AOPA Pilot Magazine - June 2014 - 16

PROFICIENT PILOT

Best for the worst

BY BARRY SCHIFF

When ditching, which aircraft fares well?

BARRY SCHIFF

has been writing
for AOPA Pilot
for 51 years. This
month marks the
anniversary.

16 | AOPA PILOT June 2014

EVERY ONCE IN A WHILE, a hangar-flying session involves
debating the best and worst types of aircraft to use when
ditching (assuming that one had a choice at such a time).
I recently overheard such a discussion at my local airport, and it reminded me of research I did about this
subject more than 30 years ago. Most pilots, I discovered (then and now), believe that the ideal light airplane
for ditching has low wings and retractable landing gear.
Statistics, however, do not appear to substantiate this.
Although low-wing airplanes do offer superior
planing and buoyancy (especially when fuel tanks are
empty), they usually should not be landed in water with
their wing flaps significantly extended because this
can cause a pronounced nose-down pitching moment
and make the aircraft behave like a submarine. Also,
extended flaps on a low-wing airplane can be torn
away during touchdown. This can create openings in
the wing structure and have an undesirable effect on
buoyancy. Without flaps, low-wing airplanes typically
splash down at a greater speed, which increases the likelihood of injury.
Because the flaps of high-wing airplanes are less
susceptible to water damage, they can and should be
used to the maximum extent possible to reduce touchdown speed.
Another disadvantage of a low-wing configuration
is that it is easier to inadvertently dig a wing tip into the
water (especially when landing in a rolling sea), and this
can result in cartwheeling. The ailerons on high-wing
airplanes are more effective in maintaining lateral control because they can be kept high and dry during the
initial phase of the landing.
Although a ditching should be made with the landing gear retracted (when possible), this should not be
construed to mean that retractable-gear aircraft are
more suitable than fixed-gear aircraft. Just the opposite
might be true. Of the 104 ditchings made in U.S. waters
during the three-year period under study, half were in
retractables, yet these accounted for two-thirds of the
fatalities that occurred during splashdown. These statistics likely are the result of retractables typically having
higher stall and landing speeds, which obviously result
in greater deceleration and impact forces.
When touching down on a clean belly, the aircraft
tends to skip, just the way a flat, spinning rock does
when tossed toward a deep puddle at an acute angle.
The initial touchdown can be quite mild-but hang on.

The second impact is likely to be much more severe,
especially as the elevator loses effectiveness (because
of airspeed decay) and the nose digs in. This can cause
the aircraft to submerge quickly. It most often, however,
bobs back to the surface and provides some time for
evacuation (unless the front windshield has imploded
and the aircraft floods).
Those who have ditched slow, fixed-gear aircraft
most often report that the main gear digging in during
initial touchdown prevents aircraft skipping and the
subsequent striking of the water in a nose-low attitude.
Instead, the aircraft simply decelerates rapidly with the
nose burrowing only slightly. It is generally agreed that
this is safer than having to endure the secondary, noselow impact associated with ditching retractables.
Although initial touchdown should be made as
slowly as possible, a full-stall landing should be avoided
because of the possibility of the nose dropping and causing the airplane to strike the water nose first. Instead,
it is recommended that fixed-gear airplanes land in a
10- to 12-degree nose-high attitude and retractables in
a five- to eight-degree attitude.
Most airplanes come to a stop in a nose-down attitude because the center of gravity is typically ahead of
the center of buoyancy.
Considering the variables, there does not seem to
be a consensus as to the optimum aircraft for ditching-
except that perhaps it should have STOL characteristics,
be built of wood, and be stuffed with ping-pong balls.
This study, however, was made prior to the advent of aircraft equipped with full-airframe parachutes. Given the
choice, I think I would be tempted to select a Cirrus. I
presume that it would simply plop onto the water with
hardly any horizontal forces to threaten those inside.
The U.S. Coast Guard says that approximately onefourth of all ditchings involve fatalities and points out
that most of those who perish survived the ditching
itself. Most fatalities occur after evacuation and usually are caused by drowning because flotation devices
are unavailable, out of reach, are damaged during evacuation, or fail to inflate.
Ever wonder why landing a landplane in water is
called ditching? It originated as a Royal Air Force term
that meant landing in the English Channel, which was
colloquially known as "the ditch."
AOPA
WEB

www.barryschiff.com

http://www.barryschiff.com

AOPA Pilot Magazine - June 2014

Table of Contents for the Digital Edition of AOPA Pilot Magazine - June 2014