2008-10 - Extra Aircraft

OCTOBER 2008 

OFFICIAL MAGAZINE OF THE INTERNATIONAL AEROBATIC CLUB 

• Community Relations 

• 1st Time at AirVenture 

• Aerobatics for Non-Pilots 

Walter Extra’s 

Tumbler: 

The Extra 

330SC

Bonnie Kratz 

The Extra 

300SC 

Walter Extra’s New Unlimited Contender 

Budd Davisson 

At the pointy end of the aerobatic totem pole—the Unlimited category—winning is 

measured in micro-points, and this week’s killer competition airplane is next week’s 

also-ran. It’s an increasingly brutal arena in which the dance steps demanded by the 

choreographer would leave old Count Aresti breathless with astonishment. And it doesn’t appear 

likely that the trend toward extreme performance from both the airplane and the pilot will let up 

anytime soon. 

The recent drive to design aircraft that clearly outdistance the pack has forged a razor-edged 

competition between the various airplanes that are expected to successfully compete (read that 

as “win”) in Unlimited competition. At the same time, an unlikely market has developed just 

outside of competition in which pilots who have the wherewithal to own the most recognized, 

butt-kicking aerobatic bird will buy one just like their hero flies even though they have no 

intention of ever competing in it. It is this group that actually forms a market base wide enough 

to support the development of a new airplane, and it is a market Walter Extra, he of 

the airplanes of the same name, knows well. He has created a small empire 

by understanding that, if he builds a winning airplane flown by 

well-known champions, he will sell many more of the 

nearly identical airplane to serious pilots 

who just want to own the best 

aircraft available. 

6 • OCTOBER 2008 SPORT AEROBATICS • 7

The Extra 330SC is a definite departure from previous designs. The small canopy and redesigned tail are noticeable changes. 

The operative word in the foregoing equation is “winning 

airplane.” He knows well that the adoration 

and financial attention will quickly shift focus once 

one design has been eclipsed by another. It wasn’t until 

his airplanes began to lose favor, and Kramer Upchurch 

of Southeast Aero in St. Augustine, Florida, and champion 

competitor and air show performer Mike Goulian laid 

it on the line to him, that he took up the challenge to 

update his Extra 300 series. 

“Walter is an extremely creative guy,” Upchurch says. 

“But the company was focused on their corporate aircraft, 

the 400 and 500, and the 300S began to lose ground to 

the CAP 232 and the Edge 540. Serious competition pilots 

always buy the very best there is, and quite a number of 

top-level pilots left the Extra for a CAP or Edge.” 

Upchurch and Goulian visited Extra in 2005, and Walter, 

himself a winning competition pilot, responded by 

diving into his 300S, working down the items that were 

on the Upchurch/Goulian wish list. 

Pilots such as Mike Goulian had flown and competed 

in just about all of the existing Unlimited airplanes, and 

there was a wide consensus of opinion that the 300S was 

still a fine airplane. But if it was going to win Unlimited, 

some areas had to be addressed. 

“Everyone wanted more roll rate,” Upchurch says, 

“which, considering that it already rolled at 330-350 

degrees per second, shows just how demanding the competition 

market has become. However, it was more than 

just roll rate the pilots were looking for. They wanted the 

airplane to have more all-around maneuvering capabilities, 

particularly at lower airspeeds in the 60-knot range.” 

“Pilots also wanted more vertical performance,” says 

Upchurch, “which sounds a little crazy considering how 

far it would go vertical already, but there were airplanes 

with more vertical performance, so, if Walter wanted to 

keep selling airplanes, his had to go higher for longer and 

still be rolling well when coming to a stop at the top.” 

The competition guys were, in point of fact, becoming 

just a little spoiled and a tad blasé. With airplanes such 

as the Edge, Sukhoi, CAP, and Extra, the performance bar 

had been raised so high that incremental improvements 

were going to come slowly to an airplane such as an Extra 

300S, but they expected it and they were willing to pay 

for it. And then the air show and freestyle parameters 

were stirred into the mix. 

Kramer points out another wish list item that’s new to 

this generation of aerobatic pilots. 

“The ability to tumble easily, predictably, and for longer 

periods of time has become an issue in recent years,” 

says Upchurch. “Where in the past any tumbling maneuver 

was just a novelty, they are now an aerobatic staple, 

and pilots—and audiences—expect them. Walter had to 

redesign his tail to make the airplane more aggressive in 

the way it tumbled.” 

The concept of intentionally tumbling an airplane isn’t 

something that’s taught in aerodynamic classes. Not even 

in graduate school. In fact, tumbling is the antithesis of 

what an aeronautical engineer strives for. He wants smooth 

flow, stable handling, and, until very recently, couldn’t 

computer-model (or even imagine) what the forces were— 

and where they went—in an airplane that was being made 

to act in a dynamic fashion that was anything other than 

aerodynamic: Tumbling often reverses the forces on the 

airframe but in ways that still aren’t totally understood. 

