I don't do alot of flying to actually go somewhere, so most of my flying time is spent practicing the basics: stalls, s-turns, turns around a point, touch-n-go's with short and soft field set-ups, etc... I find that it is more fun to try to improve my skill at those things then just going from point A-B, landing at B, and then coming home again.

I do make a point of practicing stalls regularly, although I can't really say why because I've never had one occur unintentionally. Maybe it's because of that brief but distinct sense of urgency that you get when the stall first occurs or maybe it's because of all those crashes on take-off and landing that I read about in the back of GA News. Who knows. Anyway, it can't hurt to practice.

Joe in MT.

I'm on the road in Colorado, but I will chime in:

I think practicing stalls and slow flight are invaluable practice. I'm no expert, but I think that in our little corner of aviation-- flying the backcountry-- slow approaches and high AOA flight conditions are the norm. Constantly inducing stalls and close-to-critical AOAs and slow flight can only help you know what to expect on a slow appraoch where you might no be able to make it with much of an airspeed safety margin and the need to stay perfectly coordinated is of great importance.

When I get home I think I'm going to definitely practice some of this stuff cuz I'm pretty rusty.

I couldn't disagree more with whoever called it practicing stupidity.

As has been very well stated the low slow end of the flight regimen is right on the edge of a stall most of the time. While actually being in a stall may not be of supreme value learning to recognisee all the symptoms of a stall is.

Next time you practice stalls see how long you can hold the plane right on the edge of breaking over and still maintain some degree of control to all axis.

I don't see how anyone can learn to recognisee all the signals of a stall unless you actually go through the whole process and stall the plane. Getting comfortable with this and with recovering from it just might allow you to recover from an un intended stall some day.

Shane

Looking at this debate from the middle of the fence it seems each side has its points. From the stupidity side of stalls, I think that taking off in any aircraft, climbing 5,000 feet then pulling the power back to practice stalls could be considered ill advised, maybe stupid.
Its not good for the engine no matter what engine you fly. Gas powered piston engines like consistency, they like to be flown the same way every time. 200's 320's 360's all are portraied as being bullet proof and they are, if flown within the normal operating range and temps.
I personally think that practicing stalls and slow flight is good and useful. I prefer to practice stalls in uncoodinated flight up at altitude to get a feel of the airplane in real low and slow conditions. I think that most pilots can recognize the basic pre-stall condition. Don't be affraid to take the airplane to a nose down pre-spin. When a stall can bit you is when you are hanging the plane on the prop in a deep canyon and a gust of wind turns you sideways.
The way I look at it, I am still a student pilot and any chance I get to learn more about the airplane in controlled conditions is time well spent.

Practicing stalls won't hurt your engine a bit. If what was just stated about engines, we'd all be in trouble. Every time you land, you generally close the throttle at some point.

Ya can't stay up there all the time,

MTV

Anything that I have tried that reduces stall speeds, VG's, droop tips, flaperons, increasing flap angle etc; seems to make the stall a little more abrupt. Maybe because when you get slow the difference between just barely flying and stalled is the same percentage, but the MPH difference is smaller because of the slower speed to start with?
STOL devices seem to work best when put on an aircraft that has gentle stall charateristics to begin with.
If a stall scares you and you want to put on a STOL kit to avoid being scared, don't. You will probably be even more scared in a STOL equipped airplane in a stall.
If you are comfortable flying your aircraft in the pre-stalled condition and want something to get you into and out of even smaller fields, then a STOL kit is for you.

On the engine. I will admit that recip's seem to like consistancy the best; But the recip engines that I see that seem to consistantly make TBO are on trainers. It would seem that this should be the worst thing you could do to an engine. Wide open - off - wide open - off, repeat forever. I think they make TBO because they are flown frequently, so the best thing you can do for you, your airplane and your engine is to fly several times a week.

AH64,

Exactly! You are 100 % correct on the engine thing.

