Disconcerting news...

....about fatal stall accidents. As an EAA Flight/Tech advisor, I/we get mailings from EAA Hq's from time to time and the most recent one shows some grim figures.

The FAA and the EAA have come together to study amateur-built issues. One of the statistics that jumps out is the fact that of all fatal accidents (91) in FY 05-07 is that 51% of the fatalities were stall/loss of control accidents and that 60% of those were stalls in the traffic pattern! They point out that loss of control due to stalling is far and away the greatest cause of fatal acccidents in amateur-built aircraft. These accidents accounted for 34% of the total fatal accidents in the study period. No other single cause reached double-digit percentages.

I don't quite know what to say to this, other than the fact that I and other CFI's preach regularly about precision airspeed control, especially in the pattern. The past two years at Oshkosh and Sun 'n Fun remind me of at least two stall/spin fatalities in the pattern from base to final.

A suggestion that I have, and hope other CFI's will chime in, is to go and get an evaluation from a good CFI or go and practice your slow flight airspeed control at a sufficient altitude. I don't like reading about our EAA guys augering in, or anyone else, for that matter. Let's wake up guys and pay better attention in the pattern.

Regards,

I have often said that in the pattern too many times pilots will attempt manovers or slow flight that they have not practiced, and when at a big airshow the mistakes and bad jugement are compounded by the heavy traffic and excitment of being at "the big show".

Practice, practice, practice. Maintaining airspeed is fairly important for flight.

One thing I've found with people I've given BFR's to, is a lot of guys like to land with zero, or partial flaps. When I ask "Why?", they say it gives them a smoother landing. That's all nice and good, but I'm a big promoter of landing with full flaps, unless conditions warrant otherwise. Of course, after that, we go on to demonstrate soft/short field landings which incorporate the use of full flaps...but since guys are used to landing with other than full flaps, they always fly way too fast! Hence, we wind up spending a lot of time in the pattern until they can demonstrate proficiency in max performance TO&L's. I understand that BFR's are to knock the rust off of our procedures, but after the fact, it's up to every one of us to maintain our proficiency. If the only time you do full flap landings, stalls, slow flt, etc, etc is at your BFR, how do you expect to remain proficient?
Not to deviate too far from the subject, but I teach slow flt with full, partial, and zero flaps. I believe the accidents in the pattern are usually with zero or partial flaps, and when airspeed has to be reduced to follow traffic...and guys are used to putting a certain amount of flaps on downwind, base and final...they're in an unusual situation of trying to fly slow flt at less than full flaps, and they're not proficient at it.
Bottom line...stay proficient.
My .02 cents worth.

I'll try to not get on a soap box here, but it is a whole lot more than airspeed. As a a CFII ASMEL, I am a firm believer that the pilot should be able to completely fly the pattern with a totally inoperative airspeed indicator (soley speaking about piston GA aircraft here). The traffic pattern is the one time when the head and eyballs should be almost 100% focused outside the airplane. I watched a multi-thousand hour airline pilot land his Maule long and wreck it because his airspeed indicator was reading low, and he was entirely comsumed by the airspeed indication. I found the leak and demonstrated it to him after the plane was fixed.
Most GA piston airplanes can be flown by feel. Stall speeds as published are only good at 1G. Any tight turning or un-coordinated turning and all bets are off. Distractions can and do happen---everything from ATC to someone else in or outside of the aircraft causing a distraction. A good practice is to plan for every pattern to be an aborted landing and be primed for it. And never, never relinquish control of the airplane to someone on the ground, such as ATC telling you to slow down due to traffic ahead of you, if it makes you uncomfortable. You, and only you, can affect the safe outcome of th eflight from where you sit.

Vic

vic syracuse said:

snip...I am a firm believer that the pilot should be able to completely fly the pattern with a totally inoperative airspeed indicator ...snip

Click to expand...

Great point, Vic. I agree.

Having done this a couple of times myself (pitot cover left on / kinked static line another time giving low readings) I'm a firm believer in letting the plane 'talk' to you. I'm so use to my AOA indicator now that my body is fairly trained to various feels at different airspeeds. If the airspeed goes inop on me I'm (now) completely comfortable. Not the case a few years ago, of course.

b,
d

vic syracuse said:

I am a firm believer that the pilot should be able to completely fly the pattern with a totally inoperative airspeed indicator (soley speaking about piston GA aircraft here).

Click to expand...

Absolutely!

Don't forget gliders!

We regularly cover AS and Altimeter, and expect a student to fly us back to the field. Since we don't have stall warning horns or AOA indicators, they're not a distraction to the task at hand.... flying the aircraft!

I will admit that I don't normally do this with students younger than 14, but then.......

I've also taken to trimming for a slight nose down condition in the pattern. In the event of a distraction, and I lose my focus for a few moments, it's easier to recover from an overspeed condition than an impending stall.

Good point Dave. I remember doing this in glider training as well. Usefull when circling in thermals at min airspeed when your head MUST be outside looking for other traffic. You shold be able to hear and feel the pre-stall conditions - and normal flight conditions for that matter. Good lessons for us all.

If you are flying to one of these big airshows - SNF, Airventure, etc. - spend a little time before you practing "wierd" patterns. Are you comfortable flying five miles to the airport at 85 kts like you would if you got stuck following sombody slow? Can you fly a tight pattern where you turn base over the threshold and land halfway down a long runway? Are you comfortable in a crosswind like you usually find in Fla on arrival to SNF? Flying an odd arrival at the end of a long flight into a strange and VERY crowded arrival pattern can lead to distraction and accidents if you're not prepared.

vic syracuse said:

...Most GA piston airplanes can be flown by feel.

Click to expand...

This is certainly true for my RV-8, in which the CG is nearly always in the forward range. However, I'm not so sure about other experimentals. The stick force vs. airspeed curve published by CAFE for for the Tailwind for example shows an extremely shallow gradient compared other aircraft (only two pounds difference over a range of 100 mph!). In general there's no guarantee that experimentals will have the same stability characteristics as certified. Might this be part of the reason for some pattern accidents?

I don't get it

Unless these are due to lack of stall warning device.

