Extra’s aerobatic aircraft are a common sight at both competitions and displays but its high-performing two-seat top model, the 330LX, now has a ‘better’ brother – the Extra NG. What’s more, this one’s all composite…
Words Heike and Henry Sauels. Photography Jean-Marie Urlacher
11 July 2023
Walter Extra (yes, that’s really his name) was a successful aerobatics pilot during the 1980s, even getting to compete in the 1982 World Aerobatic Championships against such big names as Victor Smolin, who won flying a Yak 50, Kermit Weeks, Leo Loudenslager and Jurgis Kairys. OK, so Walter only came 41st but these are the best in the world remember.
Walter was flying a Pitts S-1E back then but was already inspired to create his own aerobatic aircraft. As a qualified mechanical engineer he had the knowledge and skill but his first effort, the Extra 230, had a wooden wing that limited its abilities.
Walter was determined to aim high, so set about creating an Unlimited class single-seater, the 300S. This had an immensely strong wing with a spar made from carbon fibre clad in sheets of more carbon fibre. It also had a wing shaped with a symmetrical aerofoil and mounted at mid-point so that it would fly the same inverted as right way up (and any angle in between). The fuselage was constructed of a welded steel tube framework that was extremely strong, clad in aluminium and, in some places, more carbon fibre bodywork. It was very light and was powered by a 300hp fuel-injected Lycoming engine. It was a winner.
Since then, various other Extra models have been produced with startling results. The current top model is the single-seat Extra 330SC. At this year’s World Aerobatic Championships in France, the top four all flew 330SCs. Out of the top 35, only three flew an aircraft other than an Extra. In the Advanced (one down from Unlimited) World Championships held in Poland, only seven out of the 38 competitors were not flying an Extra. It’s an extraordinary takeover of aerobatic competitions.
But not just competition. Many flight schools also have an Extra on the fleet, often the Extra 200, a lower-powered two-seater that’s ideal for teaching aerobatics and for Upset Recovery Training (UPRT)… and for fun. If you’ve never had a flight in an Extra aircraft, book one now. The difference between one of these razor-sharp handling aircraft and a standard touring aircraft can only be appreciated with one hand on the stick, other hand on the throttle, an empty sky and an accomplished instructor.
With such a successful pedigree, why would Walter Extra change from his established construction formula to the new NG with its all-composite airframe? For even more performance, easier production or what?
One reason is to produce a slightly more ‘comfortable’ aircraft. Aerobatic pilots often have long ferry trips between competitions and displays, and aircraft produced specifically to fly this well don’t have many creature comforts or places to put things. With the trademark steel tube framework gone, with the NG it was possible to add some nice and useful design points.
From its looks though there’s no doubt that the NG hails from Extra’s aeroplane maternity ward, but the differences between the siblings go further than the obvious change from steel to carbon fibre and bigger tailplane and rudder. Next up on the ‘clear to see’ list are the big holes at the back of the spats (more later) and the change from analogue to Garmin’s G3X Touch, complete with an optional autopilot.
Staying inside the cockpit, the key has been moved to a new position at the bottom of the stick where it’s much less likely to be disturbed during times of high and extreme pilot workload, and the contact breakers now sit behind a couple of small doors which are so close fitting that should one pop, the door is pushed open making it much easier for the pilot to notice that something might need attention.
There’s a new canopy locking system which, in combination with the change of material, makes the cockpit significantly quieter than other aerobatic Extras.
Outside, there’s a pair of small wings sitting either side of the spinner in the cowling’s cooling air intakes to better direct air to the rear two cylinders which often run hottest.
You have to be a little more familiar with a standard Extra to notice the 15cm wingtip additions. These are said to reduce the turbulent air at the end of the wing – vortices – and to reduce the wing loading. They also slightly reduce the roll rate but if you’re looking to squeeze every last bit of aerobatic performance out of the NG, they’re easily and quickly removed for competitions (or bragging rights).
Fuel capacity is marginally more (6 litres usable) when compared to the current LX two-seater, but accessing the central tank for any work means taking the engine out. If you need to ship the aircraft for international competition or display purposes, the wing is removed from below the fuselage, so you have to remove the undercarriage and you’ll need a way of suspending the aircraft for the work.
