10 August 2014
This is a difficult subject. Some of us might one day be involved with on-scene initial investigation of glider accidents involving injury or fatality. In discussions with Regional Managers Operations, Chief Flying Instructors, Level 3 Instructors, colleagues have expressed a need for guidance on how to prepare for an accident scene, what to bring, what will be demanded of them. This article assumes that the investigator is assisting police, coroner, perhaps ATSB and CASA on the scene of an accident. These notes draw upon lessons learned in practice, my own experience, and those of others in similar difficult circumstances.
The whole issue of what to investigate, and how, is much more complex and context dependent. The investigator’s prior experience and expertise will have a major bearing on this. I also commend people to consider attending ATSB Transport Safety Investigators and Human Factors for Transport Safety Investigators courses, or military equivalents.
Anyway, in the hope this this may help others…
GLIDER ACCIDENT INVESTIGATION PREPARATION
PRE-READING AND USEFUL REFERENCES
- GFA Human Factors Handbook. See Gliding Australia website, Operations, Ops Docs, Manuals folder
- ATSB Human Factors course notes. See Gliding Australia website, Operations, Ops Docs, Human Factors Resources folder.
- ATSB-DDAAFS Civil and Military Aircraft Accident Procedures for Police Officers and Emergency Services Personnel.
- ATSB-DDAAFS Hazards at aircraft accident sites – Guidance for police and emergency personnel.
- GFA SMS or Club Emergency Response Plan. See Gliding Australia website, Safety, SMS documents folder
- GFA Manual of Standard Procedures. See Gliding Australia website, Operations, Ops Docs, Manuals folder
- Transport Safety Investigation Act 2003, Australian Government ComLaw website
MATERIALS FOR GLIDER ACCIDENT INVESTIGATION – CHECKLIST
- Camera, lenses, flash, spare batteries, new memory chip
- Photographs taken from your gliding expert perspective will be important. Thorough photographic records should be taken to verify or study details offsite. You should also take photographs of relevant pilot and glider documents, flight records. You may need close up, macro, wide angle, and/or telephoto perspectives. You do not want to mix accident photographs with personal and family snapshots. Flash photography will consume battery capacity quickly.
- Notebook, pens/pencils, blank witness note sheets, blank GFA SOAR accident/incident reporting forms, graph paper, folder and clips
- You need to provide pilots and witnesses the means to independently record their observations and recollections, in a structured fashion. Stationery is normally rudimentary on an airfield. Folders and clips are important to aid in organisation and retention of reports, drawings, diagrams, pilot and observer recollections. Provision of ATSB and SOAR reports is mandatory for fatal accidents or those involving injury or substantial damage, your assistance will be important in providing complete and accurate reports.
- Marker pen, masking tape or stick-on labels
- Labelling and identification of debris, key components, may be important.
- Torch and spare batteries, handheld and/or headband type
- Investigation activity may continue well after sunset. Investigations in confined spaces within the glider structure may require good hands-free lighting.
- Work gloves, disposable gloves
- You may have to work in a biohazard environment or with glider debris, or manhandle heavy or sharp or hazardous materials
- Band-aids, hand cleaner, antiseptic
- You may incur minor injuries, or work in biohazard, hazmat or dirty environment
- Handheld VHF radio, multimeter
- Checks of battery, exposed wiring, radio, instruments or electrical components may be required, when safe to do so
- Multi-tool, basic tools
- Tools will often be needed to access components behind damage, or remove access panels
- Inspection mirror
- Investigations will often require visual checks of low visibility components, or components behind other structures or crash damage
- Tape measure or expandable ruler
- Distance measurement will be important to accurate reporting and analysis, correlation of damage, impact marks etc.
- GPS, Compass, Inclinometer or Smartphone Apps with GPS, compass and tilt measurement functionality
- Position, direction and angle measurement will normally be important in both operational and airworthiness analysis and reportin
- Laptop computer, USB drive or memory card, modem or network access dongle, adaptors for data logger and FLARM downloads
- Portable computing facilities are important to collecting data, particularly from damaged or volatile sources, saving investigation data in devices that might be shared with police and coroner. You do not want to mix accident data and images with personal data.
