Engine-out Landings
On 17 May 2006, Alan Coates died in a
crash of his Gyrobee. It appears that he suffered a partial or complete
engine failure, possibly while climbing out after takeoff, and within seconds his machine
impacted the ground at high speed and a very steep angle. We may never know the precise
sequence of events leading to this tragic incident, but it is clear from a lot of
post-accident discussion, that there are issues that need to be addressed with respect to
engine-out landings. This is especially true with respect to the Gyrobee!
This is not because the Gyrobee is more hazardous in such a situation, but
rather because landing a 'Bee under such conditions should be easier than many gyros! Over
the years I have tried very hard to avoid treading on the turf of flight instructors.
However, with more instruction being flown in machines with four-stroke engines, I think
pilots tend to emerge from training inadequately prepared for the reality inherent in
two-stroke engines.
Let me emphasize that what follows is not some piece of
theoretical BS! I have had 16 engine-out landings in fixed-wing ultralights and three such
landings in the Gyrobee. I will almost certainly mutter a few choice
expletives the next time the engine quits, but I most certainly won't freak out or wet my
pants. Note that I wrote when the engine quits, not if the engine
quits! You must always be prepared to keep flying when the engine quits, for it
will, and if you can't handle that, you have no business flying, let-alone in an aircraft
powered by a two-stroke engine! The discussion which follows will be divided into several
sections - engine restarts, airspeed management, landing techniques, and an analysis of
engine-out landings in three different contexts (takeoff, cruise flight, and landing
approaches).
Engine Restarts
NEVER, NEVER attempt to restart the engine! The reasons are
pretty simple:
- The engine has already quit on you and, even if it were practical to
restart it, it can't be trusted!
- If you have a pull-started that can be reached from the seat, it will
take both hands/arms to do the job and this is not a situation where you want to lose
control.
- You will waste valuable time and altitude that is better expended to
optimize the inevitable landing
You must accept the fact that, when the engine quits, you are going
to land right now! Your job is to keep flying so as to bring the flight to a
successful conclusion. If you keep your head, there is no reason why you have to damage
your aircraft, let alone injure or kill yourself!
Airspeed Management
When flying a fixed-wing, maintaining airspeed is the highest priority
following an engine failure - particularly on a full-power climb-out. If you don't get the
nose down right now, you will stall and, without sufficient altitude for recovery, you
will die. This simple fact programs fixed-wing pilots for a reflexive forward-stick
reaction the moment the engine quits or sputters.
While you do have to manage airspeed in a gyro, there is never a need
for instantaneous stick movements since a gyro cannot stall! If the engine fails,
deliberately use the stick to trim your airspeed. In the case of a Gyrobee,
your target airspeed is surprisingly low! Most Bees will show their best
climb at about 35 mph. Not surprisingly, all other things being equal, this is also
the Gyrobee's best power-off glide speed. If the wind creates a
wind-gradient or there is a gust component, you may want to crank the airspeed up to 45
mph or so. Just remember, there is no hurry - don't jam the stick around, just use it as a
trim control in pitch.
How slow can you fly and still execute a solid
round-out? Well, 25 mph is no problem at all. My slowest engine out approach (see the next
section) ever was 15 mph with me in the seat (220 pounds) and a full tank of gas! The
result was a perfectly good no-roll landing, but that was in a lightly-loaded Part
103-legal Bee. If you have a heavy machine and/or a smaller rotor disk, I
would stay at 25 mph or better.
Landing Techniques
Your training for off-field/engine-out landings begins when you start
your fundamental flight instruction and it never stops. Here are a few of the things you
should be doing:
- Low-Throttle Approaches. As soon as practical you should begin
making all your landing approaches at low throttle. This may seem demanding at the outset,
but if you gradually carry less throttle into your landings, it soon becomes second
nature.
- Know Your Machine. As early as possible, practice gliding and
maneuvering at low throttle. In a fixed wing, all your approach maneuvers are delicately
done with the engine out since you cannot afford to stall the aircraft. A gyro is a
different beast and, compared to most gyros, a Gyrobee is a real floater if
you built it light. You will be amazed at what you can do to fit into tight spots and you
should get to the point where you have an instinctive feel for straight-ahead gliding
flight and the increased altitude loss in turns. Remember, there is no need for excessive
airspeed in any of these maneuvers - 35-45 mph is just fine! Along with this, learn to
judge your altitude accurately (especially low-down) without referring to your altimeter.
- Learn to Appreciate Grass. If most of your flying is from paved
runways, get some experience landing on grass. The experience will prove invaluable. Also,
study your local crops at different seasons of the year. As just one example, the top of
full-season corn can be 6-8 feet above the ground. If you round-out at tassel level, it's
a long way to the ground!
