Thursday, 23 June 2016
Acknowledgements: John Zimmerman/AIR FACTS
Flying an airplane is a never-ending series of decisions. Is the airplane airworthy? What’s the weather like? Where is that other airplane going? When should I turn base? Failing to ask these questions and make timely decisions can earn you a place in an accident report if you’re unlucky.
But there’s another decision-making error lurking out there, more common yet rarely discussed: we view most aviation decisions as binary. Yes or no, black or white. It’s rarely so in aviation, which is more about subtle clues, 50/50 decisions and shades of grey.
For example, the “go/no go” decision. A pilot looks at his airplane, his skills and the weather, then decides if it’s safe to fly the planned trip. A simple yes or no question. But it is hardly that simple. It’s really a series of questions with a variety of possible answers; rather an essay than a single “true/false” question. Here are four ways to help expand your view of the flight planning process:
· Go now or go later/earlier?
First off, the estimated time of departure (ETD). Viewed as a binary choice, that line of storms bearing down on the airport looks like an easy no go. But what about leaving an hour earlier, before the storms get close, or leaving the next morning, when skies will be clear? That flexibility is what helps make general aviation so much fun. Most pilots know this, but many don’t take advantage of it. Don’t get so locked into your original plan that you fail to see attractive alternatives.
· Go direct or go around?
My multi-engine flight instructor would challenge me during pre-flight planning by saying: “you have to go, so show me a route that is safe.” An exaggeration, as in truth we never have to go, but he wanted me to get a feel for his decision-making mind-set. It’s amazing how often a flight can be completed safely and comfortably if you’re willing to deviate. On a 400-mile trip, even a 100-mile detour will be quickly forgotten if you have a smooth ride. Arriving is half the fun anyway!
· Go all the way or go part of the way and stop?
Naively blasting off and hoping low-level IFR conditions will magically disappear is a bad idea. But flying as far as the weather allows and then diverting can be smart and effective. It might mean an hour or a day on the ground, but done with firm limits in mind, it can be a useful tool in the pilot’s bag. Similarly, you can choose to go some of the way and turn around if it’s worse than forecast.
· Go solo or take another pilot?
Some days, especially when the forecast involves thin cloud layers or gusty winds, the safe answer is no go. But if you’re willing to push yourself, it can be a valuable learning experience to go flying with another, more seasoned pilot. This way you get “on the job training” without scaring yourself. Just be sure to obey two rules: know and trust who you’re flying with, and thoroughly brief as to who is pilot in command before starting the engine.
All of these demand careful planning and discipline; they can’t be used as shortcuts or excuses for poor decisions. But grappling with tricky decisions and thus expanding one’s personal skills is the one of the real joys of being a pilot. As GA pilots we have the ability to control when and how we fly, and can each establish our own Standard Operating Procedures. If we give up that tool without a second thought, we may make our flying less useful, less enjoyable, and perhaps less safe.
So next time don’t ask yourself “go or no go?” Instead, consider “under what conditions would this flight be safe and enjoyable?” At the very least, it’s a valuable exercise for your decision-making muscles.
Wednesday, 1 June 2016
(Acknowledgments: Nigel Everett, GASCO Flight Safety)
Hi Folks! The following is taken from an excellent editorial by Nigel in the current edition of the GFS Magazine, based on the GASCO Stall & Spin Study of 2010.
A Student pilot can be led to believe that a large, perfect field is essential, because the instructor always opts for such a one when demonstrating emergency landings. As a survivable deceleration (9G) from 50 mph requires just under 10 feet of landing space, it is often better to select a clear approach zone, even if the field is small and rough.
In itself this is no protection. In stall/spin accidents, a fatal outcome is more common amongst qualified PPL/CPL holders than amongst Student pilots, and 22% of all such accidents occur with an instructor on board.
Ditching, when the aircraft is flown to a conventional wings-level touchdown and occupants are wearing life jackets, is very likely to end in survival. Of 179 ditching cases studied over four years, only 12% involved fatalities. Bear in mind, however, that in most water landings an aircraft will not remain upright, leading to injuries and an immediate survival situation.
Flying an aircraft under control into treetops is very survivable, often with no or only minor injuries. Only 6% of landings into trees involved fatalities.
Better odds than water or trees, as only 3% of field landings resulted in fatalities, and these almost always involved inattention to airspeed leading to Loss of Control (LOC) whilst manoeuvring for landing. Striving to reach perfectly level ground, or an airfield beyond realistic gliding distance, will very likely end in LOC.
Whatever surface is available, the goal is to achieve the lowest forward speed whilst minimising the rate of descent. The human body is better able to absorb forward speed than vertical speed, which is what compresses spines and ruptures diaphragms.
It is prudent therefore, whilst staying well clear of LOC parameters, to practice glide approaches regularly by making a proportion of normal landings completely power off, both to achieve slow arrival and to remain familiar with the aircraft’s glide capability.
One thing is relatively certain. The aircraft will probably be a write-off, so if a forced landing situation arises the pilot must forget sentiment and consider the aeroplane to be nothing but an expendable collection of aluminium, steel, rubber and fluids.
Forced landings are frightening but they can be made without serious injury provided that the pilot remembers the first rule of aviation:
“No matter what, always fly the aeroplane!”