Marauder
Cleared for Takeoff
- Joined
- Oct 24, 2012
- Messages
- 1,463
- Display Name
- Marauder
Chuck Yeager's opinion on AoA indicators, a little past 2 minutes into the video.
http://youtu.be/19nIwIXL32s
http://youtu.be/19nIwIXL32s
Oh jesus!
How about learn to fly the damn plane lol
Maybe if he wasnt soooo busy looking at all the flashing lights and dials he could have hit that center line![]()
It is "FAA approved" but only to the extent that the FAA has officially recognized that the installation is a minor modification and does not require a STC.
..the Alpha System device is not considered primary for stall indication. A placard should indicate this..
I would be cautious on relying on the Alpha System, specially under icing conditions. AOA are very helpful in determining proximity to stall under icing conditions. A frozen AOA sensor could mislead you to believe you are not close to a stall condition when in fact you are. This is one reason why they need to be FAA approved
I would be cautious on relying on the Alpha System, specially under icing conditions. AOA are very helpful in determining proximity to stall under icing conditions. A frozen AOA sensor could mislead you to believe you are not close to a stall condition when in fact you are. This is one reason why they need to be FAA approved
So are you stating that AoAs serve no purpose? If so, why are they required in so many aircraft?
A 172 isn't a Lear, but that doesn't mean there aren't benefits to be had.
The AoA meters, lights, etc do as advertised, no question.
However in a small plane light like a 7AC, 150, 172, PA28, many small trainer twins, etc, you REALLY should be able to feel your wings just fine, furthermore these small planes will tell you in a million ways, sound, feel, buffeting, stick force, etc WAY before you get into the big boogie man stall spin they keep talking about.
My personal plane doesnt have one, nor does she have a stall horn or light, I can sure as heck tell what my wing is doing though.
Perhaps the money spent outfitting a 172 with AoA meters would be better spent on some REAL spin and maybe aerobatic training??
You've got it exactly backwards. One can stall at any airspeed, but always at the same angle of attack. And please, listen just this one time. The lives of your passengers are in danger.An AOA does not tell you that safety margin but the airspeed indicator does.
Way to miss the point. It's all about the reserve of what Langeweische calls "buyoancy". Everyone can sense when airplane is about to stall, duh. But it's too late unless you're about to touch down. And making that "WAY" uppercase still doesn't do it large enough.However in a small plane light like a 7AC, 150, 172, PA28, many small trainer twins, etc, you REALLY should be able to feel your wings just fine, furthermore these small planes will tell you in a million ways, sound, feel, buffeting, stick force, etc WAY before you get into the big boogie man stall spin they keep talking about.
TSOs are not required for "supplemental" equipment (i.e. items not required by FAR or TCDS). All the aftermarket AoA systems are supplemental and the only ones that require any certification are the kind that tap into the existing pitot static system.Headset are a minor installation still they need to be TSOd for use in aircraft. AOA indicators for certificated aircraft need to be FAA TSO-c54 approved, like the Safe Flight devices. However it could be because the airplane already has a certificated stall indicator that the Alpha System device is not considered primary for stall indication. A placard should indicate this. AOA sensor installation is not trivial and is unique for each aircraft model.
The Alpha AoA probe can include a heater which provides good protection in icing conditions, something I can vouch for personally. And due to the geometry of the probe the gauge always reads zero (fully stalled) if you leave the heat off and it ices up. IMO (based on several years of flying a deiced twin with AoA) your concerns are unfounded (but worth considering nonetheless).I would be cautious on relying on the Alpha System, specially under icing conditions. AOA are very helpful in determining proximity to stall under icing conditions. A frozen AOA sensor could mislead you to believe you are not close to a stall condition when in fact you are. This is one reason why they need to be FAA approved
José
....
Now let's take a look at the accident statistics which seem to indicate that many people fail in this department for one reason or another and do stall/spin/die. ....
... But it's too late unless you're about to touch down. ...
So in 54 posts or less we are at the point that one can fly without an AOA device and we are reminded that we can fly without most of the instruments and tools which reside in our 1/2 decade old aircraft.