Also it would be nice to know if the ones crashing have stall speeds that are relatively high.

As far as flap and airspeed habits, I don't know why those would cause different results in a homebuilt.

It doesn't matter what flap setting you use, as long as you use an airspeed appropriate for that setting, and as long as that airspeed is appropriate for the runway length. I like to use pattern airspeed that are the 60 degree bank stall speed, which are 1.414 x level stall. I have POH's or checklists of all the airplane I ever rented or owned marked up with this number for all flap settings. If I really need to land short I have 1.3x in my pocket and I know 1.2x is down there in the "bush pilot zone" if my life depends on it.

I'm embarrassed to say I almost spun in years ago when I was a new (<100hrs) private pilot. I was practicing landings at E16, making high approaches with aggressive slips in a C152. On one of these I let the airspeed drop until the stall horn went off, corrected, then it happened a few second later on the same approach. I'm sure I would have been quite dead without the stall horn since I was all crossed up and very close to the ground.

I scolded myself for weeks (actually for the last 18 yrs) and have not let that happen again - even once.

The AOA indicator in my airplane is not set up to give warnings. It has crossed my mind, that fallible as I am, I might need that warning some day.

Vic makes a good point about being able to fly by the seat of the pants. When I got my RV checkout it was in an RV10. The owner/CFI forced me to do no ASI landings.
When he first said he wanted me to do it I thought he was kidding. When I learned he was serious I thought he was crazy. He insisted, and I figured he wanted to live as much as I did.

It wasn't nearly as hard as I thought it would be, even in an airplane I had barely flown. The runway was long, so I flew fast and let the airspeed bleed off over the runway where my "seat of pants" was enhanced by the visual perspective of the runway. The solid feeling of a bit fast is unmistakable, the mush of just right or a bit slow seem a gray area to me. I am not good at flying no ASI.

I'm thinking I might turn off the D10, cover the ASI, and try "landings" at about 5000 feet until I actually feel comfortable doing it.

That said, high incidence of these accidents does not shed any light as to the underlying cause. The need to manage airspeed within the aircraft operating limits is the same for homebuilt as certified. Seems important to find what is causing the difference. I tend not to suspect basic flying skills since HB pilots should be a cross section of the overall GA population.

Huh ???

This discussion is all well and good but doesn't it apply just as much to store bought airplanes ? Given thousands of pilots flying each type, wouldn't you conclude that the pilots are not a factor in the difference in stall/spin accidents ?

If there is a much higher stall/spin rate in Experimentals, then there must be something fundamentally different about these planes. What is it ?

One obvious difference is that all factory planes are required to have a stall warning device. Virtually no Experimentals have them. Could it be that simple ?

John

Another problem that can occur is aircraft load and W & B. I know in years past I used to fly a C182 alone or with maybe one other person. But on rare occassions I might have 4 people and luggage. On those trips you have to really pay attention - when in the pattern you can't grab the trim wheel and give it the usual spin that you do when you are alone. The nose comes up and you really slow down. Fortunately that old Cessna had a stall warning and I corrected or I could have been one of those statistics.

People flying to fly-ins could certainly be exposed to this.

Danny

DSmith said:

Another problem that can occur is aircraft load and W & B. I know in years past I used to fly a C182 alone or with maybe one other person. But on rare occassions I might have 4 people and luggage. On those trips you have to really pay attention - when in the pattern you can't grab the trim wheel and give it the usual spin that you do when you are alone. The nose comes up and you really slow down. Fortunately that old Cessna had a stall warning and I corrected or I could have been one of those statistics.

People flying to fly-ins could certainly be exposed to this.

Danny

Click to expand...

I think that right there pretty much sums up why people have problems....

Lots of pilots get used to rote sequences of steps instead of simply using the control inputs necessary to accomplish what they need the airplane to do.


Maybe it's a symptom of the 'checklist' mentality.... perhaps I should start a campaign to get rid of checklists for safety reasons

Well, So What?

If you don't fly the plane right you are probably going to crash. Any transitional region of flight would be expected to be the most dangerous and produce the greatest number of fatal accidents. They tell us the safety of flight situation is improving so you would expect the "percentage" of those in the most dangerous collection bucket to increase. The only way to eliminate landing accidents of course is to eliminate takeoffs. If this thread is to raise sensitivity I guess that is OK but if it is a soapbox for holy CFI downtalk it grates my sensitivities. If a pilot can't sense an impending stall in a plane flown by a large portion of the pilot population that pilot probably can't be taught that sensitivity.

Bob Axsom

vic syracuse said:

I am a firm believer that the pilot should be able to completely fly the pattern with a totally inoperative airspeed indicator

Click to expand...

I agree with that statement completely. I recently flew a friend's RV-6 that has an EFIS for flight data. I'd never used one before. It took me a few minutes to start getting useful information from it to my brain. In my own
RV-6 I fly approaches at 80 mph with the flaps down. On base leg in his airplane, I was looking for airspeed and was pleased to see it at 80 mph. Huh, just like mine. Even feels the same.

It saddens me greatly to read of accidents where the pilot was making a forced landing and had the field made, but stalled and stuck the nose in the dirt, killing himself and his passenger. I'm an old guy who learned to fly not long after the CAA did away with spin training in the private pilot ciriculum. My instructors really hammered stall recognition home. Their hammering stuck. I've flown with pilots who are very timid about flying the airplane near the edges of the flight envelope. I wish I could help them understand, without seeming like a know it all. I also know CFIs who are real light weights as pilots. One didn't know how I could control my glide path to the runway in a Cessna 120 without flaps.

