Sport Pilot Talk

Widgeteye · Joined: 19 Jul 2011 Posts: 10 Location: Amarillo, Tx

What are the pros and cons between low wing and high wing aircraft? Which would be best in this windy part of the country? I live in Amarillo on the high plains and the wind is a constant.
Thanks

drseti · Joined: 28 Nov 2009 Posts: 1390 Location: Lock Haven PA

It's largely a matter of personal preference, although high wing aircraft tend to be easier to land (that's because a low wing gives you a more pronounced cushion of air under you when close to the ground -- a phenomenon known as ground effect). Increased ground effect means an increased tendency for the plane to float on landing, if your airspeed control isn't precise. For that reason, I prefer to use low wing for primary flight instruction! (No, I'm not a sadist. I just think dealing with ground effect, and learning to control approach airspeed, from the start makes you a better pilot.)

Another consideration is that, landing in a crosswind, you can drop an upwind wing farther with a high wing than you can with a low wing. (In the extreme, with a very low wing, you could scrape a wingtip on the runway when landing in a slip.) Thus, with a strong crosswind, side slips to landing are more common in a high wing, whereas in a low wing, you're more likely to use a crabbed approach. Of course, no matter what kind of aircraft you're flying, you will want to have learned both techniques.

zdc · Guest

One disadvantage of a low wing model with a bubble canopy is that when it is sunny you bake like a cake [even with those shades on the top]. One thing some people overlook when selecting an airplane is ventalation. An airplane with poor air flow in the cabin can become quite uncomfortable on warm/hot days and contribute to motion sickness.

With a high wing you are sheltered from the sun and you can keep the door open when taxing. Doesn't sound like a big thing but in the summer it saves you a lot of sweat.

drseti · Posted: Wed Jul 20, 2011 7:07 pm Post subject:

zdc wrote: One disadvantage of a low wing model with a bubble canopy is that when it is sunny you bake

True, though mostly a problem on the ground. If you go the bubble canopy route, make sure the plane can taxi with the canopy open. Also, check for good canopy vents (mine has two in front, pluse a sliding window on each side of the canopy). Some LSAs and sport pilot eligible antiques have sliding canopies that can be left open in flight. Ercoupe 415C and Techam Sierra are essentially flying convertables!

zdc · Guest

Widgeteye wrote: What are the pros and cons between low wing and high wing aircraft? Which would be best in this windy part of the country? I live in Amarillo on the high plains and the wind is a constant.
Thanks

If we are talking about high vs low wing in the LSA catagory, in your part of the country, I would go with a high wing, maybe something like a REMOS that you can fly with the doors off. Look how close to the ground the wing is on low wing LSA models. Even if you use the crab method on x wind landings you eventually have to staighten it out and lower the wing into the wind. Some of the low wing model LSA's look as if it would be easy to strike the wingtip on the pavement.

If you are like most recreational flyers, most of your flying is going to be in the summer. If it is sunny. hot and windy I would select a high wing.

Jim Stewart · Guest Joined: 12 Oct 2006 Posts: 259

You can usually still exit a high wing aircraft if it ends up on it's back. That's the overriding safety concern for me.

Jack Tyler · Posted: Thu Jul 21, 2011 5:39 am Post subject:

Widgeteye:

Just putting 'low wing, high wing' into Google will produce a long list of discussions on this topic, just waiting for you to visit them.

Like discussing other fundamental design choices, it's easy to generalize accurately while also misrepresenting. E.g. I did a test flight hop on a low-wing LSA (one of Vans RV-12's) in Sebring where the temporary FAA tower was reporting a 90 degree cross-wind '15 gusting 20' with no wing-scraping drama...and that was true for every low-wing LSA flying in those cross-wind conditions at the Sebring LSA Expo. So...one factor to consider? Sure. A deciding factor? Hardly. Seemed to me, watching from 'Vulture's Row' alongside the runway, that the high wings had the harder time being controlled in those gusty cross-wind conditions, and I attributed that to their tail feather designs. Most high-wing LSA a/c have to be relatively short-coupled, and for low speed control and safety reasons, they have a LOT of vertical surface back there, both above and below the stabilizer. (Look look at today's Cessna 162 and consider how it was modified after its spin difficulties).

The 'bubble canopy' vs. hot summer weather is another such generalization, a reasonable caution to raise but hardly a disqualifier. I just flew an RV-9A several days ago with such a canopy (temp was 95F with CAVU skies) and the accordion-like shade device one sees everywhere now is very effective in reducing heat build-up. Having done all my flying while based in relatively hot/humid/sunny Florida, I'd say the best features for crew comfort have been the large air vents Paul mentions, a canopy that can be taxi'd while cracked open (which is possible with some tip-up canopies, as well), overhead shade protection of some kind, and being able to fly with a sliding canopy slightly open (such as we routinely did in our Grumman during the summers). Flying with open doors is great fun at 65 kts on short flights, but hardly appealing when doing a cross-country at 100+ kts.

