Frequently asked Questions
What was the intent of the Acrolite 1B design ?
What we really wanted was an aircraft capable of Pitts like performance with out the six digit price tag. We wanted it to be easy to build in a traditional manner from traditional materials. We also wanted it to meet the Canadian ultralight regulations so it could be flown with an ultralight pilot permit. Any airplane is a compromise but I think we have more than achieved most of our goals. In Canada it can be licensed as a basic ultralight or as an amateur built. In the United States it must be built under the home built regulations and qualifies in the Sport Pilot category. In Australia it can be built as either an ultralight or an amateur built. The light weight and low stalling speed allows a choice for many builders as to how they want to fly it.
How long will it take to build the Acrolite 1B ?
This will depend on your skill level but it typically takes about 2000 man hours to build an aircraft, this amounts to about two hours a day for three years. Less time than most people spend watching television and they have nothing to show for it. The best way to speed up the project and have fun, is to get a few friends involved. Many people are willing to help out just so they can say they helped build an airplane. Do not take on this type of project unless you enjoy building and creating mechanical things or it will never get finished. Most of the enjoyment is in the building.
What will it cost to build an Acrolite 1B aircraft ?
This will depend on the builders ability to scrounge materials. There are often materials and partially completed kits that can be bought inexpensively from other builders whom for one reason or another cannot complete their project. Used engines are often available and a little scrounging can save you money. Purchasing the complete kit and plans from Aircraft Spruce will cost just over $8000.00 U.S., add in for a few extras not included in the kit and for tooling and other miscellaneous items the completed airframe should cost less than $10,000.00 U.S. A complete materials list is included in the plans package if you decide to purchase just the raw materials. Always use top quality aircraft grade materials in your aircraft, your neck rides on every part. Traditionally in light aircraft the engine is half of the total cost. A new Rotax twin cylinder engine will cost between $5000.00 U.S. and $6000.00 U.S. and a four cylinder is between $9,000 U.S. and $15,000 U.S. This will put the cost at $13,000 U.S. to $23,000 U.S. for a new completed aircraft. Not a bad price for an aircraft of this performance level.
What will it be worth when it is finished ?
This is difficult to determine. While it is impossible to get payment for the many hours you put in to building the aircraft you should be able to recover the cost of the materials and tooling. Many home built aircraft sell for much more than this and a few of the less popular designs for quite a bit less. The quality of materials and workmanship are big factors in determining the value of an airplane. While the Acrolite is new on the scene and prices have not been established it appears that the resale value will be quite high judging by the offers we have had for our completed aircraft.
Why a single place aircraft ?
The aircraft was not intended to haul your family or friends around the country on a Sunday afternoon, if you want to do that, there are other aircraft that are more appropriate. We wanted something more challenging and exciting to fly. Look at it as you would a dirt bike, snowmobile or personal water craft, something you do alone or with a few friends to have fun.
Why design a biplane?
The stalling speed of an aircraft is determined primarily by the wing area. Since one of the goals of the design was to meet the Canadian ultralight standards this meant a stalling speed of less than 45 mph. To do this in a monoplane and still meet the 6g structural requirement for aerobatics would have required a very heavy wing structure. Biplanes have a large wing area for their weight and are very strong due to the box like layout of the wings. Biplanes also have more total drag than a monoplane due to the interference between the wings, that is why we went to a single strut, lots of stagger and a very efficient airfoil. Besides I think biplanes have a classic look and they attract a lot of attention wherever you go.
Are there any special construction methods I will have to learn ?
The Acrolite uses traditional aircraft building techniques. The wings can be built of either aluminum or wood depending on which materials your most comfortable working with and the availability of the appropriate tools . The tail group is riveted aluminum plates and tubes so all that is required is a hand drill and a rivet gun. The welded steel fuselage seems to turn some builders away but the welding of chrome-moly tubing is not very difficult to learn and if you have a friend that does bodywork or similar gas or Mig welding it will not take him very long to pick it up. Keep in mind that there is nothing stronger in the event of a forced landing or crash than a welded steel tube fuselage.
Should I build the wings out of aluminum or wood?