Plus, a traditional engineer is going to have next to no 

experience—practical or theoretical—in what you have to 

design into an airplane to make it better at tumbling. 

Much of what the engineering community knows 

about tumbling is empirical: Pilots figured out how to 

tumble the airplane in various ways and, when they broke 

something, the engineers had another data point to work 

with, which helped them in their design work. However, 

there aren’t many engineering types out there like Walter 

Extra who can tumble an airplane with the best of 

them. He came at the tumbling problem, as well as the 

other wish list improvements, from an entirely different 

perspective: He, more than most tech types, understood 

exactly what the market was saying it wanted and knew 

how to deliver it. 

Walter had lots of ideas about how to attack the wish 

list, but central to everything was improving the powerto-weight 

ratio. That meant more motor and less weight. 

He had already begun using the AEIO-580 with 330 hp 

on tap. However, to put the horsepower to work in the 

Bonnie Kratz 

330SC, as the new design was called, he used a new prop 

from MT that was specifically designed to give more lowspeed 

thrust. It had fatter, wider blades that were more 

efficient at putting the ponies on tap to work. 

“When it comes to weight,” says Upchirch, “Walter is 

fond of saying you lose it a gram at a time rather than 

pounds and kilos. But in this case, the grams removed 

total up to nearly 150 pounds lower than a 300S.” 

When shaving weight off of an aerobatic airplane, you 

don’t just start using smaller this and lighter that. It must 

be done while keeping the ultimate strength in mind at 

all times. Nothing can be compromised. In the case of 

the 330SC’s evolution from the 300S, the weight came off 

through the use of technology and careful planning. All 

push-pull tubes in the control system, for instance, are 

carbon fiber. The same carbon fiber concept is used on the 

wing ribs: Where once they were plywood, they are now 

carbon fiber. The firewall was lightened using titanium. 

The final airframe is rated at plus-and-minus 10 Gs, but 

loads to destruction show its limit actually exceeds 24Gs. 

Everywhere you look in the airframe there are new, stateof-the-art 

components. 

The roll rate issue was tackled in a very non-Extra sort 

of way. The ailerons are hinged so that, when deflected 

past a certain amount, the leading edges protrude a sizable 

distance above or below the wing. In so doing, to 

those of us in the cheap seats, it appears that rather than 

acting like regular ailerons that generate lift by changing 

the camber of the wing, these create a slot effect. At large 

deflections, this effect makes the aileron act as if it is a 

separate surface that generates lift on its own, independent 

of the wing. This is probably where the increased roll 

rate (430-450 degrees per second) gets its start. 

Although the new trapezoidal planform of the ailerons 

has to be pointed out to be noticeable, the unusual shape 

also helps in the roll rate department. Rather than being 

rectangular, as is traditional, the tips are quite a bit wider 

than the roots. It’s our guess that by moving the center 

of pressure of the aileron outboard, it gains leverage and 

can, with less effort, more quickly move the wing. It’s also 

worth noting that there isn’t even a hint of an aileron 

shovel to be seen, although Upchurch indicated that for 

European Aviation Safety Agency certifications, the shovels 

will go back on. 

An even more subtle change is seen in the taper of the 

wing. At the tip, the chord is much shorter, which, when 

combined with the new aileron, achieves the desired roll 

performance. 

The art of tumbling is one thing. The art of figuring 

out how to make an airplane flop end over end in a more 

predictable manner has to be something of a black art, part 

of which includes making the airplane snap outside better. 

This Walter knew how to do, but some of those changes, 

notably the new horizontal tail, helped in both areas. 

He went to slightly thinner airfoil sections with less radius 

on the nose. This made them more critical, so he could 

get them to stall more predictably. The span is shorter and 

the elevator balances are noticeably different. 

Continued on page 12 

8 • OCTOBER 2008 SPORT AEROBATICS • 9 

Photos by Budd Davisson and Craig VanderKolk 

From nose to tail, the new Extra 

330SC incorporates changes 

that make it lighter and more 

maneuverable. Mechanically 

adjustable foot pedals and carbon 

fiber push rods save weight, while 

trapezoidal ailerons and new 

geometry on the tail improve rolling 

and tumbling maneuvers.

“Extra Extra! Read All About It!” 

OnE MAn’S OPInIOn OF THE ExTRA 330SC 

Carl Pascarell 

Doug Vayda, chief pilot for Southeast Aero, launched me in 

the SC with uncharacteristically subdued advice: “Don’t 

have too much fun and don’t hurt yourself too badly.” 

