[nucleus]

Yesterday I got close to a stall in the pattern for the first time in my flying career...

Inbound traffic was getting intense yesterday morning at KBZN, we had jumpers on the south side and about six planes inbound including a heavy on long final the controller had doing S turns.

I came in on a tight right base for runway 30 and had just pulled the throttle out and gotten the plane slowed down to 80 knots and deployed full flaps, when the controller who thought I was too close to the Cessna touching down ahead of me told/asked me to make a left 270.

I added a little power and and watched my airspeed drop through 70 knots as I initiated the turn, thinking how this was an odd spot I was in, a steep turn at low speed and low altitude and full flaps... I was using very little backpressure, and looking for a stall, when during the last part of the turn I felt the subtle start of that aileron shake before a stall. I of course pushed the nose down and landed uneventfully.

Hans

 

[Mike S]

Good job, no matter what, fly the airplane.

 

[Mel]

I was using very little backpressure, and looking for a stall, when during the last part of the turn I felt the subtle start of that aileron shake before a stall. I of course pushed the nose down and landed uneventfully.

Hans

Are you sure you weren't crossing your own wake turbulence?
Making a tight turn with full flaps, you were "low speed, high lift". This configuration creates maximum wing tip vortices.

 

[Ron Lee]

Mel may be right but here is a learning moment?.

Why did you let the airspeed get low...with a reported "tight turn?" Neither was needed since anything that places you at jeopardy merits an "UNABLE" response to the tower.

Straight ahead. Climb. Add power. Whatever is prudent. Frankly you may have been able to land without the turn...or add power and do a go around side stepping to one side of the runway.

Just thoughts. Never ever let any controller lead you down a path of doom. You are the pilot.

Better to be yelled at on the ground than a NTSB entry.

 

[Andy Hill]

Just a thought Hans... Full/Landing Flaps (v Half/Takeoff Flaps) are really for drag, not lift. I am not aware of any type that routinely you take Full Flap for level flight? Typically you configure some flap in the pattern / level flight, and final stage(s) of flap at top of drop / in the descent / final.

As you found, the high drag configuration does not leave so much performance, and you are flying in a tight band of airspeed between min acceptable / flap limit. Add in a distraction, turn (more drag) and you saw the effect

Andy

 

[apkp777]

I agree with Andy, I am not questioning your technique. I am sure you do the right thing. But as a rule I teach my students to only use full flaps in two scenarios, emergency descents and when fully committed on short final.

Still what you experienced I am sure was an eye opener for you. A good lesson for us all.

Stall recovery when low and slow is a real problem. Most people have a normal tendency to pull up when the nose pitches down close to the ground. Thus, making things a whole lot worse. Break the stall, recover the altitude. NO matter how close you are to the ground!

 

[rv8ch]

Great thread

Thanks for starting this one, Hans.

Quick question for you - do you have an AOA indicator? Just curious. Good job staying alert and letting us know what happened.

 

[Sam Buchanan]

<snip>
I came in on a tight right base for runway 30 and had just pulled the throttle out and gotten the plane slowed down to 80 knots and deployed full flaps, when the controller who thought I was too close to the Cessna touching down ahead of me told/asked me to make a left 270.

I added a little power.......
<snip>
Hans

Returning to level flight or initiating a go-around with full flaps requires a lot of power.............

 

[Brantel]

An RV7 will climb well at full power (180hp/FP) with full flaps and will easily exceed max flap speed if you are not careful.

I had that exact situation when my flaps blew a fuse and I did not know it...would'nt you know it happend when I had to do a go-around.

My vote is that this was wake turbulence. I hit some of my own one day while doing turns and it will do exactly as you describe.

Someone can do the math but I would say you would need a good bank angle to stall at 70 unless your IAS is off or you were over gross or at a high DA..

Tons of people always do full flap landings in RV's. I normally get em all out as I am turning base. I am not one that likes to drag an RV in since if you lose that engine on final and your dragging it in, you will most likely not make the field in an RV.....The extra drag helps me keep the speed under control while keeping a steep approach angle.

