Loss of Control in Flight is by farthe most common cause offatalities in General Aviation fixedwing aircraft in the UK, USA andmost other parts of the world.Consequently it has been thefocus of much of the attention ofmany safety agencies throughoutthe globe including GASCo. Thisorganisation produced a paper in

2010 that studied fatal stall orspin accidents to UK registeredlight aeroplanes during the period1980 to 2008. Its principleconclusions appear in theAppendix to this report. Thereport led to further practicalresearch by Dr Guy Gratton ofBrunel University and hisconclusions also appear in the

Appendix. Dr Mike Bromfield ofCoventry University has beenworking in recent years withGASCo to pursue the issuesinvolved and the seminar held inNovember 2014 aimed toassemble some of the experts inthis field and to review thepresent state of knowledge.

INTRODUCTION

LoC I (Loss of Control In Flight)

The Report of a Seminar held in November 2014 at Coventry University arranged byGASCo (General Aviation Safety Council) and the Faculty of Engineering andComputing at the University.

page 1

Because, unlike Civil Air Transport (CAT), General Aviation (GA) is not mandated to report Occurrences it isdifficult to get hold of LoC statistics for this sector. This lacuna could present a good subject for a researchproject.

The sectors within GA that Pedro has analysed in respect to LoC are:

Aeroplanes (single engine piston

Three axis microlights

Gliders (including powered gliders)

The four main occurrence categories are:

IMC Operations, including Controlled Flight Into Terrain (CFIT) and LoC in IMC

Mid air collisions

Collisions with obstacles during take off and landing

LoC in VMC

An analysis of loss of control accidents using the humanfactors analysis and classification system (HFACS)

PEDRO PINHEIROPedro Pinheiro is a Safety Performance Analyst at the UK Civil Aviation Authority andis particularly concerned with the statistical analysis of GA accidents. Because of hisunavoidable absence his paper was delivered by Nils Jamieson, one of GASCo’s RegionalSafety Officers.

This last category represents 1.2occurrences per 100,000 hoursflown for the 10 year averagefrom 2004 to 2013.

This value of 1.2 should becompared with the figure of 1.9that represents occurrences of allcategories from which we seethat as much as 70% of the totalof occurrences are down to LoCin VMC.

If we could eliminate LoC in VMCaccidents we should make adramatic difference to the overallaccident rate.

2 page

This dominance by Loc I VMC accidents of the total of all fatal accidents as was revealed in Pedro’s study 2003to 2012 is echoed in two previous major studies: CAP 667, a review of GA fatal accidents from 1985 to 1994,and RR 2006.

Phases of Flight

The distribution of fatalaccidents between differentphases of flight shows lessconsistency between thethree analyses, possiblybecause of variations in thecategorisation. Take off andInitial Climb take up 17 to33% of the total, Cruisemuch the same amount,Climb less than 5%, OtherManoeuvring (includingaerobatics) around 26 to35% and Approach andLanding 9 to 17%.

Currency in the above chart is hours flown in the past 90 days.

The conclusions that Pedro draws from this chart are that neither age nor experience are likely to indicatewhether a particular pilot is less or more likely to suffer a LoC VMC accident. A young and experienced pilotis just as much at risk as is an old and inexperienced pilot.

On the other hand, experience on type and currency are significant factors.page 3

AEROPLANE TYPESCOMPAREDThe GASCo report of 2010showed the fatal stall/spinaccident rate per 100,000 hoursfor all the aeroplane typesinvolved and the Cessna 150showed a remarkably high figureof 0.72 as compared with 0.04 forthe Cessna 152, 0.23 for theCessna 172 and 0.37 for the PiperPA28 Cherokee.

The significantly high rate for theCessna 150 led to practicalresearch and test flights by MikeBromfield from which someinteresting conclusions about theimportance of stick force weredrawn. Two versions in particular of the Cessna 150 have unusually low stick forces in pitch and these versionssuffer unusually high incidences of LoC. This research was the subject of an article in the Spring 2014 issue ofGASCo Flight Safety.

WHAT IS LoC I?LoC I is defined as a deviation from the intended flight path in flight and it is an extreme manifestation of such adeviation. “Loss of control” may cover only some of the cases where an unintended deviation occurred. To meetour definition it must occur during the airborne phases of flight, it can be in IMC or VMC and it may occur as aresult of deliberate manoeuvre such as an intentional stall/spin. It may involve the configuration of the aircraftsuch as the raising or lowering of flaps, pilot induced oscillations, icing related events and may follow less severesystem or component failure.

CAUSAL FACTORSAs the pie chart below shows, LoC was the outstanding causal factor in UK GA less than 5,700 kgs fixed wingaccidents during 1980 to 2006.

