. Hence pays to fly XC at a reasonable altitude (e.g. 2 -3000 ft). More time to restart engine/choose landing site/ MAYDAY on engine failure. Abnormal Perceptions • Hallucination. Imagined stimulus (not real) • Illusion.Misinterepretation of a stimulus. • Agnosia. Brain disorder that interferes with correct interpretation of a stimulus • Always cross check interpretation if you can e.g compare visual image with instrument information. Don’t rely on “seat of pants”.

7. Human Factors and Pilot Performance 3.3 Memory • Storage and retrieval of information. • 3 or 4 mechanisms depending on how long information needs to be kept before use. Sensory memory. Sensory information is retained long enough to be useful and is then forgotten • Visual images – 1sec, • Sounds 5 secs (long enough to see if sentence applies to us and then remember the start of it if so) Short-term memory • Holds a few items for a short time • “typically” 7 items for 15secs, but variable e.g. phone no, ATC frequency change. • Don’t rely on it! Better to write items down as they are received –helps accurate read back.

8. Human Factors and Pilot Performance Chunking • Group nos. together or use mnemonics • e.g. 13673948 - easier to remember as 1367 – 3948 and only 2 items that way • e.g. FREDA(CH) (enroute) checks – fuel,radio,engine,direction,altitude, (carb heat) Working Memory. • Contains information we have selected as relevant. • Needs to be rehearsedto stay current, or erncoded-elated to something familiar. E.g. altitude of airfield/radio frequency e.g. Birr 250 or Kilrush 260 123425. Long-term Memory. Where information that has been sufficiently rehearsed or encoded is stored, available considerable time later (may be years).

9. Human Factors and Pilot Performance • Two types of storage • Meaning. E.g. use/structure of language, words Semantic Memory • Events. Can be reconstructed if necessary – but not always accurately • Information stored there for ever? Probably slowly decays (becomes less accurate with time). Also different people may store it (and therefore remember it) differently. • May also be processed on way out (re-interpreted) • Long Term Memory useful when relating new information to a previous event - can be built up. • E.g. visual approach – can recall principle of a generic visual approach, don’t necessarily have to remember all the details of a visual approach to each individual airfield

10. Human Factors and Pilot Performance 3.4 Workload • Workload varies with state of flight • highest during approach and landing, • take off usually less • may be high on the cruise e.g. air traffic, weather • in fact can be high at any time • Thom 6-7 (compare with 5.2) • Ability to handle workload varies with stress – see Section 2 II

11. Human Factors and Pilot Performance • Mental workload Compare Thom 5.2 (79) and 6-7 (115). • Best performance when pilot has combination of high level of skill (well trained), knowledge and experience and optimum arousal (see Thom 6.6). • These depend on pilot, training etc • Arousal depends on cockpit design, ATC, weather etc. i.e. depends on things outside pilots control (“environmental”) • Mental workload too high, over arousal = important tasks may not be done (not enough time) = low performance • Too low, under arousal = important stimuli not noticed =low performance • In between: things dealt with as they arise (high performance)

12. Human Factors and Pilot Performance • Mental overload. • Sensory memory-too many stimuli. While responding to one (rough engine), another may be missed (ATC call) • Short term memory – too much info or time delays. Includes poor radio. 7 items retained for 15-30 secs only. New info will replace • CDM – overloads if conflicting information cannot be resolved easily e.g. visual and balance, instrument confirmation not available or • too many decisions required at once • pilot is overstressed (lack of knowledge or experience)

13. Human Factors and Pilot Performance 7 7.0 Judgement and Decision Making • Skills that can be learnt. MAKING a decision is probably most important of all. e.g. whether to continue a flight into dodgy weather • Two types of judgement Perceptual judgement • rate of descent, flare height but also dealing with experience (situation similar to onsemet before) Thinking (cognitive) judgement • much more complex. • Risk analysis based on information available e.g. whether to continue a flight or divert. Based on skill, knowledge and experience. Training involves transferring as many thinking judgements or components of them to perceptual judgement.

14. Human Factors and Pilot Performance Judgement makes use of • Knowledge • SOPs • Experience (understanding and thinking ability) • Practical skills Making a decision requires: • collecting and evaluating relevant information (knowledge and experience) • keeping feelings out of it.Deal only with facts. Gethomeitis • considering alternatives • make a timely decision (engine failure) • taking action • right attitude – balanced and calm, aware of risks and how to cope with them, confident in your abilities

15. Human Factors and Pilot Performance • Resource Management • good preparation. Don’t allow distractions (at any time when you need to be concentrating on a specific task) • passenger briefing before startup (safety belts and emergency procs) • all equipment readily available in cockpit • SOPs for everything • Situational awareness (position, weather,other planes, fuel, time,radio) • Avoiding overload • Managing risk • Being in control and totally professional at all times