- Learn to Round-out Without Fixating. Too many pilots are staring
at the surface just in front of their machines, learning how to round-out using the
texture they see and get used to. This can lead to serious problems if you are landing on
an unfamiliar surface. You should learn to round-out while looking well forward of your
machine and taking full advantage of your peripheral vision. This is the most reliable way
to judge altitude when you are close to the ground!
- Learn to Read the Wind. Windsocks are great things, but there may
not be one in sight if you have to land off-field. Learn to read wind direction, strength,
and gradient from nature's windsocks. Smoke trails, wave patterns on water, wind movements
on tall grass, wheat, corn, or forest canopy are all cues as to wind direction. No matter
where you are flying, you should keep track of your flight heading relative to the current
wind pattern. The best landing options are straight into the wind and you may not have
time to figure everything out if you wait until the engine quits.
- Practice Zero-roll Landings. The ability to make zero-roll
landings is one of the most amazing aspects of gyros in the eyes of conventional pilots.
It is this capability that means that you can put a gyro down on a surface, such a plowed
field, with no damage compared to tearing up almost any other type of flying machine.
Properly built, a Gyrobee is so lightly-loaded that zero-roll landings are
easily achieved, even under no-wind conditions. Run-on landings have their place in normal
airport operations, but you should regularly practice zero-roll touch-downs.
- Practice Spot Landings. Given the ultra-short roll-out of a
typical gyro, it is easy to get lazy and just land anywhere along the length of an airport
runway. This is a very bad habit as it makes it very hard to land on that one really good
spot on the day your engine heads west! On every landing, pick the exact point on the
runway where you will put it down and then make it happen. Here's a hint your instructor
should have passed along. If you are on final, the spot where you will touch down on your
current glide path is the point that neither rises nor falls in your current field of
view. This is easier to check if you have a fixed airframe reference point such as a
instrument pod. If the spot you have picked stays put, that's where you will touch down.
If the point rises with respect to your reference, you will touch down short of your
point. If the point drops, you will land long. Learn to adjust your glide angle and sink
speed to land precisely where you want to each and every time and you will be ready if it
suddenly gets very quiet!
- Mental What-If Exercises. Take the time to think about landing
off-airport. How could you handle different field layouts or different crops? What's the
best way to go down in the woods or into water? Combine these with actual flight
approaches to different fields while you are out just flying around. The moment the engine
quits is not the first time to entertain such thoughts.
- Learn to Spot Hazards. Each area is unique in terms of specific
ground hazards that can turn a routine landing into a tragedy. You must learn to recognize
wires and fences. It goes without saying that you should thoroughly know your own local
flying area, but you should also be able to spot potential hazards from the air or, if
nothing can be seen directly, where can you assume there might be power lines and fences.
In the best of all possible worlds you would make a careful circuit and analysis of any
unfamiliar field prior to a landing attempt. Unfortunately, that leisurely look is not an
option in an engine-out situation.
Departure Failures
Engine failure on take-off are the most common scenario in ultralight
aviation. Just a short time earlier, the engine was cold, yet now you are demanding full
throttle, with a corresponding rapid rise in CHT. Engines are like anything else in that
they are more prone to failure when pushed to their limits. Here are a few points to
ponder that relate to engine failures on take-off:
- Over the Runway, Plenty of Room. This is simple and a
non-event.Gently trim for your normal approach airspeed (typically 35-45 mph, depending
upon the wind) and shoot a normal landing.
- Over the Runway, but Tight on Room. First, you have to gently
trim to around 35 mph and then make a quick evaluation of your situation. If you are high
enough that making the runway is problematic, you have some options, depending upon your
situation. If the area beyond the runway is landable, then do it. If, in contrast, the
over-run area is a problem for some reason, you will have to look at what it would take to
use the runway that's left to you. DO NOT slam the stick forward and point the gyro
at the ground - you are not flying a fixed-wing! Instead, slow the machine down! The
descent rate will increase while your forward speed decreases - just what you need. That
evening that I discovered that the Gyrobee would land at 15 mph, I had an
engine failure with very little runway left in front, followed by a road with ditches on
the near and far sides, followed in turn by some harvesting machinery on that was normally
open field. Normally I would have landed in the field without hesitation, but the
unexpected machinery demanded a steep, low-speed approach. The Gyrobee was
able to execute a round-out at such a low airspeed - your mileage may vary if you fly
something else. The point is, any slow-speed scenario is better then the high-speed lawn
dart option. The faster to are going, the more time is required to slow down and any
failure in depth or altitude perception can have catastrophic consequences.