Hidden by Numbers?The Human Factors Behind LoC Statistics

Dr. MIKE BROMFIELDMike Bromfield is a Senior Lecturer in Aerospace at the Faculty of Engineering andComputing at a Coventry University and a member of the Vehicle Dynamics and SafetyApplied Research Group. He is a Chartered Engineer, a member of Royal AeronauticalSociety and the Society of light Test Engineers and a PPL.

4 page

THE HEINRICH PYRAMIDThis is a graphic illustration of theproposition that for every accidentthere are a great many moreincidents (30 times more inHeinrich’s estimation) and forevery incident there some 30times as many occurrences.Within UK GA only accidents arerequired to be reported so thatmany incidents and mostoccurrences are known of only bythose involved.

SUMMING UPLoC can happen to anyone and pilots, whatever their experience, need to recognise this. Commercial pilots fly onaverage some 800 hours a year and can thus amass a great many flying hours over the years but as their average sticktime is only three hours a year, an ordinary GA pilot may be the more experienced as regards handling.

Within Commercial Air Transport throughout the world a taxonomy is evolving; this is an agreed convention of termsand categories for the analysis of accidents and incidents particularly with regard to causal factors. What UK GAgreatly lacks is an equivalent common, systematic and holistic taxonomy to analyse Human Factors competently sothat we may acquire in depth insight into accidents and incidents.

When we come to make these analyses we must remember that every one of the components need to be considered.The Task, the Pilot, the Aircraft and the Environment are all likely to be essential components of any analysis.

page 5

HOW ACCIDENTS HAPPEN ... THE SWISS CHEESE MODELThis model assumes that the defences against an accident occurring are represented by a series of slices of Swisscheese in which there are the distinctive random holes. These holes represent failed or absent defences againstan accident. If the slices are assembled together and a continuous hole can be seen through them you have themakings of an accident but if everyone involved can keep the number of holes to a minimum and the number ofslices to a maximum the possibility of an accident can thus be limited.

To drive the point home, Mikeproduced a packet of Gruyèreand attempted the insertion of apencil through the assembledslices.

HOW LoC ACCIDENTSHAPPENThe case study below illustrateshow failed or absent defenceswithin organisational factors,unsafe supervision, preconditionsfor unsafe acts and unsafe actsthemselves can lead to accidentand injury. The various areas offailure are listed.

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THE CAUSAL PATHWAYThis usually starts with a major distraction, possibly of a life threatening nature; the engine fails for example. Stressfollows inevitably and this may be augmented by the pilot experiencing indecision: this will aggravate the degree of stress.

At such a time of stress the human mind tends to narrow its focus. The pilot is likely to concentrate on one task to theexclusion of others. This may quite possibly be the selection of a landing site followed by a determination to reach it.Alternatively the mind may focus on cockpit tasks such as securing the engine and making a MAYDAY call. Such tasksare valuable where there is height and time to complete them without prejudicing the vital priority of flying the planebut sometimes they are turned to almost as a displacement activity.

If the narrowed focus is on any task other than flying the plane the pilot will neglect speed control in favour of thepreferred activity and in that case will also fail to retrim, leading to a greater likelihood of acquiring an unsafe angle ofattack.

A consequence of the heightened stress will be muscle tension, possibly causing lack of feel for the controls. If reachingthe landing site is the focus then the pilot may attempt to stretch the glide and/or initiate a turn.

A Causal Pathway leading to LoC I Accidents

Dr. DAVID JOYCEDavid originally intended to become an aeronautical engineer but instead became aconsultant gynaecologist. He took up flying in his mid forties and has a wide experiencein power flying and gliding. When he retired from medical practice at 60 he built his ownEuropa and has visited over 30 countries since. He has in recent years acquired aparticular interest in stall spin accidents.

6 page

IT CAN HAPPEN TOANYONEAs a demonstration of the factthat anyone can suffer a stall spinaccident, consider this tragedy inthe USA where both the pilotand his passenger, someone else’schild, died. The aircraft was aLancair, which can, admittedly,exhibit some slow speedhandling challenges, but the pilotwas a graduate of the US NavyTest Pilot School with very manyhours on type and was aninstructor and examiner inmultiple types. He was aged 45and had over 4,500 hours.

HOW CAN WE PREVENT IT?Firstly we must break thesequence. Training has hithertoproved to be of only limitedeffectiveness and highly qualifiedand experienced pilots suffer LoCaccidents just as much as the rest.So training often fails to overcomethe tendency of pilots to headdown the causal pathway todisaster. The standard stall warnerseems to be of only limitedeffectiveness and although virtuallyevery certified GA aircraft is sofitted the stall spin accident figuresdemonstrate how they often fail tograb the pilot’s attention in time.