Full flaps or not, RV's have a high sink rate if you get slow and behind the power curve....


Not sure how correct this chart is but if it is correct....

Van's quotes 48 knots stall on an RV6A at gross so 70/48=1.46 so according to that chart you would need to be around 60° bank to stall????

 

[David-aviator]

AOA can save your butt.....

Installation and use of an AOA is a good idea.

If understood and used properly an AOA can prevent incipient stall spin accidents and provide most useful information for a straight in short field approach.

It's not much good for take off, but most useful for landing. I use it and like it very much.

 

[Ron Lee]

The graph in post #9 looks more like a load factor graph...not increase in stall speed as a function of bank angle. Look at the chart on this link

http://www.canyonflying.com/canyonturns.html

 

[Brantel]

Might be but it works out about the same at that bank angle....

 

[RV8R999]

those factors only apply to level flight. Stall speed only increases with AOB when attempting to maintain altitude at that AOB. The Critical AOA of the wing has nothing to do with the geometric relationship of the wing to the earth, which is what AOB is. Its load factor that cause the stall speed to increase not AOB. It is only in that a relationship between AOB and load factor exists in level flight that a correlation can be made.

Next time you go flying climb to altitude, roll into a 60 deg AOB turn and allow the nose to drop and then note your G-meter. Yep - 1.0 (or so). Stall speed is the same then.

 

[Brantel]

I follow you....but he was trying to execute a level 270 degree turn correct?

 

[Walt]

AOA, important stuff to keep you safe

Installation and use of an AOA is a good idea.

If understood and used properly an AOA can prevent incipient stall spin accidents and provide most useful information for a straight in short field approach. I use it and like it very much.

I believe that if every RV had an AOA we would see a significant reduction in the accident rate. The last couple of incidents have all the signs of the age old stall/spin in the pattern scenario.

Sometimes I get the feeling that it's kinda like the tail wheel versus nose wheel debate... "real" pilots don't fly with nose wheels or stall warning devices, it's very un-macho

Call me a sissy if you like, but I installed an AOA when I built the plane and am very glad I did!

 

[Ironflight]

Sometimes I get the feeling that it's kinda like the tail wheel versus nose wheel debate... "real" pilots don't fly with nose wheels or stall warning devices, it's very un-macho

Huh?! I bet if you surveyed the aircrfat belonging to ex-military pilots, you'd find a much higher percentage of AOA-equipped planes than in the general RV fleet....AOA is MACHO!

Now stall warning horns, they're for sissys....

 

[Brantel]

I am learning to trust my AOA indicator/alarm more and more every day!!!

 

[Walt]

AOA Survey

Huh?! I bet if you surveyed the aircrfat belonging to ex-military pilots, you'd find a much higher percentage of AOA-equipped planes than in the general RV fleet....AOA is MACHO!..

Good idea Paul, maybe we should set up a survey and see just how many RV's out there have installed AOA's (or other stall warning device) and if possible, what percentage of those folks are military.

 

[David-aviator]

those factors only apply to level flight. Stall speed only increases with AOB when attempting to maintain altitude at that AOB. The Critical AOA of the wing has nothing to do with the geometric relationship of the wing to the earth, which is what AOB is. Its load factor that cause the stall speed to increase not AOB. It is only in that a relationship between AOB and load factor exists in level flight that a correlation can be made.

Next time you go flying climb to altitude, roll into a 60 deg AOB turn and allow the nose to drop and then note your G-meter. Yep - 1.0 (or so). Stall speed is the same then.

You are absolutely correct.

But an insidious danger factor of making a 60 degree bank descending turn to final is if the flight is not on runway center line target (over shoot), it is natural and easy to tighten the turn with back pressure to get lined up properly. That's when the G load goes up and so does the stall speed.

Unless the pilot knows exactly what is going on in terms of G load and increased stall speed by "feel", and that is difficult to determine flying by seat of pants, the flight could end quicker than expected.

