There are some with conventional gear. I have heard from others that Chris Heinz, the original designer, does not recommend it. Probably because the people this plane attracts are newbies like me, and because his lawyers told him to say that.
tom

zero.one.victor wrote:Has anyone built one of these (Zenith or Savannah) with tailwheel gear? Seems like a natural.
Usually 912 powered, eh?

Eric

Whew! Talk about a hijacked thread!

I finally got out to fly after weeks of single digit weather with a 400 foot ceiling and did some checking of the minimum radius data in the graph I uploaded. (This is in a C-180 with Micro Aero VG's)

I tried several wingovers from cruise (140) first, assuming that I could easily beat the level turn radii. Boy, was I wrong! I did the wingovers at cruise power, starting with a straight pull-up until about 60 kts, then rolling left to about 75 degrees and ruddering it around, recovering at about 50 degrees nose down 180 degrees from original heading and then letting the airspeed build back to cruise while pulling out at the original altitude. It seemed like I was turning on a dime, and the ground reference indicated that I was about 500 feet sideways.

Then I tried the canyon turn method, slowing to 65 kts with 20 degrees of flap in level flight, rolling into a 55 degree left bank while adding full power, pulling hard and dropping the flaps to 40 degrees. To my surprise, I could not hold altitude or airspeed, and ended up 150 feet lower at 80 kts.

I then tried again at the same speed with 20 degrees flap and full power but not changing the flap setting. It came around like on rails and right on altitude. I looked at the AI, which was right on 60 degrees bank and the altimeter steady at 6500 feet. Roll-in and roll-out were at max aileron deflection. It worked exactly the same on two more tries.

When I got home I dumped the GPS track and lo and behold the three steep turns at 20 degrees of flap beat the wingovers by some 200 feet!

The best I did was about 600 feet diameter at 6500 ft and 40 degrees OAT with an IAS of 65 bleeding off to 60 at 180 degrees of turn. This is pretty close to the prediction of the graph. The stall warning was going off as soon as the pull reached 2g's but the plane was rock solid with no difficulty holding altitude, unlike the full flap attempt.

Now I'm sure with more practice I could get closer to a hammerhead type of manouever with a smaller radius but I'm wondering if it would ever be something I could pull off without any recent practice in a tight canyon with no time to think about it. I remember thinking 30 years ago about a canyon crash: "If the guy had only known how to do a wingover!"

I now believe that a combination of the two manouevers will offer the best chance of a successful 180 in the aircraft most of us fly (PittsPilot excepted). If you have any excess airspeed add max power and/or climb until you are at the correct airspeed while getting as close to the appropriate wall as possible, lower the nose and roll to 50-60 degrees while adding half flap (at least in a Cessna), pull until the stall warning starts, then hold it just at that point until you have come 180 degrees.

The important thing to get from all this discussion is the critical importance of airspeed on turn radius; even 5 kts too much for your chosen bank angle can add 150 feet to the diameter. Another thing is that any bank angle less than 45 degrees will not cut it either.

Besides, this was FUN! Imagine some guy on the ground noticing an airplane moseying along towards him at just above idle power when suddenly ROOWWR!, he looks up and the plane is already going in the opposite direction! Well, on second thought, maybe we don't need anyone on the ground seeing us practicing this manouever, they'll probably call the cops thinking we've dropped a bomb or something.

Cheers,

Rocky

Rocky,

Yep, that's what I've found to work best. The wingover is a pretty extreme maneuver as well, which in a clutch situation might be more than most could pull off gracefully. Ungracefully done, it will result in a big nasty stall.

Also, why are you turning around in the first place? I have found it a rare occasion to be in a confined area, in clear air, then run into a wall of weather ahead. It happens, but it's much more likely, based on my experience, to be slithering up a canyon in LOW weather, and come around a corner to find the thing blocked. In that case, the wingover won't work, cause you probably can't climb.

I'll stick to my original level turn. Practiced just a bit, anyone with halfway decent skills can pull it off safely, and it works.