As to STOL kits for the 170, you will not be able to install a Robertson STOL kit on a 170. They never produced a kit for either the 170 or 172. The 182 was the smallest aircraft they built a kit for.

If you are interested in a STOL kit for the 170, my recommendation is to install the Sportsman STOL kit.

That kit installs a rather aggressive leading edge cuff and aileron gap seals. It is available and stc'd for the 170.

While I don't totally disagree with AH64 on the general effects of STOL kits, you will find that the Sportsman REALLY almost does away with the stall in Cessna aircraft. The airplane will simply nod it's head, you can put your feet on the floor, and drive the plane around in a full up elevator condition with almost no attention to rudder. The kit also slows the stall speed by at least a few knots.

I am a big fan of the Sportsman kit. I have also flown the Bush STOL kit on a 170, and while it does modify the characteristics of the plane a little, it does hardly any real good, in my opinion, and costs just as much as the Sportsman to install.

The VG's on these airplanes, are in my opinion, a waste of time and money. And I have a set on mine .

MTV

mtv,
I'm not trying to split hairs here, but what you describe may not be fully stalled. On the Thrush AG plane we build when the hopper is empty it dosen't really stall. What happens when you slowly pull back on the stick fully with the engine at idle is that you get a prounced pre-stall buffet and the nose will climb and drop repeatedly. You still have full control both in ailerons and rudder and can even make standard rate turns with the stick against your gut.
With the Thrush what is happening is that the inboard sections of the wing are stalled, but the tips and at least some of the ailerons are "flying" so that you still have control.
With our AG plane it's the "accelerated" type of stall that will get you. It's one way to really fully stall the entire wing and possibly just one of them at that.
I haven't flown your 170 of course, but I would bet that the STOL kit you have is so good that it keeps an appreciable amount of the wing "flying" even when the airspeed get's so low that the portions of the wing that are still "flying" cannot support the aircraft, but will still provide some control.
If I'm right then be wary of conditions that could cause an accelerated stall, sometimes all it takes is turbelence or sudden wind shifts or any number of things in mountain flying. Even a docile cherokee 140 can bite in an accelerated stall.
Two things I feel pretty sure of. If it fly's, it can be stalled. If it can be stalled, it can be spun. I admit that in some aircraft you may have to operate it outside of the factory limits to get it to stall / spin, but they all can.
on edit: VG's are worth the investment in my opinion if your airplane has a problem to begin with, like maybe lack of ailerion authority on an early model Maule M-6, but if you have a good handling airplane to begin with then VG's aren't going to do much for you.

Just to say something about the VGs. We put them on our pacer and it made a huge difference by lowering our stall speed by at least 7 mph.
So for our airplane which is similar to the early maules it made a huge difference.

I've been following this thread with interest, and thought i'd chip in.
Firstly, I feel that practicing stalls is a 'sensible' thing. It makes sense to actually have an innate understanding of how your particular aircraft is going to respond when it doesn't want to fly any more. Even a cursory understanding is important. And as indicated previously, there is only one way to find that out.
A64, you are on the money with your engine thoughts. I just wrote a whole diatribe on the subject, and am now about to delete it. Work it regularly, don't let it sit. Enough said.

Secondly, on MTV's comment regards the Sportsman Stol Kit. We've got a Sportsman kit on the 185, and it makes for the most docile of Stall characteristics. At low airspeeds, you retain positive control authority of the aircraft; it seems happy to mush its way along, until you decide to change the situation.

There's a blurb about the Sportsman Stol Kit on the Stene Aviation Site , including 170B figures. http://www.steneaviation.com/sportsman.htm

AH64,

Note in my post I said that the Sportsman kit "almost" does away with the stall.

You are absolutely correct that you can aggravate the stall, by accelerating it, in any of a number of ways. That said, the Sportsman equipped aircraft behaves with great docility (if that's a word), even in a badly aggravated stall.

