The Ultimate Commuter Plane?
Text and Photos by Budd Davisson, Air Progress, Nov, 1975
Here’s a little airplane that, at the time, I figured would be a real winner. But, I was wrong. For whatever reason, the market didn’t go for it, which I think is a shame. Today, it would make a great LSA possibility, although the stall speed would have to be worked on. For years, I’ve always figured that if I were to need an airplane for commuting to a distant office, this is what I’d build. Plans are possibly available, but you’d have to go through the DA-2A group to find them.
After you’ve been around Leeon Davis or awhile, the thought occurs that maybe, just maybe, he got permission from that great Fed in the sky to design his own body. his own personality and his own thought patterns. He is, like the airplanes he designs and builds, possessed of nothing extraneous. Slight of frame. with an excellent strength-to weight ratio, he moves and talks with the deliberateness of a man not given to meanderings. He lives and performs. His airplanes do the same …in spades!
Leeon Davis and his unique airplanes have been with the homebuilding movement almost as long as it’s been a movement. He’s respected by all who know him. Unfortunately, not enough folks take the time to get to know him, or his machines. The Davis man and machine are not high profile entities. They don’t jump up and grab you by the wallet to sell themselves. It’s not that they don’t want to be sold. It’s just that so many others are jumping higher and faster that Davis is overpowered by their advertising hype. Leeon Davis works with what he has: enormous tenacity, limited finances and a fantastic eye for simplicity and performance in airplanes. And Leeon Davis succeeds.
The latest Davis machine takes all the basics of the “Davis design philosophy for cheap speed and crams them into one tiny little rectilinear package that epitomizes the performance and ease of building that Davis is always striving for. It also takes every single Davis trademark and scrunches them so close together that the new DA-5A could be a caricature of Davis design. For that matter, this could be Leeon Davis carved out of aluminum. It’s lean, fast, and has no hair (Leeon’s balding).
Leeon’s first airplane was a five-place monster. Then came the highly successful two-place DA-2A: an uncompleted four-place, and now the single hole DA-5A. However, regardless of scale, all of the airplanes have shared the same approach. Davis figures if you build it light you don’t need big engines. If you don’t need big engines, you don’t need big tanks. If you don’t need big tanks, the airframe can be lighter. Carried to the extreme, the Davis fetish for lightness would give him a lighter-than-air machine with wings.
He gets his lightness from several very obvious approaches. First of all, most of his monocoque areas, such as the fuselage, eliminate stringers and some bulkheads by utilizing straight line bends to gain the basic taper. He could have done the same thing with curves and gained a little weight, but that would have frustrated his goal of keeping it simple. His entire airplane can be whacked out on a bending break with no form blocks as would be required for rounded bulkheads.
The DA-5A landing gear is another area where simplicity and lightness work together. The main legs are streamlined tubing contained in a box that’s filled with rubber. Thus, the legs are rigid and the shock loads are absorbed by the rubber mounts. The nose gear consists of a couple of nested steel tubes with the vertical movement limited by a stack of rubber doughnuts resembling old Ford motormounts.
On the theory that most builders can bend tubing better than form fuselage frames, he has the cockpit area laced with ½ inch 4130 square tubing, which replaces any stressed aluminum members that may be too complicated for the backyard builder to bang out.
There are probably some advocates of the “sleek” and “sexy” that are totally turned-off by the cubic appearance of Davis’ designs. However, parked next to a piece of Wichita sheet iron, even something as small as a C-150, the Davis comes off looking as if it ought to have a glow plug sticking out of the lower cowl. When walking around it, you literally have to bend over to look at anything. Even the top of the canopy is less than chest high.
Leeon has great faith in his designs and the way they perform. He feels that any klutz who can get something like a Yankee up and down can easily handle his airplanes, and he proved it by letting me fly it. As I was standing on the wing (which made me tower over the airplane). he continued to sooth my fears by telling stories of how easily his son Harold, having only a student ticket, flew the airplane. So even I should have little trouble.