MTV

Hi everybody,
For what it's worth, a real chandelle is nothing like what the FAA PTS calls for. I'm sure you all know the history of the maneuver from WWI, and that it is a reversal maneuver. The basic elements are similiar to the FAA version in that the first portion is constant bank and the last half is constant pitch, but the turn is entered at Va and the maximum bank angle(ie..limit load factor) and is a very dynamic turn.
Also, if you do some research you'll discover that the turn radius for a maximum bank turn(Again pulling the limit load.) at Va is smaller than a maximum bank turn at 1.3vso. There's a great graph in "Aerodynamics for Naval Aviators" that illustrates this point.
I think the real take away message is that a turn near the performance limits of the plane is something that needs to be practised before it's needed. The thing we keep comming back to is that we need to be able to fly the plane near the limit in order to be safe in the back country.

Yesterday I went out and practiced some of these turns (at altitude), and I was really impressed with how tight my gps told me I was turning. The terrain database worked nicely because I could fly over a canyon at a safe altitude and pretend I was flying in it for the turn.

The problem I think is one of nerve. Practicing at altitude is fine and dandy, but it doesn't give any preparation for the mental strain of doing it close to the ground. Doesn't give you the same sight picture, either.

I'm not planning on doing it, but does anyone out there go out and practice minimum radius turns at real-life (death?) altitudes?

The way to gain confidence in a maximum effort manouever like this is to start just like Ravi did, at a nice comfortable altitude, get it down pat, then start adding complexity. Start with a poor or nonexistent horizon such as a cloud or mountain in the 90 degree quadrant (a good distance away of course), then maybe hide the airspeed or altimeter, then go to a lower altitude in flatter country, and only then start finding larger canyons (or ridges) to practice in with calm winds. When any given set of conditions makes you uncomfortable, it's a signal to continue practice at simpler and easier sets of conditions. I would NEVER suggest that anyone try to practice this at 500 feet AGL unless they had an acrobatic low-level waiver, in which case they probably wouldn't need to practice it in the first place.

One thing that has not been said yet in this thread is the virtual impossiblity of actually MEASURING a canyon's width accurately! You can measure it approximately with a topo or GPS, but that last plus or minus 100 feet can be a real thriller.

So therefore, the second most important thing about practicing these turns after getting the numbers and the feel of it down is to visually and/or mentally SEE and remember what is reasonable to expect at different density altitudes. Most of the VFR high mountain accidents involving tight terrain constraints might have been avoided if the pilots had realized just how much room is really needed for whatever manoeuver at density altitudes above, say, 10,000 feet. The graph doesn't lie, but who is ever going to use this graph in flight? The whole point of this thread is to get people thinking about and hopefully proving to themselves what is or IS NOT possible with a given set of conditions in their own aircraft.

So someday get up real high on a hot day next to a mountain and do a plain 30 degree banked 180 degree turn (away from the mountain of course!); I guarantee it will be a real eye-opener! If you work the math on the chart, you will see that you need roughly TWICE the diameter of a sea level standard atmosphere turn of whatever bank angle for the same turn done at 14,000 feet and 60 degrees OAT.

Y'all be careful up there! (Sorry, I stole that from John Deakin, next thing I know folks are going to start calling ME an ancient pelican.)


Rocky

One thing that has not been said yet in this thread is the virtual impossiblity of actually MEASURING a canyon's width accurately!

Looks like you pointed out a niche that needs to be filled. Come up with something like a horizontal fishfinder and make your millions!

The best way to turn in a canyon is not to be in a spot where you NEED to do one.

Like flying in bad weather, always give yourself an out. Recognise when your Aircraft performance starts to deteriorate from false horizon effect and use close flying one side to give enough radius for a turn. Using any wind effect can decrease turn radius if turning into wind, flying on the upwind side of a canyon can utilise updraughts for better performance. Getting stuck on the downwind side can increase your turn radius and give you unmanagable downdraughts.

Aircraft familiarity is also critical, don't try any of this unless your completely comfortable with your Aircraft and it's handling.

