Boats or Floats?

They are leviathans sleeping on the tarmac. Towering amphibious floatplanes, boasting adventures of which their landlubbing cousins only dream. Nearby, small flying boats, engines mounted oddly above the fuselage, ponder remote lakes brimming with bass. If youre pondering whether to take the aqua plunge, the next question is floats or boats?

Flying boats, or hull designs, splash down on their bellies and have small floats, or sponsons, under each wing for stability on the water. Floatplanes are common aircraft that sit atop two pontoons. Which you choose will depend upon your anticipated missions and your budget. The decision may also have a substantial impact on your future safety.

Some hull planes will take rougher water than a floatplane, says A.G. Tripp Wacker of Ryan Aviation Seaplanes at Flagler County Airport in Bunnell, Fla. A hull planes lower center of gravity makes it less likely to flip in waves, or with a slight tailwind. On the other hand, floatplanes depart more readily from glassy water because the pilot, aided by engine torque, can bank onto one pontoon and eliminate half of the water drag while building enough speed to fly.

With a hull plane, you must depart from the large surface area of the entire hull, sometimes deliberately pitching up and down to break free. If not done correctly, the aircraft can porpoise dangerously and crash.

Other differences are also apparent. In general, the wings of a floatplane are much higher above the waters surface than the wings of flying boats. This extra clearance allows the pilot to depart from smaller confined areas by banking the plane in tight circles on the water while building speed for takeoff. Exceeding the limited wing clearance of a hull design will bring the wing or its float into contact with the water – resulting in damage, water loop or inversion.

There are many pontoon designs, and floatplanes give you the option of selecting those specific to the type of water on which you intend to operate and the nature of your missions. With flying boats, you cant change the hulls design to suit your needs.

After a seaplane shuts down pointed into the wind, the pilot can sail backward over the water, using rudder and aileron to control direction. Beaching tail first avoids the need to turn the plane around for departure and keeps the nose pointed into prevailing winds. Floatplanes sail better than hull designs.

If youre thinking about parking at a dock, keep in mind that a hull plane doesnt do too well. The sponsons hang too far down to allow the wings to clear the wood, meaning you have to dock directly nose in – which makes departing a hassle. On the other hand, if you intend to beach the airplane or lower your landing gear and roll onto a beach, hull designs are less likely to flip forward when they encounter resistance and have sturdier landing gear.

Despite a floatplanes parking advantages, seaplane mechanic Harry Shannon, who owns Amphibians Plus in Bartow, Fla., and the FAAs 1999 Mechanic of the Year, prefers to get wet in a flying boat. In my opinion, the Lake Amphibian hull design is easier to fly on water than a floatplane, Shannon says.

Will You Be Carrying On?
Loading varies between the designs, too, because pontoons do generate some lift.

When you put pontoon floats on a plane, you increase the allowable gross weight of the aircraft because the floats decrease the stall speed, Wacker says. Despite the increase in gross weight, floatplanes carry less payload than comparable flying boats.

Compare, for instance, the Cessna 180 on amphibious floats to the Lake Buccaneer. The Cessna generates 30 more horsepower but the Lake can carry a higher ratio of payload to gross weight. The Cessnas equipped useful payload is 26 percent of its gross weight, while the Lakes is 39 percent. You can put more stuff in the flying boat. On the other hand, you can lash a canoe, or other potential flotsam, to the pontoons under the Cessna. Dont try tying anything to the outside of the Lake.

While carrying more payload, the Lake will go 3.3 nautical miles farther on a gallon of gas at 75 percent power and cruise three knots faster than the Cessna. The Buccaneer can be operated on 620 feet less water than the Cessna.

Weight and balance are important considerations, and will vary among floatplanes depending upon what kind of pontoons are installed. Flying boats like the Lake can be trickier to load because the engine sits behind the center of gravity. Even though you may have gross weight to spare, your mother-in-law might be left standing on the dock because the flying boat just wont balance.

Mounting the engine high and behind the center of gravity does create some handling quirks.

In Lake Amphibians, for example, reducing power pitches the nose up. When throttling back after gliding onto water, the nose can rise and launch the plane back into the air at a high angle of attack. Without sufficient airspeed, the flying boat will stall onto the surface in a nose-high attitude. Pulling power in a floatplane leads to a more conventional response – the nose will drop.

Pitch control on landing is as crucial as in any airplane, but the unconventional response of most flying boat designs means a steeper learning curve and the possibility of mistakes by pilots who fly more than one type of airplane. Careful pitch control is critical to takeoffs, too.

As floatplanes and flying boats build speed in water during the takeoff run, hydraulic pressure increases, causing the pontoons or hull to rise from the water and hydroplane. This phenomenon is sometimes called getting onto the step. Solo pilots call it, Wheee!

Improper elevator input while wheeeing sets up pilot-induced oscillations. Because water is not compressible, hydraulic pressure beneath the hull increases each time the nose rocks back onto the surface, launching it higher with each pitch cycle. Before you can say Flipper, the plane is porpoising dangerously at high speed.

The high prop on flying boats also affects the way it handles in the air, creating adverse yaw when banking with power. On a floatplane, the more conventional engine placement means the center of thrust remains through the longitudinal axis.