- Battery chargers for portable equipment and phone
- Investigation tasks will often require more battery power than that available in portable devices, so recharge capability is vital
- Moisture proof groundsheet
- A groundsheet may be important in protecting yourself on the ground when inspecting damaged components, or retaining components and preventing loss during disassembly
- Storage box and bags
- Useful for retaining any information, tools, equipment, papers used in the investigation, preventing loss.
Any investigation of a serious accident, particularly one involving injury or fatality, will be emotionally confronting. Involved parties may include gliding friends, people who will be suffering from shock, trauma or emotional distress. You will need to prepare yourself emotionally to deal sympathetically yet professionally, with both empathy and objective detachment, with confronting images and behaviour.
In the worst case, you may have to conduct initial investigation inspections and work around the remains of deceased persons. Any police or emergency services personnel in attendance will usually be very experienced with such scenes, and will usually be able to help you deal with these difficult circumstances. You should consider discussing with your partner or loved ones how this activity might affect you, and your own needs for consideration and support.
These investigations will invariably be very time consuming. When attending the scene for the first time, you should anticipate long delays and long on-site duration, and therefore make suitable provisions for warm clothing, hydration and nourishment. You may need to sleep in a nearby motel, rather than undertake long road trips at night after the initial on-scene investigation.
It is well worth spending time to translate your personal written notes to electronic form as soon as possible after the event, to improve retention and accuracy of important information, and to manage your own exposure to emotionally demanding material. Demands on your time and energy in report compilation, support to police and coronial authorities, working with GFA, CASA and ATSB will be considerable.
You need to be mindful always that in coronial cases, you are subject to coronial law and must protect confidentiality of information. It is for the Coroner to attribute cause and manner of death. That said, your role is investigation for the purposes of improving gliding safety. Annex 13 to the Convention on International Civil Aviation, Section 3.1 states “The sole objective of the investigation of an accident or incident shall be the prevention of accidents and incidents. It is not the purpose of this activity to apportion blame or liability.” A focus on deriving lessons for improving operations, airworthiness, airfields, ground environment, safety, training, human and organisational factors will assist in achieving this objective. GFA Operations Department Officers will be able to assist with resources, reports and advice.
Chairman of GFA Operations Panel
* * * * * * * * * * * * * * * * * * * *
16 June 2014
For many years we have been working to improve gliding training to better ensure that pilots avoid a most dangerous scenario – undershoots. On further study we found that the way the human brain is ‘wired’, to see rates and changes in angle with greater accuracy than estimating actual angles, has a bearing on how we perceive and react to deteriorating circuits. Language too is important: “steepening” and “flattening” or “shallowing” generates different perceptive cues than “high” or “low” or even “steep” or “flat”. This change in training methods is to be incorporated in the next major rewrite of the GFA Instructors Handbook. The following article has been published in Gliding Australia…
REDUCING UNDERSHOOT RISKS AND
IMPROVING SAFETY IN GLIDING CIRCUITS
Canberra GC, Regional Manager Operations NSW, GFA Operations Panel
Flying from Bunyan airfield, home of Canberra Gliding Club, is exhilarating and demanding. The “weather factory” gives us thermal, ridge and wave lift. The geography and meteorology combine to keep us on our toes. None of our grass runways are flat, all sloped, plus we have hills in the circuit area and limited off-runway landing options. Given the strong effects of wind, lift and sink at our site, high operations and training standards plus vigilance are needed to reduce low circuit and undershoot risks. The lessons we have learned and applied can be of benefit to the wider gliding movement, to improving training and the safety of our operations.
This article is intended to help instructors and pilots understand undershoot risks better, to understand and apply suitable risk mitigation measures, and in particular to adopt practices that will make for better, safer pilots, in all environments.
