Safety
People sometimes ask me: "how safe is gliding?".
This is an interesting question! First and foremost, it must be said how hard it is to make absolute statements about safety, or to compare and rank the safety of different activities. But it is useful to know some facts and to appreciate the risks of any new activity with your eyes wide open. A sound knowledge of the risks tends to reduce their likelihood of happening. So in an attempt to answer the question, here are some facts and some personal opinions.
Gliding has a good safety record. This record depends upon the continuous and consistent application of many procedures and practices that are based upon decades of operational experience. The dangers become greater when people start bending these rules, whether they realise it or not beforehand.
At my local airfield (near Aboyne), Deeside Gliding Club has operated very safely for more than 30 years. In common with most gliding clubs, it has had its share of bumps and bangs, but if there is any damage it is usually to the glider rather than the pilot. Glider wings are great at absorbing impacts, and the four or five point harness is much better than a car seat-belt. At Aboyne there have been a handful of minor injuries and very few serious injuries, usually with a full recovery. There has only been one fatality - many some years ago, and in unusual circumstances. There was nothing wrong with the glider. It seems that the pilot lost consciousness while performing deliberate spins as a quick means to lose height, so the glider just kept spinning until it arrived in the trees across the river from the airfield. The loss of consciousness was blamed upon a head injury received earlier - and not when flying. With hindsight, the pilot should have recognised the risks of this injury and should not have flown until he was fully recovered. But as always, 20:20 hindsight is a wonderful thing.
Like the rest of aviation, most gliding accidents worldwide are blamed on pilot error - usually in a serviceable glider. Sometimes this is due to the pilot taking obvious risks like flying into bad weather or over un-landable terrain. Sometimes the pilot has knowingly exceeded his/her abilities by venturing beyond their competence or experience. And in line with most accidents, there is usually a sequence of individually avoidable events, until the last one that makes the accident unavoidable.
A common cause of pilot-error glider accidents is a mid-air collision. Some collisions happen when aggressive pilots cram into the same thermal during competitions. But collisions have happened when there are only two gliders for miles around. That is why keeping a lookout is the most important skill taught early in training, so it becomes a habit for life. Before a mid-air collision when both aircraft are flying straight, the other aircraft seems to be in the same relative position until it suddenly grows much larger in the last few seconds. This lack of relative movement underlines the need to carefully scan the sky.
"Always keep a good lookout - the other glider might not see you"
Modern instrument "conveniences" like GPS navigation and LNAV flight computers can simplify cross-country navigation and competition flying, which in turn may cause less distraction to the pilot. On the other hand, unless the pilot is fully trained in their use, he/she can spend more time "head-down" in the cockpit, which reduces their lookout effectiveness. On the other hand, improved instrumentation can result in a direct gain in safety. The biggest step in the right direction in recent years has been the audio variometer. Rather than constantly monitoring the variometer needle when trying to optimise lift (e.g. within a thermal), the pilot can keep his/her eyes outside and listen instead to the rising and falling tones of the instrument.
The risk of a collision is a major reason for wearing a parachute. Parachutes should definitely be worn if aerobatics will be performed. It is normal for parachutes to be worn at Deeside Gliding Club (all club gliders are equipped with parachutes). Even though modern parachutes can work successfully from only a few hundred feet, statistics from collision accidents below 2,000 feet show only a 60% survival rate (when the pilot was capable of jumping). It takes a few seconds to get out and pull the ripcord. So the higher you are when you jump, the better your chances.
There has been only one parachute jump at Deeside. Before a demonstration flight to a prospective buyer, the pilot was distracted and omitted the positive control checks after rigging (assembling) his glider. He realised his predicament when he had trouble maintaining pitch control during the aerotow. Luckily there was enough friction in the loose connections to retain some control. After climbing to a decent height and releasing the aerotow, he jumped. When he landed safely the glider flopped down nearby - and I understand that he still managed to sell the wreckage (albeit presumably at a knock-down price!).
As the above incident illustrates, another major cause of pilot-induced accidents is incorrect control connections. This can be avoided by performing highly recommended positive control check after rigging. Some modern single-seater gliders can be assembled and towed to the launch point by an individual without assistance. That can discourage the pilot from seeking assistance for a positive control check. But the statistics show that overcoming this inconvenience can be a wise investment.
Another major cause of accidents is stalling and/or spinning close to the ground when there is insufficient height for a recovery. This is more common at winch-launch sites where the glider is flying very steeply in the early stages. If the cable breaks it is essential to lower the nose and gain speed before attempting to turn. Deeside only uses aerotow launches as the airfield is too small for a winch. As the motto says:
"Never fly low and slow"
A surprisingly large number of accidents (with 20:20 hindsight) are completely avoidable. For example, flying into the ground while trying to close a flapping canopy early in the aerotow, or even trying to swat an insect. The worst I heard a pilot's cat sleeping in the tail-boom before take-off, then waking in a rather alarmed state when airborne, claws drawn and swinging.
