GLIDING – THREAT AND ERROR MANAGEMENT
or How to Reduce Mistakes and FLY SAFELY Part 1 of a 3-part series
This series on Threat and Error Management were originally printed in Soaring NZ some years ago and is reproduced here with their kind permission. There is a whole new group of pilots who will benefit from a reprint as the advice given is a relevant as it has ever been.
Arthur Gatland started flying in 1963 at age 13 and has accumulated 17,000+ flying hours including 2,500 hours in RAF fighters such as Harriers, Hunters, Hawks. Arthur has now retired after flying Boeing 777 for Air New Zealand as both Captain and instructor, and ten years as Manager of Training and Flight Standards. He is an A Cat glider instructor, with a Gold C and 3 Diamonds, and was a previous CFI of the Auckland Gliding Club.
Our gliding accident rate in recent years has not been good. The fact is that on average we have one fatality a year, with all the tragedy that this brings to families and friends, not to mention the huge cost in damaged and destroyed gliders and associated increase in insurance costs etc. Yet gliding is inherently a relatively safe sport, and historically has been second only to airline flying as one of the safest types of aviation. To my knowledge, none of our spate of accidents has been the result of structural or mechanical defects – all have resulted from pilots unnecessarily putting themselves in a situation that for various reasons have resulted in a crash. Ridges, rocks and trees do not suddenly leap out and hit gliders – yet we manage to collide with them on a regular basis. And despite the fact that gliders are safer, have better handling and performance, better airbrakes, more comfort, and better visibility than those of 30-odd years ago, our accident rate is worse.
Why is this – and more importantly, what can we do about it?
Already, I can see a number of pilots losing interest in this discussion – because “This doesn’t apply to me – I’m experienced / skilled / smarter / an above average pilot (delete where applicable) and I don’t make those mistakes.” If you really believe this of yourself, then you can replace those descriptions with “arrogant / overconfident / unrealistic / unaware” (delete where applicable).
This series of articles applies to every glider pilot in New Zealand, regardless of experience.
I believe that, like many accidents where contributing causes are often small but multiple, there has been a lowering of our flight standards for a number of reasons. These include:
* lower average flying hours due to less leisure time and financial constraints
*higher performance gliders that create an unrealistic expectation that we always get home from cross-country flights
* changes to national culture where people think they have the right to be more independent which leads to less discipline, reluctance to ask for on-going training, less time to talk to and listen to more experienced pilots, and unfortunately a lowering of instructing discipline and standards.
We all – individually and collectively – need to look at ourselves and see where we can attack these issues and reverse the slide in our flying standards and safety.
One technique we can all use to improve our flying safety is the use of Threat and Error Management, which I will describe in this and following articles. This is a simple technique of understanding the type of situation where we are more likely to make a mistake and toprevent making errors which might lead to disaster.
“TO ERR IS HUMAN” (Cicero, 50 BC)
In other words, we ALL make mistakes. Accepting this is an important step to understanding when and where errors occur, and therefore how to prevent errors. Pilots who think they don’t make mistakes are (a) seriously mistaken (b) dangerously over-confident (c) have a limited life expectancy!
Errors are most likely to occur when we are faced with a THREAT, that is, something that presents a change to what we are used to, or what we are comfortable with. To understand what constitutes a Threat, I will introduce the concept of a Pristine Flight (courtesy of Continental Airlines). In this first article, I will concentrate on a local soaring flight and discuss possible threats, and in part two and three we will expand this to cross-country flights, and competition and other specialised flights.
This is a simple gliding flight where everything goes exactly to plan. You arrive at the airfield and the club glider you want to fly is available, already DI’d and at the launch point. Helpers are readily available to pull it out for you, and a towplane is waiting. You are current on type and an instructor is happy to authorise your local flight. There is no wind and no lift or associated sink. There are no other gliders flying and no delay to your takeoff. The weather is pleasant; not too hot. You aerotow to 2000 feet and glide gracefully back to the circuit, practising a few turns and speed control. Your well-planned circuit is uninterrupted by other gliders or crosswinds and landing is uneventful. This is a Pristine Flight – arguably a bit boring, but with no real interruptions to your simple plan.