Full Flaps?

jmbrwn said:

One thing I've found with people I've given BFR's to, is a lot of guys like to land with zero, or partial flaps. When I ask "Why?", they say it gives them a smoother landing. That's all nice and good, but I'm a big promoter of landing with full flaps, unless conditions warrant otherwise. Of course, after that, we go on to demonstrate soft/short field landings which incorporate the use of full flaps...but since guys are used to landing with other than full flaps, they always fly way too fast! Hence, we wind up spending a lot of time in the pattern until they can demonstrate proficiency in max performance TO&L's. I understand that BFR's are to knock the rust off of our procedures, but after the fact, it's up to every one of us to maintain our proficiency. If the only time you do full flap landings, stalls, slow flt, etc, etc is at your BFR, how do you expect to remain proficient?
Not to deviate too far from the subject, but I teach slow flt with full, partial, and zero flaps. I believe the accidents in the pattern are usually with zero or partial flaps, and when airspeed has to be reduced to follow traffic...and guys are used to putting a certain amount of flaps on downwind, base and final...they're in an unusual situation of trying to fly slow flt at less than full flaps, and they're not proficient at it.
Bottom line...stay proficient.
My .02 cents worth.

Click to expand...

I usually land clean if I have more than 2500 feet of runway and I don't see the need to use flaps in this case. Landing clean teaches you better airspeed control technique. Guys want to use full flaps on every landing and I ask why. Engine out on final with full flaps and are you are deep trouble IMO. Your rate of descent is vastly higher and elevator authority is considerably reduced in the flare. The last instinctive thing you will do is push forward to maintain airspeed as the ground rushes up to meet you full flap. Finally, you WILL land short FF if the engine stops unless you are aiming for touchdown halfway down the runway. Use flaps if you need 'em, leave them up otherwise. The flap motor lasts a lot longer too.

Pay attention to airspeed, bank angle and G and you can never have an accident like this. My low limits in the pattern clean are 75 knots, less than 30 degrees of bank and less than .3 G. Can use the GPS as a crude backup to airspeed if you lose the ASI.

I do think people get suckered into following a slow aircraft too slowly sometimes or hot dogging it on departures or tighten up the turn way too much to final. There have been plenty of these types on RVs that I can recall. Break your personal safety limits and maybe you break your neck.

My .02.

We are not all the same

I live in the country and the road in front of my land has a slight, 15 degree curve in it. I average 3 people per year who either go airborne or roll their car into my fence/front pasture because they missjudge the curve and get their front tire off the 3" pavement and into the gravel. Even though we're all taught to not brake, get off the gas, hold course and ease the car back onto the pavement, some panic and immediately spin the steering wheel in a desparate attempt to get back on the road. Some people, most I guess, have an instinctive feel for driving while others must be taught every little nuance. Others are hopeless and drive our insurance rates up and make the news. Flying is a lot like that.

John_RV4 said:

If there is a much higher stall/spin rate in Experimentals, then there must be something fundamentally different about these planes. What is it ?

One obvious difference is that all factory planes are required to have a stall warning device. Virtually no Experimentals have them. Could it be that simple ?

Click to expand...

Type certificated light aircraft are required to have "... clear and distinctive stall warning ..." and this stall warning must be at least 5 knots above the stall. Furthermore, stall warning that requires attention in the cockpit is not acceptable (all these criteria from FAR 23.207).

Many of the most popular family of amateur-built designs, short wing RVs, have essentially no stall warning at all (some RV-8s excepted). I haven't flown an RV-9 or RV-10, so I don't know how the stall warning is in those aircraft. Yes, there is a tiny amount of buffet that can be noticed about a half knot before the stall, if you are looking for it. But, if you are not looking for the tiny amount of buffet, you could easily stall the aircraft if you pull too hard coming around the base turn.

Some folks fit an AOA device that requires the pilot to look at the indicator, but this provides no warning if the pilot is looking outside.

If we want to improve the stall/spin accident rate, we should ensure that our aircraft has clear and distinctive stall warning - either from aerodynamic buffet, or via a loud aural warning from an AOA system. Many of us will argue that due to our superior piloting skills, we don't need stall warning. Well, many of the guys that died thought the same thing. And they died anyway.

Once my RV-8 is flying, I will see whether I am one of the lucky ones that has a nice aerodynamic buffet before the stall. If not, I will experiment with stall strips on the leading edge, to see if I can trip a vortex that will go over the horizontal tail, providing prestall buffet, without having a significant effect on stall speed. If that doesn't do it, I'll add an AOA system with aural stall warning.

Kevin Horton said:

Many of the most popular family of amateur-built designs, short wing RVs, have essentially no stall warning at all (some RV-8s excepted)... But, if you are not looking for the tiny amount of buffet, you could easily stall the aircraft if you pull too hard coming around the base turn.

Many of us will argue that due to our superior piloting skills, we don't need stall warning. Well, many of the guys that died thought the same thing. And they died anyway.

... I'll add an AOA system with aural stall warning.

Click to expand...

Kevin hits the nail on the head here with RVs- little or no stall warning so that is something you should not depend on. My RV6A's stall is pretty nasty and not something you'd want to deal with below 500 AGL. The aural AOA is a great idea as a backup to inattention, fatigue or ASI failure. Aural is way better than visual when it comes to warning pilots.

I don't have superior piloting skills but try to make up for this deficiency by making good decisions before I create a problem requiring superior piloting skills. Make your rules and don't break them. This goes all the way back to stepping into the plane in the frame of mind and level of alertness to do the job safely. The personal checklists discussed in the IFR thread are excellent.

There is no excuse for departure stalls while showing off- fix is, don't show off and maintain safe airspeed and bank angles. You tighten up the bank to 45 or 60 degrees at 60-65 knots and pull some G trying to make the turn to final and you will have a bad day. Break one rule, you might get away with it, break a few and it will catch up with you.

Good decisions and standardized procedures can help avoid many types of accidents. A little bit of technology like AOA can't hurt either.

Paying attention and noting flight attitudes in different phases and configurations can be helpful when something unexpected happens too.

RVs are fun to fly and fling around, this brings out the best and worst qualities in pilots. Enjoy the RV response at safe altitudes and within the envelope. Respect the consequences of abuse at low altitudes. Give some thought as to what would happen right now if the prop stopped.

tmbg said:

I think that right there pretty much sums up why people have problems....

Lots of pilots get used to rote sequences of steps instead of simply using the control inputs necessary to accomplish what they need the airplane to do.


Maybe it's a symptom of the 'checklist' mentality.... perhaps I should start a campaign to get rid of checklists for safety reasons

Click to expand...

It's not just the pilots either - the pilots learn from the instructors, and there are way too many instructors out there who only know what the book tells them.

