As an aerodynamicist for Germany's Fiesler Corporation, Dr.
Sighard Hoerner, Ph.D., worked on the Fiesler Storch (Stork),
a short takeoff and landing (STOL) reconnaissance and liaison
aircraft. During the Second World War, Hoerner worked as head
of design aerodynamics for Junkers and later for Messerschmitt.
After the war, he was invited to come to the United States to
work on aerodynamic research at Wright Field, in Dayton, Ohio.
There, while working on new concepts for high performance for
Navy fighters, Hoerner designed the wing tip that bears his name.
He was one of the first aerodynamicists to acknowledge the existence
of the wingtip vortex, the corkscrew-shaped wake that forms on
a wing's outboard edge, and the Hoerner wing tip was specifically
designed to minimize the effects of wingtip vortices on lift,
drag, stability, and control.
In 1953, Tom Hebert quit work as an aeronautical
engineer for Douglas and started his own company at Fullerton
Airport, in California. Friends described Hebert as "a genius." He
described himself as "a character." His new company,
Met-Co-Aire, seems to have reflected both portrayals. His company
was the first to offer "metalizing" of Stinson and
Cessna wings, stripping off the fabric covering and replacing
it with aluminum. Hebert's tricycle gear conversion for the
Cessna 170 was copied by Cessna and gave birth to the Cessna
Hebert was the first to hang 180-hp Lycomings on the popular
but underpowered Piper Apache.
Hebert decided that Hoerner's efficient, high-performance wing
tip design ought to work on civilian light planes, too. His only
major change to the Hoerner wing tip was in materials. At Wright
Field, Hoerner's design was rendered in metal; Hebert chose high-quality
Met-Co-Aire's Hoerner wing tip did not catch
on right away. The Hoerner design first appeared on Piper factory-built
in 1974, but av-gas was cheap and customers seeking better
performance could ignore fuel efficiency. Still, word got around.
and Met-Co-Aire were building a solid reputation for producing
high-quality, high-performance fiberglass wing tips and replacement
parts at affordable prices. Hebert passed away in 1976, and
Ron Van Vliet took over at Met-Co-Aire, assuming leadership of
but very dedicated" group of craftsmen.
Then fuel prices went ballistic. Suddenly, fuel consumption
was an important factor in aircraft performance. About the same
time, the growing popularity of homebuilts and Experimentals
began raising the flying public's interest in modifying factory-built
airframes. Met-Co-Aire re-emerged as a leader in the design and
production of high-performance wing tips, tip tanks, and fiberglass
BETTER THAN NEW
The original tips on most factory-built aircraft were cast from
Royalite, an ABS plastic. Stabilizer caps, fin caps, dorsal fins,
tailcones, fairings, and interior panels and moldings have all
been made out of Royalite. ABS plastic is an ideal material for
manufacturing. It is inexpensive, lightweight, and flexible,
and it can be vacuum molded easily and efficiently into an endless
variety of shapes and components. Unfortunately, Royalite is
a poor material for use on airplanes. It has low tensile strength
and shear strength. (That's why it tends to crack or break around
mounting screw holes.) Heat and cold turn Royalite brittle so
that it cracks more easily. Most mechanics say that Royalite
is impossible to repair.
According to Van Vliet, Royalite was never meant to be an exterior
plastic. It is much better suited to interior parts and panels.
But even inside the airplane, heat, cold, and sunlight discolor
it and turn it brittle.
Fiberglass is much more durable. It resists chemical action
and aging. It can be molded into complex shapes. Ounce for ounce,
fiberglass is as strong as mild steel and has twice as much flexibility.
It is easily drilled, sanded, or painted, and it is easy to repair.
Met-Co-Aire's mainstay is the Hoerner-designed wing tip. Because
they are made of such durable stuff, Met-Co-Aire wing tips are
a popular choice for replacing the cracked, yellowed, or scuffed-up
Royalite tips found on most factory-built light planes. Met-Co-Aire
tips often cost less than original manufacturer's replacement
parts and they come with an iron-clad warranty. If the buyer
isn't satisfied with any Met-Co-Aire part for any reason (or
for no reason), Ron Van Viet promises to buy it back, no questions
asked, for 100 percent of the purchase price, for up to 100 days
after the purchase.
The tips come from Met-Co-Aire with a tough, glossy white gel
coat finish. With a little sanding, the gel coat is a good primer
for any type of finish coat.
New stainless steel mounting hardware is supplied
with Met-Co-Aire's replacement wing tips, and installation
is almost a no-brainer.
Just take the old wing tip off (usually "the most interesting
part," according to Van Vliet). Match and drill the mounting
screw holes. Plug the existing nav light into its pre-drilled
mounting hole. Then put the tip on the wing and install the mounting
screws. An A & P or a seasoned shade-tree mechanic can
install both wing tips in two or three hours.
The hardest part, aside from getting the old
tips off, is match drilling the mounting screw holes. (Matching
the holes, instead
of pre-drilling them at the factory, ensures a better fit.)
A gadget called a "strap duplicator" makes this task
a lot easier. Met-Co-Aire can supply one; so can most aircraft
DO THEY PERFORM?
Met-Co-Aire says that its Hoerner wing tips "will definitely
add to the performance of your aircraft." They say the
Hoerner tips will increase aircraft range by 1 to 2 percent,
rate of climb by 60 fpm, boost cruising speed by 3 to 5 mph,
cut takeoff distance by 15 to 20 percent, reduce stall speed
by 4 to 5 mph, and improve overall aircraft stability.