When you first approach the airplane, you get a sense of its 

performance while still 50 feet away. Simply put…big motor, 

little airframe. This is no doubt gonna be a monster. But no ogre 

this—oh no. The ’580 is so elegantly cowled, the rest of the airplane 

just seems to flow back from it. The fit and finish are firstclass, 

consistent with the established Extra tradition. This particular 

SC, with its Mirco Pecorari custom-designed paint scheme, 

dripped with performance potential and raw sex appeal. 

Entering the cockpit is typically Extra: foot step on fuselage, 

stand up on seat, and wiggle your feet forward under the instrument 

panel and onto the rudders. Rudders on the SC are not 

electrically adjustable as on the other Extras. (Remember the 

weight thing?) Fortunately, the seat is three-way adjustable, 

allowing Patty Wagstaff-sized pilots as well as Doug Vayda-sized 

pilots an easy fit given two minutes and a couple of “pull pin” 

seat adjustments. To me (5 feet 10 inches, 180 pounds), the 

cockpit felt just about perfect: a definite “wearing the airplane” 

sort of impression without feeling cramped or jammed and just 

enough headroom to allow for the “negative G” stretch. 

Several “consumable” but less than ideal ergonomic features 

were noted, however. For instance, when at idle, the throttle is 

located too far aft to reach easily. A bit awkward initially, but 

once the throttle is advanced at all, this ceases to be a factor. 

Secondly, the aileron push-pull tubes pass directly under the 

pilot’s knees/calves and actually rub against those areas when 

the stick is pushed side to side. This is an issue for most averagesized 

individuals. Having said that, when in flight and particularly 

during maneuvering, it is scarcely noticeable and presents 

no impediment to control feel or response. 

Finally, there is an electric pitch trim toggle switch located on 

the upper instrument panel. It’s not convenient, and Doug assures 

me that on this and future examples the trim will be relocated to 

the stick, as with military fighters. Fortunately, because the airplane 

flies as if balanced close to the “neutral point,” very little trim is 

required throughout the normal range of speeds. Still, I would prefer 

good old-fashioned manual trim in an airplane like this. 

Engine start is straightforward and welcomes you with a 

jumping rumble under the hood reminiscent of a top fueler 

“nitro idling” on the starting line. The big ’580, with its six-intoone 

exhaust, sends pulses of power through the airframe and 

into your body, adding to the airplane’s already formidable 

presence. The taxi to the runway was expeditious in part due 

to the wide-blade MT dragging me along but also because of 

my eagerness to get airborne and explore this thoroughbred’s 

awesome capabilities. The wind was light and variable with the 

temperature at 79 degrees, and the airplane was loaded with 

full “aerobatic” fuel: 25 gallons and empty wings. 

Take-off acceleration was consistent with the current crop of 

high-powered competition machines, which is to say…exhilarating. 

I let the airplane fly off tail low and rotated to a truly 

ridiculous attitude in an attempt to hold what I figured was the 

best angle. Passing through 1,000 feet 14 seconds after liftoff— 

that’s right, 14 seconds—I turned west out of the pattern only 

to realize I was still only halfway down the runway! As you 

might imagine, 3,000 feet came pretty quickly, and the flight to 

the practice area was 190-knots quick. 

I have to admit, my initial impression was that the ailerons 

were heavier than I would have preferred. The very next flight 

I changed my mind. It was as if the ailerons got lighter. They 

didn’t, of course, and upon reflection I think my sense of what I 

expected the airplane to be may have colored my assessment. 

I decided further that the airplane is meant to be flown aggressively. 

When flown as such, the roll axis seems just about right. 

In fact, the more aggressively one flies the airplane the more 

harmonized the controls seem. 

Roll accelerations are extraordinarily high, generating rates in 

excess of 440 degrees per second with virtually no ramp-up. It’s 

like…Move aileron…Get roll….Right now! Here’s the kicker. A lot 

of airplanes roll like crazy. It’s not that tough a thing to get them 

to do, but not all of them can be well controlled. Frankly, this 

has been an issue for me with many of the Extras I’ve flown. The 

ailerons are just too “bobbly” for my liking: no real center and, on 

some, an almost negative stick force gradient that makes precise 

roll control a chore until you get used to them. Well, fear not. The 

SC has set a new standard of roll control and authority for the 

Extras. In fact, with the possible exception of the old ’230, it has 

the finest ailerons of any existing Extra. Crisp stops and lightningfast 

starts are well controlled with very little practice. Four-point 

rolls up, down, or anywhere in between are a head-banging, 

gear-shaking, bang, bang, bang, bang affair. Would I like them to 

be a bit lighter? Probably, but I’m likely just being picky. 

Overall, I felt the airplane’s basic handling qualities were 

pretty well managed. Stick forces in pitch were fairly light. 

Somewhat lighter pulling than pushing, but that suits me just 

fine. Things such as rolling turns suffer just a bit because of it, 

but only at first. The difference, as they say in test pilot parlance, 

is “consumable”—that is, adequately manageable. 

