Pete's Plane

Welcome to Pete's Plane

G'Day my name is Peter Leonard and I am a member of SAAA Chapter 15 based in Brisbane. This is a little webpage about my aeroplane project that I am currently working on. My aeroplane is similar to a Vampire Jet (picture below) in that it is a twin boom aircraft and has rear propolsion. The similarity probably stops there.

Vampire_Jet

Instead of a jet at the rear of the fuselage my plane will have a pusher prop. The tail plane is between the tops of the rudders well out of the prop wash. It is a two seater with side by side seating. All up, it will weight 1400lbs (636kg). Its primary purpose is to convey two large persons (198lbs (90kg) each, 6ft (183cm) tall) cross country in relative comfort. Therefore I have designed it with a 46in (117cm) wide cockpit. It will be built out of composite materials (Epoxy Reinforced Glass Mat).

I have started construction and I am currently building male plugs to make female moulds from. Once I have completed the female moulds I will start construction on the plane itself. When will I be finished????, 2 to 3… years I hope. That makes my finish date around 2010, 2011. We will see how progress goes over the next year or so. Oh, I meant to mention my plane will be powered by a 100hp engine. Which engine I hear you ask, either a Rotax 912 or the Jabiru 3300, no firm decision on that yet only my design calculations have been based on a 100hp engine with a fixed pitch timber prop.

I have male plugs for the front and rear fuselage, rudder, horizontal tail and wings, I am currently working on booms and boom connection to the wings. The wings (each side) will be removeable from the fuselage and the tail booms detachable from the wings. The whole aircraft will be trailerable. The aircraft uses building techniques from the Europa, Jabiru and Glasair aircraft. I hear some of you asking how fast will it go, my calculations predict it should do 130knots at around 75% power setting. It has been designed to be aerodynamically clean and every effort has been made to reduce drag in the design.

The pusher prop will be mounted approximately 2ft (60cm) behind the trialing edge of the wing. I have done this to try and get out of the vortex sheet that comes off immediately behind the wing, and to have a clean (or relatively clean) inflow of air into the propellor face. It has also been done to reduce noise, apparently if the prop cuts the wing wake to close to the trialing edge it will produce a lot of prop noise as the prop slaps the wake coming off the wing. Its also recommended to have the prop at least 25% of the prop diameter away from any surface.

The aircraft is basically a conventional design, what I am doing different to other aircraft is the front canopy. The complete nose (front canopy) will slide forward to allow pilot and passanger access in and out of the aircraft. I saw this idea on a sailplane, it also helps to get clean air flow over the front half of the fuselage. Effectively the whole nose cone structure will slide forward approximately 2ft (60cm). This should allow easy access to the inside. eg. No stepping over wings and sliding into the cockpit, simply step into the cockpit and sit down then slide the canopy shut. Another way to think about it is; the nose cone/canopy is a fairing only, it is not fixed to the aircraft's main structure other than when it is closed. Totally confused, sorry about that, you will just have to wait to see the real thing.

The landing gear will be tricycle gear and hopefully retractable. I have designed a retractable system that will be manually operated by the pilot. I saw this design in the Bede 5 and have come up with my own version of it. The downside of retractable gear is the increase in weight, complexity and the ongoing maintenance. Whether its worth it is a matter for debate. The increased weight will add more induced drag, whether the increase in induced drag will be less than the parasite drag of a well faired fixed gear can be calculated. I believe its worth it and put the effort into designing a retractable system. If it doesn't work the design can easily be made fixed with little change from the retractable design.

The wing area will be approximalely 87 sq ft (8.1m^2) and with an AUW of 1400lbs (636kg) you can work out the wing loading (about 16.1 lbs/sq ft). The wing will also be tapered with a 0.7 taper, a 0.7 (straight) taper gives you the closest shape for a elipical lift distribution. The wing will also have 1.5 degrees of washout and 1.5 degrees of diehedral. The wing will be positioned on the top of the fuselage (ala Cessna 172 style), oh by the way no strut. As mentioned above the wings will be removable, they will have spar spurs that will cross over each other inside the fuselage and bolt to the fuselage sides similar to a number of sailplanes and the Europa. The wing will have a 18 percent thick root section and a 15 percent thick tip section. This give me a fairly deep/thick spar at the wing root which in turn will give me a lighter spar. The spar will be designed for +/- 6g.

The wing will have simple split flaps for approximately 60% of the span. I have chosen these because they are simple to make, have fairly good lift coefficient. They will also create lots of darg when fully extended, when fully extended they will deflect 60 degrees. I suspect I may need these to pull up quickly. The wing will also have slotted (differential) ailerons. With the wing twist, slotted ailerons and the 15% thick section at the outboard wing, I hope it will have gentle stall characteristics. The wing section I'm using also has a gentle stall. Fingers cross it all works out. The wing also has the fuel tanks in the front "D" section between the spar and the leading, I plan on carring 200lbs of fuel and will almost be right on the CofG, so no CofG problems as fuel is burnt off.

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