That's why the AOA system is so cool. It knows the critical angle of attack and it doesn't matter what the AOB is - just bring the little meter into a cross check and know what it going on instantly, no guessing if your pants are talking to you straight. I did a steep bank (at least 70 degrees) turn today at 100 KIAS at WOT, sure enough the AOA picked it up by coming off the bottom of the green scale, was alive but not yet up into the yellow or red scale. The system works. I've done full stalls to check its brain and it is reliable.

 

[gasman]

I came in on a tight right base for runway 30 and had just pulled the throttle out and gotten the plane slowed down to 80 knots and deployed full flaps, when the controller who thought I was too close to the Cessna touching down ahead of me told/asked me to make a left 270.

I added a little power and and watched my airspeed drop through 70 knots as I initiated the turn, thinking how this was an odd spot I was in, a steep turn.

When the controller requested a 270 degree turn, he expected you to take 90 seconds (a standard rate turn) to make that turn. This should not have been a steep turn.

 

[Andy Hill]

Re AoA gauges... well I'm ex Mil, very used to flying on AoA in that environment, and never once seen a need for one in a straight wing light/simple piston They come into their own with swept wings, large weight ranges, and complex limits (in Config X limited to X units, Config Y another value).

In the above posts, there is talk of needing to "monitor" the AoA - well, just as well monitor the ASI. "Warning horn"? Well, as Paul says, most light aircraft have a AoA warning system - it's called the stall warner

I'm not knocking the systems - if you want one fine, fit one - but I would not agree to them being the safety system to "solve" the stall/spin scenario - the tools and skills to do that are already present, but they do need obeying/monitoring, as does AoA

Andy

 

[Kevin Horton]

Not sure how correct this chart is but if it is correct....

Van's quotes 48 knots stall on an RV6A at gross so 70/48=1.46 so according to that chart you would need to be around 60? bank to stall????

This chart looks approximately correct, but you need to be careful not to take it out of context. The chart shows how much the stall speed increases in a turn at a particular angle of bank, IF you are pulling exactly the g needed for a perfect level turn. In the real world we are constant modulating the g we pull as we note that the altitude is changing, so the stall speed factor will be varying around some average value.

Also keep in mind that this chart assumes there are zero errors in the airspeed system.

Hans - Good job on recognizing the incipient stall and recovering the airplane. What would you do differently next time to avoid the incipient stall in the first place?

 

[JordanGrant]

AOA is a very good thing

My 2 cents:
1) On the standard-rate turn comment, that doesn't necessarily apply since he was in a VFR pattern. Had he been flying IFR in the radar pattern, then yes he would have been expected to fly a standard-rate 270 deg turn.
2) I'm a military pilot, but I do not have an AOA in my plane - yet - I am planning to install one in the near future. AOA gives you so much more and better information on performance (to include stall margin) than the very crude, sometimes inaccurate and indirect measurement of Indicated Air Speed. Although useful for avoiding a pattern stall, a better example of where that information can be a lifesaver might be the post-stall recovery. We all know that when recovering from a stall or incipient stall, you must first decrease the AOA by pushing the stick forward (even when close to the ground). But to minimize the altitude lost, you must push only enough to break the stall, and then you must keep the right amount of back pressure to max-perform the aircraft in the recovery. With an AOA indication, you can keep your aircraft flying at the exact AOA needed to recover your aircraft without threatening to stall again.

One may argue that you can get very close to the perfect AOA by feeling the aircraft - and they would be right. But you need to train yourself to that exact feel when you are out doing practice stalls and slow flight - and this again is where the AOA indication can help, by allowing you to cross-check the perfect AOA and get used to that exact feel. That's how I've done it in the USAF, and it works mighty fine.

Now I need to go spend the money get it for my airplane, too!

 

[Walt]

Re AoA gauges... I'm not knocking the systems - if you want one fine, fit one - but I would not agree to them being the safety system to "solve" the stall/spin scenario - the tools and skills to do that are already present, but they do need obeying/monitoring, as does AoA

Andy

What I like is the AOA also gives you an audible cue in your headset. As everyone knows airspeed can bleed rapidly on the RV when you're low/slow with low power set.