Let us ask some fundamental questions. Why do glider pilots sometimes get caught out, too low on base or final approach, trying desperately to get back to the home airstrip or facing an outlanding close to the field? Why do seemingly experienced, well-trained pilots sometimes find themselves in dire straits, facing undershoots or dangerously low approaches? Why do normally sensible pilots sometimes erode their safety margins, either scaring themselves or damaging their gliders and injuring themselves? Why do high wind conditions and turbulence markedly increase the risks of undershoots? What shortcomings are there in the gliding training system that might be contributing to undershooting incidents? How might pilots modify their flying practices and perception so that they may reduce their exposure to undershoot risks?
Limiting the consequences of errors is important. We must always, at all costs, avoid straining ourselves through a fence. This is a particularly nasty type of accident, with very high damage potential for both pilots and gliders. We must also avoid stall-spin accidents, low energy arrivals with high vertical rates of descent. These, too, will ruin your day, your health and your glider. We must also avoid loss of directional control, burying a wingtip in the ground or a fence, or another glider, or hitting obstacles short of the safe landing area. Wing to ground impacts during final turns and undershoots are exceedingly dangerous.
The opposite category, overshoot accidents, hitting an end obstacle on landing, is comparatively rare. Note that the risk of hitting overshoot obstacles is higher with launch failures, where a late approach to an unexpected landing is attempted far down the strip.
We all know the theory of what we need to do to avoid undershoot; or so we think – until it happens. We have all heard the words drummed into us; “safe speed near the ground, fly a safe circuit pattern, watch wind drift, move the base leg closer in high wind conditions, turn in early if in sink”, et cetera. So why does it happen to pilots who should know better? What factors increase the probability of pilots making errors, or being exposed to environmental conditions resulting in undershoot? What are the risk drivers? (Try listing some of these before reading on… J)
In summary, key undershoot risk drivers include these:
- poor circuit joining, often exacerbated by a late break-off decision, or joining too low for the conditions;
- poor energy management, management of attitude, airspeed and height in the circuit, poor monitoring of the available energy budget, often due to flying by landmarks or fixed ground reference points;
- poor workload management in the circuit, leading to a lack of monitoring of the important energy and angle issues;
- poor time management, exacerbated by lack of awareness of the (limited) circuit time budget, particularly the short time from abeam the aiming point on downwind leg to the base leg turn;
- poor monitoring of the vertical angle between horizon and intended aiming point, and the rate of change of that angle (flattening), particularly from abeam aiming point on downwind to the base leg turn;
- insufficient response to perceived changes in this vertical (flattening) angle or rate of change of angle;
- excessive aiming point or launch point fixation, pressing on in a marginal circuit instead of turning in early and modifying the circuit;
- denial, decision paralysis, freezing under stress;
- exposure to exceptionally strong microbursts, rotor and thermal downdraughts, associated with local area meteorological conditions;
- exposure to low level curl over from slopes, outflow winds, wind shear, wind reversal, wind gradients, rotor turbulence, associated with the terrain on the approach path;
- optimism error, over-estimation of glider performance, particularly when flying a lower performance glider after recent operations in higher performance sailplanes;
- wet wings, ice on wings, or glider incorrectly configured and producing excessive drag;
- pilot incapacitation or degradation induced judgement errors, such as from heat stress, dehydration, low blood sugar or illness; or
- sheer stupidity.
Let’s look at these risk drivers in turn and see what we can do about mitigating them.
- First, think about the landings you have done which have been less than tidy. How many of those were preceded by a poor circuit, joining too wide and flat, too low, too slow, too late, or even too close overhead, from a crowded position? Poor circuit joining is a common precursor for flat or shallow circuits, low scrapes and high undershoot risks. Skinny, low flat and low energy final glides can contribute to this risk driver. Also, late decisions and poor break-off discipline contributes to degraded workload management. In cross-country flying we must be aware of these risks, build in a suitable safety factor so that we join circuit at a safe height and angle to the aiming point; not a flat, late and scary shallow position.