Don't just think about the design influences as they relate to flying, either. There are structural consequences resulting from each wing design that you have to live with. I think that one reason I find high-wing LSA's to feel more confining and offer - in general - more restricted visibility is that the main wing spar has to be carried through the full overhead cockpit area of the a/c. Low-wing designs have cantilevered spars, which places the weight of the structure at a lower CG and makes the plane 'feel' a bit different in flight while opening up the cockpit viz. You'll also notice that most low-wing cockpits are placed a bit further forward relative to the location of the wing (than on Part 23 a/c like Pipers), which opens up a bit more 'underneath' viz to the pilot.

Altho' there are advocates for both wing designs, to me it's not about 'better/worse' but more about each design having its own benefits and consequences. And as you'll notice, Texas is no stranger to both designs. My hunch: Until you buy, there are many other variables that are more important for the student pilot: rental cost, location, number available for training, quality of instructors for each LSA type available, etc.

dstclair · Guest Joined: 06 Mar 2008 Posts: 212 Location: Allen, TX

Jack - well said. You hit all the points before I had a chance to hit reply :)

I fly a bubble canopy, tinted glass, out of Dallas. Ventilation on the ground is the key. I have a cheap suction cup mounted shade that works fine. Neither design is going to be 'cool' on the ground with the reflective heat exceeding 100 but both are OK once you start up the fan. It takes me 6 minutes from the time I start to when I rotate so I wouldn't make the cockpit temperature a deciding factor.

As one SP student has commented, winds in Dallas were in the twenty plus range from the spring to the current heatwave. Flying was more dependent on the skill of the pilot versus the location of the wing.

If you're buying, fly as many LSAs as you can and you'll find the design that works best for you.

saintlfd · Posted: Thu Jul 21, 2011 9:18 am Post subject: How's the RV-12?

Jack, I have to ask--what did you think of the RV-12?

Jon V · Guest Joined: 21 Apr 2011 Posts: 156 Location: Dallas...

zdc wrote: ... If we are talking about high vs low wing in the LSA catagory, in your part of the country, I would go with a high wing, maybe something like a REMOS that you can fly with the doors off. Look how close to the ground the wing is on low wing LSA models. ...

With appropriate disclaimers for my limited experience...

I wouldn't view high wings as an indication of crosswind ability. E.g. the Remos has a max demonstrated crosswind of 15kts - not very high at all. From what I can tell that is a result of the relatively undersized rudder. I've landed other planes in >15kts crosswind and I wouldn't want to do it in the Remos.

Besides.... If my napkin calculations are correct, high to low wing probably only amounts to about a 10-15 degree difference in max bank angle before tip contact. That's assuming the wings are 3' higher at the tip, which "seems" right but I don't have dimensioned drawings so YMMV.

Maybe it's my noobness speaking, but but if I've got to hold more than 20 degrees bank in the flare I'm probably going to find another airport with more favorable winds, and that's true whether I have an extra 10 degrees available before I drag a tip or not.

zaitcev · Posted: Thu Jul 21, 2011 12:57 pm Post subject:

The biggest thing that determines the demonstrated crosswind is the landing speed. With very low Vs0 mandated for LSA, they cannot have good crosswind capability.

rfane · Posted: Thu Jul 21, 2011 7:16 pm Post subject:

zaitcev wrote: The biggest thing that determines the demonstrated crosswind is the landing speed. With very low Vs0 mandated for LSA, they cannot have good crosswind capability.

That's why I prefer to use no flaps and keep the speed up in higher wind conditions.

dstclair · Guest Joined: 06 Mar 2008 Posts: 212 Location: Allen, TX

VS0 and demonstrated crosswind aren't necessarily related. My Bellanca Super Viking had a stall around 60kts and Cherokee 180 stalled at ~50kts. Both happened to have 17kt demonstrated crosswind rating as does my Sting which stalls at 34 kts. I believe the Tecnam Sierra has a demonstrated crosswind of 22 kts as well. All are low wings -- wonder if I have a bit of a bias :)

And, yes, demonstrated crosswind may not equal actual crosswind capabilities but most accept that it's a good idea to stay within the tested limits of the aircraft, otherwise you become the test pilot.

Jon V · Guest Joined: 21 Apr 2011 Posts: 156 Location: Dallas...

On the subject of "doors off": This AM I flew the Remos sans doors for the first time...awesome.

drseti · Posted: Fri Jul 22, 2011 3:53 pm Post subject:

dstclair wrote: And, yes, demonstrated crosswind may not equal actual crosswind capabilities

Very true. The demonstrated X-wind component is merely the crosswind that was present at a particular airport on a particular day, when a particular test pilot flew the plane using what he or she considered the normal techniques used by an average pilot. It in no way indicates the limits to the plane's capabilities. As a beginning pilot, you will want to do your landings with no (or very little) X-wind component. As you gain experience, your personal minimums will expand, until you are confident in your ability to handle winds up to the demonstrated figure.

Still later, you may learn that a particular airplane can readily exceed those limits, using a particular technique. But, it's best to verify that technique by going up with an instructor intimately familiar with that particular airplane, before trying it on your own.

It's good to know how to handle crosswinds in excess of the "demonstrated" value. Otherwise, you may take off one day with winds straight down the runway, and then run out of fuel while circling and waiting for the winds to again shift in your favor! :wink:

Of course, the best crosswind insurance is another airport nearby, whose runway is perpendicular to the one at your home field. It's better to tie the plane down somewhere else overnight, and wait for better winds, than to try to force the plane on the ground when the wind sock is sticking out sideways.