"Darling" Aircraft project
Some of the following literature on this site was developed for marketing the Darling as a kit, it is used now to illustrate and document the project.
The state of finish you see here was accomplished in 890 hours over the course of 15 weeks. The original paint scheme was yellow over purple as seen further below. This included the engineering, 2d cad drawings, tool & jig fabrication, scratch building every component and delivering it to the airport painted ready to fly. (and an inclosed patio addition to the back of my garage for forming sheet metal and painting)
This is not a turn key "kit" business but is a proven prototype design with good flying qualities, balanced controls and good performance. I still have most of the tooling, all the documentation.
The Darling could be a great start for any experimental aircraft entrepreneur. It was briefly featured in the "Experimenter" (1996 Oshkosh issue), "Sport Aviation (1996 Oshkosh issue)" and "Kitplanes" (January 1997 p60) magazines. Editors were eager for a flight test and photos prior to pulling out of the market. This aircraft was built primarily to demonstrate the companies abilities to meet budget, schedule and performance criteria towards the goal of securing funding for the Aurora project as featured on the Erospace home page. This kit was not marketed so as to free company resources towards the Aurora program.
The Darling is on the horizon to transport aircraft enthusiasts into their dreams of flight. The Darling is an all metal single seat design just a bit smaller than an RV-3 and much simpler to build. Utilizing blind rivet construction and common high grade aircraft aluminum the builder can easily assemble the Darling in as little as 400 hours. The design will be offered in the form of A-B partial kits, full kits and fast finish type airframes. Smaller canopies can be purchased for shorter pilots, the one shown accommodates a 6'4" 200 lb.
The manufactured components in the kit provided to the builder include all the machined parts, TIG welded 4130 assemblies, pre-formed leading edge radius skins, pre-bent spars / stringers etc. All the skin patterns are traced on the raw sheet stock and all the necessary hardware, rivets and other fittings are provided. Pre-formed fuel tank, landing gear legs and fiberglass cowling are also provided in addition to a very complete assembly manual.
The Darling can be flown with a minimum of 40hp and up to 60hp! This is a Rotax 447 fan cooled installation. Partial to full kits could be made available including a fast build option! I am at the controls below and my dimensions are 6'4" 170 lb.'s, in the photo you can see the rollover structure which comes as a standard feature. T he powerplant of choice is now the Hexadyne Hexatron two cylinder 60 horsepower 4 stroke aircraft engine.
The Darling utilized twin Mikuni Super Bn floatless carburetors to maintain a clean aerodynamic cowling exterior. The Darling can utilize air-cooled two or four-stroke powerplants in the 40 to 60 hp range. Pictured above is the Rotax 447 fan cooled installation being ground run.
This was the original documentation, a 2d AutoCad engineering drawing for layout of the airframe.
This was used for critical and major items, alignment and rigging, controls layout, etc.
Everything else in between was fabrication on the shop floor to fill in the blanks.
The 3D model below was created four years after it was already flying.
The design has since been modeled in SolidWorks.
Current configuration is a tricycle gear. I'd like to acknowledge a few men who without their help
the Darling would not have turned out as well as it did.
Fred Weick, he created the Ercoupe. He was critically influential in the development of Streamlining of the early engine cowls and propeller design, saftey etc. A prolific contributor to aircraft development and a member of our EAA chapter in Vero Beach.
A gentleman by the name of Grahame K. Gates, former Corporate Director of Advance Engineering for Piper. Also a member of our EAA chapter in Vero Beach. A man remembered with the dryest wit.
Or by Jim Stewart, former design engineer for Pratt&Whitney, holder of many patents and designer of the S-51d. Video here. He and his wife Peggy are two of the sweetest people I have ever met.
Scott Swing of Velocity Aircraft for his material and logistical support during the projects building and testing.
And Jeff Kerlo of Orion Aircraft for his freindship and support over the years, a fellow dreamer of big things to come.
Prior to first flights it was a convertible to facilitate getting out with a chute if nessesary.
(Before the gear leg fairings were installed)
This aircraft was designed and fabricated by John Harvey in fifteen weeks. John's background is in R&D, production engineering and industrial design with the emphasis in conceptualization. Prior to this project John's company, ETI, provided design development engineering and tooling services for LoPresti Speed Merchants' new Howl Cowl design, Velocity's new Elite door system, and Fillet fairings, weldments, tanks and other details on Jim Stewart's scale S-51 Mustang. John's background in experimental aviation dates back to the Polywagon in the late 70's. Prior to being full time with ETI in '93, John worked within Bombardier Sea-Doo's design group providing direction in vehicle dynamics and systems integration for their personal watercraft products since its inception in 1987.
8/13/96 Since our debut' at Oshkosh this year we have decided to offer an FAR part 23 Aerobatic capability to the kit, +6 g & -3g, pricing to be announced (probably not much difference).
8/13/96 Also we will be dropping the use of the Rotax 447 in favor of the 503.
8/13/96 We will be resuming our flight test program soon and look here for the latest information as it becomes available. As soon as we can we will post the observed flight performance and inflight photos!
10/17/96 4 hours of flight time on the prototype. Everything going very well. Tail incidence modified, prop dialed in, cruise prop = 800 fpm climb / 125 mph cruise!
11/02/96 Spin testing, 2 1/5 turns, conventional recovery technique, Stall testing, Full flap approaches good and steep. Up to 160 mph indicated, VNE 147 mph. Flutter resistance good
11/15/96 26 hours total time now. Having a great time! Flew a 200 mile course hands off entire flight, excellent!
*503 installation includes, engine, mount, ducting, twin Mikuni Super BN carbs, electric starter, ground adjustable prop, spinner, rectifier/basic wiring
Altitude |
0 |
Wing area |
57 ft2 |
Span |
20 ft |
A/R |
7.1 |
Empty weight |
374 lb |
Useful load |
246 lb |
Gross weight |
620 lb |
H.P. |
42 |
|
|
|
Take off roll |
1200' |
Landing roll |
800' |
|
|
|
Climb rate seal evel |
1000 fpm |
Best L/D Speed |
78 mph |
Max speed Vne (mph) |
147 |
Cruise speed (mph) |
120 |
Fuel capacity (gal) |
12 |
|
|
|
Cruise endurance |
3.0 hr |
Stall no flaps (mph) |
65 |
Stall with flaps (mph) |
60 |
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