Now let’s talk about likely variations – many of them very common – that can upset your plan. You planned to be at the airfield by 11.00am but you are annoyed that you are late because your partner was late getting back from shopping. No-one has bothered to get the glider out of the hangar and it hasn’t been DI’d. You are short of time so you must hurry these processes. The only instructor is flying, and you haven’t flown for 2 months so although you think you might need authorisation, you decide it’ll be OK to go without. There is only one other person to help push the glider on to the start line, an inexperienced student who you need to brief. After the exertion of pushing you are hot before you even get into the glider. You strap in and as you are doing your pre-takeoff checks, someone interrupts you to ask if you’ve remembered about the night’s barbeque. It’s a bit windy and you haven’t briefed the towpilot, so after takeoff he annoyingly takes you downwind to what he probably thinks is a good looking cloud. You don’t find lift, but you practice a few turns, then head back to the airfield, encountering unexpected sink on the way. Your circuit is lower than you would have liked and you are concerned about another glider on circuit at the same time. Your circuit is a bit rushed, and with a short finals, you don’t quite sort out the crosswind so the landing is a bit untidy. After landing the next pilot points out that the DI hasn’t been signed today.
All of these variations to the Pristine Flight constitute Threats that will increase the likelihood of you making a small slip, or an error in judgement, or forgetting something – regardless of your experience. Let’s review what these Threats might include:
Cross-country introduces an additional list of threats which we will discuss in the next article.
Note that many Threats are normal and some even desirable. For example a moderate wind might be appreciated for ridge soaring, but result in a crosswind takeoff and landing, and result in a headwind when returning to the airfield. Good thermals can also cause unwanted sink on downwind leg in the circuit. You may be aiming for your 5-hour endurance, but this will raise threats of thirst, hunger, fatigue, etc.
All threats increase your likelihood of making an error. A proficient pilot can easily recognise all threats, and implement a strategy to prevent an error resulting. Some examples might include:
* Interruptions: If someone talks to you when you are halfway through your pre-takeoff checklist, recognise that this threat is likely to result in your forgetting something, and start again from the beginning.
* Procedural uncertainty: Any time you hear that nagging voice questioning something (are we clear for take-off, did I do my checks, did I sign that DI, do I need instructor authorisation, did I remove the tail dolly) – then STOP and double-check. Observers always respect someone who acts professionally and questions some small detail, in stark contrast to someone who makes an assumption and is proven to be an idiot.
* Time pressure: Any time you feel pressure to hurry – for whatever reason – you should be aware that this is a major cause of errors, through forgetting processes (tail dolly removed?), forgetting to take essential equipment (maps, drinks, hat etc.), ignoring procedures (takeoff checklist) etc.
* Other traffic: A good pilot will always join the circuit assuming there will be other gliders rejoining, and have sufficient height to give way to a lower performance glider. He/she will also know the rules regarding landing if there is a glider ahead on final approach – where to land etc.
* Unexpected sink: Always anticipate sink in the circuit. However if a circuit is flown using correct techniques this should be self-correcting – don’t rely on the altimeter, or ground features for turn-in points, but assess your angle to landing point. Any unexpected sink can easily be corrected by adjusting distance out and turn-in point – if a pilot is alert to the possibility of unexpected sink.
INEXPERIENCE and INSTRUCTOR RESPONSIBILITY:
Early solo pilots cannot be expected to recognise all threats existing on any particular day. This is why an instructor must authorise and brief early solo pilots. It is the instructor’s responsibility to assess all threats and brief an early solo pilot accordingly. The brief might be along the following lines (abbreviated):
* I have checked your logbook and confirmed you are current on this glider type. Your aim of today’s flight is to search for lift and practice thermalling. There are several other gliders airborne, so let’s review how you join a thermal if another glider is there first. Remember when you are concentrating on thermalling and speed control that lookout is actually more important. There is a moderate northerly wind today, so stay upwind of the airfield. Always keep the airfield in sight and have a plan on how to rejoin circuit if you don’t find lift. Be aware of the likelihood of sink in the circuit area. Where will you land if another glider has landed ahead of you? It’s hot today – have you got a sunhat and sunglasses? Now make sure you take your time getting comfortable in the cockpit and doing your checks – don’t let anyone rush you. Any questions – anything you have any doubts about?
The main ways that new pilots can gain experience and knowledge is by instructors or experienced pilots passing on these thoughts, OR learning by making mistakes! Which method is better??!!
