I think a secondhand Sonex is right for me, Seeking Opinions

[EchoFoxtrot]

Hello all! I'm a low time PPL about ready to get in the market for my first aircraft, and I've reached the point where I thought I should stop lurking and ask specific questions. From my research, a Sonex (or Waiex) seems like the right airplane for my budget and mission, and I was hoping the collective wisdom (or collective peanut gallery) would want to weigh in.

I live in Charlotte, NC and am looking for a something to do fun local and moderate cross-country flights. I have about 60 hours and currently rent a C-150. I learned in a Grumman Tiger and was thinking of tailwheel endorsement training. The passenger and I are both 5'6" and we weigh a combined 300lbs soaking wet. My budget is tight by airplane standards but seems like it should handle a Sonex. (~$20-35 purchase, ~$6k/year operations, maintenance, insurance).

I have a friend-of-a-friend who has agreed to take me up in his 3300-powered Sonex to see if I like the way they fly, but the weather has been poor lately so I haven't gone yet.

Question one: The airfield, the engine, the tires.
No concrete runway within 100 miles has hangars. On the other hand, there is a private grass field (Bradford Field) with available open front sheds at a reasonable price close to the house. It has a 3200ft grass runway facing the prevailing wings in moderately good condition, trees on one end. I would expect to fly out at or near gross weight frequently. Can I do this with the 80HP Aerovee, or do I have to spring for the turbo or the Jabiru 3300? Can the standard tires handle grass every flight? (I assume I would find a tailwheel for sale first)

Question two: The cross-countrys. I have family in Atlanta, Destin FL, and Lafayette LA. The four cities make a chain with straight-line distances of 200, 237, and 287 nautical miles, and they could be broken up overnight. How good are the various varieties of Sonex at handling these legs? If the answer was "Honestly, not good" I might need to keep saving money for the next airplane. Can I get some honest cross country planning figures? We're youngish, so our spines could probably take it.

Those are the dealbreakers.

The maintenance: I'm handy and good at maintaining other things, but I'm not Tony Stark with a wrench. I can, however, follow a procedure exactly (I'm an engineer in nuclear, I love written instructions). Which engine has the best maintenance/operations/support?

I've read some of the other excellent chains written for first time buyers, but in light of this ^ information, does anything else occur to y'all?
Thanks!
Emile F.

[WaiexB22]

Welcome to the forum!

I am located in your area (Denver, NC) and I am working on a b-model. You are welcome to check it out sometime. I looked at Bradford, but the deal breaker was the runway condition after rains. I lucked into a spot in a shared hangar at 14A. When it is dry the sonex shouldn't have any trouble with grass including at Bradford.

I cannot comment on the aerovee performance or range.

[Bryan Cotton]

At your combined pilot/pax weight of 300 lbs, you are in the perfect Sonex range. We are more typically at 400lbs of people two up. Grass strips are fine. I always argue against bigger main & tailwheel tires because of weight, but then again at 300 lbs you can afford 5 lbs for bigger tires if you feel you need them. Our longest XC to date is 430nm, broken up into two legs. That was C77->KBGM->KRKW. At 400 lbs of people we could not take all 16 gallons though.

The main downside of the AeroVee is it requires more maintenance. This is both planned and unplanned maintenance from my experience and other's posts in this forum. It is an easy engine to work on.

We have flown solo out of grass strips less than 2000'. On the right day with the right wind it is actually not bad at all. Two up we have departed 2500' of grass before, at a couple of different airports. Not really enough margin for us. If we were 100 lbs lighter it might be a better story. And the little tires really impede the acceleration to flying speed if it is rough.

For XC planning we use 100kts and 4GPH. Depending upon weight and density altitude we take between 12-14 gallons two up. At your weight you could easily take the full 16 gallons in an A model, or 20 in a B model.

There are other engine options out there. I think there are a couple of Sonexes with Jabiru 2200s out there now. They are lighter, so more of an aft CG, but your 300 lb figure makes that not a problem at all.

$6K a year is generous based on what we spend. But if you hire a pro to do everything that cost will go up. You will need to find an A&P or better to sign off your annual.

As a low time pilot you will need some training - it's not a C150. But it is not hard to fly. As far as tailwheel goes, it's probably the most forgiving tailwheel airplane I've flown.

I'll see if I can find those two Jab 2200 Sonexes and post them in the classifieds.

Good luck!