A more effective low speed/highAngle of Attack warner could bethe best way to break thesequence.

Secondly we must take steps tosteer our pilots away from thatindecision that can follow thestartle of a sudden emergency,leading to accentuated stress anddangerously poor piloting. This

means training pilots to know whatto expect of their aircraft inemergency situations and suchknowledge can come only withtraining followed by repeatedpractice. The frequent practice ofrealistic emergency scenarios isessential and while the practiceforced landing on to the airfieldfrom three thousand feet above isa useful exercise, pilots need to beable also to react correctly and

instinctively to an engine failureafter take off or on the go around.This can be achieved andmaintained only be frequentrehearsal.

If the UK GA fleet comprisedmore spin resistant aircraft thatwould also improve the positionbut turnover from old to newdesigns within the fleet is veryslow.

BREAKING THE SEQUENCEIn addition to the standard stall warner, which has proved disappointing in use, there are now three models ofeffective low speed or high angle of attack warning systems on the market.

They are:

page 7

YOUR PLANE’S PERFORMANCE IN EMERGENCIESEvery pilot needs to know:

• Where is the safest place to crash land?

• What height do you need to turn back?

• How to turn with minimal height loss?

• What is your plane’s best glide angle?

• How far can you glide from 3000 ft?

• Are you confident side slipping?

IF YOU CANNOT AVOID ACRASH LANDING

WHERE IS THE BESTPLACE TO CRASH?

These devices give a read out of airspeed modified by prevailing G forces in the case the SmartASS 3 or Angle ofAttack in the case of the Bendix KLR 10. The readout is aural and is on demand but will cut in whenever the speedbecomes less or the angle of attack becomes more than a typical cruise condition. The read out sounds increasinglyurgent as the condition gets more critical.

The cost, fitted, is in the region of £200 for the SmartASS 3 and this is appropriate equipment for a non certifiedaircraft. Certified aeroplanes will need the Bendix King KLR 10 and generic modification approval from EASA alreadyexists. The cost, fitted, will be around £2000.

8 page

HOW BEST TO TURNOne might imagine that the most

efficient turn in terms of height

loss against amount of turn would

be at best glide speed with a

reasonably shallow angle of bank.

The subject was researched in

1994 by David F Rogers of the US

Navy Academy in a paper entitled

The Possible Impossible Turn and

the results appear online. His

conclusion is that the most

efficient turn is at an angle of bank

of 45 deg and at as slow a speed as

is safe.

My own explorations of David

Rogers's recommendations have

revealed that in my monowheel

Europa a 360 deg gliding turn with

the engine at tickover returned a

height loss of 1070 ft at an angle of

bank of 30 deg and a speed of 70

Kts (best glide speed). At 45 deg

angle of bank and 50 Kts the height

loss was 440ft. The difference is

considerable and surprising.

Obviously to carry out this

manoeuvre safely at low level calls

for a good deal of practice leading

to competence and confidence -

just the circumstances needed for

lowering stess and enhancing the

possibility of a safe outcome.

WHAT EVERY PILOT SHOULD KNOWWhile landing ahead is often the best and safest course this is not alwaysthe case provided that there is sufficient height in hand for other options. If,for example, a pilot suffers engine failure after take off and landing aheadwill deliver the aircraft into a housing estate it will be enormously useful toknow the height at which a turn back to the airfield will be a safe alternative.

It is far too late to commence this sort of speculation when confronted bysuch an emergency but carefully exploring the issue well in advance andthen regularily practising the manoeuvre will avoid the dangerous pitfalls offirst and second thoughts leading to enhanced stress, poor decision makingand dangerous performance.

To be able to cope with such an emergency it is important that the pilotshould be thoroughly familiar with how to turn with the least height lossfor a given amount of turn. The pilot should also know from actual andrepeated practice at a safe altitude how much height is needed for a safeturn back to the airfield.

DR JOYCE'S PRESCRIPTION

1. Get some clever kit, such as the SmartASS 3 or the Bendix King KLR 10.

2. Learn and practise slow turns at 45 deg, forced landings and side slipping.

3. Practise again.

HOW FAR CAN YOU GLIDE?Pilots need to know the gliding characteristics of their aeroplane. Typical figures are:

Bear in mind that inaccurate speed keeping will degrade the glideperformance and the wind will have a significant effect. So the speed anddirection of the wind must always be taken into account. Furthermoreyou must always reserve some height for manoeuvring when you arriveat the chosen landing point. Sometimes it is necessary to lose unwantedheight and the sideslip can be a very useful manoeuvre at such a time.

