Cross-country with two aboard: Tricks for making it work?

[vigilant104]

The Sonex is a great, versatile plane, but every plane must be a basket of compromises. To get sporty handling, light weight, and good performance on 80HP, we give up some room and payload. With one person aboard there's plenty of room and weight capacity for traveling, but it'll be a lot more limited with a passenger.
So, I'm wondering how folks have maximized the utility of the Sonex for trips.
1) Where to put stuff? The cargo area seems large enough for some changes of clothes and things for a short trip, but with 40 lbs back there, 360 lbs in the seats, and a light Aerovee under the cowl, I'd be concerned about CG at low fuel levels. Are there accessible nooks and crannies in a more forward spot? (the space forward of the seat/below the knees?
2) Packing light: This will be key. I'll have to bother my backpacking pals, but any tips would be welcome.
3) Other: It probably makes sense to mail/UPS the bulky/heavy stuff to Grandma's house rather than take it with us, and do the same thing with any treasures/gifts found during the trip.

Thoughts/experiences are solicited. I know the Sonex isn't a C-172, but I think there are probably ways of doing minimalist cross-countries and enjoying that 4 GPH fuel burn.

Mark

[MichaelFarley56]

Hi Mark,

I'm sure you've read lots of stories of people doing cross countries, but as you said a lot of them are normally solo. Do you have any specific flights in mind you want to eventually do? I do think the 40 lb limit still allows a lot of stuff to be packed in the baggage area. I've seen lots of people really pack that area full of stuff.

In my opinion, the bigger challenge may be center of gravity, depending on the individual plane. Tri gear planes may be a little better with more weight in front. Are you still heading down to look at the Sonex in Texas? Good luck!!

[vigilant104]

Mike,
Yep, the CG issue might be a factor. If we could get 40 lbs in the baggage area and stay within CG, I think we'd be satisfied with that.
Planned trips: We'll have to see how things go, but maybe a "long" 700 mile trip to see family in Mobile, AL. That's about 5.5 hours in the air, plus a stop for fuel etc. If my bride and I are still talking to each other after that, maybe we'll consider other jaunts!

An aside: I also do some traveling for business, but that would be solo. I've given some thought to that, and it turns out that 600 miles would be the limit for these trips regardless of which plane I owned/how fast it was. That's because, without an IFR panel AND "flight into known icing" capability, I'd always need a backup mode of travel for these "got to be there tomorrow" business trips. And, since a commercial ticket might be unavailable or prohibitively expensive when bought on the date of travel, travel by car is my only alternate travel mode. That sets my practical limit: 600 miles. It wouldn't much mater if I had a Cirrus or a Sonex, it would be the same for this set of circumstances.

Mark

[dcstrng]

Okay, I’m imposing on a thread already in progress, but what the heck… As a new plans purchaser (they’re not here yet) I’m sorta of looking at the same issues.

From what I’ve seen, I look at the Sonex family as sorta of a Miata or Harley… superb for solo, amusing for occasional joyriding or impromptu overnight with a grandma or one of the grandkids, but for my purposes I think any serious cross-country endeavors will be solo, or on rare occasions with one of the younger grandkids.

Assuming my presumptions to be halfway correct (heck even when I used to herd Cherokees and C172s it was rare for anyone to ride with more than an hour at a time…), then I figure CG isn’t a big issue because any serious baggage will probably be in the seat beside me. Packing light is easy – I’ve ridden many thousands of miles cross-country (am an Ironbutter although I don’t ride as much as I used to), but I’ve never had much luck with long-range riding two-up and doubt that the Sonex was designed to do much of that either…

I figure once built, the Sonex will likely be my grandma-chaser for my golden years – she’ll go by Delta and I’ll pop in wherever she is, as I can get free from work…

Thoughts ???

-- Larry

[vigilant104]

Larry,
You wrote:
"I figure once built, the Sonex will likely be my grandma-chaser for my golden years – she’ll go by Delta and I’ll pop in wherever she is, as I can get free from work…"

Maybe that's what I was getting at with the "send the baggage ahead separately" idea. (That's a joke. If my wife ever logs in here and sees that, I'll never have to worry about flying with her again! "I don't mean you, honey!")

I

[GWMotley]

I have done a little cross country solo. I made a 4500 mile trip last month from Colorado to Florida and back last month. While it can be done, it is a little bit of work especially VFR. What works for me is to pack a small suitcase which I can set next to me. This makes for a good arm rest anyway. Then I can put the bulky, but light stuff in the baggage area, such as canopy cover, jackets, flight bag, tie downs, etc. I can not however, see flying more than an hour with an adult in the seat next to me unless " child like in size". This is a personal problem for me as my new girlfriend is tall and not child like in size. :). I know some have even secured things along the flap tube on the floor as your legs would not notice any objects there anyway.

[daleandee]

Having owned a Sonex with an Aerovee I personally don't think it makes a very good cross-country airplane for two people of my size (195 lbs) with luggage and full fuel. I had flown mine from South Carolina to Tennessee twice for the ASA meeting solo and it performed fairly well. But if it had been at gross weight trying to get over the mountains it would have been working the little Aeroveee extremely hard. Most of these are coming in about 650 lbs empty. Add two "FAA sized" people, 40 lbs of luggage, and full fuel and you are 26 lbs over gross. Trying to get to 8K over the mountains would be a challenge if your climb rate is down to 2-300 fpm, meaning that you would be running the engine WOT for 30-45 minutes in a climb. They don't cool well enough to do that on a warm day. It was a great cross country plane but I never felt comfortable enough to try to take someone with me on that trip.