Floatplanes handle, more or less, like the birds most GA pilots have come to know, making the transition to floatplanes easier than the transition to flying boats. Even though flying boats may have a steeper learning curve, the pass rate for checkrides is the same as for floatplanes. Ive seen no difference in the pink-slip rate, says Designated Pilot Examiner John Castronover.

Unique Dangers
Seaplanes carry a threat of disaster unique to ordinary general aviation operations: splashing wheels-down onto water. Floatplanes will flip when landed gear-down on water. Thats not always so for flying boats.

I know of several occasions when Lake Amphibians have been landed wheels-down on water without incident, Shannon says. These landings were made at minimum airspeed using the stall technique. I know of no successful wheels-down water landings of floatplanes.

Flying boat pilots make stall landings on rough water by flying in low, pulling power and holding the nose off until the empennage splashes into the drink. The plane may bounce a bit, but is unharmed. By the time the improperly extended gear touches liquid, the plane is securely entrenched, preventing the craft from flipping forward.

When floatplane gear touches water, the planes high center of gravity and heavy forward engine propel it into a nosedive, flipping the airplane inverted.

Although you have a slightly better chance of surviving a gear-down water landing in a flying boat, that should not be the deciding factor in favor of the hull design. You would be prudent to assume that such landings are likely fatal and avoid them by meticulously using a water-landing checklist and visual confirmation to assure the landing gear is safely stowed.

The overall accident and survival rates for floatplanes vs. flying boats are unknown because the NTSB does not compile these statistics. While numbers on flying boats are fairly easy to get because of the limited number of models, a wide variety of airplanes can be converted to floatplanes and the NTSB does not differentiate, statistically, between a Cessna 180 and a Cessna 180 on floats, for example.

In an emergency, however, its clear that seaplanes are more versatile than their land-locked brethren. In case of inclement weather, landing strips can be as close as the nearest lake or river. And if theres no water around, floatplanes can often land without incident wheels-up in a field because the prop is out of the way, the pontoons are strong and wide, the structure is sturdy and theres no nose gear to snag.

Some operators routinely bring floatplanes in on grass, Walker says. With a hull design, you dont have that kind of stability. If Im flying a seaplane and an engine fails, Id rather be in a floatplane than a hull design.

Going for It
Like any kind of specialty flying, seaplane instruction requires a competent teacher. A mere 46 seaplane instructors list their services on the Seaplane Pilots Association website, www.seaplanes.com. Only 15 offer instruction in flying boats. Of the 51 seaplane schools shown on the website, only 14 offer flying boat instruction, mostly in Florida. Most people will find it easier to find local instruction in a floatplane than in a hull design. And, it will be cheaper, too.

Depending upon your proficiency, expect to spend about $1,000 learning to fly on floats. Hull design instruction is 30 to 50 percent more, due largely to the higher cost of insuring the flying boat.

Because of insurance restrictions, its almost impossible to find a seaplane to rent without an instructor aboard. Of the 65 seaplane schools listed on the seaplane association website, only 14 offer planes for solo flight. All are floatplanes, with not a flying boat among them.

If your water flying will be limited to rental aircraft, youd better train in a floatplane. If the flying boat is more your style and you decide to buy one, your insurance options will be limited.

A lot of insurance companies wont insure planes that operate on water, says David Fenton of Airsure Ltd. in Philadelphia.

Underwriters willing to insure seaplanes charge high premiums and often impose Draconian requirements. Lake Amphibian pilots must complete annual recurrency training with a factory-authorized instructor in order to be eligible for coverage from the only company with the courage to insure them. Not that this is a bad idea, but it does cost another couple of hundred dollars every year.

Maintenance is another issue. If youre accustomed to getting $600 annuals, you might want to apply for a home equity credit line. Not only is the basic annual fee 25 to 60 percent higher for seaplanes, but expect to spend more on maintenance. Corrosion can eat the landing gear and even the aluminum structure of your airplane. Water spray can pit your prop and you should annually fog your craft with an anticorrosive. Thats true no matter which design you opt for.

If you operate solely from water and dont need wheels, you can save a bundle. It is considerably cheaper to operate with straight floats than with amphibious floats, says Shannon. A lot of money is spent maintaining the landing gear mechanism.

Seaplanes may be one way to turn a large fortune into a small one, but they do have their rewards. Remember the thrill of learning to land a tiny Cessna? You can recapture that excitement, and satisfy your BFR requirement, by earning a seaplane rating. And the adrenaline rush doesnt fade.

Every time youre about to land on water, you encounter different conditions which require you to make important decisions. Is the surface too choppy? Which landing technique should I use? Will I hit an alligator/log/boat/sandbar? Where are the power lines? Is there enough room and obstacle clearance to take off again?

Flying seaplanes provides an exciting new way to exercise your FAA-given right to bet your life and be captain of your fate. Whether you choose floats or boats, youll take your flying and risk management skills up a notch, and unlock new adventures exploring remote lakes, camping in untouched wilderness, and fishing where its just too damned far to drive.

After all, why should ducks have all the fun?

Also With This Article
Click here to view “Floatplanes Love Gymnastics.”
Click here to view “Flying Boats that Didnt Flip.”

-by Breeze Geier

Breeze Geier is a Lake Amphibian owner whos been nuts enough to fly it all over the country.