I had a young instructor freak out on me once on a BFR when I did a power on stall at his request in a C-172 and dropped a wing pretty good, and I recovered using rudder and aileron. He starts freaking out about using aileron to recover wings-level in a stall, until I pointed out to him that he should have noticed he was floating in his seat as I was raising the low wing. "So? What does that have to do with it?" It means I pushed the nose over and the wing is unloaded - meaning unstalled - so I'm not entering into a spin while using the aileron. It took me a good 20 minutes to get him to understand the concept. I shouldn't have to be instructing the instructor.

Full Flaps - NOT!

If you ask 10 CFIs about the use of flaps during landing, you would probably get 11 different answers. I for one also DO NOT believe that every landing MUST use full flaps. Bob Miller of Over the Airways recently had a very good podcast about this on Aero-News. Published on May 12th, it is titled Misunderstood Flaps.

If everyone used full flaps, this statistic would not change much IMHO. Audible stall warning on the other hand, would improve this situation. Many experimentals lack this basic tool simply because it is not required. That my have something to do with these appalling statistics for experimentals.

vic syracuse said:

I'll try to not get on a soap box here, but it is a whole lot more than airspeed. As a a CFII ASMEL, I am a firm believer that the pilot should be able to completely fly the pattern with a totally inoperative airspeed indicator (soley speaking about piston GA aircraft here).

....You, and only you, can affect the safe outcome of th eflight from where you sit.

Vic

Click to expand...

I'm not with you on the first statement. It suggests a pilot should fly by feel and not trust an instrument. This can be very much of a problem learning to fly on instruments. It is a whole different issue.

The gist of the thread is stall spin accidents in the traffic pattern - they are happening because pilots are not paying attention to airspeed not because the ASI is inop.

Yes, one needs to be able to fly to a safe landing with an inop ASI, and I don't think it is a big deal having done it. Keep the airplane going fast enough to provide good solid feel on the controls and find a nice long runway. Don't mess around with minimum control flying speed, these RV's break very quickly without much warning. I demonstrated that to myself at altitude just last week, the stall is quick and can be recovered just as quick if you're ready for it, but woe to the pilot not paying attention in the traffic pattern. I would never fly the pattern with anyone practicing an ASI out approach. It has to be done at altitude along with slow flight training. For the most part, all that has been done in the PP curriculum.

The problem is pilots get sloppy once they are licensed and turned loose or become easily distracted and unfocused when anything unusual happens.

Nothing is more important in the traffic pattern than a constant uninterrupted awareness of airspeed. Traffic watch does not have to be compromised to maintain that awareness. It takes an attitude, I will fly this thing safely FIRST, LAST and ALWAYS. Nothing will break that code be it a clutz in front slowing too slow too soon at an air show gathering, or a controller who needs to be told, negative, unable to comply.

I agree with the last sentence of your post - it says it all.

I think the nail was hit on the head when it was stated that people need to be the PIC not the guy in the tower. Fly ins are the worse, many people coming in and the tower wants to get them all in, he or she doesn't care if you are a fast airplane with a stall of 58 and the airplane in front has a stall of 38, he or she put you in a possision that you want to make him happy, before you know it you are running a thin line with your airspeed. Heck if I am put in this situation I'll move along side that airplane and if I pass him so what, I'm safe and I'll do what it takes to be that. I knew people that did the bad thing and tried to follow, ended up in a ball on the ground.

I never do just one type of landing, I always mix them up, short, long, whatever. I land on the numbers, move over and land on the left edge, right edge, on each of the taxiway intersections, whatever. If I need to change at the last second, fine I'll do it, should I say, I can do it. I think also people have no idea what wake is, even a cessna puts it out, not just the big boys. Oh and those helicopters, watch out for those. How about a shear wind on landing. How are you on tail wind landings. I had a flyin that was a busy one and they only published an approach for rwy 16, what did they do when the winds were about 14 the other way, nothing, they landed everybody on 16.

I know a guy that does his final 3 mph above his stall. I tried to educate him but he was insistant that his airplane does just fine like this. One little booboo and down HE goes.

David-aviator said:

The gist of the thread is stall spin accidents in the traffic pattern - they are happening because pilots are not paying attention to airspeed not because the ASI is inop.

Nothing is more important in the traffic pattern than a constant uninterrupted awareness of airspeed. Traffic watch does not have to be compromised to maintain that awareness. It takes an attitude, I will fly this thing safely FIRST, LAST and ALWAYS. Nothing will break that code be it a clutz in front slowing too slow too soon at an air show gathering, or a controller who needs to be told, negative, unable to comply.

Click to expand...

Absolutely agree and you are NOT a good pilot if you stall and spin in the pattern with a working ASI and brain. How much more simple can this be? I don't see any big mystery here. You fly the aircraft, not the controller. Speak up and exercise your authority here.

It's a BALL

Not one person in this entire thread mentioned you should look at the slip ball when turning downwind to base and again when turning base to final.

Those are two good times to check your airspeed and make sure you are making a coordinated turn.

Keep your speed where it should be and keep that ball centered and you will not have a problem! Oh, and there is nothing wrong with lowering the nose in a turn to keep your speed up. Once you are wings level, let it return to its trimmed (approach) airspeed.

The other thing I've noticed in flying with friends is how inaccurately they fly. 500' altitude and 10 degree course deviations are not uncommon.

I'm not the best pilot in the world but every time I fly (when I'm not screwing around) I try to hold my altitude and heading dead on, and no, I do not have an autopilot. I also try to land on the center line on the spot I pick. It is just a little challenge I give myself every time I fly that helps keep me sharp.

On the landing thing, I recently flew with a friend who did a great job of landing in the center, the center between the centerline and the edge of the runway. The frightening part was we were on the downwind side of the centerline when we touched down and he never attempted to move towards the centerline.