- We put much emphasis on energy management in our glider pilot training. The sad fact is that when flying in strong winds or turbulence, some pilots struggle to maintain safe energy, often because of poor management of attitude and insufficient use of trim. Chasing the ASI in lumps, bumps and gusts is a recipe for trouble, for being “behind the aircraft”, and when that happens, the focus on height and changing angles back to the aiming point is diminished. Those who fall into the trap of flying circuits by landmarks and fixed ground reference points, expose themselves to much greater undershoot risks in high winds and turbulence. Circuit judgement is supposed to be adaptive, not formulaic. Establishing a well-trimmed configuration early in the circuit, occasional quick glance checks of airspeed and trends (slower or faster) combined with good attitude control enable better control in gusts and turbulence, better anticipation and less risk of sinking below a safe glide slope back to the aiming point.
- Poor workload management, leaving FUST checks and radio calls too late, focussing on the wrong thing at the wrong time, not monitoring the right things at critical times in the circuit, particularly height loss and flattening circuit angles, is a major undershoot risk driver. High workloads and stress also lead to fixation on single stimuli and problems, to the exclusion of all else. Workload management problems leading to “cognitive tunnelling” and “single issue focus” can lead to missing other high priority tasks and fundamental errors. The converse, good workload management and a clear focus on high priority issues, is effective in mitigating these risks. This also goes with good circuit joining judgement and discipline.
- Time management practices are closely related to workload management, but the key issue here is an awareness of the (limited) time budget available in the circuit. There are numerous variables that may affect the time taken to fly downwind, base and final legs. Glider performance, circuit height, circuit width and length, airspeed, wind speed, turbulence, approach glide slope, all may vary the time taken. Try timing circuits, yours and others! You may be surprised how little time is taken in some conditions.
Now this is the critical issue! When flying in strong winds, note how much this diminishes your time budget on downwind, from abeam the aiming point to needing to turn base leg. Think about it. If you are used to 60kt circuits in still air or 10kt winds, your downwind ground speed may be 60-70kts. When weather brings 25kt winds, you may be flying at 70kts, with a huge tailwind, probably stronger aloft, covering the ground at 95kts or more. You may have only 10 seconds in strong winds past the aiming point to the base leg turn, depending on your circuit height, maybe less in a low circuit, and the effects of a 5, 10, 15 sec delay error in starting that turn will be all the more serious.
The lesson is this. In strong winds, you have much less available time on downwind leg. Don’t stuff around. Once you fly past the aiming point, your time management focus must be on monitoring height, attitude for safe speed, vertical angle to the aiming point and the rate of change of that angle. When past abeam the aiming point on downwind, focus! Time means energy.
- How do we judge height or altitude above ground level? There are lots of cues and clues for seeing altitude above ground level, many of which we use unconsciously. They include the ability to see detail of objects on the ground, surface texture, relative size, changing perspective, shadows, rate of movement over the ground, plus our eye height relative to distant high ground features. There’s an altimeter, too, which could mislead some and lead to laziness in judging height by eye!
Our training emphases seeing “the correct angle” between horizon and the intended aiming point. We are coached to see circuit angles that might be steep, or flat, and to correct them in flight. Now ask yourself, why is it that pilots find it difficult to judge and consistently fly downwind legs at a correct vertical angle between horizon and aiming point? Why do we find it difficult to accurately estimate angles other than 45, 90, 180, 270 and 360 degrees? What angle is a “correct” angle below the horizon for a typical circuit, or a high wind circuit?
Here’s where we get to an aspect of human perception that many people are not aware of. Human beings are quite prone to errors in seeing and estimating absolute angles. Human beings are, however, much better attuned to seeing rates of change of angles. We are in fact very proficient at seeing angles changing, and reacting in ways to minimise that rate of change of angle. We might find it difficult to accurately estimate the actual vertical angle between the aiming point and horizon – but we find it easy to see whether that angle is changing, flattening or steepening, or staying constant.