Pacer--There is no doubt that VG's have VERY different effectiveness on different airframes. Best thing ever invented for a Scout, for example. Pretty good thing on a Cub, all in all. I have no experience with them on a Pacer. On my 170, they are a waste of money, in my opinion, but that does not reflect on their effectiveness on a Pacer.

That said, how did you derive your stall speed change? If you did it purely as indicated airspeed, you are fooling yourself. The VG's do allow one to drive the airplane to a slightly higher AOA. That in and of itself will change the angle of the pitot mast enough to indicate a significantly different speed.

The only way to reliably measure stall speed differences is with a four cardinal heading check, using ground speed from a GPS, unless you have a flight test probe on your airplane.

Not challenging your numbers, just asking the question.

As I noted, my 170 did not change stall speed appreciably with the addition of the VG's. Maybe a knot. Neither have a couple of other airplanes I've flown before and after VG's-again, a knot or maybe two.

Doesn't mean they don't do other good things for the airplane, though. The claims of a certain brand of VG manufacturer are a little, er, fictional, in my opinion. Ask them whether those numbers were derived from an airplane with a calibrated flight test airspeed boom, and they'll probably change the subject.

Note that the way they are getting the FAA to approve VG's is by demonstrating that the VG's "do not create any unusual or adverse flight characteristics". In other words, they certify to the FAA that the plane flies pretty much as it did when it came out of the factory.

If they want to "OFFICIALLY" claim a reduction in stall speed, they would have to do what Robertson did when they STC'd their kits, which is a full flight test program, with a calibrated test boom, AND the production of a FLIGHT MANUAL SUPPLEMENT, which gives different numbers for the stall speed than what is offered in your POH.

Do you have a flight manual supplement for your VG kit?? Didn't think so. Stall speed is a TC'd deal. If they claim the device reduces stall speed to the FAA, they are going to have to produce and have approved a Flight Manual Supplement.

Again, that does not suggest that VG's are bad, or that they aren't in fact the greatest thing since sliced bread on many airplanes. I like em on some aircraft, but not because of any change in stall speed, but rather because of the change in STALL CHARACTERISTICS. That's where they shine. Again, that's my opinion, and we all know what those are worth.

Just remember that manufacturers can claim anything in their advertising. What they demonstrate to the FAA is more realistic, though.


MTV

My experience with Sportsman STOL is a bit different than above. I have a C180 with stock wings. My buddy also had one with stock wings. He wanted to go slower so he installed the Sportsman kit, but first we went out and stalled them side by side. Mine is 100 lb. heavier and stalled fractionaly sooner than his, almost no difference. After he put the kit on we went up again and there was no noticable difference from the first test. So then my buddy put VGs on and again no noticable difference. He thinks he has a better role rate on the edge, than he did before but his plane is about 8 knots slower in cruse now, though it was a bit slower before. We did the test flights at light weight, so there could be some difference there but I suspect that I can go anywhere my buddy goes. So I'm not in to wing mods much, though I flew an R STOL 206 once and it seemed like it did pretty well.................Ron

Redbaron,

From the sounds of it, I'd bet dollars to doughnuts that whoever installed your friend's Sportsman kit installed it WRONG.

I have flown several airplanes before and after, including two extensively, as in thousands of hours. None of those airplanes slowed measurably, and that's four ways with GPS, on multiple occasions to verify.

I'd bet they installed the kit without enough "droop" to the leading edge.

Too bad.

MTV

I wouldn't know anything about the installation and we didn't really do any speed comparison until after the mods, it might have been slow before......Ron

It is entirely possible to install the Sportsman cuff at a different angle than it was intended to be installed at.

If one were to install it at the wrong angle, I think you could easily achieve the results you describe your friend had.

On the other hand, the several Sportsman equipped aircraft I've flown all had noticeable stall speed reduction, and very nice handling characteristics at high AOA, with little if any, cruise speed reduction.