I can't watch the airspeed all the time... when I hear the "Angle-Angle-Push-Push" in my headset I know immediately that the airplane is getting ready to stall.

 

[Toobuilder]

I don't consider a stall buffet in the pattern a big event. I have encountered it many times including once just yesterday. The key to making it a non-event is to know what it feels like and keep the ball centered. If the ball is centered, recovery is often nothing more than a slight, almost inperceptable relaxation of back pressure.

While I'm sure that AOA indicators are a great addition to the panel, they are hardly required on aircraft like these. I think your eyes need to be outside when in the pattern, not searching the instrument panel.

 

[ccarter]

Fly the airplane..

I still remember the exhortation from the PPL training. Fly the airplane. My eyes are outside the airplane in the pattern with occasional glances at the airspeed indicator and flap position (which is usually over my left shoulder even with the indicator on the EFIS.

I've been thinking seriously about an AOA for my Dynon but to be honest, I have plenty of equipment in the cockpit. I don't think there is much of a substitute for being an intuitive pilot, trusting your eye/hand (and butt) input feel the plane, listen to the wind around you and know in advance what your emergency procedures are.... just my 2 cents.

btw, I think these disucussions are great. It's the simplest things that can be fatal when flying these wonderful machines and kicking them around this way makes us all stop and think.

 

[IowaRV9Dreamer]

AOA in turbulent climbs?

This is a great discussion, especially about the AOA. I'm planning on it for my -9A (part of AFS EFIS), but I've never flown with it.

For those that have, do you get momentary AOA "beeps" during turbulence? The Skipper has a little tab on the leading edge for a stall warning horn. Sometimes climbing out at 63 KIAS (which is my Vy, pretty far from stall) if there is a lot of convective bounciness I get little beeps out of the system.

I was just wondering if the same thing will happen with AOA?

 

[Walt]

I have the AOA sport model in my 7 and have never had a false alarm. To my surprise I have had her "speak" to me at 140+kts doing steep high G turns, I was just about to enter an unplanned accelerated stall

 

[Ironflight]

I was just wondering if the same thing will happen with AOA?

It probably depends on the AOA system that you have, how it works, and how much filtering it has in the software (if it is software based).

Personally, I have no trouble at all flying without AOA - I only got it with a software upgrade to my EFIS a year or so ago - but I think that they CAN improve things for some folks down at the low end of the range. It is a good way to fly very short approaches, and stay safe. RV's have adequate aerodynamic stall warning, but it is nowhere near as much as you might be used to with the average SPAM can. If you are inattentive to what you are doing, you CAN suddenly find yourself in a regime where you don't want to be.

Paul

 

[mike newall]

It is a good way to fly very short approaches, and stay safe. RV's have adequate aerodynamic stall warning, but it is nowhere near as much as you might be used to with the average SPAM can.

Paul

In the UK, the LAA (EAA in the 50's) insist on a stall warner for the 7 due to 'little or no natural buffet'.

Can't see it myself but we have to comply.

We can use an AOA provided it lights a light or sounds a horn.

 

[nucleus]

It Was Wake Turbulence

Are you sure you weren't crossing your own wake turbulence?
Making a tight turn with full flaps, you were "low speed, high lift". This configuration creates maximum wing tip vortices.

You know what Mel, I think that is exactly what happened. I was probably a little hyper alert because of the situation, so when I felt that wake burble I assumed it was the beginnings of the RV pre-stall aileron shake. I was crossing my own wake turbulence.

When the controller requested a 270 degree turn, he expected you to take 90 seconds (a standard rate turn) to make that turn. This should not have been a steep turn.

I think the controller said "make a quick 270 just for spacing". It was clear from the traffic situation that 90 seconds would have been too long. Thank you for bringing that up though, I don't think that I have been keeping standard rates in mind.

I am not questioning your technique. I am sure you do the right thing. But as a rule I teach my students to only use full flaps in two scenarios, emergency descents and when fully committed on short final.