There is a general rule for all flying. You should devote your attention in this order of decreasing priority:
"Aviate (fly
the airplane)
Navigate (know where you
are)
Communicate (talk to
others)"
And only then think about other tasks like setting a GPS, folding a map, or searching for sunglasses.
Strangely enough, the risks to the tug pilot have traditionally been greater than to the glider pilot, although this has improved in recent years. The biggest risk to a tug pilot is an inattentive glider pilot during an aerotow. If concentration is lost it is all too easy for the glider to zoom up behind the tug, dragging the tug's tail upwards and backwards. The tug usually stalls badly (i.e. stops flying and dives). Although the tug pilot can release the tow rope from his end, this type of "upset" can happen extremely quickly with no warning, and with very little time to react. If it happens low down, there are usually limited options for the tug pilot. Ironically (albeit fortunately), the glider pilot usually lands safely after such an upset.
U.K. Air Accidents Investigation Board data suggests that gliding is a little more dangerous than flying light powered aircraft, but gliding is safer than hang gliding, and safer still than paragliding. Although there is no engine in a normal glider, glider pilots are better trained in landing at only one attempt, and are more experienced in landing in fields. And there is no risk of an engine/fuel fire in a normal glider!
What about the raw data? In gliding during 1987-1997, there were an average of 3.5 fatalities and 6.1 serious injuries per year to glider pilots/passengers (data is from the BGA web site courtesy of ESGC). In a good year there are up to 150,000 glider flights. So that means the risk of a fatal flight is only 1 in 40,000, And the risk of a serious injury is only 1 in 15,000. Alternatively, there are about 10,000 permanent and 35,000 temporary members of gliding clubs (excluding air cadets). So the chance of being a fatality is around 1 in 13,000 flyers, and the chance of being seriously injured is about 1 in 7,000 flyers. This average is fairly meaningless of course, because the number of flights per member varies hugely. It is better to consider the number of flights as above.
How does gliding compare to other "adventurous" activities? Based on UK government data, the risks of gliding seems to similar to the risks of driving a motor bike, although this may be misleading as the number of hours flown is usually much less than the number of hours on the bike, suggesting that gliding is in fact more dangerous than biking. But like anything you do, the more you do it the greater the risk. And the risk when gliding is quite low and very manageable.
A well-trained pilot who understands his or her limitations and who flies regularly and practices little-used skills is much less likely to have an accident. Safety is very much under the control of the individual and is not a complete game of chance. The best way to keep safe is to be well trained and current, to apply diligently what you have learned, not to take risks or shortcuts, and to know and stick to your limits. If you are not sure about anything, ask! If you have not experienced something before, or are out of practice, then ask for a dual flight with an instructor. Examples of this might be field landings, landing in a strong crosswind, or a sideslip approach without airbrakes. Most clubs have rules that require one or more check flights after a lapse in flying, especially for low-time pilots using club gliders. Remember the old saying:
"I'd rather be down here wishing I was up there, than up there wishing I was down here."
It can be comforting to know that gliders are increasingly built for safety. As technology has evolved, designers have paid more attention to safety while having to meet the requirements of good gliding & soaring performance. Sadly, a glider built like a tank wouldn't fly too well (and the legendary T-21 is the closest thing to a gliding tank I have seen). But simple modifications can make quite a difference. For example in Holland it is now mandatory to install canopy impact bars (like rollover bars in a convertible car), which may appear more in the U.K. With the more recent focus of safety in the automobile industry from F1 to Ford, there have been spin-offs for glider design. Most gliders have four-point or five-point harnesses and six-point harnesses are now available. Some glider manufacturers are researching more crash-resistant cockpits and airbags are being considered. The best modern fibreglass cockpit designs being worked on are similar to the cockpit of an F1 racing car, from which a driver can walk away after a 180mph impact into a concrete wall. Provided the costs of such developments can be managed when migrated to gliders, car safety technology has clear advantages for gliders.
More innovative solutions are emerging, such as ballistic parachutes to safely lower a damaged glider to the ground with the pilot strapped safely inside. Of course, although we are already seeing the fruits of these labours in new aircraft, the life of a well-maintained glider can be decades, so it will be a while before most club gliders catch-up with the state-of-the art.
I hope that this frank article does not cause undue concern to the aspiring pilot. I believe it is better to enter any new sporting activity with both eyes wide open. In particular, an understanding of the risks makes it easier to avoid them. Gliding obviously carries a bit more risk than sitting at home with a cup of tea and a pair of slippers. But life for most people is all about responsibly managing risks, whether that means taking up an adventurous sport - or simply continuing to smoke.
Gliding is a well-regulated sport with high standards of training and supervision that are constantly refined to maximise safety. If we all stick to the rules and avoid taking unnecessary risks then the sport will continue to be intrinsically safe and keep getting safer.
(Note: This article is an update to replace an over-simplistic statistical analysis of risks that unfairly exaggerated the risks of gliding. My thanks go to John Wright for suggesting a more balanced and representative analysis.)
For a very good article on gliding safety, see this article published in 1993 in Aerokurier, now available in English on the DG web site on page http://www.dg-flugzeugbau.de/safety-comes-first-e.html