Back when I was learning to fly gliders my instructor taught me to fly turns in the pattern with my nose down a bit. Not so much that I zoom through them but enough that my wings angle of attack is kept lower and the ability to gather more speed is closer at hand. Something I have never heard a powered flight instructor mention. I've carried this technique along with me with good results ever since. Something that I've noticed in this thread is the reference to flying with an AOA. It's all well and good when the direction of travel is fairly much straight forward but AOAs are only giving you information from one location on one wing. Not to rehash old news but pattern stall spins are usually, it seems, caused when an aircraft is flying from one leg of the pattern to another and the wing inside the turn stalls while the outside wing is lifting. If your AOA is on the wing that's still lifting your angle information wont mean much.

At UPT we did AOA only approaches in the T-6. The AOA probe on all of the aircraft I have flown since have them on the fuselage, which gave a pretty accurate picture of the complete AOA on the aircraft. AOA doesn't care if your turning or not, it only cares what the relative wind is doing, and thats all a stall really cares about too. Therefore AOA is somewhat a function of your speed.

We still have an AOA in our tanker and I try to reference it quite a bit. If you want a good instrument that will give you more info about a pending stall, I would put in a AOA gage. In fact thats one of the first additions I would like to make to my -8.

pierre smith said:

....about fatal stall accidents. A(snip)

I and other CFI's preach regularly about precision airspeed control, especially in the pattern. The past two years at Oshkosh and Sun 'n Fun remind me of at least two stall/spin fatalities in the pattern from base to final.

Click to expand...

Absolutely on point, but I would suggest that airspeed is really only an imperfect proxy for AOA. Wings stall based on AOA. Although the stall speed is always the same for the same conditions of weight and g-loading, it can vary significantly if you change those conditions.

In experimentals, which tend to have lighter empty weights, this has more important. When you add in typically lighter pitch forces (which make it easier to pull "g") and the almost universal lack of stall warning equipment I don't find those numbers at all surprising.

IMNSHO, AOA devices are very important for safety. At the low end, you can cobble up something like a piper stall warning vane for a few bucks. The LRI is a beautifully simple device that works very well. If you've got a bigger budget, the "ladder" type electronic AOA is really nice to have.

In my airplane, I have an AOA system (was PSS, forget who owns the rights now) which is completely redundant--I added a second pitot tube on the opposite wing and it has its own static ports.

RVs are wonderful airplanes, with outstanding handling qualities and very low stall speeds relative to their overall performance. They do not (with the exception of the RV-8) have much natural stall warning though. The stall itself is benign, with an almost instantaneous recovery, but the departure occurs without much warning.

A handful of RV pilots and their passengers die pretty much every year, because they made a single mistake and stalled the airplane too close to the ground to recover. Frequently they are outside their normal "comfort zone" and loaded over their normal weight, at a higher density altitude than they are used to, or "task saturated" like in the Oshkosh arrival. Good stall warning or AOA devices might have saved some of these people.

Sorry for the long post, but this gets me wound up.

Slow Flight

pierre smith said:

A suggestion that I have, and hope other CFI's will chime in, is to go and get an evaluation from a good CFI or go and practice your slow flight airspeed control at a sufficient altitude.

Click to expand...

I have seen the nose angle of approach (AOA) speeds in an RV is quite appreciable- the 20 MPH between 90 and 70 indicated is a difference like seeing the touchdown zone or only seeing the trees beyond the runway. I?m still a low time RV?r though but I think it does have great behaviors with one acception: When It?s done flying- It?s done, ?I?m Outa here and going to drop this wing even more if you don?t lower that stick pressure- and I mean ?oh toooo late!

Even a long time CFI friend is not really itching to get in the RV. I think as it is a leap in capabilities, it is also a leap in pilot abilities/training.

I think Pierre has hit this right on- keep practicing slow flight at a safe altitude; I?m still doing that once a week!

At our flight school we find that the first two skills lost by experienced pilots are slow flight and steep turns. Nobody wants to practice those. IMHO if one needs an AOA to keep one out of a stall situation they need more training.
tm

BFR...

tin man said:

At our flight school we find that the first two skills lost by experienced pilots are slow flight and steep turns. Nobody wants to practice those. ......tm

Click to expand...

So that's why those two items were the first exercises on my recent flight review....

The regular practise idea seems like a good one.

gil A

I'm an avid cyclist and often find myself sitting at a traffic light watching people corner in their cars. From this point of view it's easy to see (and hear) just how close many folks are to losing control by cornering too fast without ever realizing it. You can hear and see the tires beginning to break loose and in two cases I've seen people lose control and spin a full 180. I figure that with the stereo turned up, windows up, and modern suspensions, it's just very hard to detect where the edge really is. I figure the only cure for this would be to either stay waaaay inside the envelope, or go to a track and figure out exactly where the edges are. The same is true in airplanes. Lots of people get their ticket without really exploring the edges of the flight envelope. They know the edges are out there somewhere, but mostly just try to err on the conservative side and hope that they never screw up. I think a lot of the stall/spin stuff could be prevented by getting some unusual attitude/accelerated stall/spin/acro training. IMHO of course.

AZ - Don't get confused AOA means angle of attack - It the difference the chord line and the relative wind. This difference is what actually causes the wing to stall which is why people you AOA guages.

tin man - An AOA gage is a mere tool at the pilots disposal. lets say that you loss your pitot static system on take off or in the weather. now what? In the tanker we get to see how exactly weight can play with that AOA. The Heavier we are the higher the AOA goes faster.

AOA

Several people have noted the usefulness of an AOA indicator in addition to the airspeed indicator. I wonder which of the current EFIS systems use the same probe for the airspeed and AOA indicator. On the Diamond DA20 I used for my primary training, the stall warning port was independent of the pitot tube. Thus, if one of the two got blocked, you still had the other one. I'm not sure this redundancy is common with the systems on many RV's or other experimentals.

...."Maintain Thy Airspeed Lest The Earth Arise And Smite Thee.
Don't remember the who wrote it but it works for me.

Glenn Wilkinson

STALL STRIPS AND AOA

T-18's have been adding stall strips to the leading edge to give a more pronounced stall warning. Might be a good idea on RV's as well.

On my RV-4, I have redundant pitot/static systems. One for my Dynon D-100 and the other for my "steam gage" ASI and Alt. I also have the PSS A0A, one for both seats. I asked my check out pilot what instrument he would want in the back seat if he had only one choice. He said AOA, hands down. The PSS AOA has an audible warning.