SOME EXAMPLES of THREATS and ERRORS:
An experienced pilot was rigging his motor-glider for a flight from a remote airfield where there were no other glider pilots around, although a number of interested spectators were watching and talking to the pilot. While rigging, he was further interrupted by a phone call, and failed to mount the tailplane correctly. After takeoff the tailplane detached and the pilot was killed.
* A pilot elected to fly his new motor-glider to a family farm, where he flew a circuit, while extending the engine to carry out an approach and motorised go-around, to ‘show off’ the glider. The engine failed to start, and while flying the circuit he got low and slow, stalling on base turn. The pilot was killed.
PROCEDURES THAT ASSIST WITH THREAT and ERROR MANAGEMENT (TEM):
We already have a number of checks and procedures that have been developed over the years, all of which help with TEM. Some examples:
Checklists – all are designed to ensure we have completed all essential actions, and/or to check the position of equipment (gear down, flaps set) or the operation of controls (airbrakes check). By completing a checklist diligently you remove any nagging doubt you may suddenly have, for example during takeoff (I can’t remember if I took off the tail dolly...???).
Eventualities planning – this is a required part of pre-takeoff checks, allowing you to plan for unexpected threats or emergencies. It should also be an on-going thought process throughout the flight. (If that glider joins the circuit ahead of me, what will I do? If this cloud has no lift, can I get back to the airfield etc.)
Standard Operating Procedures – normal procedures, circuit procedures, right of way rules, ridge flying protocols, are all part of TEM.
Make sure you understand WHY we do certain things – for example:
* Strap in before doing control checks
* Don’t attach towrope until fully ready to launch
* Specify nosehook or bellyhook open
* Check full operation of airbrakes on downwind
* Maintain safe speed near the ground.
* Always secure the wingtip when parking a glider
All of these procedures have resulted from learnings from previous accidents!
CONSEQUENCES OF ERRORS:
An important part of Threat and Error Management (TEM) is to understand the consequences of possible errors, and to make doubly sure the most consequential errors do not occur. Forgetting your map on a local flight may not be important at all, but forgetting your map on a cross-country flight could lead to navigation uncertainty, infringing controlled airspace etc. Stalling while pulling up into a thermal might be slightly annoying, stalling on base turn may be the last mistake you ever make.
Some errors have downstream effects. Forgetting to raise the gear after takeoff has often resulted in gear being raised instead of lowered for landing which has lead to a wheels-up landing. This is also a good example of ‘seeing what you expect to see’ – you can’t believe you landed wheels-up “because I know I did my pre landing checks diligently!”
Every flight involves some threats and all pilots must ensure they recognise these and have a strategy to manage the threats and prevent errors, and/or have a process to catch errors or slips that may have occurred. Remember we ALL make some mistakes on every flight – the important thing is to ensure they are not critical ones, or that they are captured before they lead to an undesirable situation.
USEFUL STRATEGIES: The following are just a few examples of TEM strategies that should become automatic to a skilled and safe pilot.
THREAT AND ERROR MANAGEMENT: was introduced to Air New Zealand around 15 years ago, and is a mainstay of pilots’ briefings for every takeoff and approach/landing. It is a proven technique for assessing and mitigating risk and has been accepted worldwide as a powerful yet simple tool in improving safety and preventing errors. It is imperative our gliding movement adopts this tool – individually and collectively – to stop our slide in safety standards and return to a safe and proficient operation – and still have great fun!
A MESSAGE TO INSTRUCTORS and EXPERIENCED PILOTS:
You have a particular responsibility for ensuring Club operations are always carried out professionally and responsibly. You can do this firstly by setting a great example with your own diligent procedures. You should also be watching what other pilots are doing as they prepare to fly, or when they approach and land. Never let your guard down – lives have been saved because someone had doubts about what another pilot was doing, and ‘interfered’ by questioning something...
TO EVERY GLIDER PILOT:
Acknowledging your vulnerability to mistakes is actually a sign of strength. In flying, you never stop learning. Every flight, whether you have 50 hours, 500 hours, or 15,000 hours, presents us with the same threats that must be recognised and managed. On every single flight you need to ask:
What are my threats today?
How will I manage and mitigate these?
IN THE NEXT ARTICLE I will continue the theme of Threat and Error Management into cross-country flying – which is an area that has resulted in a significant number of serious accidents.