As I channeled my legs under the panel, Leeon adjusted the seatback to give me adequate headroom. Two or three times we slammed the lid to check the fit. and then quit when the seat was as far back as it would go. He said he was going to extend the fuselage 2 inches to give six-footers more room. The airplane is plenty wide, however. If you can’t wedge your backside into this fuselage, you’d be over gross anyway.
As I locked the canopy down, I had the some feeling I had the first time I was screwed into a diver’s hard hat. The windshield wraps around (storm door plastic, bent without heat) and forms a perfectly positioned viewing port. The fuselage and cockpit surround you like a spacious diving bell. For no particular reason, it is a very nice feeling.
Leeon had the cockpit setup backward …I always feel strange with a stick in my left hand and the throttle in the right. No matter, I figured if things got hairy, I could always change hands. The brakes are a single lever, which gets both binders at the same time (economy: one master cylinder instead of two). You keep the nose headed in the right direction through the super-direct nosewheel steering. The only hang-up with this arrangement is the turning radius is limited so it’s not impossible to taxi into corners.
The thing I wanted to know, however. was how did it fly? Leeon walked up to the front (one giant step), called for mags and brakes, flipped one blade on the A-65, as if he were firing up a Fox .35. I was soon trundling down the taxiway to go play test pilot.
Taxiing was a snap, as you’d expect. and the longish nose looked as if it would be a good reference when it came time to land. One thing I hadn’t given any thought to was the effect I was having on other pilots. I was lined up beside a Bonanza and a Baron doing my simple little run up (right, left. carb heat). As I taxiied toward them to await my turn, I found both airplanes full of smiling, pointing people who were busy smudging plexiglass with their noses as they looked at the toy airplane parked beside them. Both pilots beckoned me on, giving up their slots to watch me bounce across the tar joints to the runway. I smiled up at them and mouthed a “thank you.”
Lined up, I dropped the hammer (a tiny one for only 65 hp) and smiled a little as the sections of white stripe got closer together. At about 65 mph, I tightened my grip on the peashooter-sized stick to bring the nose up. When the nose came up, the airplane followed and I was climbing out at 90 mph as if I’d done it a thousand times before.
Forgetting to ask what the best rate of climb was, I picked 100 mph and kept it there as I wound my way up out of the pattern. The cockpit noise was very moderate, and I could almost hear myself as I whistled the cadenza from Victory at Sea while clearing for traffic.
The temperature was something else, however. Ground temperature was just a tad shy of 100 degrees and the combination of that plexiglass canopy and my hyperactive adrenalin pumps were running my personal head-temp off the scale. I untaped the vent Leeon had pointed out in the top of the canopy and promptly taped it shut again. With it opened, it sucked my hair out through the opening and tied it in multiple granny knots.
In normal flight, your hand appears as if it’s stationary. If you can see your hand move, the airplane has just done its fighter imitation and sucked you into a 45-degree bank. It’s actually a very nice combination. There is little or no chance of over-controlling because the forces make you think about what you are doing, but the travel is short enough that you can really make the airplane do your thing without pushing and jabbing.
Bringing the carb heat out, I pulled the nose up and waited. I don’t know what I was waiting for, but if it was a stall, I could have waited until my beard filled the cockpit. At full back stick, even with a little power, it felt so elevator limited that the best I could get was a wallowing mush. I was sitting there with the stick full against the stop, clawing through the air at about 60 mph and 1000 fpm down. There isn’t much buffet, so it’s up to the pilot to keep himself out of that mush area because there’s little warning other than an increasing sink rate.
An airplane such as the DA-5A is built to go places, not just run left hand rectangles around the local aerodrome. So, I motored around and did my best to imagine myself on a three-hour cross-country. Squirming around in the seat, I found that the slightly supine position with nothing more than two inches of foam between me and the aluminum was incredibly comfortable. Visibility was excellent, and the wing didn’t do much to cover up check points. It would have been nice to have a larger diameter grip on the stick. The stability is a little less than we’re used to in factory-built airplanes, although it’s better than many other homebuilts. Again, about the only airplane I could compare it to in this area would be the Yankee. Hands off, it will gently deviate, usually to the left and a little touch on the stick is needed to bring it back level. If you flew X-C with one finger on the stick, you could almost go to sleep in it. It’s pretty neutral in most stability modes. If you bank it, it stays banked for a long time. Displace the nose and the nose stays displaced for awhile.
