My APIS(maybe J) Project
I recently received my AMS-Flight APIS self launching kit-glider. The skies of east Texas may never be safe again :-)
Why own instead of rent?
- I've wanted my own airplane for years. Now that I found my aviation niche in soaring, found the right plane/kit and have the right circumstances to build and own a plane, I'm going for it.
- No more fighting other soaring club members for rental glider time slots. I takeoff when I want, I land when I want (or when the conditions die). Landing early cause someone rented the glider after you, or missing out on the prime hours of a day is just plain evil.
- Rentals are usually old, low performance and/or club class performance. The Apis is by no means a thoroughbred racer, but higher performance than what’s available to rent and on the low end, it should outclimb just about anyone.
- Put in the features I want. I pick the vario, I pick the radio, I pick the decals. Looks and feels just how I want it.
- Rentals have issues. Rentals never get treated and maintained as well as personal gliders. No more scratched finish, missing seal tape, miscalibrated instruments, missing fairings, etc...
- Soaring holidays. With my own glider and an open weekend, I hook up the glider trailer to my Toyota, bring a sleeping bag and fly in a new location. Summer thermals in Texas rock, but I also love ridge and wave soaring.
- Long cross countries. You can't get far and back when all you are guaranteed is a 2 hour time slot. Even though I can usually get away with longer times if no one rents after me, I have to be on call to return the glider after my 2 hours is up meaning I have to be local at that time.
- No annoying club limitations such as maximum cross country distance and no aerobatics.
Why a self launcher?
- No more being grounded when the tow plane is. One day I drove an hour to Caddo Mills gliderport just to find out the towplane was down as of 5 minutes before I arrived, needless to say, that sucked ass and I was pissed.
- No waiting in line for your tow. I hate staying on the ground like an idiot waiting for a tow with 3 gliders still in front of me waiting for their tows.
- Fly out of any airport. TSA is a pretty ideal place for gliders and it's a great place with good people and lots of fun hangar flying. Unfortunately, it's also over an hour away from my house, and with today's gas prices it costs quite a bit just to get there and back even in my economy car. If I don't need a towplane, any place with a wide enough runway will do.
- Self retrieve. I’ve landed out at other airports twice in my Libelle. It was a hassle and aero retrieve charges are a real raping. I don't even wanna think of the hassle and risk of landing out in a farmer's pasture.
- Much lower operating cost. A $30 tow becomes a few dollars of fuel.
- More flying during weak conditions, especially winter. At the moment, I don't usually do more than 1 tow per day, if conditions suck too much to keep me airborne till the end of the day, I head home as opposed to forking out a bunch of cash for a tow that could potentially get me only 15 minutes of flight time. With the low cost of self launching, I can go up again without thinking twice. Besides, a sleigh ride is better than being grounded.
- Launching even if you're not sure conditions are ripe yet. If I stay up, awesome. If I come back down, I wasted a gallon of gas and I try again in an hour or 2.
- No worrying about getting back to the home airport on a long cross country. If conditions are deteriorating and I see I can't make it back to home base, instead of landing at another airport and getting aerotowed back at ridiculous expense, I can come back to home base under power where all I pay is a bit of gas. This soothes my inner jew enough a bit to be more daring with how far away from home base I got.
- Operate even when the club is closed. Pretty nice considering the club is only open 3 days a week.
What's wrong with the Libelle?
Don't get me wrong, I love my Libelle and I'll have some hesitation when it comes time to sell her, but the Apis is way better in many ways.- Doesn't self launch.
- Isn't aerobatics capable.
- Isn't flapped.
- Poor glide performance above 75 knots once the wing transitions to turbulent flow.
- Way under ruddered.
- Lack of aileron control at the beginning of the takeoff roll.
- Her trailer is a homebuilt, wooden piece of junk that was pretty poorly designed, has tons of detachable fittings and dollys and requires a lot more time assembling and disassembling the glider than it should.
- The detachable canopy is kind of a hassle considering you can't secure the canopy yourself.
- Glide computer is ancient with no GPS.
- Finish could be in better condition.
Why not a 2 seater?
- I regularly fly over 3 hours, and when the thermals die and I have to land I'm still bummed it's over. When I come into work on Monday and gloat about it to my coworkers, the consistently ask me, "don't you get bored?". Doing demo rides I also noticed most people don't like flying for more than hour. I like flying as long as I can, passengers generally don't.
- From my powered flying, I found that circling, flying low and flying into bumpy air is what makes passengers nauseous. Incidentally, this is how you spend a great deal of your time soaring :-).
- Some, but not that many people are really begging for me to take them up since I got my sailplane rating.
- If I really need a 2 seater on occasion, I can always rent it.
