Success! -- DaSH Flies, 5-Dec-2015

DaSH first flight, 5-Dec-2015, 7:32 a.m.

The DaSH Human Powered Airplane flew for the first time on Saturday, December 5th at 7:32 a.m.  at Half Moon Bay Airport in California.  It was a culmination of over 12,000 manhours of work by hundreds of volunteers, and it was a fantastic first flight and a great feeling to see after so much hard work by so many people.

The first flight of DaSH was 233 meters long and 37 seconds duration.  Configuration: standard wingspan (33.3 m version), pilot max weight at just above 90 kg (198.5 lbs -- myself, a bit out of shape and about 15 lbs heavier than optimal).  The airplane weighs a bit over 45 kg.

It flew a lot easier than expected (meaning less power required than I thought it would) and handled great.  There was a bit of PIO in the middle of the flight as I sorted out the handling (we slowed the servos way down to avoid moving our delicate control surfaces too fast -- but we need to speed them back up a bit).

I felt I could have flown the length of the 5,000 foot Half Moon Bay, CA runway (we started about 1,000 feet down the runway), but the flight was cut short when the vertical tail mount failed.  The landing was uneventful.

The failure occurred because we cut a flange too close to the core material at the high stress part of the mount (the test articles had gone through extensive truck testing at higher than max speed with full control deflection, but they didn't have the defect in the flange).  We've repaired the mounts with more carbon and wider flanges and tried to fly on Sunday, but got rained out.  We'll try again in January.

We're very happy with how this first flight went.  It's a long one for a brand new HPA, and we're looking forward to flying again soon.

-- Alec

Project Blog:  http://dashpa.blogspot.com/

Videos

First Flight of DaSH, from the East side of the runway

by Rodrigo Damazio

Reverse Angle from West side of runway

by Ron Smith

Edited video from onboard and off-board GoPro Cameras

by Walter Colby

(A must watch!)

A shortened version of the GoPro camera video (1:38)

by Walter Colby

DaSH PA Half Moon Bay from Kirk Moore on Vimeo.

Time Lapse Video of DaSH test assembly on Nov. 21st

Photos

Above Photos by Chris Colohan

Link to more photos by Chris C

Above photos by Ferdinand Ngotiaoco

Press

Article about DaSH first flight in the Half Moon Bay Review by Clay Lambert

Finish Fuselage Fairing

On Friday we completed the last major part of the airplane -- the fuselage fairing.  Pretty much done and ready to fly!

The fairing has aluminized Mylar in back to keep the heat load down, and a cooling duct that should direct air onto the pilot's head.  The Mylar is not fully tightened yet in these photos, and we hope to be able to remove at least some of the remaining wrinkles before flight.

The shape is somewhat modified from the original concept to make enough clearance for the feet around the pedals and cranks.  This means there is a bit more of a protrusion at the nose than originally intended, but it came out pretty well.

If we ever do a version 2.0 of the fuselage fairing, the bottom tub and front nose portion would be replaced by a molded Kevlar tub.  What we have now, which uses only formers and ribs made of laminated balsa and carbon fiber, is lighter, but isn't as aerodynamically smooth as a molded tub would be.

It will be interesting to see how this current version fares on first test flights.

Getting into the pilot seat is a challenge.  The second rib from the bottom is fairly low so the pilot has to carefully duck his head underneath when getting in.  One also needs to make sure the feet are carefully moved until they get onto the pedals -- the very lightweight materials used for the ribs, formers and tub are fairly delicate.  With a bit of practice, though, it becomes second nature.

The completed fuselage fairing (in test rig frame)

Aluminized Mylar on back half to reduce heat load.  Still needs more tightening.

Finished fairing with open pilot door.  (Can be covered after ingress.)

Idler pulley assembly with chain

Alignment issue with front idler pulley -- we'll fix with angled washers

Testing out the new fairing -- thicker 0.010" Mylar provides a clear view out the front

Working on the air inlet

Side view

Full Assembly at Hiller Museum

With the wings complete, we did a full assembly of the airplane to check the fit and learn about the transport, assembly and disassembly process.

The Hiller Aviation Museum (http://www.hiller.org) generously agreed to let us use their large atrium space near the entrance to house the airplane

The airplane as shown is complete except for the fuselage fairing, and the wheel brackets are mockups (both to be completed later).  Also, the kingpost we tried to use was too flexible, so we'll be making a stiffer one out of aluminum for the first test flights.  (The airplane can fly with or without a kingpost -- having one just makes ground handling easier, but adds about 5 Watts worth of drag.)

We learned a lot about what to pack, how to transport, and how to assemble the plane.  Now we just have to finish the final details, and the airplane should be ready for flight!

DaSH assembled in the Hiller Aviation Museum

Loading wing sections into the trailer

Transporting the tail boom

The DaSH trailer

Wing assembly frames and some parts

Bringing a wing in

Attaching to wing sections

Securing the wing section with a frame (in lieu of the kingpost)

Putting the end wing section on

A view of the top of the wing

DaSH among the planes on display

Working on the kingpost

Widening a hole for the kingpost wire fitting

Installing the kingpost

This kingpost proved too flexible, we're designing another

Working on the servos

Installing the horizontal tail surface (all-flying elevator)

Installing the vertical tail surface (all-flying rudder)

Testing the prop

Adjusting the prop pitch

Fully assembled plane (sans fairing)

Thinking about the handlebar and control location

Adjusting the idler pulley assembly

Part of the assembly crew from the DaSH team

A view from above

Showing the entire 36.7 m version of the wing from end-to-end

Tightening the Mylar on a wing section

Taping the gap between sections

Prior to tail boom attachment

Panorama from beneath the airplane

Panorama from the front, capturing most of the span

Answering questions