N6EA,

The AOPA ASF online program is a good intro to mountain flying concepts.

The video you described was, I believe, taken from an L-19 in Colorado a number of years ago. They were doing some sort of wildlife census or radio telemetry work.

Plane wasn't found for some time, when they found it, the film was still good in the camera, hence that last little bit of it.

The program is a good place to start.

I think the "established mountain flying courses" have priced themselves out of the range of a lot of little airplane pilots, frankly--and that's too bad-the "Basic" course is $2200. Don't get me wrong, I'm not suggesting that this would be money not well spent. My point is simply that's a lot of money for some training in your own airplane, and additional expenses are going to run that cost up to what??? $4000 before you're done, depending on how far you have to fly to get there?

I think these are great programs, but they are now, like a lot of aviation, catering to the big money end of aviation. Not everyone can afford that, and unfortunately, its harder to find a good mountain flying instructor for an hour or two of dual, because they don't have a web site, etc.

There is obviously a need for perhaps a little less rigorous, but certainly less expensive intro course.

Maybe the online course is a good start in that direction.

Everyone used to say, stop on your way into the mountains and get a couple of hours of dual instruction in mountain flying. In many cases, even an hour or two would help.

Learning to navigate via maps would also be a boon to most pilots.

Boy, do I see a near total inability to use maps today amongst newer pilots.

MTV

Slow down and configure the airplane before you get to the tight spot: 70 mph and flaps set to 20 degrees. Depending on the operating weight, 70 knots is a little over 1.3 Vso.

When the airplane is trimmed, roll smoothly into a steep, coordinated turn. This doesn’t have to be a maximum-rate roll—steady and smooth works here.

As you pass 30 degrees of bank, apply full power, and up-elevator to initiate the turn. Continue the roll to 50 degrees of bank. With practice, you’ll find a pitch attitude (generally a little higher than cruise attitude) that will maintain altitude. The idea here is to turn with minimum radius, while holding altitude. Keep pulling hard as the airplane turns, and at the 180-degree point perform a smooth rollout and power reduction.

The airplane should come around as if on rails. If it buffets a little in the turn, back off the pull just a tad. With full power, the airplane will tolerate a lot before it stalls. Practice at altitude to perfect the technique and to determine how much pull it takes. And remember, in actual practice, this is a last-ditch lifesaving maneuver. Done well, the airplane will finish at the same altitude that you entered the turn. Practice the maneuver until you nail the altitude every time.






This can be done but is a pretty violent manuver and quite frankly simply not necessary. Flying at the same speed simply roll into a 45 degree bank. The radius difference is negligible and it is one hell of a lot safer. Practice in a canyon near you and only getting in a canyon will tell you that if you need the difference between these two manuvers you screwed the pooch to start with. Even in my Bonanza flying at 100 mph, flaps 15 a 45 degree turn is a pretty narrow radius. You don't realize how narrow until you start going into ever smaller canyons, seeing how much room you really have and then thinking what putz puts himself into a situation where a full power 60 degree bank is necessary and a 45 degree bank won't work. If you're in that position you're gonna get what you deserve and I for one won't shed a tear.

what putz puts himself into a situation where a full power 60 degree bank is necessary and a 45 degree bank won't work. If you're in that position you're gonna get what you deserve and I for one won't shed a tear.

And presumably your passengers deserve it too. Thank you for providing all of us with a clear indication of your attitude, BM. I'd hoped BCP wouldn't need an "ignore" button.

CAVU

what putz puts himself into a situation where a full power 60 degree bank is necessary and a 45 degree bank won't work. If you're in that position you're gonna get what you deserve and I for one won't shed a tear.

The problem with your scenario is people get in trouble when a turn becomes necessary because the airplane won't climb out of harms way at full power and vx airspeed. I would assume that the decision to turn is rarely made while at cruise airspeed and power while in level flight. From what I can tell, both Sparky's and Berks accidents were the result of a stall from being behind the power curve. No violent manouvers are possible then, you just don't have the energy to do so.