[Bryan Cotton]

I'll also mention that after 2+ hours in the airplane I'm ready to get out for a while. It's actually very comfortable but 2 hours in a tin can grinding along is enough for me, then I want to get out and stretch. My son and I are both broad across the shoulders so it is tight in the cockpit.

[daleandee]

Great comments thus far.

Anyone that knows me will attest that I prefer and recommend a properly built Corvair conversion for these airframes. Good performance, great reliability, low maintenance, & smoooth! Taildraggers are also preferred as you get to have a bit of swagger when you walk (although the Sonex taildragger has to be the easiest tailwheel plane to land that is currently on the planet). I fly a fair amount from grass fields and Bryan's comments are spot on. The small wheels do work (I have a 5" tailwheel and the standard 11X4-5 mains) but if the field is soft or wet the tail wheel can dig in. Been flying my current Corvair/tailwheel for 12 years.

I owned a nose roller Aerovee powered Sonex for five years. It was a fun airplane and I fell in love with the airplane handling but found the Aerovee a bit much for maintenance and a bit lacking for performance in demanding situations (hot temps, high density altitude, heavy loads i.e. near gross weight). I'm not a fan of a turbo on a VW engine and as much as I love the Jabiru engines they have had some nagging issues and service & parts have been tough to get for some folks. But I admit that when I flew my friends 3300 powered taildragger I knew that I needed more power than the Aerovee was giving me. Power made it come alive!

That being said, the factory does not and never will endorse a Corvair conversion for any of their airframes. Rotax has a good option and there are others but money and installation becomes a factor. The final word I would say is to get as much reliable power on the nose of the airplane as you can afford, learn all you can about the maintenance & care of the airframe, and enjoy the ride. They are a blast to fly but they are not a C-150 so you will need some trsansition training.

Some videos for your consideration:

https://www.youtube.com/watch?v=0afcagd70UE

https://www.youtube.com/watch?v=Hg0fgs4cFuE

Dale
3.0 Corvair/Tailwheel

[pappas]

Having 2 150-Lb people is awesome for the Sonex. I built 2 Waiex's. One Legacy model with the Jab 3300 and a B model with the Aerovee turbo. The airframe is strong and capable, easy to fly and land and you will like it. I have flown quite a few hours with the normally aspirated Aerovee as well.

If I were to build a 3rd Sonex, (could happen), after having flown 80, 100, and 120 hp up front, I would choose a minimum of 120 hp, no less no way! With the current choices of engines it would be a Jab, a UL, or a Rotax. The Aerovee required more tinkering than I wanted to do and was just too hard for me to keep from leaking although I know others have done it. The Jab 3300 gave me no trouble and required only oil changes after the cht's settled in at break-in. The Rotax is the most prolific engine in light sport for a reason but really pricey. I have not flown an aircraft with a Corvair. But, I did own a Corvair, for less than a week. I hated it and sold it on.

If you worry about fuel burn, nothing says you have to have the throttle WFO all the time. The Sonex will fly just as well at 100mph as 150 mph. But if... if, you find yourself in need of more climb with a full load or in high-density altitude conditions, you can not get more out of 80-100 hp than 80-100 hp.

As a pilot with more than 30 years of building and flying ultralights and experimentals and a few more than one "off-field landings" due to non-dedicated aviation engine stuff...I would recommend an engine that was designed for airplanes from the first second that the designer's pencil touched the paper.

Get the most HP you can afford in a reliable aircraft engine. You will not be sorry. Remember the pilot' mantra..."If only my airplane could climb a tiny bit better, cruise a tiny bit faster, and go a tiny bit farther.... I would be happy with it!

[Skippydiesel]

I have a Sonex Legacy/Rotax 912ULS, with Airmaster Constant Speed Prop.

This is my first tailwheel aircraft and I agree with all those who said it is possibly the easiest taildragger to fly.

The down side of a small tailwheel is the tendency of the 4" to dig in to soft ground. My local grass field is dominated by nose wheel aircraft - after heavy rains, they are always flying days before I can even taxi. This is likly a combination of soil type, poor drainage and our local weather ,which is inclined to heavy cloud bursts, flooding the strip.

Most aircraft in this class, handle very diffrent to the GA's you have flown. Low inertia and less stability takes time to get used to. Get some transition training.

Cant speak for other Sonex, however the undercarriage is super springy, making anything other than a perfect landing, likly to deliver a bounce. Grass strips with uneven surface, increase the challenge considerably.

My Legacy;

Will not legally lift two adults with any more than 30L of fuel on board (no luggage). When you are looking at aircraft, be sure to get the correct (not aspirational) empty weight - this will determine how much you can carry, including fuel.