Wally Hunt
Rockford, IL
VAF # 476
RV-4 Finishing Kit

szicree said:

I'm an avid cyclist and often find myself sitting at a traffic light watching people corner in their cars. From this point of view it's easy to see (and hear) just how close many folks are to losing control by cornering too fast without ever realizing it. You can hear and see the tires beginning to break loose and in two cases I've seen people lose control and spin a full 180.

Click to expand...

Hmmm. Just like some airplanes give little pre-stall buffet, some cars give little warning before snap oversteer. However, it's a question of car design and driver skill. Lots of RWD cars can happily corner tail-out, but most of today's drivers couldn't get them to do that without spinning it. Most AWD cars will go into 4-wheel drift rather than spin unless you're way too heavy on the throttle and crank the wheel over - the A4 is a hoot when in 4-wheel drift.

Anyway, to bring it back to aviation, I suspect that the general wisdom that the lack of stall warning and/or pilot recognition is not helping the RV series in this regard. I'm flying the ASK21 glider for my glider add-on right now, and I can't believe how much warning the thing gives you - the whole **** airframe shakes before stalling. You would be hard pressed to stall it in the pattern.

TODR

Glider noise...

the_other_dougreeves said:

......
I'm flying the ASK21 glider for my glider add-on right now, and I can't believe how much warning the thing gives you - the whole **** airframe shakes before stalling. You would be hard pressed to stall it in the pattern.

TODR

Click to expand...

Yes... and you can easily judge the glider's airspeed by the volume of the "air whistle".... which is easy to hear since there is no big noisy fan up front.

When it goes really quiet, you are about to stall.... ...even if the airframe isn't shaking (the earlier ASK-13s......)

gil A

All CFIs not created equal

airguy said:

It's not just the pilots either - the pilots learn from the instructors, and there are way too many instructors out there who only know what the book tells them.

I had a young instructor freak out on me once on a BFR when I did a power on stall at his request in a C-172 and dropped a wing pretty good, and I recovered using rudder and aileron. He starts freaking out about using aileron to recover wings-level in a stall, until I pointed out to him that he should have noticed he was floating in his seat as I was raising the low wing. "So? What does that have to do with it?" It means I pushed the nose over and the wing is unloaded - meaning unstalled - so I'm not entering into a spin while using the aileron. It took me a good 20 minutes to get him to understand the concept. I shouldn't have to be instructing the instructor.

Click to expand...

Because I've moved a lot, I've flown with a relatively high number of CFIs between training, rental checkouts, and such.

At the top end are some very smart and skilled CFIs that know how to fly the airplane, and really understand the physics of flight, airplane systems, etc. I always learn something from them, even if just a tidbit. There seems to be no correlation between this high level of competence and their number of hours. The guy I finished my instrument with only had a little over 400 hours, and he sticks in my mind as one of the best I have flown with.

At the other end are CFIs who fly at least decent, but don't really seem to understand the underlying physics or systems, and can't get away from obviously incorrect dogma (like not flying "oversquare", always landing full flaps, etc). With these I focus on appeasing their irrational hot buttons and getting through the checkout so I can rent the airplane.

Included in this last group are some who are down right dangerous. One that sticks in my mind (from 1990) tried to convince me it was ok to take off with one rough mag because we had a second as backup. I reported her to the local FSDO, who seemed to take little interest.

The good ones always push me to do something I haven't done before, or am uncomfortable doing. That's why I learn something from them (+ the fact they actually know something I don't). Though several of them mentioned it was doable, only one of the several good ones pushed me to no ASI landings.

So, I think at least part of this problem is a CFI problem. A pilot trained by a bottom level CFI, is going to have problems. IMO the bar for becoming a CFI needs to be raised high enough to strip off the bottom performers. That will not only improve safety, but will financially benefit the ones who make it since reducing the supply of CFI's will tend to drive wages up.

I'm glad to see that Pierre posted the info that started this thread, and glad to see that it has attracted so much attention. I got the same newsletter just as I was leaving town th other day, and was going to write about it when I had the chance. While all of the comments on the importance of airspeed control, training and practice are right on, the rally interesting part of this has only been addressed by a couple of folks - and Kevin Horton nailed it - the difference here is between Experimental's and Certified airplanes , and their stall characteristics/warnings.

We must constantly remember that experimental just do not have the same "tailored" stall warnings as the certified plans that most people learn to fly in. Spam cans are much more forgiving, by design - when we set of to fly experimental, we have to have a different (in my mind, more "serious") mindset - we need to be much more ready for those "edge of the envelope" experiences.

Paul

TankerBob said:

AZ - Don't get confused AOA means angle of attack - It the difference the chord line and the relative wind. This difference is what actually causes the wing to stall which is why people you AOA guages.

tin man - An AOA gage is a mere tool at the pilots disposal. lets say that you loss your pitot static system on take off or in the weather. now what? In the tanker we get to see how exactly weight can play with that AOA. The Heavier we are the higher the AOA goes faster.

Click to expand...

I think the AOA is a good thing, I'm actually putting one on the RV. But I must caution use of all the fancy guages when landing, your focus is no longer on the runway, it's on the guages, very bad. You might turn out like the latest accident, on top of another airplane.

A couple days ago I made a post for the kitfox list on landing a fox, seems people have a real big problem landing this airplane. So I wanted to give a count down of speeds, seems I couldn't do it because I really didn't know, so I had to go out and WATCH my guages for landing, I was surprise to say the least, I had a hard time doing both(looking out at the runway and looking at the air speed). But what I did learn is if you watched the IAS on landing you loose all sights of the runway. I'm sure glad I learned to land by feel.

When I hook up my AOA it will be on sound.

Yep..

Ironflight said:

We must constantly remember that experimental just do not have the same "tailored" stall warnings as the certified plans that most people learn to fly in. Spam cans are much more forgiving, by design - when we set of to fly experimental, we have to have a different (in my mind, more "serious") mindset - we need to be much more ready for those "edge of the envelope" experiences.

Paul

Click to expand...

