FLYING A PIECE OF HISTORY
By
The late Hardy F. LeBel
 
The Twin Bee rides well on the water and breaks fairly cleanly despite the four foot extension added to the hull aft of the cabin.  Some pilots claim the Twin Bee operates well in three foot waves because of its rugged construction and STOL capability.

     The twenty four UC-1 Twin Bees made by STOL Aircraft, Inc.during the 1980’s occupy a unique place in aviation history. They were the last multi-engine flying boats produced in the United States. Through a quirk of fate, mine, hull #23, is the newest of the type still flying and, as such, is a unique historical artifact. The FAA Aircraft Register lists thirteen UC-1’s. NTSB accident reports show that three of these were destroyed in crashes. A correspondent tells me he has the engines off a fourth. That reduces the total to no more than nine. The Twin Bee indeed is indeed an endangered species.

This detail of the rearward opening cockpit doors demonstrates the potential problem should one accidentally come open during flight.  The doors have three latches each as well as an emergency warning light.  Also visible is the Twin Bee’s roomy five place cabin.
   When Joseph Gigante and his colleagues of United Consultants undertook to design andproduce a multi-engine amphibious flying boat, they decided not to go through rigors of obtaining a new type certificate, but rather to modify the existing Republic RC-3. They removed the 215 horsepower Franklin pusher engine, added two and a half feet to each wingtip, spliced a four foot section into the fuselage just aft of the cockpit and put two 180 horsepower Lycoming fuel injected IO-360 engines with constant speed, full feathering Hartzell propellers atop the wings. 

   The result was funny looking and had serious center of gravity problems. It still looks funny. The center of gravity problems were solved by increasing the 75 gallon main fuel tank to 85 gallons and adding a 16 gallon fuel tank near the tail to or from which fuel can be transferred in flight to adjust the center of gravity.

   How does it fly? Over the past half century, I’ve learned that funny looking planes fly funny. That said, let’s go for a ride.

   You can get into very serious trouble just by not properly securing the doors. The pilotand copilot doors are trapezoids measuring three feet by three feet that open to the rear. As if the fact that an opening door would swing back and slam into the fuselage were not enough, an errant door will also swing into the propeller arc and send the plane out of control. There are two extra fasteners on each door, a red flashing light if the doors are not locked and a steady yellow light if they are. What me worry?

   Directional control on the ground is a challenge. The vertical stabilizer is a huge flat thing sticking twelve feet into the air. The tail wheel swivels. The brakes fade when they get hot. A quartering tailwind while taxiing on a narrow taxiway has embarrassed the best of us. Directional control on takeoff and landing is simplified by a locking tailwheel. Fear not, should you forget to lock it, you’ll know within seconds of advancing the power. Land with it unlocked and you stand a good chance of producing a 3,000 pound lump of crumpled sheet aluminum.

The Twin Bee’s relatively wide, flat bottom is reminiscent of the Consolidated boats of the late 1930’s. The landing gear merely rotates out of the way for water operations with no accompanying decrease in drag.  The tail wheel rotates ninety degrees clockwise.
   Takeoff is short, three hundred and seventy-five feet on land; eleven seconds off the water.  Like all flying boats, adding power causes the left wingtip to go down.  This is not particularly serious with Lakes or RC-3’s, but the multi-engine boats have a propeller out there that can suffer serious spray damage if the pilot is not careful.  Unlike the over-powered Widgeons, nose oscillation during takeoff is not likely and easily arrested should it happen.  From land or water, takeoff is quick and spectacular. 

   A light twin (two wing mounted reciprocating engines and weighing less than 6,000 lbs.) is not required to maintain altitude on one engine.  The book says a Twin Bee will climb at about 200 feet per minute at gross with one feathered.  However, NTSB records show at least one instance where it couldn’t.  If someone shows you an ATP gotten in a Twin Bee and all the events were honestly done, you stand in the presence of a person to whom Chuck Yeager would demur.

   During trimmed, steady-state cruise, every once in a while the Twin Bee will make up its mind to go wandering off.  It suffers from phugoid, or long term, oscillation.   Try as one might, you can’t trim it out.  This doesn’t hurt anything or present a danger.  It’s annoying.  During a five hour flight there will be several unexpected minor “attitude excursions.”

   Landing is a piece of cake with the caveat, “Thou Shalt Not Get Slow!”  With no flaps, the entire wing stalls at the same time.  With flaps down, the tips stall first, but not by much.  If you’re slow with low power, the Twin Bee can suddenly drop out from under you.  If you hit too hard bulkheads collapse, rivet lines rupture and the hull floods.  Hit nose hit first and the part of Bernoulli’s Law speaking to the greatest force being perpendicular to the greatest curvature comes into play and over you go.  NTSB records tell of an accident in which a student attempting a no-flap landing came to grief.  The feds don’t speculate.  However, my reading of the report suggests the plane stalled, dropped and flipped.

Traveller IV at rest on the shore of Pleasant Lake in the Adirondacks at the FAA’s annual Seaplane Safety Seminar on Pleasant Lake near Speculator, New York. 
   Amphibians were designed without a landing gear warning horn.  Being a longtime member of that majority of amphib pilots who have landed gear-up on a runway, I ordered Lake and Air’s “Landing Gear Position Announcing System.”  Now, for less than $2,000 installed, I have a nearly fool-proof system.

   Flying boats failed as airliners because loading and unloading on the water is inconvenient.  The wingtip float keeps you from siding up to a dock.  Nose-to docking requires a crew, spring lines and bumpers.  Loading and unloading from a lighter at a mooring usually degenerates into a gymnastics exhibition.  The most convenient way to load and unload a flying boat is on solid ground, and even that is not always graceful.  If you must fly a boat, you have to accept that loading and unloading is not a single person activity, and it usually requires special equipment.


   Despite its looks, nasty habits and glacier slow cruise, I love owning and flying a piece of history.



Traveller IV’s instrument showing all the bells and whistles including a three axis autopilot and GPS that this onetime Part 135 bird is fitted with.
The overhead panel has the engine controls, trim wheels and engine instruments.  Reaching up to change power settings seems a little strange to some when they first start flying boats.  In the foreground are the elevator and rudder trim handles.  Next is a panel light. 

Traveller IV beached.  This shot typifies the difficulties with loading a flying boat.  If the surface is firm enough and there is enough room, the flying boat can be taxied far enough onto the beach to allow boarding from dry land.
If the surface is firm enough, the Twin Bee can be taxied far enough onto the beach to allow passengers and freight to be loaded on dry land.  If not, you will get your feet wet.  This shot also show the advantage a flying boat with conventional gear has over a flying boat with tricycle gear or a float plane when leaving the plane “beached” over night.
A deserted beach after the FAA’s safety seminar at Camp of the Woods on Pleasant Lake near Speculator, NY. An amphibious flying boat, such as the Twin Bee, has the advantages of being able to operate from a hard surface, a remote lake and in the IFR airways system.
Traveller IV on take off on the Connecticut River near the Goodspeed Seaplane Base. The plane is just rising on the step.  Shortly, the pilot will correct the left wing low condition characteristic of a flying boat at this stage of acceleration, and complete take off.

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January 28, 2003