Why am I labouring the point on terminology issues? The reason is referring to angles in absolute terms like “good”, “steep” and “flat”, the size of the angles, trigger you to different perceptive cues than words describing their rates of change, “constant”, “steepening”, “flattening”, “shallowing” or “worsening”. The human brain is wired to work better with changing angles. Some of our best instructors already use this technique and language instinctively, intuitively, and unconsciously – because most of us are unconscious of why we are so adept at operating in a 3D world. In the air, in a circuit situation, we not only see the horizontal angle between straight ahead and the aiming point, and vertical angle between the horizon and the aiming point, we also see the rates at which those angles are changing.
So here’s the key issue – we must be attuned to seeing the vertical angle to the aiming point, plus the rate at which it is flattening or steepening. The faster it is flattening, the bolder the correction. When you fly from still air into sink, the vertical angle goes from being near constant, to flattening, to flattening even faster – and this is the visual cue we must be attuned to reduce undershoot risks.
“If it flattens, a turn in happens.” Think about it, remember those words – when embedded in your mind they have the power to improve your monitoring and trigger the correct response to worsening (too flat, flattening) vertical angles.
Let’s assume you can see the angles flattening – but what happens if your correction is not enough? The angles will still flatten, but slower. What happens if you over-correct? The angles will go from flattening to steepening. It is self-evident that under-correction to flattening angles is potentially more hazardous. Again, the faster it is flattening, the bolder the correction. This is particularly important in high wind circuits, when several corrections may need to be made, and quickly!
- Flexibility and adaptability to changing, worsening situations requires us to be prepared to acknowledge that your plans to land at a chosen point might have to change. Why do pilots get “press-on-itis”? Why do we get launch point fixation, and leave the decision to modify or land elsewhere too late? Here you have to look for answers within yourself, as to your own character, your psychological predisposition to accept risks, to stick with a decision – or your preparedness to choose to change, to reduce risks, to accept less convenient yet safe options. In check flights, this is also a test of instructor risk tolerance and discipline, a test of thresholds of intervention. Undershoot risks must be managed properly, with great care and discipline to avoid realising the risks inadvertently.
- If you have difficulties managing high stress, high workload situations, or a tendency to freeze, then this might require some deliberate training and confidence building, some scenario analysis and practice under instruction. Pre-planning emergency responses helps reduce stress and workload. For example, we routinely assess launch failure options in the O check in CHAOTIC. On a given day, we should assess other suitable runway or paddock options if caught out. If training does not help, then this begs the question as to whether gliding is the right sport for you.
- Another risk driver is meteorological. Any one of us can get caught out flying into adverse gusts and downdraughts. At one level the risks are avoidable – we can choose not to fly in conditions conducive to downdraughts. The reality is conditions can change, very quickly at our weather factory, so some of the risk mitigations are linked to your own deliberate exposure to “interesting conditions”, plus development of your own meteorological knowledge and ability to read the sky.
The good news here is that there is much informal learning to be gained on the airfield, just talking with your flying peers. Delving into good gliding weather texts, meteorology office web resources, weather watcher and aviation weblogs and forums, also helps to build this ability to read the sky. Some of us are “weather nuts” and love to understand and discuss these phenomena. Knowledge helps us to reduce the risks, to avoid the bad air, or if encountered, to get the safest path to the ground (which in some cases, might not be the home airfield!)
10.Peer knowledge, local briefings and knowledge are also critical to understanding the smaller scale meteorological risks associated with the terrain overflown during the final approach. Curl-over, wind shear, gradient effects, outflows, even rotor, can combine to exacerbate an undershoot situation. Anticipation of these localised effects is a key risk mitigation strategy, keeping that extra margin when operations on a particular airstrip, terrain and wind combine against the pilot.
11.The next risk driver is associated with human factors; a fallible human element. When we fly one or two glider types frequently, we can “get in a groove” regarding their expected performance. If they are relatively high performance gliders, then a pilot launching and landing in a lower performance glider can unwittingly over-estimate the glider performance and fly too flat a circuit. Sometimes this is referred to as a “recency effect” or an “optimism error”. Human beings being diabolically complex, it is also possible for optimism error to set in when flying a higher performance glider, again being over-optimistic in allowing for its improved glide path.