BM,

What I described (and please note that I stated a 50 degree bank, not 60--and that is within the Commercial PTS, by the way) is SPECIFICALLY NOT a violent maneuver.

Go out, at a safe altitude and GIVE IT A TRY, before you make statements like that. Then try it in a canyon. THAT is what I advocated. Every degree of additional bank will get you around quicker, but if you are afraid of your airplane, just stay out of the mountains, would be my advice.

I don't fly Bonanzas, so I'm not an expert on them. If I flew one, I'd give this technique a try.

If it makes you happy to only use 45 degrees of bank vs 50 degrees, so be it, but don't call a procedure that is well within the Commercial standards "violent".

Darwin was apparently correct--to a point.

MTV

a64pilot wrote:

what putz puts himself into a situation where a full power 60 degree bank is necessary and a 45 degree bank won't work. If you're in that position you're gonna get what you deserve and I for one won't shed a tear.

The problem with your scenario is people get in trouble when a turn becomes necessary because the airplane won't climb out of harms way at full power and vx airspeed. I would assume that the decision to turn is rarely made while at cruise airspeed and power while in level flight. From what I can tell, both Sparky's and Berks accidents were the result of a stall from being behind the power curve. No violent manouvers are possible then, you just don't have the energy to do so.

Sparky's accident wasn't flying up a narrow box canyon below weather. I was there that day, I know what the weather was. They simply screwed up and got too close to the terrain and didn't have the performance to fly out of the downdraft. As for others getting in trouble clearly that's the problem. However what are you doing in the first place in a canyon that you can't make a 45 degree banked turn to get out of? Regardless of the weather. Your main problem in that instance is right between the ears. Just like the guy who crashed the 206 going into Schafer Meadows a few years back. He was in a place he never should have been, and our stupid governor at the time gave him a posthumous medal for helping one of the passengers while still in his seatbelt. I unloaded on the governor in an email after that was announced. But for the stupid decision making of the pilot those people would still be with us.

mtv wrote:BM,

What I described (and please note that I stated a 50 degree bank, not 60--and that is within the Commercial PTS, by the way) is SPECIFICALLY NOT a violent maneuver.

Go out, at a safe altitude and GIVE IT A TRY, before you make statements like that. Then try it in a canyon. THAT is what I advocated. Every degree of additional bank will get you around quicker, but if you are afraid of your airplane, just stay out of the mountains, would be my advice.

I don't fly Bonanzas, so I'm not an expert on them. If I flew one, I'd give this technique a try.

If it makes you happy to only use 45 degrees of bank vs 50 degrees, so be it, but don't call a procedure that is well within the Commercial standards "violent".

Darwin was apparently correct--to a point.

MTV

I have done it, it's simply not necessary. It's not the bank that's the problem, anybody can do even a 60 degree bank reasonably well. It's the going to full power while you're at it. That's what will get the average pilot in trouble. A regular 45 degree bank at whatever power you have to maintain your predetermined speed in this situation is more than adequate, allowing you to concentrate on the bank and the terrain

BM,
I wasn't saying anything about weather with Sparky's accident. I believe it went something like this. They got into a descending air mass that the aircraft didn't have the performance to fly out of, The Acft owner made a turn into rising terrain, Sparky took the controls at some point and tried to turn downhill, but some one stalled the Acft, Sparky dropped the nose to keep from crashing vertically. At least that is what I read, it may or may not be fiction, I don't know. The point is that there wasn't enough excess performance available for a high G turn of any type at any time once they realized they were in trouble.
I don't know anything at all about Berk's crash, but I would bet money that the 172 he was flying also was in a position to where there wasn't energy available for any high G maneuvering there as well. If your escape plan involves executing a high G maneuver to get out of a canyon, then I don't believe you have a good plan.
If conditions exist that can get Sparky in over his head, then conditions can exist that can get me in over my head, and I would say you as well, I am one of those people that believe that "except for the grace of God, there go I"

a64 and BM,

I think it's WAAAAY too early to speculate on what PRECISELY happened in either accident. I don't disagree with BM that of course they both got into flight configurations and positions which were not conducive to a successful turn, apparently. Apparently. But, that's about all you can say at this point, and the reports from the two in Montana are just enough different to suggest that there is probably more to that story.

