Giant Extra 330L FAQ

I did not find the answer to my question here. How do I get further assistance?

Is this REALLY a good first giant scale?

Definitely. We worked hard to make this plane feel comfortable and attainable for the average sport modeler — detailed plans and instructions with all the info you need to know, including radio installation; all wood built up so no foam to learn; and most importantly exceptional flight characteristics and easy handling.

A lot of aerobatic airplanes are called 'scale' but don't look very much like their full size counterparts. How scale is this airplane?

This plane is VERY true to scale. The stab has been lowered to improve the aircraft's performance on rudder application. The gear does not recess into the fuselage. A few other minor changes have been made, but even the sheeting of the fuselage provides a scale appearance. Even the large control surfaces are very close to scale. Thanks to Extra for providing the E330L as a subject with 3D ready control surfaces!

How did you manage to make this kit so light?

There are many steps involved in keeping this aircraft as light as possible. Just a few are listed here. First, it incorporates the incredibly popular full span webs of our Giles kit into not only wing construction but also airfoil stab and airfoil fin. This approach minimizes the structure needed, and maximizes building ease as well as structural integrity. Next, the wood wings, by design, are lighter than a solid core foam wing because as much structure as is needed is provided at the root and the structure lessens progressively out the panel. The wings are incredibly light, less than 1 pound each not including the aluminum wing tube. Also, the mixed light-ply and stringer structure of the fuselage combines building ease and lightweight.

How long to build this airplane?

This will vary drastically depending on skill, detailing, equipment configurations, etc. However an average builder should be able to assemble this aircraft in roughly 60-80 hours.

Is the whole airplane sheeted?

No, the wing is partially sheeted, and the fuselage is sheeted where the full size aircraft is composite while the rest of the structure is open framework where the full size is tube and fabric. This provides a scale appearance and helps keep the plane light.

Is any of the kit laser cut?

Yes, all the plywood and balsa parts which the wing and stab tubes go through are all laser cut parts for a perfect fit.

What about hardware and fiberglass?

We heard you! This kit includes a one-piece fiberglass cowl and fiberglass wheel pants, plus aluminum main gear and aluminum wing and stab tubes with epoxy-impregnated paper tubes for mounting. The kit includes only basic hardware for such tasks as wing and gear attachment. Most giant scale modelers have very specific hardware preferences, so rather than increase the cost of the kit with hardware the modeler will likely replace, we left it out. Don't have hardware preferences of your own? We provide you a detailed guide of exactly what we used on the prototypes so you can build yours just like ours.

I don't understand the information about radio gear needed. What EXACTLY do I need?

This question is a little more complicated than you might think because we provide a broad range of options. The least expensive option for the aircraft would be:
(4) 50+ in oz aileron servos
(2) 50+ in oz rudder servos
(2) 80+ in oz elevator servos
(2) standard or mini servos (throttle and kill switch for gasoline)
servo extensions and Y-harnesses as required for your computer or non-computer radio setup.
(Don't worry - the kit includes everything you need to install the optional second set of aileron servos and second rudder servo.)

Another option is a single higher torque servo on each aileron. This may be less expensive for you, and is lighter and minimizes roll coupling of the model but is not critical.

Either way, don't worry about the servo mounting position, whether one servo or two. Both servo locations are fully designed into the model and the ailerons will function fully and properly with the level of servo called for without requiring repositioning of a single servo.

This is one big airplane. What does it take at the field to assemble it ready to fly?

Roll the fuselage out to the flight line, slip the wing tube (with a wing panel already attached) and stab tube (with a stab panel already attached) through the fuse, slide the second wing panel and second stab panel onto the tubes, and a single bolt on each side secures the panels. It's ready to fly! The canopy can easily be removed for access to your radio gear, tanks, etc but is not required for assembly on the flight line.

From 50-85 cc seems like a very large range. Which engine is right for me?

Your engine selection depends on what you want from the aircraft and also your budget. This plane is designed to be a soft, easy-to-fly first giant scale all the way to an unlimited level competitor. If you're just getting into giant scale, there's no need to purchase an 85 cc competition engine — a 50-65 cc engine is great. On the other hand, if you're looking to move up in size and placings, then stepping into the E330L and an 85 cc engine is a GREAT choice for you!

How about 3D? Is this airplane 3D-capable? Is it a good plane to learn 3D?

The plane is a good performer for 3D, and especially for learning 3D because it is so stable and light. The light wing provides exceptional roll response and crispness. The scale 330L tail and double beveled tail surfaces provide excellent response below stall. We provide 2 different leading edge templates - one sharp tip template just for 3D performance, the other is more blunt for sport pilots' comfort level. All control linkages are VERY short and tight. And the included A Look at Aerobatics booklet includes a guide for getting started and learning new 3D maneuvers, including Designer Mike Cross' signature maneuvers, the Harrier and the Flip.