12.It is possible for the glider to be producing much more drag than normal. Many plots will under-estimate the effects of wet wings or, even worse, ice on the wings. This can occur, for example, descending through moist air from a high altitude wave flight. Excess drag can also result from incorrectly configuring the glider in the circuit, with brakes cracked open, or wrong flap settings, or operating the wrong controls at the wrong time.
13.An insidious error-producing risk driver is that associated with pilot incapacitation or degradation; dehydration is probably one of our highest risk drivers here. If you have water onboard, it is usually a good idea to have a sip prior to commencing circuit. Wearing a hat and suitable sun protection is also essential, even in cold weather. The risk mitigation approaches come back to pilot health and prior preparation.
14.With respect to sheer stupidity, in my Navy service we had a proverb, “nothing is sailor-proof!” Author Robert Heinlein summarised this aspect very well in “Time Enough for Love: The Tales of Lazarus Long”, his wise advice to “never, ever, underestimate the ingenuity of fools”! Airmanship expert Tony Kern has also touched on this subject in his book “Darker Shades of Blue: The Rogue Pilot”. James Reason’s books on “Human Error” and “Managing the risks of organisational accidents” also highlight the inevitability of human beings making errors, and of us finding new ways to do that.
My intent here was to provoke readers, through a series of questions, into thinking about the reasons why seemingly competent, well trained pilots find themselves all too frequently in horrible, low, flat circuits, with undue exposure undershoot risks. Then I asked, what are the causes and what can we do to reduce exposure to undershoot risks? Some of the answers are found in improved awareness of undershoot risk drivers.
Achieving reduced exposure to undershoot risks requires us to do a whole bunch of things right, including perceiving and reacting to the right angular rate and other cues, as well as managing a tight time budget well in all conditions. Advances in the science of human perception and psychology of decision-making can help us; most pilots are quite unconscious of their innate abilities, so it is hoped that better awareness, better perception will improve pilot performance and safety. Your feedback and commentary is welcomed; we all stand to benefit from improved dialogue on these issues. I wish all glider pilots lovely buoyant skies and safe, happy landings.
The Generalised Optic Acceleration Cancellation Theory of Catching, by Peter McLeod and Nick Reed of Oxford University and Zoltan Dienes from University of Sussex, Journal of Experimental Psychology: Human Perception and Performance 2006, Vol 32, No 1, 139-148 refers.
16 May 2014
In September 2013 I had a scary, unexpected incident during our wave soaring camp. It ended well – but there were many good lessons from this incident. The following article was published in Gliding Australia, and I share it here in the hope that others can reflect and learn from my experiences.
A BLEEP MOMENT – PRACTICE BECOMES REALITY
By Drew McKinnie
Canberra Gliding Club, Regional Manager Operations NSW
I sat in the glider, still in the long grass and weeds, stopped safely in the undergrowth. For a minute I just sat there with the canopy closed, hands in a prayer-like position in front of my face, as I tried to calm down, slow my deep, fast breathing, slow my racing heart and the surge of adrenalin. I was safe, intact, and grateful to be sitting there uninjured. Scott came over the hill in my vehicle, down the side of the runway, and stopped nearby. “Are you ok mate?” he called as I climbed out of the ASW20 and checked the glider’s structure. With huge relief and a wry smile, “Yes” I replied, “I’m ok. Wow, that was scary! And close!”
* * * * * * *
About two minutes previously I had lined up in my ASW20L VH-GVN on Bunyan Runway 33, on a pleasant sunny Monday 23 September 2013 during our wave soaring camp. I was looking forward to a gentle spring thermal flight. Frank Johann had taken off in his ASG28 behind the Southern Cross tug CPU, and I was about to have first launch of the day behind the Canberra Pawnee MLS, with Jon (Blok) Blacklock at the controls. ABCD-CHAOTIC checks were completed; ‘O’ in the check had wind N at 12 kts, slightly right of centreline, landing speed 60kts, Options ahead on runway, then ahead and left of the orchard, downhill towards the hangar strip Runway 16 or the corner paddocks N and NW of the field, or Runway 12 or 09 if higher. No obstructions, competent crew.
