It is Sunday morning, April 22, and several of us are on our way to Cherry Ridge (N30) in the Poconos to go to breakfast. The air is smooth as silk at 3,000 ft and not a cloud in the sky! There is an Archer with two guys in it, a 172 with three and my Maule with one guy riding shotgun. Breakfast is great while watching planes come and go. After breakfast the pilot of the Archer wants to go to Arner Memorial (22N) and see the Seneca a friend of ours just bought. Since I have a GPS and he didn't bring his, he asks if I want to go and he will fly wing. Well, even though Arner is in the area, I have never had occasion to land there, so I said "Sure!" and off we went.

It was about 11:30 am when we took off and the sky was still perfectly clear. However, at 3,000 ft the ride was bumpy with noticable up/down drafts.

When we arrive at Arner the Archer goes in first. Now Arner is at 534 ft and the runway is 8/26, concrete and 3,000 ft long. About mid field on the north side are four long enclosed T-hangars sitting 90 degrees to the runway. Parallel to the runway, a little further out, are low hills that run the length of the field.

Before arriving at the field the local ATIS says winds are 270 at 6 and temperature is about 80 degrees. So we go in on 26. The Archer lands smoothly and my buddy radios back to watch for sink on short final. So when I roll into final I carry a little extra power to compensate for the sink. There is no noticable crosswind so I am not holding a wing down. A little past the threshold I roll out and let the Maule settle in. I get a nice little chirp and start my roll out.

Suddenly, I am being driven hard to the left towards the edge of the runway and my right wing is lifting fast! Caught by surprise I am thinking "What the .... ?" I release the brakes because I have only the left wheel on the ground by this time and slam the ailerons all the way over to the right. I am sure the left wing is going to catch and tear its self up while ground looping me! Suddenly, I am released, the right gear hits hard and I find myself bolting back across the runway towards the opposite side! I can't stop so I pick a spot between the runway lights and steer through them and roll out on the grass. My friend and I sit there trying to collect our wits. A plane waiting to take off radios to ask if we are all right. I say the first thing that comes to mind "Let me check my pants!". He replies "Well nice recovery anyway!" Boy, I sure do not think there is anything nice about that little event!

We taxi over to park by the Archer. He has not seen a thing. I check my wing tip thinking that there just has to be damage to that fiberglass drooping tip. There is a short grass stain along the back edge and that is it! It must have taken me an hour of walking around before I calm down.

I have no idea what happened. My best guess is that the wind piles up behind the north hill on fast warming day and rolls over occasionally. Then the T hangers funnel it through onto the runway for a brief burst. That would explain why I dropped so hard back onto the right gear. I must have driven through it.

Later, after the jitters subside and we fly back to our home field, the guy flying with me said he was just turning towards me to say "Nice landing" when this little incident happened. However the best compliment was that he actually got back in the plane with me for the ride back! I wasn't sure I wanted to be in the plane with me!

Rod, glad you didn't, and your still around to fly again. I miss my 180, but it's times like you just mentioned that I like my 182.

Fly safe.

Skystrider wrote:I have no idea what happened. My best guess is that the wind piles up behind the north hill on fast warming day and rolls over occasionally. Then the T hangers funnel it through onto the runway for a brief burst.

Two things come to mind:
If you landed shorter than the Archer and less than one minute after him, it is possible his wing vortex was still energized and the wind pushed it into the middle of the runway. It's a stretch, but even an Archer can put out a vortex strong enough to lift a wing and push you sideways if you landed just after him at just the right distance before his touchdown spot.

More likely, you hit a thermal just as it lifted off the ground, after it had gotten heated up in the lee of the hangars. It would have been very small but powerful enough to do what you experienced. Usually there is some rotation present, which would explain why you got thrown back the other way 2 seconds later.

I am convinced that several of the REALLY bad landings I have made in 35 years that had no other reason to be that bad were caused by this phenomenon. If there is no dust or leaves to be picked up it is an almost invisible process, and just because there were no clouds does not mean that the air was stable. If the air had been real smooth and the ATIS didn't lie (I got some great land in the Everglades for sale), then it must have been the Great God of Taildraggers giving you a swat just to ensure you stay humble!