- 2 seaters generally have lower performance than 1 seaters.
- 2 seaters are more expensive than 1 seaters.
Well, here was my basic criteria
- Available as a kit.
- Self launching.
- Single seater.
- All composite. Aluminum or wood just won't fly (pun is intended :-) ).
- Designed for one man assembly.
- Affordable acquisition cost.
- Affordable recurring costs.
- Good soaring performance across the entire flight envelope.
- Basic aerobatic capability.
Before I decided on the AMS-Flight APIS, I was also looking at the AliSport Silent2 Targa and Windex 1200C. Each design had it's own advantages and disadvantages, but in the big picture, it was clear that APIS was the best overall choice.
- Good performance in every category and flight regime.
- 15 meter span, anything less would be uncivilized.
- Big full span flaperons with reflex settings.
- Lightweight with extensive use of carbon fiber throughout.
- 6.4 to -3.9 Gs opens up the door for aerobatics.
- Powerful, light, reliable and common Rotax 447 engine. Well, this kinda backfired, but more on that later....
- Very light wings, automatic control hookups, steerable tailwheel and wingtip wheels make a crewless glider operation much simpler.
- Very complete kit includes everything minus instruments and avionics.
- Reasonable price.
- It's fun. I had a blast at the EAA SportAir composite workshop. I had fun building my fiberglass toolbox for composite construction practice in my parent's garage. I like assembling ikea furniture :-) (well minus, the crappy instructions and misshaped parts).
- It's a great challenge. This is a project on a much larger scale than anything I've done before and has much more at stake (including my life) than other projects I've done before. In one of the old National Lampoon's Vacation movies, Chevy Chase said "nothing easy is ever worthwhile", even though I don't think that movie should really be a philosophical guide, that line kinda makes sense to me :-).
- Customizations. I've already done tons of customizations on everything from the canopy latch to the landing gear and considering I'm thinking of putting in a jet, can't really do that on something ready built.
- I have the time. I spend way way way too much time at the moment watching Futurama reruns that I've seen 10 times. I should really be doing something more useful with my time. Also having no wife or kids helps.
- I have the place. Now that I own a house with a 2 car garage, I can work on the fuselage and wings in the comfort of my own home. I won't be able to actually assemble the wings and fuselage in my house, but I'll only need that for a short time towards the very end of the project.
- I have the skills. At least I think I do :-). I definitely have the composite skills I picked up at the EAA SportAir composite workshop and building my fiberglass toolbox. It's almost a shame that my kit will barely require a single lay up :-). I have the wiring skills I got from the electrical systems EAA SportAir class. I read the Tony Bingelis books. My kit is very quickbuild-ish and almost everything is molded and closed from the factory, so it will not require any extremely difficult tasks, it'll be mostly, drill this, trim that, install that. I don't think I'm super skilled, but I'll be able to handle it, and I'll pick up what I don't know as I go along.
- I have the self discipline. Back in my hardcore guitar days, I'd practice 20+ hours a week religiously and I've spent many many hours on various hobbyist software projects I've done, so I think I can see this through. Besides, I have far too large an ego to fail :-)
- Makes you more handy. After I finish tackling this project with all the skills I've gained, who knows what else I can build.
- Saves money. Let's face it, if you're reading this, you probably know me and know that I'm a cheap bastard. The kit is almost 10,000 euro cheaper than ready to fly and doesn't include anything the kit doesn't.
- Repairman certificate. I can do my own maintenance and inspections, allowing maintenance to happen by my watch, without labor costs and I'll know my own ship better than any mechanic ever will since I built it.
- No flight restrictions. After doing the 40 hour testing, I can fly wherever I please. Had I gone ready built as experimental for exhibition/racing, I have to constantly let the FSDO know if I plan to fly anywhere far from home base.
- Certification free. The FAA won't have me on a leash with every screw I put in needing the FAA's blessing. This opens up a lot of new options for things I can put in the glider and modifications I can make.
- Build time counts towards an A&P certificate.
So what's this I hear about some crazy idea to replace the Rotax with jets?
Yup, I'm very seriously entertaining the notion of using twin jets for self launching and ditching the Rotax. How serious? Well, I've already set aside money for the cost of the jets and sold the Rotax. The idea came from Bob Carlton's Silent J. I initially thought it was a gimmick and pretty cool for airshows but not of any practical use. Than a couple of things happened. I did my homework. I ran performance calculations of what kind of performance to expect and they are very encouraging. I talked to Bob Carlton personally and found out my performance calculations are pretty much on the money. He mentioned a few issues he had to deal with, but as far as what I researched most of them are fixable and a lot of em don't apply to the new crop of microjets (Bob's Silent J is several years old and there has apparently been advances in microjets). I also found out major manufacturers are working on and flying jet sustaining gliders including Schemmp-Hirth, HpH and Jonkers which is even more encouraging that there is merit to this.