Bunyan’s runways are all grass, none of them are level, all have down or up slope, with cross slope in some areas. Runway 33 sloped gently downhill. The airfield paddock is full of rocks in many places, with heavy tussock grass and weeds off the runways. Many neighbouring paddocks are also full of rocks, fences and powerlines, stock and trees; so off-field options were very limited. My options were therefore focussed, as is usual, on known clear paddocks and other runways. These options all pre-supposed sufficient altitude and energy to reach them safely and execute a turn if required.
Takeoff in GVN was normal. As the glider accelerated, I went from flaps negative to neutral, setting 3, took off, and followed the Pawnee as it separated and climbed. Everything seemed normal. Well down the runway the tug began a gradual left turn, and I no longer had the land ahead on runway option. As it approached the boundary road north of the airfield in a climbing left-hand turn, the tug suddenly seemed to stop climbing, and decelerated – then rocked its wings vigorously in the emergency release signal. We were no higher than 200ft, probably 150-180ft above the downward sloping ground, as I pulled the release. I had an “Oh Bleep” moment as I released, still in a left turn, banking steeper left with the decelerating Pawnee’s left wingtip growing closer.
It was an extremely dynamic situation – there was no thought of rolling into a right turn, as my immediate priority was remaining clear of the decelerating Pawnee and I judged I could not risk a climbing right turn. The options of reaching the paddocks north of the airfield, or Runway 16, disappeared as I tightened the turn hard left. At the same time I glanced at the ASI and saw the decreasing airspeed trend, dropping towards 50 knots, and I knew I had to gain airspeed fast – so I pitched the nose forward to regain safe speed near the ground. I remember calling out loud “No! No way! Safe speed near the ground all the way into the flare!” No way was I going to allow a stall-spin to develop, even though I was really low over rising ground as I turned left.
You cannot under-estimate how quickly bits of towplane airframe will grow in your field of view.
As I rolled straight and level, heading roughly southwards, I saw that I was way too low to turn back and uphill to runway 15 reciprocal and complete a safe turn – and there were fences to avoid. I looked ahead and right, uphill towards the end of Runway 12, again way, way too low to reach safely. My next thought was that I would have to land ahead, on the airfield paddock near the windsock, amongst the numerous rocks and holes in the long grass. I felt a stab of apprehension, as I envisaged probable damage to the glider – but at least I had airspeed and would be safe into the flare. That option would also require avoiding fences near the runways.
I looked desperately for an alternate option, and saw that the vertical angle to the fence north of runway 12/30 was improving, steepening! I headed slightly right, following the downslope of the ground towards the fence and runway 12/30, and decided to pass up the landing option near the windsock and land across runway 12/30, over the fence, with a 12kt tailwind. On the far side of runway 12/30 was an area of long tussock grass and weeds, then the main runway 09/27, then the south boundary fence. I was far too low to attempt a turn to align with runway 12, but I also resolved to try to aim and steer slightly uphill, to assist in slowing down as quickly as possible. When I was sure I would clear the near fence I turned slightly left, and approaching the fence I opened airbrakes and aimed as close as possible to the edge of runway 12.
Moments later I flared and touched down on runway 12 with full airbrake, and plunged ahead into the long tussock grass and weeds, feeding in progressive left rudder to steer more uphill. To my surprise I did not reach runway 09/27, instead slowing very rapidly in the long grass and weeds. There were no rocks, no holes, no bangs, just the whipping sounds of long woody stalks hitting the wings. I was down safely! Glider inspections back at the launch point confirmed no damage.
There was no way I was going to allow a stall-spin scenario so I was very focussed on safe speed near the ground above all else. That meant trading altitude (with not much available) for airspeed (decreasing in a steepening turn to avoid the Pawnee) and then maintaining a safe attitude all the way into the flare.