- Beyond the Runway. If you have used all the available runway
for takeoff, you probably have plenty of altitude and that translates to options for
getting to spots out ahead of you or turning back to the field. If you have taken off from
mid-field you are a fool who had better hope for some clean, straight-ahead landing
options. The reason that turning back is tricky is that it is NOT a simple 180-degree
turn. Let's say you turn 180 degrees left from your present heading. You will find
yourself headed down wind all right, but the runway will be off your left side. You would
need to turn left an additional 45 degrees or so to intersect the runway and then
45-degrees right to get lined up. Like I said, tricky and those extra turns eat up
altitude you may not have! If local conditions permit, I tend to angle off the runway to
the right on climb-out (assuming the normal let-hand turns). By the time I am abeam of the
end of the runway, a simple 180-degree turn would be sufficient to line me up for a simple
down-wind approach if the engine should fail.. Since time is of the essence, look at all
your options. If it is safer to reach an empty taxiway or a stretch of grass, take the
option rather than rolling up the machine in an attempt to reach the main runway. Always
take the simplest and safest option! Back when I was flying weight-shift Quicksilvers,
I had and engine failure right after takeoff. I landed without incident in the waste area
between a corn field and a bean field out beyond the runway. The dealership was run by two
brothers. The not-so-bright one complained that I had landed off field and felt certain
that I could have and should have made it back to the runway. The older brother - an
ex-Army chopper pilot - shook my hand and said "Nice landing"!
In-flight Failures
Engine failures are not as big an issue in cruise flight as the rpms
and temperatures tend to be fair stable. Fuel starvation, air leaks, and ignition system
failures are high on the list of potential cruise-flight problems. The big issues here are
the altitude at which you fly and what you chose to fly over! The key is to keep a
constant inventory of practical landing spots as you cruise merrily across the
countryside. Practical, in this case, means places you can reach from your present
altitude. You will find all those spots by looking down - not out! No matter what you
glide ratio, altitude is the key to optimizing your landing options. If you double your
altitude, the area you can reach increases by a factor of four!
We old-fashioned ultralight types fly cross-country by plotting a
course that strings together places where we could land should a problem arise. It's a lot
like crossing a stream on stepping stones. I can and do fly over places where I can't
land, but I always do it at an altitude that will let me reach a landable spot if I have a
problem. If that isn't practical, then I fly around the problem area. This approach
becomes second nature with practice! While such conservative flying may not appeal to
general aviation types, it is certainly the most sensible approach when flying two-stroke
powerplants.
Test yourself periodically by dropping to low throttle, trimming your
airspeed, and executing a mock approach to your preselected landing area. If you
didn't preselect a spot, you fail! When flying the approach it is generally best to stick
with your plan. Part-way down you may spot what looks like a better landing area. Almost
always, a well-executed approach to a marginal spot is superior to changing your target.
It may work if you still have plenty of altitude, but low-down it is a recipe for
disaster.
All too often you hear "The engine quit and I didn't have a decent
place to land...". The only reason you don't hear it more often than you do is that
the casualty rate is extremely high. Most people would say that was bad luck. In truth, it
reflects some very poor choices by the pilot! That said, what do you do if you have to
dump it in the woods? Opinions differ, but my own choice would be to flare to a stop over
the center of a big tree and let it settle in. If everything works right, you will be
firmly planted in the tree as opposed to the long fall to the ground if you had aimed for
a spot between the trees! That said, the best option of all was never to get stuck over
the woods in the first place!
If you absolutely have to come down in brush, trees, or
tall crops such as corn, sorghum, or sugar cane, it is always better to settle in
vertically instead of plowing on into the stuff. You have almost zero frontal protection
and late-season corn can beat you to death, let alone what can happen with brush or
branches. In contrast, coming in more or less vertically gives you the seat for
protection, dissipating energy and clearing the way for the rest of your anatomy.
Final Approach Failures
These should be a no-brainer if you have practiced your low-throttle
landings. The main thing here that can bite you are long, flat final approaches. The
preferred approach, both to preserve your options and to optimize being seen, is to come
in high and then execute a relatively steep final.
I have heard some pilots say that thinking about all this stuff takes
the fun out of flying. The truth is far from it! If you have planned and trained for the
eventuality that the engine will quit, you won't worry about the possibility and you
certainly won't panic when it happens. Ignoring a problem does not lead to peace of mind,
but knowing that you can cope does. I know I can safely land the machine if the engine
quits and that makes all the difference.