So why do I care to go with a jet instead of a prop?
- AMS's poor support, total lack of documentation and the ridiculous amount of parts in the Rotax installation give me some serious doubts as to whether it'll ever fly with the Rotax.
- There have been many vibration issues with the Rotax installation. Jets have one moving part that is perfectly balanced hence no vabriation, low maintenance and long life.
- The Rotax 447 will soon be discontinued. This will be very problematic in the future for getting spare parts.
- It'll shave 60 pounds easily off the empty weight of the glider and I like floaters.
- Simple installation, no prop lock, no transmission, minimal structure required due to the jet's small size and lack of vibration.
- Climb performance should be even better than the Rotax to the tune of 8 knot climb rate at standard conditions.
- Very small size means very low added drag with the jets extended.
- Really earn the title of experimental.
- It's a freakin' jet, how cool is that?
- Fuel consumption is considerably higher. With my calculations, at standard conditions, I should still be able to get almost 40 nautical miles of sustain after a 2000' AGL tow with the existing fuel tank. At higher density altitudes, climb performance suffers, but sustain range actually improves. I think even 30 nautical miles is enough and if it isn't, I can always add another gallon or 2 tank that will add quite a bit of range.
- Gotta watch out not to melt the tail. Can be fixed by using twin jets yawed outward so the exhaust isn't pointed at the leading edge of the vertical stabilizer. Using twin jets also increases reliability as a single jet has more than enough thrust for sustain.
- Gotta design it yourself. Time consuming, but fun and rewarding. I am gonna reuse as much as I can from the existing installation including the engine pylon pivot hardpoints, existing fuel tank, existing engine bay doors with minimal modifications, etc...
What are your plans for gettin' her done?
Well, as long as I can, I'll build her in my 2 car garage, click here and find out the details. I'm breaking down the building into 3 stages.
Stage 1: Airworthy Pure Glider
The point here is just get her in the air using traditional aerotowing with not much beyond the bare minimums. No self launching, no aerodynamic refinements, no mirror finish custom paint job, no creature comfort refinements. I'm not terribly far away from this, although previous experience has shown I shouldn't put a date on this :-). After this stage, I'll sell my Libelle and fly the Apis exculsively making incremental improvements that shouldn't take down her airworthiness for any long period of time.
Stage 2: Airworthy Self Launcher
Install the self launching system. Most likely using twin microjets. This should mostly consist of designing and builidng the pivoting engine mount, extension/retraction mechanism, electronic wiring and some fuel plumbing although I'm sure this will take a while though. This is where I'll try earn the title experimental.
Stage 3: Finely Tuned Self Launcher
Probably throw another coat of paint since the factory paint job is damn thin. Do trim painting and decals. Sand, buff and polish the glider from nose to tail to perfection. Install non critical items such as relief system, oxygen tank mounts, gap seals, flow fences. Deal with any defecincies or annoyances I discover after flying her for a while.
Why the hell ain't it done yet?
- Laziness.
- Life getting in the way.
- Not respecting the rule that a homebuilt will take considerably longer than you anticipate. Prospective builders, listen as I should have :-). No such thing as a "quickbuild" kit, just a "less slow build" kit.
- AMS Flight's lack of documentation and support. Now that Pipistrel owns the project and is updating the documentation, I anticipate (or rather hope) this problem will go away soon. Robert Mudd has been a huge help, but there have been many changes to the glider since he wrote the build manual and new systems have been introduced that are not in the build manual at all.
- Customizations and modifications eat up build time like you wouldn't believe and I'm doing plenty of em.
- My anal retentive attention to detail, although I argue this is a positive thing.
Is it a glider or an airplane?
It's a glider (not a touring motorglider) and definitely not an airplane. Gliders are designed for high aerodynamic efficiency (usually at relatively slow speeds), high glide ratio and low sink rate. Airplanes are generally designed for long range, high speed cruising. A glider's primary mission is to make sure you enjoy your weekend and have no practical purpose. Airplanes are generally designed as transportation to go from point A to point B. The glider's engine is only there for self launch and the occasional self retrieve. All the propulsion options I'm looking at are not well suited for cross country airplanes. The fuel tank holds less than 4 gallons which will barely get you anywhere. The long wings and low wing loading optimize the design for good slow speed handling with a low sink rate and a high lift/drag ratio, at high speeds these design features are detremintal. The Vne is lower than most modern general aviation aircraft's cruising speed. It makes a great recreational glider, but it's pretty lousy as a cruising airplane.