DO YOU TURN BACK?

page 9

First thoughts Second thoughts Consequence

Always Land Ahead Don’t want to! Indecision/Stress

Maybe I’ll Turn? You Mustn’t! Indecision/Stress

I’ll try anyway! Not sure How! Indecision/Stress

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Towards the idiot proof aeroplane

Dr. BILL BROOKSBill is Chief Designer at P & M Aviation, the microlight specialists. He is an FRAeS andholds degrees in Industrial Design, Aircraft Design, and composite structures. He hasmore than 3,000 hours in a wide range of aircraft including many experimental machinessuch as the Pilcher triplane replica which he part designed and built. He is well knownon Scrapheap Challenge, the Icarus HPF cup human powered flight competitions andthe Worthing Birdman competitions.

10 page

CFM shadow

Near perfect safety record Gentle stall Will not spin Good control authority

of tail surfaces

page 11

The Rallye Automatic slats Fowler flaps Very slow stall/mush Known as the tin parachute

Canards

Statically stable canard cannot stall the mainplane Within correct CG limits cannot be spun.

Grumman (Bede) AA5 Sharp stall, aerofoil later modified. Tail blankets rudder in spin. Unrecoverable spins.

12 page

THE CTThis modern compositemicrolight has a wide speed rangeand considerable appeal butexperience in use has led tovarious modifications. Stallbreaker strips have been fitted atthe wing roots to give airflowseparation at this location andconsequent buffet on the tailsurfaces. Trailing edge strips onthe elevator give better feedbackto the pilot. There is a ventral fin

to increase spin resistance, an aileron spring to centralise this control and a two degree right thrust line tocounteract a bias to the left under power.

THE FLYING FLEAThis innovative design in the1930s was immensely promisingand a great many set of planswere sold. Its big safety featurewas the inability to cross thecontrols as it had no ailerons.Direct pitch control by movingthe wing forwards and backwardsgave a direct response and goodgust alleviation. Unfortunately itproved to have other seriousdesign flaws leading to itswithdrawal until significantmodifications to the design hadbeen made and proved but by thistime it had lost its popularity.

THREE AXIS CONTROLThis has been the conventional control system from around 1912 to the present day but is can present a fewproblems.

1. The aileron can generate a wing drop.2. Crossing the aileron and rudder controls close to stalling speed can lead to a spin.3. Mishandling the elevator at the stall can cause a nose drop.

The only counter to these problems is thorough training of the pilot.

THE SPRATTCONTROLWING FLYING BOATThis another design where wingsmoves and in this case they moveindependently thus giving controlin roll as well as pitch. Apart frommoving fore and aft they alsopivot.

PEGASUS WEIGHT SHIFTMICROLIGHTA weight shift aircraft is anotherdesign that is proof againstcrossed controls. Howeverweight shifters present their ownparticular hazard which is thetumble where the machine entersan irreversible pitch down mode,tumbling head over heelsindefinitely. There is no means ofrecovery from this conditionexcept perhaps an airframeparachute. The Pegasus is sodesigned that a tumble could beentered only by a substantial andsustained control input.

Some other examples omitted forbrevity's sake.

page 13

CONCLUSIONOne approach to the design of an idiot proof aircraft would be to seek an advanced computer control andstabilisation but Bill has concentrated here on the design of a simple aeroplane. Aircraft design is always acompromise and if there is no overriding requirement for performance at any cost, it is possible to designaircraft which are less demanding on the pilot. The conventional controls system has its advantages butalso its shortcomings and various alternatives have been reviewed in this presentation. No system is idealin all respects.

Hang point set well forwards to give high hands off trim speed Bungee trimmer to pull trailing edge down allows gust alleviation Optimised aerofoils based on the UI1720 give high lift with small pitch moment and soft stall characteristics. Optimisation = add camber to the parts of the wing which are not stalled. Tumbling still possible but the pilot has to make long sustained strong inputs to achieve Spinning not possible. STARS roll augmentation system incorporated. Neutral spiral stability to improve roll response. Stall 38mph, Vne 120, cruise 60 100, climb 1200fpm.

Spratt in 1974, son of George A Spratt who was contemporary

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PITCH AND POWER COMBINATIONSThe stall recovery actions to be considered involve either pitchingforward or increasing power or both. In the case of both, one mayprecede the other or both may be applied simultaneously. We consideredfour common stall recovery procedures and these represent the leadingschools of thought on this subject although there are no doubt otherminority schools advocating yet other methods. The four recovery actionsresearched were:

The CAA/EASA method.Immediately apply stick forward and power.

The FAA method.Immediately apply stick forward and as soon as the wing has unstalledapply power.

