THIS IS A SIMPLE, multipurpose low-cost Profile Proto Speed model that is easy to construct and offers plenty of fun for kids and adults. Profile Proto is an excellent entry-level event for anyone who is interested in Control Line Speed flying.  It's an exciting pastime that's bound to get your adrenaline flowing. Little Tiger has had a good record at AMA Nationals, placing first in Junior in 1995 (and second in 1996); in Open class it placed third in 1995-6-7 and first in 1998. With slight modifications, the model has served a couple of different purposes.  It began as a trainer for my stepson, Jeff Macapinlac, in early 1995.  Since then it has been primarily a contest model.

	"Simple, exposed controls are  required for Profile Proto" says the author. No Blinding or  sloppiness allowed
	Pressure Line goes to top of tank; fuel  feed line comes from bottom.  Keep nose  up after filling to prevent flooding.
	"My cool control system," says Dave Hull. "It stays real cool out in the open breeze,  while moving through the air at 105mph." Canopy is Plexiglas.
	Elevator control horn is made from  .015 tin. Marks on stabilizer are from  Nats processing.

It is very important to make Proto Speed models as light as possible, for good acceleration at takeoff.  My model
weighs approximately seven ounces.

Empennage: Cut the stabilizer portion of the tail surfaces from firm 1/8 balsa sheet.  Sand to a symmetrical airfoil,
with rounded leading edges and sharp trailing edges.  Connect the elevator to the stabilizer with Perfect brand cloth
hinges and cyanoacrylate (CyA) glue, applied only to the nonmoving part of the hinges.The rudder and wingtip
control line guide can be cut from '/32 birch plywood.

Fuselage: Use the hardest piece of 1/4 x 2 x 12 balsa that you can find.  The nose section of the beam-mount
fuselage should have '/4 X -'/16 maple engine mounts sandwiched between two 1/8 birch plywood doublers,
bonded with epoxy.  The canopy is carved and shaped from a sheet of Plexiglas.

The landing gear is formed from '/16 steel wire and is securely attached to the fuselage with safety wire and
epoxy.  One-inch-diameter streamline wheels (from K&B or Glenn Lee) are held in place on the landing gear
with small washers soldered in place.

Wing: The wing is made from a stiff and firm medium-hard piece of 1/4 x 4 x 16 balsa that is carved and sanded
to a symmetrical airfoil (NACA 63-009).  A slot is cut in the center of the wing for a ¼ square spruce spar four
inches long that is used for the bellcrank anchor (bellcranks can be obtained from Ned Morris or Kustom
Kraftsmanship).The pushrod is made from .035 music wire.  I made the control horn for the elevator from .015 tin.

Engine: Our airplane was fitted with a Cox Black Widow .049 engine for its training flights; a Cox Tee Dee was
used for the first Proto Speed flights. When we got to the Nationals, a CS .049 engine was installed and was
used for our winning Proto flights.

The fuselage plan shows mounting holes for a CS; other engines may use adapter plates for mounting. The
plates are secured to the fuselage with 3-48 screws and blind nuts, using the CS holes.  The Tee Dee and
Black Widow engines are lighter than the CS, and must be mounted farther forward for proper center of
gravity placement (within 1/8 inch of the wingtip leading edge).

Our CS engine is basically stock, with only a couple of modifications:
The exhaust port is raised to an open timing of 157 degree (stock timing is 142 degree). The easiest way
to do this is to simply shim up the cylinder liner .025 inch with a gasket under the top flange of the cylinder
liner where it seats into the crankcase. The other modification to engine was to install a hemi head (made by
Jerry Rocha) that accepts Nelson glow plugs. The head is similar in design to ones made by Doug Galbreath
and Walt Gifford (as specified in the November/December 1996 issue of Speed Times, publication of the
North American Speed Society).

In my experience the stock CS head works well, but needs to be set up higher than the hemi.  You may have
to play with cylinder head gaskets to raise or lower the head, depending weather conditions, in order to get
optimum performance. I use a crankcase pressure fuel system with a .010 pressure fitting that is tapped into
the center of the engine back plate. For all-out racing, the fuel formula I use is 10% castor oil, 10% Klotz
synthetic lubricant, 10% propylene oxide, and 70% nitromethane. The propeller I used was a fiberglass
41/8 x 41/8 prop made by Mike Hazel. Other fliers, such as Al Stegens and Warren Kurth, have had good
results with the gray Cox prop found in any hobby shop. In 1997 Kurth went as fast as I’ve ever gone,
and he did it with a Cox prop, proving that it will work. If you go with the Cox prop, get the gray 51/2 x 4 prop,
cut the diameter down to 43/8 inches, then carefully balance it before you run it.

Finish/Final Assembly: Prime and sand all parts smooth before final assembly. I applied K&B Super Poxy
primer and paint. Use no more paint than absolutely necessary to finish the job, and keep the weight down.
Medium CyA is used for final assembly. Make the fuel tank from 008 tinplate or brass shim stock and solder
together. The tank is simply held in place by rubber bands attached to a couple of .035 wire hooks looped
through the fuselage.

FLYING
Always keep safety in mind when preparing to fly.  Give the airplane a thorough preflight check to ensure
that all fuel lines, glue joints, screws, nuts and bolts, etc. are secure.  You want kink-free flying lines,
properly attached to free-and-easy working controls, with so binds in them.

To fill the fuel tank you disconnect the pressure line from the tank to vent it, and fill through the fuel line
after disconnecting it from the needle valve assembly.  After filling the tank, I like to keep the nose of the
airplane pointed up until it's time to start the engine.  This prevents fuel from leaking into the engine and
flooding it.  Stay clear of the prop, which is hard to see when the engine is running.

I prefer to fly this model clockwise around the circle, so engine torque will help keep the lines tight for
takeoff.  If you are flying counterclockwise, be prepared to step backward if necessary to maintain line
tension and good control at the launch.

Your Little Tiger will accelerate quickly from the launch, and will be a fast, stable, exciting airplane to fly
as it zings around the circle in the thrilling manner that only a high-performance Proto Speed model can
give you.  So have fun and enjoy it!

Editor's note: After the text was submitted, Dave Hull won the 1998 Nats with this model.
His comments on the Nats win follow:

"The new best official speed is 109.98 mph for a standing-start Proto flight.

"Earlier, Al Stegens clocked the airplane at 120 mph flat for the top end, and 114.68 mph standing-start
Proto time.  It would have been a record had I not failed to get into the pylon in time.  The rules require
that you get into the pylon in I'/2 laps, and the airplane surprised me by accelerating so fast from launch
that it took me two laps to catch up with it before I could get in the pylon, so the flight was disallowed.

"The head clearance was set at .008 on the winning flight and on the unofficial 114 mph flight.

"I dropped the oil content in the fuel from 20% to 14% for these two fast flights.  Afterward I noticed the
engine had lost some compression, so this was inadequate lubrication, and I wouldn't recommend that
anyone else try it, unless they want to wear out their engine in three or four runs.

"In the future, I intend to stick with at least 18% total oil, with four percent being castor oil and the
balance Klotz synthetic oil.”