Paul hits the nail on the head here. I tell and show every guy that comes down here for transition training, to really learn the aircraft's attitude for a given airspeed in the pattern for exactly these reasons.

We not only have to have a different mindset, we have to ratchet up our finesse and our touch in these RV's. They're great airplanes and easy to fly and land but very unforgiving at low airspeeds and high angles of attack since the sink rate can catch you by surprise. The normal reaction for some guys is to raise the nose to supposedly "stretch" the glide when in fact it does the reverse. Sink rate is controlled by power, airspeed by elevators on final. Pay particular attention to your airplane's attitude for the speed you want and then duplicate that with the same power settings and it'll become second nature before long.

Thanks for all the constructive comments everybody,

Regards,

allbee said:

I think the AOA is a good thing, I'm actually putting one on the RV. But I must caution use of all the fancy guages when landing, your focus is no longer on the runway, it's on the guages, very bad. You might turn out like the latest accident, on top of another airplane.

A couple days ago I made a post for the kitfox list on landing a fox, seems people have a real big problem landing this airplane. So I wanted to give a count down of speeds, seems I couldn't do it because I really didn't know, so I had to go out and WATCH my guages for landing, I was surprise to say the least, I had a hard time doing both(looking out at the runway and looking at the air speed). But what I did learn is if you watched the IAS on landing you loose all sights of the runway. I'm sure glad I learned to land by feel.

When I hook up my AOA it will be on sound.

Click to expand...

Along this line, some EFIS have a 'copilot' mode where they can be configured to start announcing air speed (using audio) at some set interval, below a set airspeed. Seems like this might be useful if the air speeds are accurate and not distracting.

I've been flying for more than 50 years. I am likely out of step with much modern thinking. I don't think I need some instrument to tell me about my condition of flight. I've considered myself pretty good at flying the airplane. Since the purchase of my RV-6 four years ago, I've become a better airplane driver than I've ever been. My RV-6 makes me do it right. It is a different mindset. When the airplane talks to me, I pay attention.

I got some stick time in a Lancair Legacy a few days ago. It's another step up from our RVs. The consequences of not understanding that, can't be accepted.

One important difference between RVs and factory built airplanes is elevator authority at or near the stall regime. While a factory airplane's elevators will barely take the wing to the edge of a stall with the throttle closed, the RV's elevators will take the wing well into a stalled condition. If an RV pilot looses the engine his life depends on flying the airplane to the ground. If the factory airplane pilot finds himself in a forced landing situation with the stick near the up elevator stop 25 feet from the ground, he'll pancake into the ground and might survive. In the same situation, the experiemental pilot probably won't. We need to keep our survival instincts sharp. If the unthinkable happens we need to react properly, and fly the airplane.

Enough preaching to the choir

A very interesting subject here...
Its very difficult to compare handling characteristics between homebuilts and certified aircraft since there are no standards for the latter.
Areas like stall warning, stability,stick force gradients, roll/yaw coupling etc. etc. vary greatly on the homebuilt side and thats without considering variations in construction, CG, etc.
I can't think of one homebuilt that I've flown that would be certifiable from a handling standpoint. It doesn't make them bad airplanes. Airplanes I've owned like the Cassutt, Tailwind and Homebuilt Pitts are great flying machines.
I learned doing certification flt. test how much time, energy and resources manufacturers spend getting their products to meet the requirements and still retain the desired/advertised performance.
If we expect our homebuilts to behave like certified airplanes we might expect things like larger tail surfaces,higher leading edge down angles on the H-Stab, more fwd CG limits, redesigned control/trim systems, stall strips and or wing twist etc,etc, all of which would add weight and decrease speed.
And we haven't even talked about the systems or structure yet !
Maybe thats why comparable certified airplanes cruise a lot slower but cost a lot more.
Still an interesting subject...
Mike

Goes in Cycles

As a CFI, the FAA gets the word out they want to emphasis something, like stall/spin accidents, which go in cycles. The private pilot standards and regs are very focused on stall awareness and recovery. It should be taught very well to Pvt pilots. The problem is after Pvt pilot, many don't remain current and flight reviews might not cover it. So skills get rusty. Frankly some are scared of stalls or just never got it during primary training, so there is not room to fix it. I understand that, but its something to work through.

Why are so many pilots afraid of stalls? It is just part of the normal flight envelope, albeit at one corner.

Many pilots don't like to practice stall entry, recovery and slow flight. Many pilots, after they get their rating, avoid stall practice (awareness, recovery) like the plague. A few times a year practice stalls from all attitudes, configs and wing loading (to standards of the rating you hold). Power On (departure), Power off (approach), Accelerated (turning) stalls and slow flight (aka maneuvering at min control speed) are actually fun and WILL improve your pilot skill and feel. Don't do it with passengers unless they're into it.

I guarantee if you practice you'll gain more confidence and competence, but keep practicing. If the only stalls and slow flight you have done where during your initial Pvt Pilot training and a few during flight reviews, every two years, you might not have the skill to affect a proper recovery close to the ground, in a real critical situation.

I also like to practice stalls with intentional uncoordinated flight controls. This can result in spins so if you are not prepared for a potential incipient spin and recovery than keep your stall practice coordinated. However many low to the ground stall spin accidents happen in part BECAUSE of uncoordinated flight control inputs. If you have got into and out off a one turn or 1.5 turn spin you really have not been in a spin. That is called an incipient spin. A full spin might take three turns. I don't recommend spins for some one who has no training in them, especially in some RV's which can really crank up the rotation rate. Spins can be disorientating to some and "freeze them in glue". Don't be afraid, just be aware if a spin STARTS into a spin recovery is usually easy and quick for the first turn or two. Of course you have to have the recovery as part of your "learned response". The "classic" response is idle power, natural stick, rudder opposite of rotation and than lower nose slightly to break stall. The nose down attitude can be more than you are use to so be ready to recover from a nose low attitude before gaining too much speed but not too fast to stall again.

Bottom line if you maintain airspeed (for load factor) you can't stall. If you don't stall you can't spin.