Pitch Delayed method.Immediately apply full throttle and maintain attitude. (Taught by many commercial schools.)

Power Delayed method.Immediately apply stick forward and when the speed has attained 1.2 Vsapply full throttle.(Advocated by Séan Roberts)

WHICH IS BEST?Before one can answer this question one needs to define what is meant by 'best'. A possible response to thisquestion might be the method that delivered the least loss of height in safety. One also needs to considerwhether one method is universally 'best' or whether different methods suit different aircraft. If, in fact, onemethod is universally 'best', which one is it?

A RANGE OF STALLRECOVERIESStall recovery is animportant subject because astall, particularly at low level,so often leads to a fatality orfatalities. The FAA in theUSA calculates that 40% offatal accidents involve a stalland in Europe this figure is ofa similar order. Surprisingly,there is not just onerecommended stall recoveryprocedure but a range ofthem, depending on whoserecommendations youfollow. So there is a clearneed to establish whichprocedure is the optimum:with a colleague I thereforeembarked upon somethoroughgoing practicalresearch into the subject.

Finding a single set of stall recoveries

Dr. GUY GRATTONGuy is head of the UK's facility for Airborne Atmospheric Measurements currently ona sabbatical at Brunel University, London. He is a test pilot for both the BMAA and theLAA and an EASA Class Rating Examiner. He has a B Eng and PhD in aeronauticalengineering, has flown 102 types and publishes books and papers on aviation safety andresearch flying.

14 page

THE RESULTSThe good news is that every method resulted in a recovery from the stall for every type whether withwings level or turning and in either the cruise or landing configuration.

However, we were somewhat concerned to discover that the Pitch Delayed method (immediately applyfull throttle and maintain attitude) could lead to a tendency to a further loss of control. This occurred inthe case of six of the 14 when in the cruise (T67, PA38, C152, C172, C182P and Safir) and with eight of the14 in the landing configuration (the six above plus the Easy Raider and the Auster).

On the other hand, this method returned the least loss of height with five out of the 14 aircraft when incruise configuration and two out of the 14 when in landing configuration.

METHODTwo of us embarked upon an 'opensource' test plan and invitedcollaboration: this led in due course tosome useful aeronautical engineeringdissertations. We managed to arrangetest pilot time on a wide range ofaeroplanes totalling 14 types in all. Eachof these was flown by both the testpilots and one was flown by both pilotstogether so that we could be sure ofachieving uniformity of method.

page 15

PLAN CONTENTWe confined our study to Single Engine Piston types and 3 axismicrolights. We took each aircraft with its weight, centre of gravityposition and state of modification as we found them, thus providingexamples of typical aircraft as they are encountered in the field asopposed to the factory.

We explored all four recovery methods with each type: the CAA,the FAA, the Pitch Delayed and the Power Delayed methods andwe stalled each type both with wings level and while turning. Inevery case we investigated both the cruise and the landingconfiguration.

SO WHAT IS ‘BEST’?The CAA, FAA and Power Delayed methods all delivered satisfactory handling while positively recovering fromstalls in the various conditions. Our investigations showed that pitch control is of primary importance in stallrecovery and power is secondary. The Pitch Delayed method was the only method where secondary stalls couldoccur and it is clear from this that ignoring pitch in favour of leading with the application of power is potentiallyill advised for some types in some conditions.

As for height loss, the result are shown below. They show the mean height loss over all types tested in feet fromstall to start of climb.

Note that while the CAA method returns the least height loss it also causes the greatest pilot discomfort. Atthe other end of the table the Power Delayed Method gives the poorest height loss but the least pilot discomfort.

FINALLY, TWO PRACTICAL LESSONS LEARNEDI can now say from actual experience that an open source test plan did no harm at the very least and some

limited good. We shall try this approach again.

As regards flight testing in a student dissertation, I have learned that it does work, that heavy mentoring is

required and that students tend not to appreciate without this mentoring that forward planning and a prior

safety assessment are vital.

FOUR QUESTIONS FOR THE AUTHORITIESIt would be helpful if the authorities could agree amongstthemselves on the following issues:

1. What is the best recovery? Is it the recovery that is easiest to fly or is it the one with a consistent recovery and minimum height loss?

2. Is is desirable that Europe and the USA should have different standard stall recoveries for SEPs?

3. Are SEP recoveries being influenced by practices?

4. Do we have aeroplanes being flown to one recovery method that were originally tested against another?

Cruise configuration

Engine idling Wings level

Lsnding configuration Engine idling Wings level

Finals turn.