Rocky

Wouldn't argue with any of the suggestions offered by Rocky, and would add this one:

Occasionally in conditions precisely as you describe, you'll see dust devils (small tornados) stirring up the dust here and there. The conditions you describe would be perfect for that as well. It's possible you just rolled into one of those just prior to its touchdown. They are impossible to see prior to touch.

These little religious moments are brought to use to remind us that we are mere humans, not birds, and that we can be smitten from the skys any old time. Or some stuff like that, anyway.

Congratulations on dodging the bullet. You've now used up one of those .

MTV

it has always surprised me how much turbulence you can encounter when at pattern altitude or lower on a seemingly calm day when the weather is warm/hot. glad no one was hurt and there was no damage

In OZ they call dust devils willy willy. That is apt as they will give you the willies when you are slow, but still making lift and find one like you may have.

Good on the recovery.

Dane

Mike, I'm sure one of the glider gurus will chime in here, but aren't "dust devils" just visual evidence of a thermal?
There were tons of them abound here today.

Rob,

A dust devil is a small cyclonic wind, whereas a thermal is simple air that is rising as a result of surface temperatures heating the air. A thermal can be a bit of a hiccup as you enter and/or leave it's effect. It is not cyclonic, however. A dust devil is a little tornado, with very quick changes in wind direction and velocity. A thermal has to be pretty strong to create that much energy right at the surface, since it is heating of the surface that's creating the rising column of air, so the energy at the surface is less than at higher altitude.

There is no reason the two can't be associated, but they are two very different beasts, and may not be associated either.

MTV

Rocky, I think you may be right about the thermal. It makes sense because the day was warming up fast. I had actually pulled a 360 prior to entering a left crosswind to give me more separation from the Archer. They were on the ground before I started downwind.

The thought that I missed some clues that I should have known really bothers me. I am still chewing on that.

When we departed the airfield the Archer went first and used 26. I pulled out on the taxiway about mid field to follow and the windsock was 180 degrees from the one at the start of 26! Just a plain squirrelly day!

Im going to throw a different theory into the mix. I have been tought and have observed myself that vertical motion of th air decreases almoat completely once less than 20 feet from the ground. Things can be brutally rough on final but most up and down motion dissapears once you are in ground effect simply because the ground is in the way. My theory is that you were simply hit with a powerfull gust of wind from about 85 degrees off your nose, allowing one wing to produce substantially more lift than the other and lifting it off the ground enough for the wind to catch the wing and lift it the rest of the way, the braking action on only one wheel contributed to the turn. By the time you put in opposite aileron the gust had blown out causing the violent landing back on the other wheel.

Im not saying that a thermal diddnt cause the gust of wind as air rushed in to fill the void that it left, bit I dont think your wing was lifted by the rising action of a thermal itself. Or it could have just been a gust of wind.

Glad you made it out with no damage, sounds like it was a hell of a ride.

Rob wrote:Mike, I'm sure one of the glider gurus will chime in here, but aren't "dust devils" just visual evidence of a thermal?
There were tons of them abound here today.

The relationship between dust devils and thermals has been debated for decades by glider pilots. My understanding from 1500 hours of soaring experience (although most of it was 20 years ago) is that as the thermal starts to lift off the ground it has to be replaced by surrounding air from all directions. If there is any wind present, there is a tendency for little vortices to develop. If the conditions are right (and nobody seems to know just what IS right) one or more of these little vortices may get bigger and stronger and become a dust devil. If there IS no dust, they are invisible. Once formed, they tend to take on a life of their own, and can go off downwind a long way from where the thermal was formed or the thermal column is still sucking warm air from the surface. If the surface heating is strong enough to support a column thermal as opposed to a bubble thermal, the surface effect of inrushing air will stay where the heated area is while the vortex goes off on it's own.

Glider pilots look for dust devils when down low and faced with a land-out because there is usually a thermal nearby, although many report nothing but moderate to severe turbulence impossible to center and climb in. The thermal may have already lifted off and be above them while the vortices are still on the ground.