I think the fear of spins is what makes pilots reluctant to practice stalls. Although not spins are required for the pvt pilot rating, which I agree with, I think of you want to upgrade your skills go up in a Citabria or Aerobat with a CFI and get some spin entery, recovery training. Stap on some confidence (a parachute) and get comfortable with it. It was not till I did spins did I get comforatble with stalls.

Even in a Boeing we practice stalls (imminent to stick shaker) and recovery. It's quite spectacular in a simulator. Other jets and turbo props have STICK PUSHERS, that will not allow you to stall. The mantra in the Boeing is "Respect the Stick Shaker". Obviously a sweep wing jet is different but the skill, feel, motor skills are all the same, break the stall, level wings, add power and recover in a climb. In a jet we have two scenarios, terrain a factor and terrain not a factor. One obviously means you have less room to "break the stall" or lower the noise and requires a more subtle def touch. Stick shaker is not a stall but its as close as you want to get in a real jet. In a GA plane by all means take it to a full stall break. If you need to get a CFI and go up and practice till you are comfortable.

If you are afraid to practice stalls don't feel bad, I was like that as well when I was a private. I did not love doing them. However it was not until I got my CFI and into aerobatics, intentionally doing spins and spin recovery did I lose my "Fear" of stalls. HOWEVER I never have lost my respect of spins. SO WHEN I AM CLOSE TO THE GROUND I WATCH MY AIRSPEED, SLIP/SKID BALL AND STICK-N-RUDDER LIKE A HAWK.

Fact, you will lose altitude in a stall. Even if you're Joe/Jane expert stall/spin recovery dude/gal, if you stall close to the ground, you may not have enough room to recover. It's just a fact. In an engine out emergency/forced landing I will say "don't stall, don't stall, don't stall". I know in the pilots mind, under high stress (and wishful thinking) they might keep pulling back to extend their glide, but sometimes its better to lower the nose and fly into whatever and take your lumps. Hitting (I mean landing) on the ground, under control is far better and more survivable than a stall/spin into the ground. A medical fact is the body in a sitting position can take more "G" force in the fwd direction than vertically by a large large factor. A spin puts major vertical loads into the body and plane.

I was never saying that you need to focus on the instruments. In fact quite the contrary if you over focus on either one you can get sucked into it. I think its great that many of you know your aircraft well enough to know what pitch attitude goes with which speed. Its a great skill that is developed through time and flying. Unfortunately, not all pilots are at that level. And as has been discussed there are people who have learned from horrible instructors.

Call it what you will, but I was always taught and will always emphasize to people is aimpoint - airspeed. I am not saying tunnel vision into airspeed. I am saying glances. If you can't glance at the airspeed indicator, process the info in your brain, and not veer wildly off course and slope, then sorry you need to practice more and develop a faster scan.

If you are a fly by feel person, great more power to you. But remember not everyone is there. Otherwise these people would not be stalling and spinning the aircraft into the ground. It is a loss of concentration and a loss of focus. I would advise not to get wrapped up in your aimpoint completely either. This can lead to a correction without having enough energy, which I would hypothesize is what led to many of these accidents. Hey I could be wrong.


Oh and I forgot, our tanker doesn't have a stick shaker or a horn to let you know of impending stall. Without the AOA gage and initial buffet, which we only practice in the sim now, you don't know until you are there. Except of course the AS indicator.

Where in traffic pattern?

Look at the graph - as your angle of bank increases, so does your stall speed.

I wonder if most of those accidents were base to final?

Webb said:

Look at the graph - as your angle of bank increases, so does your stall speed.

I wonder if most of those accidents were base to final?

Click to expand...

Yep, this is where a good portion happen, turn too late, tighten up the bank angle, stick back a bit which adds some Gs, ball off center and WHAM instant stall/ spin, shocked pilot doesn't respond or altitude is simply to low to recover.

What can we learn here? Use your brain and plan the whole circuit in your head before commencing.

1. If you know where the wind is from and how strong, you should have a good idea when to initiate the base to final turn.

2. If you screw up number 1, don't rack it tighter, wait a little longer to intersect final at nominal bank angles. You could also unload the airplane to reduce the G. Be aware that power off, at low speed in a tight turn, and RV bleeds airspeed (putting you closer still to the stall) a fair amount due to the low aspect ratio wing and relatively high induced drag.

3. There is no particular reason to be going really slow base to final. Add some knots.

4. As far as departure stalls go, again, there is no particularly good reason to be going 60 knots with the nose 30 degrees above the horizon at 200 feet.

These accidents are caused by sloppy piloting skills. Period.

Great points George.

Good Topic Which is

fitting in with my phase 1 flying in our 9A.
We're into our 20th hour of the necessary 40, and I'm just starting to feel comfortable when entering the airport traffic area. The biggest problem has been getting used to flying slower, as our flapless, aerobatic One Design needs over 125 mph on downwind to have some form of forward vision for traffic safety.
What I'm finding is I have to fly the 9A like I used to fly the Mooney which had a slow gear and flap speed, and that was to start preparing for the airport arrival at least 5 miles out if I was high. Further out if I was really high.
Today, I used only about one second of flap (not really sure how that relates to degrees), thinking back to a past post on this subject about not using any flaps at all. Kept the airspeed at 80 mph on base and final turn. Plane actually felt better and was more responsive when using the throttle to adjust decent to compensate for a gusting headwind. Landing roll was not much farther than normal, and was able to keep nose wheel off ground much longer.
I guess the norm now is to AOA, but with over 6000 landings in 6000 hours of flying, I'm not sure if I need one.
Jack
N99552

rv6ejguy said:

Yep, this is where a good portion happen, turn too late, tighten up the bank angle, stick back a bit which adds some Gs, ball off center and WHAM instant stall/ spin, shocked pilot doesn't respond or altitude is simply to low to recover.

Click to expand...

Where it gets even worse is where the pilot starts to realize that he's using an awful lot of bank, so he shallows it out, but then proceeds to try to increase his rate of turn with inside rudder. Now, due to slip/roll coupling, he needs to add OPPOSITE aileron to keep the airplane from rolling back into that excessive bank angle he was trying to avoid.

Now we're crossed up, but unlike a forward slip, we're crossed up in a turn with excessive bottom rudder. Deadly scenario.