Space -
This is one squeezy aircraft. Pilot & passenger need to be on very very good terms. I consider my aircraft to be a 1+1, meaning it's really a single seater that can on occasion carry a second adult (weight & space).
Luggage capacity is extraordinarily bad.There is a, 18kg luggage space, volume about .25 cubic m, behind the seat. In my Sonex this is a roughly cubic shape carrier, with a zip lid (prevent escapes in turbulence) . The lid acts a a tray for maps etc. In addition, I have made a modification to allow stowage behind the back seat pan. It's not much, but it allows me to stash all those items that you might need, hope never/rarely to use (jack/tyre repair/tie downs/first aid/emergency rations/tools/etc). There is the option to do the same thing below the seat pan - may do one day..

FYI- I am about 60kg. when young, maxed out at 5ft 8"

Fuel
I don't have a front of canopy fueling point.
I have wing tanks (30L) & a fuselage header tank (40L) = 100L capacity. Being a tailwheel I can only fill the header tank to 35L, so 95L usable (fix this in the future). This gives a duration of 6.5 hrs (to empty) at 75% cruise power 5000-5200 rpm using around 14L/hr ULP

Without autopilot, she requires developing intuitive handling, to keep anywhere near straight & level - Sonex are designed to airobat so are not as stable as your GA training aircraft. Turbulence will see very quick & significant departures from your preferred altitude. These departures will not self return to original setting, like a GA aircraft, but require pilot input.

Economical & great fun to fly - planning on a trans Australia trip this coming spring.

[Bryan Cotton]

All good discussion. I don't disagree that more power is better, but I'm also happy with my AeroVee. Especially solo, performance is good. Two up it is ok, but better in cruise than climb.

Regarding the landing gear, it's no worse than a C140. It's not hard to do good landings but of course they are not all good, and so far my gear has been up to the task.

Avoid heavy aircraft. The 620 lb empty weight is a fantasy. Our Waiex is 673. There are a bunch of ~650 lb aircraft out there and that is awesome. There are some way over 700 lbs and be aware of what that does to climb performance, payload, stall speed, and landing gear loads.

I've never had issues with baggage volume. Weight becomes a problem first.

[Kai]

I got my polished DS SG Legacy airborne in 2005 with a 85 HP Jab 22A and 5 in wheels. Flying from a 1800 ft grass field, the power up front was just not sufficient- especially with two up. So in 2011 a 120 HP Jab was shoed in, which really did the trick performance wise- save for the fact that the thing was a can of worms both cooling- and maintenance wise, with all sorts of hefty SB´s popping up from the engine manufacturer at depressingly regular intervals. When finally parts sourcing (pistons and cylinders) became an issue in 2018, I picked up a time expired 2014 year R912ULS that I then had Edge zero time, with piston cooling (the fuel we get these days!), BB (1484 ccm) and EFI (no turbo- I´m a low down pilot). The thing now puts out 123 HP at 5800 rpm/29.92 in on the dyno. The airframe has a little over 700 hrs by now, with this EP915ECI closing in on 110 hrs. Save for scheduled maintenance and frequent visual checks, I have not touched it since installation. Empty weight with this engine is 680 lbs which includes a 10 gal alu seat back fuel tank, and I cruise it at around 125 kts at 4800 rpm/23 in. Fuel consumption is then around 4.5 gal/hr. Best climb with one up is 1500 ft/min. Flat out at 3000 ft it does 156 kts/5800 rpm with a fp 2b Sensenich paddleblade up front. It could probably do better with a cs prop, but those things are so heavy. As of now, I am very pleased with it, and have no intentions of selling. Compared to a Cub, it handles like a sweet old lady on the ground, but there is a hefty pull to the left at t/o: right rudder! My landings are at best average, but so far the gear is holding up-I make sure to check the angles every now and then. Someone tufted the Wings for stall characteristics a while back with no nasty surprises, and the main drawback of the viceless airframe is size- it could be another 4 in across the shoulders.

[EchoFoxtrot]

Thanks guys! Great insights so far. I will mention that though I rent a -150, I did my first 45 hours in an AA-5 which requires you to actually fly it. Baggage weight and space are virtually not a concern because all the XC would be to places where we could permanently stash a suitcase and a toothbrush. I think I'm hearing that I should wait and save for a 120hp and not expect to fly off of wet grass. WaiexB22, I'd love to take a look, I'll send you a PM in a bit here.