So what do our testers think of the aircraft? We handed the NG to Heike Sauels, who came 31st at this year’s World Aerobatic Championships flying an Extra 330SC, and husband Henry, German Freestyle Champion:
On walking into the hangar at Schwarze Heide, the first thing we see is the outline of the Extra NG. We notice that the fuselage looks more aerodynamic and the empennage is different with larger control surfaces and a slightly wider span. The spats also get a redesign. Overall they supposedly create less drag, but there’s another significant benefit. If you look at the rear of the spats you’ll see two large holes, so any grass or mud caught up in them will no longer remain inside and should just blow out, but even if it doesn’t it’ll be significantly easier to remove.
The new aircraft looks fantastic, but at the end of the day it’s a tool, so how does it handle on the ground and in the air?
The first thing you notice when you get in it is just how much more space there is compared to the original Extras, with tubular steel fuselages – so the bruises you get from them during extreme aerobatics should now (hopefully) be a thing of the past. Both the backrest and the position of the rudder pedals can be adjusted electrically, so it’s easy to find a comfortable position, at least in the backseat (while the front seat pedals can be moved fore and aft, the seatback is fixed).
One small drawback is the generous length of the seat itself, so some smaller pilots may well find that it presses against your lower legs. I’m told this unintended design consequence has been identified, and an improvement is underway.
The canopy closes perfectly, creating an airtight seal, so while in the steel-tubed Extras you might want to take a scarf when you fly in cold weather, in the composite Extra NG aircraft you can do without.
I turn on the master and Garmin G3X Touch comes to life, this example is also fitted with an autopilot, which is great for long transit flights, but both it and the G3X offer capability and sophistication that aren’t really needed for serious aerobatics. The aircraft is powered by a 315hp Lycoming IO-580 that drives a Mühlbauer three-bladed propellor, and while we’re on technical details the exhaust is a six into one Gomolzig, and the brakes are from Beringer.
Lined up on Runway 26, I add full power and I am quickly airborne, the visibility ahead is better than in the Extra LX or SC models, but obviously not as good as something like a Cessna 172.
So how about its all important aerobatic capabilities? The first thing you notice is just how much faster it accelerates, I’m not talking about time on the runway, but in the air.
It’s really striking how much faster it is than previous designs, so much so that you reach Vne very quickly when flying downward vertical lines. You get used to this quickly enough, but it does mean that you’re working the throttle more than you would in the SC or LX. The added acceleration brings distinct advantages to the energy management tasks, and it’s particularly noticeable during complex routines.
The changes made to the control surfaces at the back end pay dividends, particularly during low speed figures, although at times it seems that a bit more rudder is required when compared to the SC.
After a couple of repeats I found it easy to nail the timing and the aeroplane snaps easily and confidently in and out of a spin. The ailerons are very precise and the roll rate is comparable to the LX, so about 400° per second. After just a couple of flights of 15 minutes each I could fly all of the figures I fly in the SC in the Extra NG, so tailslides and freestyle manoeuvres like torque rolls and flat spins.
The Extra NG can basically do everything the LX can do – only better. Consequently, this begs the question of what kind of pilot should consider the Extra NG? Well, if your thing is limited exclusively to competitions at Unlimited level then we still think the single-seat SC has the edge, Extra has single-mindedly designed and tuned the aircraft for pure performance. If your flying is a little more varied and includes display flying, travel, aerobatic flight training and yes, Unlimited level aerobatics, then the two-seat Extra NG is the better choice.
Heike Sauels is German Freestyle Vice-Champion and currently the only woman in the Unlimited category, while Heinrich Sauels is acting German Freestyle Champion. They’ve been flying as members of the Garman national team in the Unlimited category since 2008.