* * * * * * *
Blok, the Pawnee tug pilot, had a rotten time with engine power loss, an engine failure as I released, restarted in flight, and max 800rpm in engine power surges. He limped back with irregular and partial power to runway 09, and landed dead-stick. I understand that subsequent investigations by our LAME showed that the Pawnee had suffered a mechanical failure in the distributor, with the top bearing overheating and melting the plastic, causing the ignition timing to jump and left magneto to fail, hence severe loss of power. To his great credit, Blok also landed safely, with no further damage. We shared a few relieved smiles and refreshments later.
* * * * * * *
As a Level 3 instructor, I have initiated dozens of launch failure and rope break emergencies as training scenarios for students and trainee instructors, as well as for instructor revalidations. Many times I have arranged for tug pilots to give wave-off signals as part of emergency training. These scenarios require care to plan and execute, but they did not cause much anxiety, as I was always sure of reaching a safe runway option. I learned to fly gliders at Woomera SA on the auto tow wire, so cable breaks there were frequent, and handled properly, were safe to recover from.
On 25 August 1987 I had a launch power failure in a Schweitzer S2-22 at Bunyan, due to Pawnee carburettor icing after a high launch, and I landed ahead on runway 09. As a Pawnee tug pilot, I once aborted a launch in September 2012 due to power loss and landed ahead on runway 27. So I knew power failures were possible, and planned accordingly. As this actual emergency showed, the best plans might never be practicable.
* * * * * * *
There were some good lessons learned from this incident.
- The training works! After an initial unpleasant surprise “ oh bleep” reaction, the essential actions kicked in – get off tow NOW, keep clear of the Pawnee also turning left, manage safe speed near the ground at all costs all the way into the flare, plan the emergency outlanding, keep concentrating on flying to the safest possible land ahead option.
- We normally turn right after releasing the tow. In a launch emergency you cannot assume you will be able to turn right after release – particularly if you are already in a left turn.
- If you are flying a fast slippery glider behind a draggy towplane, and the power fails, the towplane will decelerate and you will need to manoeuvre quickly to avoid it. You cannot under-estimate how quickly bits of towplane airframe will grow in your field of view.
- The situation was very dynamic, rapidly changing, and the preconceived notions about outlanding options on other runways or adjoining paddocks were quickly gone.
- Planning ‘O’ for Outside / Options includes safe speed near the ground for the conditions on the day, as well as launch failure options. That is an essential discipline, for all pilots, every launch. I couldn’t use the planned options, and I sure needed the airspeed!
- Whilst we might plan for launch failure options, the fact is we normally expect a benign launch, given the reliability of our towplanes and the rarity of engine failure events. Launch emergencies are by definition an unexpected event, and disbelief, fear and stress will occur. Murphy’s Law may well conspire (as it did in this case) to have the emergency occur in the worst possible position.
- There was no way I was going to allow a stall-spin scenario so I was very focussed on safe speed near the ground above all else. That meant trading altitude (with not much available) for airspeed (decreasing in a steepening turn to avoid the Pawnee) and then maintaining a safe attitude all the way into the flare.
- I had a safe paddock option near the windsock – Plan A, and I would have used it if there was any doubt about avoiding fences. If I had been in the lower performance two-seater Puchacz, rather than the ASW20, I think I would have had to land ahead near the windsock.
- Monitoring changing vertical angles to fences and obstacles allowed me to find a safe alternative landing area.
- I judged that I was way too low to even contemplate turning near the ground to align myself with a runway. Landing ahead on the airfield paddock (across a runway) was far safer than risking cartwheeling the glider in a low turn.
- Put another way, even if you can reach a runway, you might not be able to land along it – but perhaps across it.
- No matter how experienced or inexperienced you are, after a fright like that you will experience strong fear responses and adrenalin letdown symptoms. The other instructors agreed I should relax and calm down for a couple of hours before flying again! Getting back on the horse later, for a fun soaring flight, was a good way to relax and recover.
even if you can reach a runway, you might not be able to land along it – but perhaps across it.