I flew a series of climbs at different airspeeds trying to determine what its best rate of climb was. The first speed I latched onto was 100 mph which gave a solid 700 fpm, very respectable for only 65 hp in that heat. I dropped the speed in 5 mph increments and soon found myself getting 1100 fpm at 85 mph with plenty still in the bank.
Going the other direction, with power completely off, 85 mph gave a timed rate of descent of around 1300 fpm and a moderate glide angle. It fell right in there with a Cherokee in the approach configuration. It obviously didn’t really need flaps to steepen the glide angle.
The last thing I did before taking it back to the barn was to find three distinctly marked section lines (for you city types, a section is a mile long) and came down to 1500 feet to run two-way speed checks on them: I got exactly the same times going both ways which indicated either no wind or a 90 degree crosswind. I fiddled with my computer and came up with an amazing 144 mph. I didn’t believe it, so I did it again—twice. All three runs came up between 142 and 144 mph in fairly turbulent air. Now that’s what I call truckin’. especially at 4 gallons per hour. That means the DA-5A has all absolute range of about 600 miles on its 17 gallons.
Since it’s a dirt simple airplane, all that’s needed before aiming down final is looking for traffic and getting the carb heat. On final, the Cherokee-like sink rate made for a Cherokee-type pattern …short and with a bit of power. There were a few humps in the air and the Davis chopped right through them with a poke or two on the stick keeping things square with the world.
At 85 mph there’s plenty of flare, although the DA-5A is small enough and low enough that ground effect really makes those squared off wings work and there’s a slight tendency to balloon. Hold it off, hold it! Chunk! And the nearly rigid gear dropped onto the runway for an absolutely boring roll-out.
The Davis DA-5A is an airplane that will, or at least should, be immensely popular in the future. As fuel prices start to climb to $2 a gallon (Ed Note from 2007: that really sucks, doesn’t it?) and engine prices continue going right out of sight, we’re all going to look for alternatives. That’s the coming thrust in homebuilt aircraft…getting the most speed with the smallest engine. The engine will be the deciding factor.
There are lots of aircraft on the horizon that look very promising from the performance/economy standpoint: for example Rutan’s VariEze and Molt Taylor’s Imp (the BD-5 has been on the horizon so long we’re beginning to think it’s a mirage). But these airplanes depend upon brand new construction techniques, engines that haven’t really proven themselves in the air or configurations that somehow just don’t go down right with the traditionalists. That’s where the Davis will make its mark—with the traditionalists. Other than its butterfly tail, there’s nothing at all exotic about the Davis DA-5A. In its backwards sort of way. it’s a more comfortable airplane for many to be around because it doesn’t present anything that’s out of the ordinary or that hints of any kind of experimentation. It seems like a sure thing.
And the beat goes on—the more adventurous among us will be whittling foam or worrying about pusher prop efficiency and others will be listening to their engine’s beat with stethoscopic ears. In the meantime, Leeon Davis and his son Harold, will be enjoying their air. plane. They have peace of mind. That might be because that’s just the way they are, or it might be because they know in their airplane everything works. They can count on having a lot of the old line conservatives, the middle mass of American aviation, following them. They look as if they’ve found an answer to the key question: How can I fly fast and cheap? Build a Davis! BD
Wingspan …………………………….. 15 ft 71/4 in
Length ……………………………………. 15 ft 9 in
Height ……………………………………. 4 ft 5/ in
Wing Area ………………………………. 57.2 sq ft
Empty Weight …………………………….. 460 It’s
Gross Weight ……………………………… 775 Ibs
Useful Load ………………………………… 315 lbs
Fuel Capacity ………………………………. 17 gals
Wing Loading ………………………. 13.5 Ibi sq ft
Power Loading ……………………. 11 11,9 lb/sq ft
Cruise Speed …………………………….. 140 mph
Engine Continental A-65