Walter Extra talks to Peter Wolter about the Extra NG…
Q. Why have you waited so long to develop the Extra NG as a composite aircraft?
A. I’m still a fan of steel tube, because they open redundant load paths in the unlikely event of failure and have great residual strength. This is one of the good qualities of steel, it bends but is still capable of doing its structural job. Carbon is different. It’s either there or not. This has always kept me from using carbon fibre in the primary structure where the wall thicknesses are small. The wing is a different matter, thanks to the spar and the thicker skins.
Q. What challenges did you face?
A. Sometimes only double layer monolithic structures can do the load-bearing work without an underlying tubular steel structure. Single layer can fail if the load goes beyond what they are designed for. Additionally, thin composite sandwich construction can be easily damaged by mistake, be it with a keychain or screwdriver. Until now, that has been a compelling argument for me not to use composite for fuselage construction. We now have a technical solution that improves this property. We have patented the idea, so I can not give details yet.
Q. Did the all-composite GB1 Gamebird provide the impetus?
A. No. Our project is older than my knowledge of Gamebird. We spent a relatively long time solving the problems I mentioned with thin-walled monocoque composite structures.
Q. Empty, the Extra NG weighs 25kg less than the LX, your two-seater. Is the difference solely due to the composite hull?
A. Yes. Although there are small changes to the tail and wingtips, they do not have a significant impact on weight.
Q. Since you now use more fibre composite, is this all produced at your factory?
A. The primary structure, i.e. the load-bearing parts, we produce exclusively ourselves. For the secondary structure, we have a supplier with whom we have been working successfully for a long time.
Q. How many aeroplanes does Extra actually build each year?
Between two and three a month – we produce between 25 and 35 examples per year.
Q. When is certification of the NG expected?
A. We expect to receive final approval from EASA on 11 October*. So we invited the EASA people to a party (laughs). Co-operation with EASA has been really effective. The Luftfahrt-Bundesamt on the other hand… (does not laugh anymore). At the same time, validation from the FAA will follow the usual procedure. (*The Extra NG was certified by EASA on 12 October 2019 – Ed)
Q. Which market are you primarily targeting with the new aircraft?
A. The largest single market continues to be the US for us. We sell about 35 to 40 per cent of the production there. Everything else is spread across countries around the world.
Q. Is the Extra NG more expensive than the LX?
A. The prices are in the same order of magnitude. Instrumentation for the Extra NG is more expensive, while on the other hand the manufacturing processes are a bit easier than with the LX.
Q. Will there be a single-seater with a composite fuselage?
A. Not for the moment. We are now fully occupied with the Extra NG, the type approval is an important and intermediate goal.
Q. And the final goal?
A. For such projects it is normal that a lot of additional development is required. It’s all about small improvements, but ‘small’ in a composite aircraft still means that you have to get new moulds – you can’t just weld a lever somewhere else like you might with a steel tube structure.
Q. Will previous models, 330LX, 330LT, 300LP and the single-seat 330SC continue to be built?
A. Yes, absolutely. There is a fan base for these aircraft, with the single-seater of course addressing a different clientele than the two-seater. The SC is for people who do aerobatics at a professional level who want every last bit of performance. The performance difference when compared to the Extra NG is not very big – you can definitely win an Unlimited competition with the NG – but perhaps when not many very good pilots with their SCs are also competing.
Q. An Extra 330, called LE, flies with an electric motor. Will work continue in this direction?
A. No, that was a development project from Siemens. We had a partnership that was successfully completed. It was not about electric flight, but about the proof that electric motors are possible as drive units for aircraft.
|Max weight normal (+6/-3g)||950kg|
|Max weight for aeros||820kg|
|Fuel capacity||196 litres|
|Max fuel for aeros||73 litres|
|Stall speed (750kg)||50kt|
|Stall speed (950kg)||56kt|
|Max speed||203kt TAS|
|Max manoeuvring speed||158kt|
|Rate of climb||2,415ft/min|
|Endurance (@ 75% power)||2hrs plus 30min reserve|
|Engine||Lycoming AEIO-580-B1A producing 315hp|
|Propeller||MT 3-blade, 1.98m diameter, constant speed, composite construction|
|Avionics||Garmin G3X Touch|
|Extra Aircraft Schwarz Heide 21 Hunxe, Germany|