CAA Method 105 ft 102 ft 123 ft

FAA Method 153 ft 146 ft 142 ft

Power Delayed Method 178 ft 173 ft 211 ft

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BASIC CONCLUSIONSI conclude that the Pitch Delayedmethod is not to be recommendedbecause of the undesirable handling thatsometimes leads to secondary stalls. Itdoes, however, give the least loss ofheight, and on occasion this can be aslittle as zero.The CAA method gives a consistentrecovery and the lowest height loss.However, it is not a gentle manoeuvreand is liable to be uncomfortable.The Power Delayed method also givesa consistent recovery and is verycomfortable to fly but it is verycomfortable to fly.

16 page

CHARACTERISTICS OF AMODERN GLIDER

While early gliders were crudeand relatively inefficient themodern sailplane is the result ofthe application of manysophisticated design andconstruction skills. In a moderncompetition glider the designer islooking for maximum crosscountry efficiency while safety inflight will depend to a much largerextent than with other types ofaircraft on competent handling bythe pilot. The structures are ofcomposite construction includingsignificant use of carbon fibre andin this respect modern glidersexhibit some similarities tomodern airliners.

Furthermore advanced avionicsand navigation systems includingvaluable devices for finding andmaximising lift are becomingcommon so that in their own wayperformance glider cockpits areexhibiting a complexityapproaching modern airlinercockpits.

Loss of Control - The Gliding Experience

CAPTAIN SARAH KELLMANSarah started gliding while at university and quickly progressed to competition flying.She was Women’s European Champion in 1999 and Women’s World Champion in 2001and again in 2007. She is Captain of an Airbus with Easyjet and was a Safety Officer forthe company until going part time in 2012. Her paper to the R Ae Soc International 2013Flight Crew Training Conference on the benefits of glider flying for upset preventionand recovery training won international acclaim.

page 17

Photo : Devon and Somerset Gliding Club

THE GLIDING APPROACHTO UPSETSWhen glider pilots find lift theyoften reduce speed to stay in it forlonger and in a thermal whenseeking maximum climb they willaim to remain within thesometimes narrow core of the lift.Consequently they will habituallyfly with only a small margin abovethe point of stall turning at a 45deg angle of bank or more.Sometimes they will be sharing athermal with several other gliders.all seeking best climb whilelooking out for the others. Theseare handling and traffic conditionsthat power pilots are trained to avoid and consequently glider pilot training has a very different emphasis.

• From the trainee’s very first launch an introduction is made to unusual attitudes.• Gliding embraces a high alpha culture with much attention to handling when approaching the stall and after

the stall.• Energy management is always vital as there are usually no other sources of energy than the glider’s own inertia

and its height above the ground.• An appreciation of meteorology is essential. A glider pilot without an understanding of what is going on in

the surrounding atmosphere will get nowhere.

18 page

WINCH LAUNCH TRAININGA typical winch launch takes the glider from 0 to 60 mph in just three seconds. The glider is then rapidly hauledinto the air reaching a height of anything between about one or two thousand feet in short order. This is a highenergy and potentially a high risk operation:

• A wing tip may catch on theground during the initialacceleration and if the pilot failsto release the cable immediatelya cartwheel is likely to followleading to serious injury orworse.• Once in the climb the attitudewill be far too extreme for thepilot to use the horizon as amarker. The ASI must be watchedto maintain the speed betweennarrow limits, quick sidewaysglances used to maintain trackand sometimes signals have to bemade to the winch driver if thelaunch is getting too fast.

E/1,$K*4,6$&?*(?)-$

CRITICAL ENGINE FAILUREThe parallel to winch launch training for anairline pilot is training for critical launch failure.In both cases it is valuable to review thepossibility of the occurrence before take offand decide in advance what the appropriateresponse should be, In that way the ‘startlefactor’ will be reduced and the pilot will bementally prepared for the emergency.

CAN GLIDER HANDLING COMPARETO THAT OF JETS?With gliders greater span tends to greaterefficiency and gliders with a span of 25 m arenot uncommon nowadays, especially wherehandicapping is not an issue. This sort of spanis not much less than a regional jet airlinersuch as the B737 at 28.9m and there is amarked handling similarity here in that bothare surprisingly ponderous in roll.

PILOTING SKILLS ISSUES IN THE TWO TYPES OF FLYINGIn normal operations an airline pilot will accept a high reliance on automation and will spend a considerableportion of flying time in monitoring the autopilot. The pilot will mostly fly straight and level and will do soconservatively to maximise fuel efficiency. There will be long periods of inactivity potentially leading toboredom in the cruise. Approaches will mostly be instrument approaches.