Do they perform? Met-Co-Aire's customers think so. Van Vliet
sends a questionnaire to every customer, and 90 percent of the
comments he gets back indicate a very high level of satisfaction
with products and the company.
Van Vliet says the company's performance claims
are actually a bit conservative. "We didn't hire a hotshot test pilot
to stand an airplane on its tail and produce inflated performance
claims for us," he said. "We believe in the empirical
evidence [from customers]. If the average pilot can't get the
results we claim for the design, then why bother?"
Still, customers can be subjective. When Al Hayes came to Met-Co-Aire
for a set of wing tips, back in 1985, Van Vliet saw an opportunity.
Hayes is an engineer with a Ph.D. from MIT, and his Cherokee
180 had just been nearly outrun by a PA-28-160 equipped with
Hoerner wing tips. Hayes agreed to run a systematic before-and-after
evaluation, with his buddy's -160 as a control. After installing
the Met-Co-Aire wing tips, Hayes reported a shorter takeoff roll,
a lower stall speed (by about 5 mph IAS), and more stability
in moderate turbulence and in rolls during level flight. He admitted,
however, that these findings were subjective.
The real test came in a side-by-side comparison of cruise speeds
between Hayes' aircraft and the -160. Across a wide range of
power settings, Hayes found an increase of about 4 percent in
cruising speed, after the Met-Co-Aire wing tips were installed.
In the 120-130 mph IAS range, he reported an increase of 4 to
Comanche owners also report dramatic reductions
in landing speed and stall speed. One owner reported that he
had spun Comanches
with conventional wing tips but trying to spin his Comanche
equipped with Met-Co-Aire's tips produced only a solid stall.
added: "Jumping on the rudder only produced a slow roll
and a nose drop." Van Vliet says about 70 percent of the
Piper Comanches currently flying carry Met-Co-Aire's Hoerner
PIPERS, CESSNAS, AND BONANZAS
Met-Co-Aire offers Hoerner-design wing tips to replace the original
tips on Beech Bonanzas (35 through P) and on a wide range of
Piper and Cessna aircraft. They supply wing tips for pre-1974
Cessnas, including the 140A, 150, 170B, 172, 175, 180, 182, 185,
Hoerner-design high-performance wingtips are available from
Met-Co-Aire for Piper Cherokees (140 through 200), Comanche (singles
and twins), Apache, and Aztec. Also for Cherokees, Met-Co-Aire
has fiberglass stabilator tips, dorsal fins, tail cones, and
fixed-gear fairings to replace the original plastic parts.
Piper Aircraft used the Hoerner-design wing tip as standard
equipment on its taper-wing Cherokees (151 through 236). Met-Co-Aire
offers high-quality fiberglass replacements for Piper's ABS plastic
For the Apache, Met-Co-Aire manufactures a one-piece windshield
and a larger-than-original dorsal fin that improves directional
For Piper Apache and Aztec owners, Met-Co-Aire has built a 24-gallon
tip tank into its Hoerner wing tip. Made of reinforced fiberglass,
the tip tanks should outlast fuel bladders or steel tanks and
are easier to repair than steel or rubber. Fuel is gravity-fed
into existing fuel lines with no new pumps or fuel selectors
needed. The tanks add 25 pounds (empty) to the airframe, increase
total fuel capacity by 48 gallons, and actually reduce the wingspan
by a few inches. Installation takes about 25 hours.
"A lot of manufacturers sell parts under a Parts Manufacturer's
Approval (PMA)," said Van Vliet. "A PMA only tells
you that a part meets the FAA's manufacturing standards. A
Supplemental Type Certificate (STC) tells you that the part
is also engineered
well-that it has passed exhaustive structural tests and flight
tests, and that it is approved for use on your airplane. All
of Met-Co-Aire's products carry both an STC and a PMA, along
with Met-Co-Aire's 100-day no-hassle warranty."
BIG BANG FOR THE BUCK
Someone once said that you can't use the words, "Cherokee" and "fast" in
the same sentence without sounding sarcastic. A lot of folks
have been proving that wrong, and creating some pretty hot Cherokees
in the process. According to their customers, Met-Co-Aire's Hoerner
wing tips offer a lot of "bang for the buck" in boosting
the performance of Cherokees, as well as Comanches, Apaches,
and Aztecs, along with Beech Bonanzas, and a whole bunch of
Besides, the factory-supplied plastic wing tips on a lot of
Pipers, Cessnas, and Bonanzas look as though they have been used
as tail skids. Met-Co-Aire's high-quality fiberglass replacements
are less expensive than factory parts, and they last a lot longer.
That, alone, makes them a good investment. The combination of
price, quality, durability, reparability, and demonstrated performance
makes Met-Go-Aire's Hoerner wing tips and tip tanks a very good
Structural integrity? - It's unequaled. Here Van Vliet stands
on his replacement wing tip for the Piper tapered wing aircraft,
holding youngest daughter Rachel, along with son R. J., and eldest
daughter Randee. (Tip mounted to shop work table. Total weight
it is supporting is approximately 320 lbs.!)
David Sakrison, Ripon, WI, is a former Editor of Cessna Owner
Magazine and Pipers Magazine. He is a private pilot and a regular
contributor to aviation magazines in the Untied States and Great