Snap rolls are quick and precise. Inside or out, up or down, single 

or multiple. This, I confess, I gleaned from watching the pros fly. 

Champions Patty Wagstaff and David Martin, each with virtually no 

time in the airplane, were snapping it as well as anything they’ve 

flown—as much a testament to their ability as the airplane’s. 

The subtleties of snap rolls and rollers are one thing, but to 

me, the truly impressive nature of the airplane is evident in the 

“wow” maneuvers. You know the “wow” maneuvers—10-roll 

torque rolls, double and triple nose-over-tail tumbles, knifeedge 

spins that you can barely hold onto, and tiny “micro loops” 

at 60 knots. These are the “YEE HA!” things that make the airplane 

so exhilarating and so memorable. 

Having quickly gained confidence in the SC, my second flight 

was in the low-altitude practice box at the St. Augustine Airport 

in Florida. My flight was a chaotic mass (or mess as some would 

have it) of one-after-the-other, body-punishing attempts to do 

all I could in 20 minutes. 

Vertical performance was exceptional, and I’m almost embarrassed 

to admit I actually pulled power from time to time to 

stay down in the box and keep from exceeding the 3,500-foot 

box ceiling and/or the 220 knot redline. now that’s precisely the 

type of problem I enjoy having in an airplane. I particularly liked 

the stability the airplane exhibited when stuck in the vertical. It 

was almost as if the airplane was flying with an “attitude hold” 

engaged. Once stuck there, very little attention was required to 

maintain the vertical. This was in part due to the low, off-speed 

trim requirement and was generally true for all lines and angles. 

I tended to concentrate on vertical and point maneuvers if 

for no other reason than they are so well done by the SC. Vertical 

four points up, inside, outside, inside triple vertical eights 

or “snowmen,” and the “how long is this gonna go on” torque 

rolls were pushing me over the “too much fun limit” Doug had 

warned me about. 

All high-alpha maneuvering was as well behaved and controllable 

as any aerobatic plane I’ve flown, the “micro loops” 

in particular. Starting at 60 knots and flown in full buffet with 

almost full aft stick, the roll and yaw axis throughout the loop 

were completely controllable with conventional control input, 

so much so that from the ground it was not apparent any buffet 

existed at all. 

All maneuvers were thrilling to say the least, but it was the 

knife-edge spins that captured my attention more than any 

other maneuver. Entry into the “knife” from a hammerhead was 

easily accomplished, even when the hammerhead pivot was 

sloppily flown. The pitch rate from the onset was eye-popping 

and almost beyond my ability to adequately hang onto. Three 

turns was the most I could hang onto, and even at that, I landed 

with the G-meter pegged on the negative end. 

My 20 minutes were up in short order and, taxiing back after 

landing, I recalled again what Doug had said about having too 

much fun. I knew what he meant. And I didn’t listen. With -+9Gs 

and -6 Gs on the meter, I dragged myself out of the airplane 

sweaty, bruised, and exhausted, huffing and puffing as if I’d just 

run 5 miles. I’m no stranger to high performance and generally 

not easily impressed, but man was that fun! It’s going to 

be interesting to see how the airplane’s future develops in the 

hands of true competition professionals. 

10 • OCTOBER 2008 SPORT AEROBATICS • 11

Continued from page 9 

At the same time that Extra was looking for better performance, 

he also included some changes that gave the 

airplane greater utility. Specifically, the aerobatic header 

tank is now 26.7 gallons, which is almost twice what it 

used to be. Inasmuch as there can be no fuel in the wing 

tanks while doing hard aerobatics, that used to make the 

trip to the practice area and back a little dicey. The bigger 

aerobatic tank also adds a modicum of safety and peace 

of mind to aerobatic practice. There are 31 gallons in the 

wings, giving a total of 57 gallons usable, which gives a 

solid three hours of cruise at more than 190 mph with a 

wide reserve margin. 

AEROBATICS 

Basic through Unlimited 

Competition & Sport 

Safety & Proficiency 

Basic & Advanced Spins 

12 • OCTOBER 2008 

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Is the 330SC the perfect airplane and is Walter happy 

with it? Probably not. No designer is ever totally happy 

with the final product, especially since an airplane is 

nothing but a bunch of compromises from the beginning. 

That’s the character of the beast. However, what is important 

is whether the competition community is happy with 

the changes that have been made and whether the airplane 

can regain its crown. The jury is still out on that score, and 

we’re at the end of the competition season. The debate will 

have to wait until spring to be settled. With all the new 

hardware showing up in the box, the coming competition 

season promises to be the most exciting ever. 

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Phone: (815) 233-5478 

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— Dealer for Strong Parachutes — 

Bonnie Kratz

2008-10 - Extra Aircraft

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