I was at pattern height, just about to turn onto short final when I got the instructions. About .3 miles from the numbers. I approached the airport on an extended right base.

I like to slow down as late as possible, then full flaps and steep descent. The constant speed prop slows me down pretty quickly; so to speak. I needed full flaps to keep in the landing zone. I only added a little power because any more and I would have been too high on final.

Thanks for the interesting discussion guys.

Hans

 

[Toobuilder]

Hyper-sensitivity to the stall buffet is useful, fear of it is not. It's great that you are that in tune with your ship... Now keep going! Ideally, you want to be right on the edge of stall buffet in the pattern. The two ways to get there safely (to the edge of buffet) is flying an AoA indicator by the numbers, or knowing what your airplane feels like in that condition. Considering even the military jets are not universally equipped with AoA indicators, it's my opinion that there is a lot more money to be made with our benign, straight wing airplanes by simply learning that corner of the envelope and getting comfortable there. Relying on yet another gadget on the panel does you and your passengers a disservice.

I'm very comfortable with my Hiperbipe flying "eyes outside", and even with my two dozen or so hours in the -8, I rarely look at the panel while in the pattern. I've found that the airplane will scream louder than any gadget in the panel... as long as you are willing to listen!

 

[L.Adamson]

I'm very comfortable with my Hiperbipe flying "eyes outside", and even with my two dozen or so hours in the -8, I rarely look at the panel while in the pattern. I've found that the airplane will scream louder than any gadget in the panel... as long as you are willing to listen!

I'm always catching the airspeed indicator in my 6A from the corner of my eye. Sure, I can land without it; but with the high sink rate of my constant speed prop...........I know that I better be close to the ground as the IAS drops below 65 kias. From that point, it's mere seconds or less before the bottom falls out, so to speak. I don't hear a scream, or feel it in my rear........either. To me, it's a visual thing, and visuals in regards to speed can be decieving. Personally, I wouldn't mind an AOA.

L.Adamson --- RV6A

 

[Toobuilder]

My normal approaches are power off from abeam the numbers on downwind... Do you want to bet which one of us has a higher sink rate?

A RV -6 is a sailplane in comparison to the HB!

 

[Walt]

More Gadgets....

Relying on yet another gadget on the panel does you and your passengers a disservice.

All those "gadgets" make flying safer today then ever before so why not use them?

I remember when TCAS (traffic) & TAWS (terrain) systems came out and became mandatory, folks (mostly pilots) balked saying the same thing "more gadgets in the cockpit won't help", bottom line is they do help.

Folks with thousands of hours and many years of flying experience still make fatal mistakes... when I hear that old phrase "just learn how to fly, listen to your airplane" and everything will be ok, well to me that's just total denial that we as humans make mistakes, and sometime we need some "help" and if I can get that help from a "gadget" then bring it on.

 

[sjjonesnz]

Remember the stall speed is affected by g-loading (and not angle of bank per se) and can easily be calculated - it's the square root of the g-load multiplied by the stall speed at 1G.

Sooo, if your machine has a dirty (ie flaps down ) stall speed of 47 knots, and you roll into a 2G turn, your 'new' stall speed is 1.414 x 47 = 66.5 knots.

Now I know I approach with full flaps at ~70 knots, so that would give me a safety margin of ~3.5 knots...which isn't much especially if the relative headwind drops off or I inadvertantly pull to 2.5G (which would give me a stall speed of 74 knots!!) I'm hoping I'm not close to the hard stuff when that happens.

Remember, we're called "Pilot in Command" for a reason and I'd much rather tell the controller that I'm unable to comply and debate it later, than have the feds (and my friends and family) ask why I did something so stupid as to stall in!!

Great thread by the way...

 

[Toobuilder]

All those "gadgets" make flying safer today then ever before so why not use them?

Gadgets help if they augment, not replace basic flying skills. Far too many of us are fiddling or monitoring when we should be flying. As the Colgan Air crash shows, all the gadgets in the world won't help if there is a fundemental lack of understanding about the airplane's behavior.