MTV

Hi everybody,
On the stall thing I'm a proponent of stalling the plane every way the manual allows. Especially turning, accelerated stalls. If you have to think about the recovery, keep practicing until it's natural. Since I started flying the Pitts, I've found a whole new world of stalls and spins. The really good aerobatic guys can feel depth of a stall better than any pilot group I've come in contact with.
As for Vg's I put them on my Pacer too, and noticed improved low speed aileron, and more importantly elevator performance. Stall speed tests were inconclusive. I can't prove it but I think they increased my ROC after takeoff too. (Delayed boundary separation at high AOA leading to a reduction in induced drag, and therefore an increase in excess thrust horsepower?)

Hello, all, Im new here, Basically i have been spending a few Hrs flying a ICP Savannah before buying my own STOL aircraft, and im From OZ.... anyway back to Stalls..

Fistrly i believe Stalls and how they are handles is overly complicated, as said before, any aircraft can be stalled, but the stall, i feel, is greatly mis-understood.

The Stall is simply a function of AoA. nothing more. with enough time in any aircraft, the stall will come at a certain stick position every time, in the Savannah after a few hrs i came to learn instinctively where the stick position will be to induce a stall.

I am willing to bet, that everyone was taught, never stall in a turn, or at least to never practice it... now. remember that the stall is a function of AOA only, when in a turn., steep or lower rates, when the stick reaches its stall point and the wing begins to stall, the natural reaction will be to roll it straight, this will be dangerous as it will change to AOA on each wing and create a difficult and very dangerous situation, the simple way to recover is to simply push the stick forward from its stall point, this will lower the AOA and recover from the stall. with practice it becomes instinct and recovery will come with little or no altitude loss.

they way i was taught this initially was to begin to do my aerobatic rating with a well know instructor, he demonstrated this stall recovery technique,
by removing the mystery and myth about the stall, and teaching just how simple it is, AOA and stick position only, he then went on to demonstrate stall recoveries from almost every conceivable attitude, including a very steep climb (70deg up) and from the inverted..

even inverted going over the top of a loop, stall recovery is simply push the stick forward, just a small movement to get it from its stall position... returning the AOA to just 1 or 2 degress below its stall AOA..

With practice, and the right information, the Stall isnt this dreaded monster, but an easily controlled and understood event.

I strongly recommend going up with a aero instructor if not just to practice and understand the stick position and the stall from unusual attitudes.

this is the Savannah, fitted with either fixed slats or VG's

OZSavannah wrote:The Stall is simply a function of AoA. nothing more. with enough time in any aircraft, the stall will come at a certain stick position every time, in the Savannah after a few hrs i came to learn instinctively where the stick position will be to induce a stall.

Control stick/yoke position is a really bad indicator of angle of attack and should not be used as such. You can trim an aircraft for a high AOA, constant sink at slow airspeeds with the controls in the neutral position.

Since the control deflection required to achieve different pitch results varies with airspeed, it really does no good to "memorize" stick position. It's the change in control effectiveness and response that should be indicative of the approaching critical AOA.

The only kind of stall I can think of where I would use a "standard" position on the stick is a snap roll: Full control deflection accellerated stall.

Savannah,

There is no way to consistently judge AOA based on stick postition. Nor is there an effective way to determine AOA by simply looking out the window. Now, some experimental aircraft have AOA indicators, but....

With some experience in an aircraft you can indeed FEEL when the airplane is hanging on the edge.

As to training in turning stalls, everyone I know trains every student in turning stalls. The most common stall drill is a turning stall in training, most places.

There are no mysteries to stall behaviour, really, that I agree on.

I also agree that stall practice is a good thing. It should be done carefully and introduced stepwise to a new aviator, and I almost never stall an airplane with a non pilot in the plane.

I flew two launches with students today, and we performed at least a total of twenty stalls in a Cub. Two of those were straight ahead type.

Four of them were falling leaf stalls.

I like stalls, my own self.

MTV