All the glider pilot’s flying will be hand flying with no automation alternative the pilot will continually bemanoeuvring with frequent steep turns that will need to be flown with instinctive accuracy. To maximiseperformance the pilot will be flying to the edges of the flight envelope. There will be long periods ofconcentration typically for five or six hours at a stretch but sometimes extending to as much as ten hours.All approaches will be visual.

In abnormal operations such as when an emergency occurs the airline pilot will suffer from reduced orentirely lost automation leading to relatively unfamiliar hand flying. There will be a high state of arousal,degraded protections and flight closer to the limits of the flight envelope. Approaches will have to be nonprecision or visual. A glider pilot’s skills will match much more closely the demands made on an airlinepilot in abnormal operations.

page 19

4567,'+*8.0'

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• The cable may break at any time. This will suddenly present the pilot with a steep nose up attitude very littlespeed and sometimes little height or time to get safely down again.

Glider pilots are trained from the start to prepare mentally for these possible eventualities to the extent that awinch launched pilot may deem it a pleasant surprise to have reached the top of the launch without incident.The British Gliding Association introduced its safe winch launching programme some ten years ago to enhanceexisting training methods and keep the subject live in the minds of glider pilots. This initiative can now claimevidence based success in the significant reduction of winch launch accidents.

PILOT PERFORMANCE CHALLENGES FACED BY THEAIRLINE INDUSTRY

• Nearly 50% of go-arounds result from Flight Management factors.

• Hand flying skills become eroded.

• There is an over reliance on automation and a reluctance to disconnect it.

• Hand flying in abnormal situations causes an unacceptably high workload to the preclusion of other tasks.

• There is a potential to fail to recognise excursions to the edge of the flight envelope as when approaching a stall.

• Pilots are inclined to rely on the Flight Management and Guidance System for flight guidance rather than check for gross errors.

• Simulators are unable to simulate the dynamic forces experienced in upsets.

FURTHER AREAS OF CONCERNThe role of fatigue in aircrew is a continuing problem and measuresto alleviate this by rostering schemes are important.

Arousal is a crucial issue. An optimum degree of stress will lead tooptimum performance.

Standard Operating Procedures (SOPs)are an important counter to low arousaland it is vital that they are followedduring key phases of flight where errorsare more critical. A good example ofsuch a phase is the descent to finalapproach. SOPs properly applied willdeliver the aircraft at the Final ApproachFix with everything configured andplanned. Failing to apply them riskssudden surprises possibly leading toserious risk.

Decision making is an area that needscareful study. It is easy to let the rationaldecision to be forgotten in the face ofthe emotions calling for somethingdifferent. Thus hearing on Final of areported crosswind just above limitsmay rationally dictate a go around andpossibly a diversion. Emotionally,however, the desire to be down on theground at the planned destination maylead to a decision to continue in hope.The rule always is to gather thepertinent facts, view themdispassionately, act accordingly andreview the decision thereafter. Thoughtsof an expected outcome must be putaside and the decision made based onthe actual facts at the time regardless ofexpectations or other pressures.

Pilots need to be continually aware ofthe limitations of automation, whichmeans being thoroughly familiar with theequipment in use, its strengths andweaknesses and how to control it in allmodes.

Distraction always has the potentialseriously to degrade a pilot’s proficiencyand needs to be recognised for thedanger that it presents so that operatingprocedures are not allowed to becomeineffective. In gliding the classicdistraction is the interruption of a pilotcarrying out the rigging of a glider.Improperly rigged gliders are all toooften the result.

20 page

M"*-$"%$K)"?#6*$

GLIDING TRAININGFOR PROFESSIONALPILOTSMany organisations recognisethe value of gliding trainingas an aid for professionalpilots. This training cangreatly enhance handlingand understanding ofimportant truths about allfixed wing aircraft. Nearlyall professional pilots withgliding experience seethemselves as fortunate tohave obtained a furtherinsight into areas ofhandling, upset recoveryand meteorology beyondconventional professional

pilot training. The IAAG at Merville, a French professional pilot school, offers a one month gliding courseat St Aubun that will provide 40 airtow launches and 25 hours of glider flying. The Brazilian Air Force offerssomething similar.

In glider flying, handling can be demonstrated approaching and post stall as well as beyond the 40 deg pitch andbank limits commonly found in power trainers. Somatogravic illusion sometimes leading to spatial disorientationcan easily be demonstrated.

CONCLUSIONS

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page 21

MY AIMI propose to present a view on the personal nature of keeping or losing control and the consequent trainingprinciples for safer aircraft operation.

In my view Loss of Control (LoC) is more related to a pilot’s skill and experience than it is to aerodynamic flightcharacteristics.

I seek to emphasise the importance of monitoring your proximity to a LoC situation.