How fast does this plane fly?

We don't have a specific clocked speed for the aircraft, as this is not something we would normally check for on an aerobatic airplane. It should not be flown at high speeds, and we advise against that with detail in the manual. Aerobatic aircraft, by their nature, are not designed to go fast and can easily be subjected to flutter. This is not a flaw at all but a bi-product of their light weight and exceptional performance.

What is the "Look at Aerobatics" guide?

This is a handy tool you'll want to keep in your flight box! It covers the basics of computer radios, a trim guide, and a guide to aerobatics, from learning the basics to 3D, all in an 8-1/2" x 5-1/2" format that's easy to fit in your field box.

Are there any corrections, changes or updates to the manual I should be aware of?

There is one pair of contradictions in the manual. On page 14, the sketch's measurements on the short side of the sheeting are both wrong. The text is accurate, so the rudder is 4-1/2" not 3-7/8"; and the fin is 3-3/4" not 3-1/2".

My aluminum stab tube fits loosely in the paper support tube. What do I do?

This is intentional to avoid any problems from the paper tube swelling during shipment. Please 'sweat' the tube by putting some thin CA on a paper towel and rub it on the inside of the phenolic as described on page 46 step 1.

My paper tube for my stab tube does not fit properly in some of the ribs.

Our apologies. We had a few kits ship with a mismatch between the tube and the stab parts. Please email with a copy of this FAQ and your mailing information and we will get you replacement parts immediately.

Where can I find full scale documentation of the model?

The model was based off photos of the full scale prototype. We obtained our photos from the November 1998 issue of Flyer Magazine. Please contact them if you wish to get a copy of this issue.

Flyer Magazine
#9 Riverside Court
Lower Bristal Road
Bath, England BA2 3DZ

Web Site:

If I side or inverted mount my engine, do I still need the right thrust?

Absolutely. The thrust angle resolves torque issues from the engine's power which do not change with the orientation of the engine. The thrust angles and incidences were extensively tested with a variety of engines and setups. Trust the incidences as listed — stab 0, wing 0, engine 0 down 2 right.

My aluminum wing tube does not reach the same length as the wing socket. Is this correct?

Yes. The wing tube ends after the mounting bolt and before the end of the paper socket intentionally to avoid having a high point of stress where both tubes end together.

Why such a huge hole in the bottom of the cowl? What about air inlet?

The huge cowl opening on the belly ensures sufficient air exit. Without enough air exit, your engine does not get sufficient air in to cool it properly. The cutouts on the cowl are specifically designed to properly cool a twin, but should also sufficiently cool a single. Should you see any signs of overheating, DO NOT restrict the air outlet—the air must have somewhere to go. Instead, baffle the air INLET on the side of the cowl where there is no head so that the air is forced over the head side.

My cowl seems to be too large. What's wrong?

The cowl is intentionally oversized in production. Cut the large breather out of the belly of the cowl, then starting from the top of the cowl hand fit the cowl to your aircraft per the instructions. This will give you a perfect fit, even if your shaping made your fuselage slightly wider or narrower or curved differently than the prototypes.

Why are the servos mounted on the exterior of the aircraft?

Every kit requires us to strike a balance between form and function. The servo placement is true to the design approach used in true performance giant scale aerobatic aircraft....lightest possible weight and shortest possible linkages. It is meant to be a true, raw function feature with the understanding that it is essentially invisible when the plane is doing what it does best—flying. It also provides the strongest possible drive to the rudder servo and minimizes flutter.

On Page 36 step 16 we install 'fuse side shapers'. What are these and how do I do this?

This is a small balsa stringer that is simply cosmetic. Rather than having a hard edge where the sheeting ends and the stringers begin, these shapers simply create a smooth transition from the sheeting to the stringer-only look at the back of the fuse. Simply sand the shaper into a soft gradual taper into the stringers.

RCM's review says the engine needs to be moved down on the firewall for a proper cowl fit. Should I move it?

No, please do NOT move the engine on the firewall. This will affect the thrust line and a variety of other factors. Due to slight differences in how a cowl is pulled from the mold some cowls may need slight sanding at the top of the cowl to gain a proper fit to your aircraft. The engine's position is accurate. Adjust your cowl slightly, if needed, to solve the problem.

Why do you show 4" wheels in one place and 4.5" wheels elsewhere?

The 4.5" wheels are for rough or grass landing surfaces.

Is it OK to cut a hole in the firewall to clear my engine's starter, module or other items?

Absolutely. This is perfectly normal and in fact was required when using the older style prototype Mac Minarelli 85 cc. The structure is designed to support the cutting of a round hole in the firewall to clear an engine box, spring starter, etc.

Back to main FAQ/Contact Info page