The HP-24 project has been, and continues to be, a long strange trip. To some degree, I've lost track of where and how everything is documented, and judging by some of the email I've received lately, I'm not alone in this. So I've decided to write this somewhat rambling recap of where we started, what we're trying to do, and how far we've come.
The intent of the HP-24 program has always been to develop a modern kit sailplane, with performance equivalent to the European racers of the 1990s, that a soaring enthusiast of relatively modest means and typical skills can build in their garage or basement. It has a gererously-sized cockpit, and many of the amenities such as nose-pivot canopy and automatic control connections, that have not been widely seen in homebuilt sailplanes.
As suggested by the program name, the HP-24 was inspired by the Dick Schreder kit sailplanes of the 1960s through the 1990s, and incorporates many of the technologies and even some of the exact same parts that Dick developed for Bryan Aircraft.
Where are we now?
As of February 2010, we have all of the major tooling in hand to manufacture sailplane kits in series production:
We have made at least one or two sets of all of the major parts for the first of two or three pre-production aircraft:
When will we be done?
We don't know, and we don't like making promises about it. We all have families and day jobs, and we don't mind writing about ourselves in the third person. We'll keep you posted; check back here for updates.
What will it cost?
We are on track to hold to the pricing announced in November of 2004 for the basic kit: $13125 in US Y2K dollars balanced for inflation, plus 175 barrels of oil. The price of oil is somewhat fluid, but in the last few weeks oil and inflation have pegged the current kit price at around $26000 in current dollars. Options such as winglets, 18m tips, ballast provisions, pneumatic tailwheel, are extra.
Isn't that a lot for a kit glider?
Yup, I wish it were less. But I think it's a fair price for a high-performance sailplane plus the education and composites training you get from building it. Consider that current prices for new sailplanes of equivalent performance are running around 5x the price even before you add the shipping and brokerage costs.
What will be in the kit?
The kit we're developing will have the major shells joined (fuselage right and left, wing skins and spars), and will mostly require the builder to install control systems, join minor composite parts (bulkheads, stiffeners, etc), align and secure major parts (wings, stabilizer, control surfaces) using factory-supplied jigs and tooling, and do all exterior painting and finishing. The builder will also have to fabricate some less-critical composite parts using factory-supplied tooling and materials. Our intent is to provide a kit and a construction process that meets both the spirit and the letter of the "major portion" rules for US amateur-built experimental aircraft.
How long will it take to build?
Assembly of a typical customer kit is targeted for 350 build hours. However, recent FAA activity around the "major portion" rules regarding homebuilt aircraft might push that higher, and might even require that the customer visit our shop to contribute to the actual fabrication of the major kit parts. We'll keep you posted.
How much room do I need to build one?
For the kit we're developing now, you need a workspace of at least 26 feet by 8 feet to work on the wings and have room to get anything done. But if there's interest, I could develop a short-room kit that could go together in as little as 20 feet by 8 feet at some modest penalty in cost, build time, and weight. Please let me know if would be interested in that option.
What will the surface finish be like?
We will probably supply the major shells (fuselage, wing and tail surfaces) with either an epoxy-based exterior finish, or with a polyester gelcoat, applied to the mold before the structural laminations of carbon or fiberglass. The customer will sand the exterior, do minor filling and smoothing along the shell joints, apply a finish coat of polyester topcoat or other similar exterior finish, and sand the wings to the 0.004" or lower wavelessness required for good performance. If you've been following the project website, you see that we made Brad Hill's wings and tail without any exterior finish. That was at Brad's specific request.
Can I help?
You probably can! Feel free to make me an offer; I'm open to the idea of trading development help or production labor for production or pre-production parts. But, sorry, I'm not open to offers for sharing reward without sharing risk.
Homebuilt aviation is not for folks who don't try things at home.
page updated 24 February 2010 all text and graphics copyright (c) 2010 HP Aircraft,
LLC