Classic Build: Flair Sunrise
Warning... This is most definitely a nostalgia build!
I wasn't fortunate enough to have owned the Sunrise but flew one after a slope meet was called off due to a complete lack of wind. Some of the older guys had come prepared for this eventuality, armed with thermal sailplanes and bungee lines. I tagged along, helped to lay out the lines and watched the guys trim out their gliders. The Sunrise immediately grabbed my attention; the glide ratio was awesome compared to any of my slope gliders. With a reasonably strong hand launch the pilot was able to fly a decent sized circuit for trimming and then catch it.
It was a cold but completely clear and sunny winters day. Not great thermal conditions if you ask some people. I've often found days like that to be ideal with a good temperature differential and bags of lift being generated by car parks, roads, houses or industrial buildings. This day was one of those. I was further impressed by the Sunrise as it returned 10 minutes from a bungee launch with no lift; other similar aircraft giving more like 5-6. Once the lift started to kick in the Sunrise had several 45-60 minute flights which were putting the larger and more expensive aircraft to shame.
After looking on and listening to the guys discuss thermal activity and flight strategy, I was offered the chance to have a fly of the Sunrise, an offer I jumped at. I had three flights, all of which I thoroughly enjoyed. My last flight came in at 20 minutes which I was thrilled with and still would be today. That pretty much sold me on the idea of silent, naturally powered flight.
Unfortunately even back then the Sunrise was a difficult kit to get hold of. Flair had stopped production of it some time ago and shops didn't seem to keep it in stock. Eventually I gave up the hunt when I was presented with the chance to buy a used Osprey 100" for next to nothing. That was a pretty good sailplane and lasted me a lot of years. It was great on the slope up to about 10mph. It's performance couldn't compare to the Sunrise but still wouldn't have too much trouble picking up thermals. I flew it in several cross country competitions, it couldn't compete with the moulded machines which were just starting to show up but it still provided a lot of enjoyment. The Osprey died several years later after I specced out, it had no air-brakes and a spin wouldn't bring her back down. I received a phone call a week later after it dropped in to someone's garden out of a tree -- six miles away!
Many years later, and many thanks to eBay I have gotten my hands on a Sunrise kit. I posted a wanted ad hoping that someone would eventually clear out their attic and find one... Someone did!
I haven't found much information on the Sunrise online so decided to post a build log for others who might find themselves doing the same at a later date. It's been a long time since I've put together a traditional wood kit so I'll also appreciate peoples input if I get stuck along the way. After such a long wait it would be a real shame if I don't build her straight and true.
There is one major issue I have with the Sunrise which is that I don't have a flying site suitable for laying out a bungee. Looking at the amount of space I have available in the fuselage my immediate thought is that the Sunrise could be electrified. One option would be to modify the fuselage and fit a brushless motor and folding prop at the front. My only problem with this is that it's non-reversible and after it taking me so long to source a kit I don't want to end up with a dud. The second option is to build a power pod to sit over the wing. The pod could house the ESC and a small brushless outrunner with folding prop. The battery would ideally sit in the compartment between the wings, or alternatively in the large radio bay designed to enclose classically proportioned radio gear.
I can't decide which option to go for as the idea of a pod sounds good but I'm concerned that it's going add a lot of additional drag. In the meantime I'll get on with building the tail and wings.
I have a second point of procrastination. Should I modify the original design and fit air-brakes. A nice to have option, the additional radio won't add much weight as micro servos are so small/light these days, I'm just not sure it's worth the bother. My previous experience with air-brakes on old wooden sailplanes is that they are a bit of a hassle to maintain. Wire runs always seemed to snag, or they wouldn't close properly etc. I do remember that some companies used to sell plastic pop-up air-brakes but I can't find any reference to them online anymore. Could anyone point me towards a source for these?