THE AIRCRAFT ENVELOPE

In the above diagram the load factor (G) is the vertical scale and the speed the horizontal scale.The Manoeuvre Limits are shown for both erect and inverted flight.

Finding a single set of stall recoveries

ALAN CASSIDYAlan Cassidy MBE is one of Britain’s best known and most highly experienced aerobaticpilots. He has been four times British Aerobatic Championship winner and a member ofthe British Aerobatic team on seven occasions. He has won numerous aerobatic prizes.After obtaining a degree in Mechanical Sciences he joined the RAF and enjoyed asuccessful 20 year career in engineering. He holds Commercial licences, is a Fellow of theRoyal Aeronautical Society and sits on the Council of the Royal Aero Club. He has beenChairman of the British Aerobatic Association since 2006 and has received manyDiplomas and Awards.

Load Factor (g)

Air Speed

Stalling

VNE

Stalling

Erect

Inverted

+

VA Manoeuvre Limit

Damage Limit

Damage Limit

Manoeuvre Limit

V-n Diagram

22 page

This diagram shows load factor against speed and includes the Stallled Region, the Minimum Level Speed, theenvelopes at aerobatic and normal weights, V max manoeuvring, Vne and VD.

-3

-2

-1

0

+1

+2

+3

+4

+5

+6

Normal@ 1,575 lb

S tructural Damage

S tructural Damage

40 80 120 160 200 240

Normal@ 1,575 lb

Vm

ax m

anoe

uver

ing

= 15

4 m

ph

VN

E –

203

mph

VD =

225

mph

Airspeed (mph IAS)

Aerobatic @ 1,500 lb

Stalled Region

LOA

D F

AC

TOR

(G)

Stalled Region

Minimum Level Speed

page 23

OUT OF CONTROL

• Whenever the aeroplane is outside your own personal flight envelope you are no longer incontrol.

• If there are two pilots in an aeroplane at any point in time it can be out of the control of one pilot and within the control of the other.

• So LoC is not about the aerodynamics - it’s about the person.

The company will require its pilots to remain withinthe Standard Operating Procedures limits.

PERSONAL FLIGHT ENVELOPES

24 page

-3

-2

-1

0

+1

+2

+3

+4

+5

+6

40 80 120 160 200 240

SOP

Similarly a newly minted PPL will be expected to keepwell within the aircraft’s limits. -3

-2

-1

0

+1

+2

+3

+4

+5

+6

40 80 120 160 200 240

PPL?

page 25

A new Flying Instructor will operate within anenvelope little larger than the new PPL.

Every pilot needs to know their personal flightenvelope.

-3

-2

-1

0

+1

+2

+3

+4

+5

+6

40 80 120 160 200 240

New FI?

-3

-2

-1

0

+1

+2

+3

+4

+5

+6

40 80 120 160 200 240

You???

-3

-2

-1

0

+1

+2

+3

+4

+5

+6

40 80 120 160 200 240

Spins

Flicks

TailSlides

Tumbles

NegSpins

This is the envelope of an advanced aerobatic pilot. Itgoes about as far as you can go.

26 page

By now the trainee’s envelope is almost as large asthe QFI’s. The trainee is approaching a limit to furtherdevelopment and a new QFI is necessary for furtherprogress in safety.

Aircraft

New QFI Please

Here an expansion of the trainee’s envelope and agraduation from a training aircraft has given room formanoeuvre.

Development

QFI

Aircraft

Moving on again, we have a QFI with a much largerenvelope and the trainee has room to expand.A new aircraft will be called for.

New Aircraft

Please...

THE TRAINING ENVIRONMENT

Here the trainee’s is straying beyond the envelope.The QFI’s remains the same and the aircraft is atraining aircraft suitable for the training in progress.

Aircraft

QFI

Training

The trainee’s personal envelope is represented by theyellow circle and the QFI’s by the blue. A routineaircraft is assumed.

Routine

QFI

Aircraft

Here the trainee has been allowed to trespass beyondthe personal envelope and this has led to disaster.The QFI’s envelope remains unchanged.

Aircraft

QFI

Disaster

page 27

A glass cockpit is no better.

TOWARDS BETTER TRAININGThe essential towards better training is to make sure that the trainee understands thoroughly at all stages offlight what the wing is doing at that moment. If an instructor tells a student to climb more steeply, add a littlemore bank, reduce power to 18 inches and select max continuous rpm, he or she will do well to add the precept,Make sure you don’t stall.

However, there is nothing on the conventional blind flying panel that will tell you directly what the wing is doing.

28 page

Nonetheless, every light aircraft flying in the UK already has an Angle of Attack indicator fitted and here it is!