This is a matter of personal preference depending on what the builder has the most experience with and what tools he has on hand. Each has its own advantages and disadvantages. The wood wing is probably easier to build than the aluminum one unless you have some sheet metal experience. However the wood wing is a lot more time consuming to build. A typical wood rib has over 50 pieces that have to be cut out, shaped and glued together, the aluminum rib is just 2 pieces to form. One of the problems most beginners have with the aluminum skin is trying to prevent it from ‘oil canning’ between the ribs. These ripples in the skin do not affect the strength of the wing but the appearance is less than desirable. Proper drilling and riveting techniques will eliminate this problem. The wood wing is more forgiving to build as mistakes (dents, bends and holes in the wrong place) in aluminum are almost impossible to fix. The aluminum wing is 2 lbs per panel lighter than the wood wing when the aluminum wing uses .020 thick skin on the trailing edge, with .025 aluminum both wing materials weigh the same. The aluminum wing spars need a ten foot sheet metal brake or hydraulic press to bend. Most small metal shops do not have this heavy of equipment and it will have to be done in an industrial shop. Once one has started gluing a part of the wood wing it has to be completed before the glue dries, unlike aluminum where the work can be stopped at any time. Swelling and shrinkage in the wood can also be a problem. If the wing skins are glued on during low humidity the skin will expand and ripple when the humidity rises. Some builders will wet the skin during low humidity to prevent this. Covering the wood wing with fabric is an additional step that is not required with aluminum. Working with aluminum is cleaner than with wood as there is no sawdust and glue to contend with. The tools required to build the wood wing are more costly than for the aluminum which requires only a drill, snips and riveting tool. Briefly those are some of the differences and problems, but the bottom line is that it is really what the builder is most comfortable with, in flight there is no measurable difference.
What part of the Acrolite 1B is the most difficult to build ?
The wing center section around the top cabane structure gives the first time builder the most problems. It is a cut and try process that just takes a little time to accomplish.
How difficult is the Acrolite 1B to fly ?
The Acrolite is a very easy aircraft to fly compared to most of the small biplanes, but we recommend a checkout ride in a taildragger type aircraft first. If you can solo in a Cessna 120-140, Citabria, J3, Super Cub or a Taylorcraft you should not have any trouble in the Acrolite. As a matter of fact we feel the Acrolite is easier to fly than any of these aircraft. We have had low time pilots fly the Acrolite without difficulty. But since everybody's skill level is different, we recommend a taildragger checkout first.
Can I use a Continental or a Volkswagon conversion in the Acrolite?
We do not recommend the use of the small Continental engines or the Volkswagon conversions because the aircraft will get heavier out of proportion to the performance obtained. The success of the Acrolite airplanes is the fact that they were designed around the high horsepower and light weight of the engines from the ultra light industry. While the performance specifications for the volkswagon engine conversions look good on paper the high rpm that these engines turn in direct drive, 3400 to 3600 rpm, compels them to use a very small diameter propeller. The slower a propeller turns the more efficient it is and the slower it turns the larger in diameter it can be. Large diameter props give good take off performance and a good rate of climb. A small diameter prop is more efficient at high cruise speeds. The Acrolite models 1B and 1C were designed as sportsman level aerobatic machines and as such perform best with a prop diameter of 66 to 68 inches (168 to 173 cm). Because of the drag of an open cockpit biplane it is not a high cruise speed aircraft, (although we have done all we could to reduce the drag as much as possible) and while the aircraft will probably fly OK performance will suffer greatly with the direct drive engine. If you run the engine with a reduction drive system this would increase the horsepower significantly and allow the use of a large diameter propeller. The disadvantage of this is the extra weight that is added, over 30 lbs (14 kg) above that for the 80 hp Rotax 912 and 40 lbs (18 kg) for the 75 hp Rotax 618. The maximum installed weight recommended for the aircraft is 165 lbs (75 kg). That is the engine with all accessories (oil, water, rad, exhaust, mount, etc) otherwise the CG gets too far forward and there is not enough elevator control to round out at landing touchdown and climb performance will suffer from the extra weight. Also the extra weight will reduce the G loading capability of the aircraft.