 

[hevansrv7a]

Stall bufffet in the pattern?

... Ideally, you want to be right on the edge of stall buffet in the pattern. ...

That's not the way I learned to fly. It sounds a little risky to me and unnecessarily so. Is it just me or not? I was taught to use a pattern speed of about 1.3x stall. There is plenty of time to get slowed down on final. If your pattern speed is at the stall buffet, how can you flare?

 

[L.Adamson]

Gadgets help if they augment, not replace basic flying skills. Far too many of us are fiddling or monitoring when we should be flying. As the Colgan Air crash shows, all the gadgets in the world won't help if there is a fundemental lack of understanding about the airplane's behavior.

We can get into a can of worms here. I know a flight instructor who maintains that the use of VOR's is basic skills, and that all cross country flight planning should involve the use. GPS is a "backup", according to him.

I say "bull". IMO, GPS is a modern day "gadget" that provides far more information in regards to safety of the pilot and passengers......than was ever available from radio nav. I have plenty of accident statistics to prove it.
So yes, I get perturbed when devices are referred to as gadgets, and especially if the word "toy" is used.

And, I'm getting off track here, since the thread is "stalls".

L.Adamson -- RV6A

 

[Walt]

Stall warning devices

A Stall warining device (or AOA with aural warning) is the most basic of aerodynamic "gadgets".

I can only ponder if some of the most recent RV accidents that appear to have stalled in the classic base/final turn, with highly experienced pilots flying, may have been prevented if they had this simple and relatively inexpesive device installed.

We love to install fancy glass panels, autopilots, dual redundant everything, leather interiors etc. but just can't seem to find the panel space, time or $$ for the lowly stall warning device, go figure.

Ok off my soap box...

Fly safe

 

[Toobuilder]

That's not the way I learned to fly. It sounds a little risky to me and unnecessarily so. Is it just me or not? I was taught to use a pattern speed of about 1.3x stall. There is plenty of time to get slowed down on final. If your pattern speed is at the stall buffet, how can you flare?

You?re right. In my mind, this discussion is less about proper, FAA approved patterns and more about max performing the airplane close to the ground for some reason (in this case, for traffic). It is in that context that my comments should be judged.

 

[John Clark]

Stall-spin

But an insidious danger factor of making a 60 degree bank descending turn to final is if the flight is not on runway center line target (over shoot), it is natural and easy to tighten the turn with back pressure to get lined up properly. That's when the G load goes up and so does the stall speed.

David, I agree but there is another important factor in the all too frequent "stall-spin" crashes that we are seeing. People try to correct the overshoot to final with back pressure and too much rudder. Adding a skidding condition to the situation almost insures the spin entry if the stall does occur. The beginning of a stall at pattern altitude can be fixed, a spin entry, not likely.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

 

[Jamie]

David, I agree but there is another important factor in the all too frequent "stall-spin" crashes that we are seeing. People try to correct the overshoot to final with back pressure and too much rudder. Adding a skidding condition to the situation almost insures the spin entry if the stall does occur. The beginning of a stall at pattern altitude can be fixed, a spin entry, not likely.

Agreed....if you are coordinated the airplane should not spin, even in a 60 degree bank when stalled.

 

[TThurston]

Gadgets

As far as I know, the Wright flyer used a bit of yarn on a stick as an AOA indicator. The yarn might not be tolerent of RV speeds, hence the need for an update. But it's an OLD gadget, as old as they come.

 

[Sid Lambert]

The RV seems to stall at the same stick position no matter what speed. Stall the airplane in level flight at the slowest speed possible and make note of the stick position. Now speed up 15 MPH, put it in a turn and stall it. The stick will be in the same aft position. You could almost put a micro switch on the stick as a stall warning system.

 

[Toobuilder]

...So yes, I get perturbed when devices are referred to as gadgets, and especially if the word "toy" is used...

I am a huge fan of technology, and it can certainly make flying safer and more efficient. I have a problem though, when the technology becomes a distraction or a crutch for poor airmanship. I know a guy who nearly had a midair because he was ?eyes inside?, playing with his new GPS. I'm guilty myself - I've spent far too much time trying to get the EGT on one cylinder within a degree or two of where I want it... Why? because the EMS display gives that level of fidelity. Where is the safety in that?

