Ray wrote:

Okay, so all kidding aside, what are the issues between high and low wings?
I know that in terms of flying, there are very few differences between your
average Cessna and Piper, but for higher performance aircraft, what are the
aerodynamic/design tradeoffs?

OK, if you want a serious answer rather than a punch line, here goes.

Typically, high-wing planes have struts bracking the wings, and those add
extra drag (some high wings, like the Cessna Cardinal, manage to avoid
struts) -- that drag can become very significant at higher speeds. On the
other hand, low-wing planes that want a lot of roll damping (such as
trainers) have to use a higher dihedral angle than high-wing planes, and
that also adds drag. If you want to build a high-performance,
highly-responsive plane (i.e. very little roll damping), a low wing is
probably the best choice, but I'm not an engineer or a scientist, so others
may step in to correct me.

High-wing planes are far better for bush work. The wings are less likely to
hit bushes, shrubs, fenceposts, and so on, and on floats, the high wings
will easily clear the dock. I'm happy to take my low-wing Piper Warrior
onto a well-maintained grass strip, but I won't land on a farmer's field
outside of an emergency. Of course, I wouldn't land a high-wing nosewheel
plane like a 172 or 182 on a farmer's field either -- high-wing or low-wing,
with a nosewheel you're only one gopher hole away from a prop strike and
engine teardown. Serious bush types around here (central Canada) normally
fly high-wing *tailwheel* planes like the Super Cub, C-180, C-182, DHC-2
(Beaver), etc. You can land and taxi those almost anywhere. High-wing
pilots also worry less about hitting a snowbank with a wingtip during the
winter -- that might be an advantage if you fly in snow country.

Low-wing planes are better for crosswind landings and taxiing, because the
wheels are considerably further apart than they can be on a high-wing
single. If you're flying mainly to paved airports or well-maintained grass
strips, that can be a measurable advantage.

Others have already mentioned visibility issues. High-wing planes give a
better view of the ground for backseat passengers, but low-wing planes give
the pilot better visibility of conflicting traffic in a turn. As a related
point, I have one daughter who gets motion sick easily, so I appreciate not
having to lift my inside wing to check for traffic before turning, the way I
would have to in a high wing. In a low-wing plane you can see the top of
the wing, which is where the ice can accumulate if you stumble into icing
conditions -- that can be a comfort if you fly IFR, but it's not a big deal.

High-wing planes can have a "both" position on the fuel selector, which
simplifies fuel management. Low-wing planes need to use pumps rather than
gravity, so they cannot have a "both" postition, and you have to manage the
fuel more actively: I'd guess that fuel-exhaustion accidents are more common
in low-wing planes (especially with renters who usually fly high-wing and
never touch the fuel selector), but I don't have the stats in front of me.

You can probably extrapolate the answers to these questions from what I've
written above:

Why are most of the more expensive private aircraft (cirrus, pilatus, pretty
much all multi engine and jet) low wings?

Why do all fighters since the biplane era have low wings?

Why do most military transports (C-130, C-17, C-5) have high wings, but all
airliners have low wings?

Why are a lot of cold weather/high altitude planes high wing?

If you're doing most of your flying to proper airports (pavement or
well-maintained grass strips), just pick the plane you like best and don't
worry about the high-wing/low-wing thing. If you're going to do serious
bush work, fly a high-wing taildragger.


All the best,


David