Wind striking obstructions can also generate vortexes, which can be in any orientation, not just the vertical. Most of these last only a few hundred yards past the obstruction, but if that's where the runway is they can be plenty interesting.

There is very little scientific data on these things, because they are so hard to observe and quantify in an experimental setting, unlike wingtip vortices which can be generated on command and made to interact with a smoke generator on a regular basis for observation and measurement.

One thing I can say from years of experience is that the probability of encountering any sort of vortex goes up in tandem with the instability of the atmosphere....when it's more unstable, more vortexes are formed and they are more violent. Those of us who live along the coasts are lucky to have mostly thick, sluggish marine air and it can be a real surprise to encounter the much more dynamic air of the deserts and mountains, not to mention the effects of density altitude.

One helpful behavior that glider pilots learn early is to really scrutinize the landing area for any clues on wind behavior. This means at least a crosswind overhead and possibly a circle or two while looking for any subtle indications like wind patterns in long grass, tree leaves, water, etc., or just visualizing the flow of air around obstructions. It is often true that one area of a longer runway will be relatively uneventful for landing while a couple thousand feet further on it's pretty wild. Think about it!


Y'all be careful out there!

Rocky

Pretty elaborate explanations and/or theories .... I just say "it was squirrelly and I had to do some of that pilot shit" and leave it at that. I reserve my heavy thinking for subjects like why no one else realizes the whole universe actually revolves around me.

Eric

Eric,

Excellent points, actually

MTV

way to go Eric, Just do what you gotta do to keep the shiney side up. IE Pilot shit.

zero.one.victor wrote:Pretty elaborate explanations and/or theories .... I just say "it was squirrelly and I had to do some of that pilot shit"

I like to do pilot shit too! It makes me feel good when I salvage a bad landing or approach. I just don't like it when I'm about a second late and wondering "what the hell caused that disaster of a landing?"

Maybe I just have too much time on my hands in the winter, but I really enjoy thinking about this sort of stuff in the hopes that I can translate it someday into a good move or good decision that saves me from an embarrassing incident.

"A really good pilot is one who uses his superior judgement to avoid having to demonstrate his superior skill" ......Who said that first?

I have been taught the hard way that my skills are no longer superior, if they ever were, so the only thing I've got going for me is judgement......and that only took 35 years to learn!

Rocky

[quote="RockyTFS] .......... "A really good pilot is one who uses his superior judgement to avoid having to demonstrate his superior skill" ......Who said that first? ............ [/quote]

A good quote, here's a couple more.

Good judgement comes from experience,which you gain by using bad judgement.

Flying is a unique learning experience in that the test often precedes the lesson.

Eric

I put this humbling incident up on the forum a day after it happened because I thought I would get some feedback that would help me get more out of the experience (I am still soaking my pants to get the stains out!). I know I carefully read the other stories here and really appreciate the discussions and insights you guys pass along. Even the humor often has a lesson in it!

Okay, time to go do some more of that "Pilot shit". You gotta love how much is packed into those two words!

I may have a different take on this subject. I have had a couple of real bad incidences like this here in Haines caused by the wind rolling over the ridge beside the runway and boiling down the side of the hill. It crosses the runway in a series of looping rolls that will lift one wing and push down on the other then change wings a second later! Not a damn bit fun as you can't see them and have no idea what is happening untill you are right in the middle of it.

If there was even a small hill upwind of you or even a big hanger might do it, this could be your culprit.

Keep the shiney side up

Shane

Rod,
Don't feel alone. I have been in to Arner Memorial several times with my M6 (we bought a D-17 Staggerwing there) and the wind rolling off of the hills east of the runway can be the culpret. I have danced down the runway not so greacefully myself. My serious wing lift came at Hammonton NJ one day. A direct X-wind from the left, coming accross an open area, caught me coming in way too slow and I was about 2" from scraping the right wing. I goosed the throttle and kicked in massive left rudder, then as soon as the left wing lowered, kicked in the right. Since then I stopped using full flaps because of the little bitty alerons and carried a bit more speed (70 down final). Since not landing on sandbars, I had no problem in and out of any AP I went to. Regretably sold my M6-235 2 weeks ago. I will be Mauled again!

Bill