More to the point of this discussion, if you?re on a left base to final turn and you need to suddenly tighten it up to avoid an airplane on a right base to final for your runway, are you going to take the time to search the panel for an AoA indicator, or are you going to simply max perform the airplane because you know how to fly it well? An AoA system is not going to "solve" the problem any more than the stick shaker and stick pusher solved the Colgan Air "problem".

In any case, I think we're in violent agreement here - all I?m saying is to use technology if it adds to your skill set, not as a replacement?

 

[JordanGrant]

Would you rather have AOA or IAS?

This is a great thread and good discussion. Here's a mental exercise for you: If you had to choose between an AOA indication and airspeed indication in your cockpit, which would you choose? After all, most of the same comments about "feel" of the aircraft are equally valid with respect to airspeed indicators. If you know what the pitch picture and feel of the airplane should be, you really don't need them to safely fly the airplane.

My answer: I'd clearly rather have AOA. Airplane performance is based on AOA - the same AOA, every time, regardless of bank angle, G, airspeed, weight, altitude, temperature, etc. That is not true of IAS.

Cheers,

 

[John Clark]

IAS vs AOA

My answer: I'd clearly rather have AOA. Airplane performance is based on AOA - the same AOA, every time, regardless of bank angle, G, airspeed, weight, altitude, temperature, etc. That is not true of IAS.

OK, but it is tough to use an AOA for Vne

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

 

[David-aviator]

This is a great thread and good discussion. Here's a mental exercise for you: If you had to choose between an AOA indication and airspeed indication in your cockpit, which would you choose? After all, most of the same comments about "feel" of the aircraft are equally valid with respect to airspeed indicators. If you know what the pitch picture and feel of the airplane should be, you really don't need them to safely fly the airplane.

My answer: I'd clearly rather have AOA. Airplane performance is based on AOA - the same AOA, every time, regardless of bank angle, G, airspeed, weight, altitude, temperature, etc. That is not true of IAS.

Cheers,

Now you're talking like an airline pilot, Jordan.

The lowest minimum approach we made (10 years ago) was a CAT3 with auto land. It was predicated on AOA, not IAS. A properly calibrated AOA is bullet proof. It knows what speed is required for safe flight, weight doesn't matter, angle of bank doesn't matter, G load doesn't matter.

It takes about .2 of a second to check an AOA gage whenever there is any doubt a tight turn or when making a critical short field approach. We all have a certain innate talent to fly by the seat of our pants, but backing it up with an instrument just seems to make good sense. That's why we are required to have flight instruments rather than use string as did the Wright brothers.

No one trusts their inner ear in a cloud, I don't trust butt feel much more. I like AOA. It is relatively simple, not all that expensive, and it works.

 

[Toobuilder]

No one trusts their inner ear in a cloud, I don't trust butt feel much more. I like AOA. It is relatively simple, not all that expensive, and it works.

...as long as you know how to use it...

But let?s keep the discussion in proper context, because it?s not about the merits of AoA as a useful tool in the cockpit.

The OP had a stall buffet in the pattern, and it was a noteworthy enough event in his life to merit a post on the forum. Several others apparently felt this buffet was a ?problem? and offered the AoA as a ?solution?. Fair enough. Now, since I encounter a slight stall buffet in the pattern quite often, I don?t consider this a ?problem? at all? It?s an easily managed, normal fact of life when flying at CLmax, and generations of military pilots know this. Therefore, I have deduced (right or wrong) that the OP and other members are not comfortable flying at CLmax because (again, right or wrong) they lack a basic understanding of what is happening. With that premise, the question of the day becomes: What represents better value ? installing an AoA instrument, or learning more about flying at CLmax? Some have opined that the instrument will save the day; I offer that learning the airplane is better.

Best of all: learn the airplane AND install AoA (then learn how to use it to full advantage)!