I now have a "Cleanex" i.e. a Corvair powered Sonex. I didn't have Jabiru 3300 money and the Corvair, IMHO, has turned out to be a better option. It is smooth, powerful, cools very well, and the cost was about 1/2 of the Jabiru 3300. With the battery in the tail the CG is such that full forward CG is with a minimum pilot weight of 180 lbs, full fuel, and no luggage. There is no loading scenario (within reason) where the CG goes too far aft. The Corvair is heavy. My gross is set to 1250 lbs giving me a payload amount of 504 lbs. So with two folks about my size I can carry 12 gallons with 40lbs of cargo or a bit less luggage and fill the tank. If I would not have added 20 lbs of paint it would have been even better. 8~)

If you have Jabiru 3300 money, or if you can get Jabiru 3300 money I'd suggest that you seriously consider adding more horsepower to your aircraft if one of your primary purposes is cross country flying. Besides. you'll love the speed and the sound is just another bonus.

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
22:30 hours - Phase One
Status - Flying

[dcstrng]

Dale your configuration intrigues me as that is where (I think) I am aimed; Corvair. Plan on a modest-budget 164 plus 0.030, with the usual OT-10, but that’s about it other than front-bearing… I’ve waffled on which aircraft over a couple of abortive projects (I’ve got more money invested in airplane plans than some put into their instrument panels I’ll bet), but the engine is coming together -- albeit, I’m having the bottom end-built and completing the rest myself.

Notwithstanding the weight liabilities of the flat-Chevy, the overall numbers work for me – solo. Although I suspect the Monnets calculated the slick design for overall speed as much as anything, it also seems to me to be pretty efficient – as they’ve noted, Wittman-esque. I don’t think I can declare above a 1150 gross and stay within LSA stall specs (with a straight face), but that’s OK because the only time I’ll be heavily fueled will doubtless be solo and I don’t figure my conservative power configuration will be asked to turn out more than 90-95hp anyway – powered more in the Bernie Pietenpol motif. But I’m reassured seeing the several successful power alternatives out there – mine is just on a pretty-fixed retiree’s budget.

-- Larry

[vigilant104]

To derail my own thread:

I don’t think I can declare above a 1150 gross and stay within LSA stall specs (with a straight face) . . .

The math shows you might be okay on the LSA stall specs at higher gross weights. The Sonex literature indicates a clean Sonex weighing 1100 lbs stalls at 45 MPH. If that's right, then the same Sonex weighing 1200 lbs would stall at 47 MPH. This meets the LSA criteria of a clean stall speed no higher than 51 MPH (45 KCAS).

The formula is:
Vs new = Vs old weight x √(new weight / old weight).

So,
Vs (at 1200 lbs) = 45 x √(1200/1100).
Vs (at 1200 lbs) = 45 x 1.0445
Vs (at 1200 lbs) = 47.0025

Of course there are other factors to consider, too: If the CG is well forward then the stall speed will be higher (due to the required downforce from the tail). And we're just talking about stall speed here, there are other factors to consider (local strength where this additional weight is carried, climb capability at higher DAs with the additional weight, etc.)

It would be an interesting design exercise to run the numbers on a "stock" Sonex in which the (stock) wings plugged into short stub wings (approx 18" each) on the fuselage. That would give about 13 more sq feet of wing, a bit more span (slightly better climb, maybe higher cruise speeds at altitude), a place to store a few more hours worth of fuel very close to the CG or a handy storage spot for some gear (reach in from the cockpit or use wing lockers). The stubs would also provide a handy spot for simple, light "pull and twist" wing fold hardware and an easy place to reach all the required linkages for folding. And the plane would still be narrow enough to fit in a standard trailer with the wings back. The additional stubs would add weight of their own (??30 pounds total?? An existing Sonex wing weighs about 58 lbs per side IIRC), but the tradeoff in utility might be interesting. We should expect slower roll rates and maybe a bit more bumpiness in rough air when flying solo. And if the tail would need to be bigger as well, then the whole exercise quickly becomes impractical.

[daleandee]

Hi Mark,

The math for a 1250 lbs Sonex gives a clean stall of ~49 mph. But you are correct other factors play into this. I've not yet done gross weight testing so I don't know what mine will test at but I'm certain it will be less than the LSA 51.8 MPH limit. As far as structure strength, run the numbers on the G-loading for aerobatic weights (6 Gs @ 950) and then run them for 1250 gross weight and you will find that you still have margin at the 1250 gross weight. In fact the margin is slightly more than the +4g to –2g for the Light Sport Aircraft category manufactured in compliance with ASTM. As experimental our aircraft don't have to comply to the ASTM standard so it's nice to know that even at 1250 gross they do.

Sonex says their design is tested to Part 23 standards and the Sonex factory specs given on their “competition comparative” page says:
+6 / -3 G Aerobatic and +9 / -4.5 Limit Load Factor. The other factor is speed. As with the Jab 3300 so also the Corvair has to have a cruise RPM limit to keep the speed Light Sport Compliant. At the builders recommended continous power of 2800 RPM I'm ~135 IAS but again I have more testing to do.

At the end of the day most of my flying is solo. With myself, 40 lbs of luggage, and a full tank I come in about 1075 lbs. I'm not here to sell anyone on a Corvair. I'm just giving my opinion of what works for me and get the truth out for others that might want to consider the option.

BTW, thanks for your input. Some of the numbers you gave earlier on has helped me in my research with this project.

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
22:30 hours - Phase One
Status - Flying