BM,

So, you are stating that, to make a steep banked turn from a slow cruise configuration, the pilot should NOT add power? You may want to go on line and find a copy of a couple of basic aerodynamics texts, or take a look at your private pilot manual from way back.

When you redirect the vertical vector of lift of the aircraft in a bank, and a 45 degree bank is just plenty to do that, you have redirected a significant amount of your vertical vector of lift into a horizontal vector. Which means one of two things will happen: Either the airplane will remain level but slow, or it will retain speed, but descend. Neither of those options would have worked for JC and Sparky at least.

Adding power is your only option for maintaining altitude AND airspeed in a 45 degree or 50 degree bank turn.

And, there is a period at the end of that sentence, you may note.

But there is another, less widely understood issue going on here as well. Power ON stall speed is ALWAYS lower than power off stall speed. Granted, I'm not suggesting that you've said you should close the throttle, but if a little power is good, a lot is better, as far as keeping the inboard section of the wing and the tail flying. That is ONE reason to use FULL power in such a turn.

The second reason to use FULL power in such a turn is that these things often happen at high Density Altitude. You say you "were there" when JC and Sparky's accident happened--so what do you think the DA was then??

I'd bet it was well over 8,000 feet. How much power does that engine actually deliver (normally aspirated, 180 hp engine) at that high or even higher DA? The answer is NOT MUCH, even at full throttle.

So, jamming all that throttle in actually gives you a lot less power than you would have on a cool day. The point is, when you are out there practicing these things at altitude on a cool day, that engine is making a lot more power. And, even then, using FULL power is not, I repeat NOT a violent maneuver at all--in fact, unlike the wingover/quasi hammerhead maneuver that's advocated by some, including apparently Sparky Imeson, what I've described keeps the airplane well within ALL it's FAA specified engineering and aerodynamic limits and load factors. In the wingover/semi hammerhead type maneuver, you definitely exceed the certification basis of any standard category aircraft based on the bank angles incurred.

Again the key is to practice these things, and be PROACTIVE.

In this regard, I concur. You have to decide WHEN to turn around, in a timely manner--that is obvious.

MTV

a64pilot wrote:BM,
I wasn't saying anything about weather with Sparky's accident. I believe it went something like this. They got into a descending air mass that the aircraft didn't have the performance to fly out of, The Acft owner made a turn into rising terrain, Sparky took the controls at some point and tried to turn downhill, but some one stalled the Acft, Sparky dropped the nose to keep from crashing vertically. At least that is what I read, it may or may not be fiction, I don't know. The point is that there wasn't enough excess performance available for a high G turn of any type at any time once they realized they were in trouble.
I don't know anything at all about Berk's crash, but I would bet money that the 172 he was flying also was in a position to where there wasn't energy available for any high G maneuvering there as well. If your escape plan involves executing a high G maneuver to get out of a canyon, then I don't believe you have a good plan.
If conditions exist that can get Sparky in over his head, then conditions can exist that can get me in over my head, and I would say you as well, I am one of those people that believe that "except for the grace of God, there go I"

I don't think we'll ever know the cause of Sparky's/JC's wreck as they differ themselves on what both of them have said happened. Part of it is natural as two people in the same plane would have differeing stories. I agree with you that if your out is a high G, hopefully low radius turn then you screwed up long before you got into that situation.

BM: you're right , alot of these wrecks are due to pilots making poor choices, or at least letting circumstances overtake them without doing enough about it. However, judging from "if you're in that position you're gonna get what you deserve and I for one won't shed a tear" and a couple of your other comments, I guess you've never,ever screwed up. You must be the only one here who can make that brag-- I've screwed up many a time, just not to that extent. A64 had it right,"except for the grace of god...".

Eric

Yup.

MTV