We also know that no instrument works in every situation and in every weather condition.
However.
Each of the tools we have is useful if not used in the extreme or to excess.
So -- the forum has given us some insight where the tools are useful and where they are not, and like most flying forums there are some strident folks which drive home the points in grand fashion.
Great entertainment Eh..
And if you read between the lines you get the benefit of many hours of flying experience.
Better than watching reruns on TV.
Oh, I do have an AOA and I like it for what it does for me. (as I do enjoy the Ipad /Garman/Zaon/ new seat covers and BAS belts...etc. )
A simple list of pros and cons would have been as useful but not nearly as much fun.
![]()
I believe an AOA Indicator in my periphery (and in my headset) makes me a safer pilot.
I don't really care if someone (even a general) thinks AOA is only needed by a weak pilot or that it serves no purpose, or that a real aviator only needs to listen to the wind or feel for the burble. But as long as I continue to see good, experienced pilots auger in on base to final, I will gladly accept a crutch and offer myself up for ridicule.
I don't know you from Adam, but you, sir, are one exceptionally intelligent man.
Which is why I wish on that revamp of the PTS the feds did a little while back they would have brought back spin training, not just BS avoidance. Prior to 1949 when the CAA REQUIRED spin training (as in demonstrating a full spin and recovery on heading).
Look even a little girl with no AOA, TCAS, G1000, BRS, Radar, Auto throttles, or even a frikin engine can do it!
Nobody is saying that AOA would magically solve all crashes. On a 777 I assume they had such an instrument, in fact, and it was probably showing that their AOA was well above normal, heading for a stall. They chose to ignore it just as they did the airspeed indicator and the outside sight picture. (This is given a certain set of assumptions about the crash and I am not trying to cast judgement on the pilots themselves yet)Notice that on the Asiana flight 214 that crashed at SFO a drop in air speed that caused loss in altitude was the root cause of the accident. There is no mention of AOA, but failure by the pilot to maintain the target speed of 137 Kts.
No, it's not. Angle of attack is what keeps the plane flying and the wing developing lift. If you want to "measure" that by airspeed, and fly based on a set of safe airspeeds, fine, but you need to have some understanding of what keeps that wing flying. I fly by a set of speeds too, and I don't have an AOA indicator, but I understand what is really happening to that wing, and how airspeed and attitude relate to the AOA the wing is experiencing.No doubt that AOA provides some added safety but airspeed is key to all phases of flight, from take off to landing.
And AOA indication is deceaving at times, like on take off. On the take off run the AOA indicates you are not close to stall while the airspeed tells you are below Vs. You go by air speed Vr to rotate at the proper time not by AOA.
But then Ted why my plane over the runway at 20kts and AOA in no stall indication does not get off the ground when I pull on the yoke. But I know that as soon I reach 80kts I can pull on the yoke and it will get airborne. You may have notice that the POH never mention AOA but airspeeds. And then how come you don't have an AOA indicator?
José
Actually during the takeoff run, at around 10 knots I get the first, leftmost red light (deep in a stall), and as I accelerate, the lights move to the right, telling me my AOA is decreasing. At around 55=60, the red lights go out, the blue light illuminates, I rotate, continue to accelerate, and I climb out with a yellow light illuminated. One technique is to use the AOA indicator to determine when the plane will fly, independent of weight and other factors.
Notice that on the Asiana flight 214 that crashed at SFO a drop in air speed that caused loss in altitude was the root cause of the accident. There is no mention of AOA, but failure by the pilot to maintain the target speed of 137 Kts. No doubt that AOA provides some added safety but airspeed is key to all phases of flight, from take off to landing. And AOA indication is deceaving at times, like on take off. On the take off run the AOA indicates you are not close to stall while the airspeed tells you are below Vs. You go by air speed Vr to rotate at the proper time not by AOA.
José
But then Ted why my plane over the runway at 20kts and AOA in no stall indication does not get off the ground when I pull on the yoke.
Interesting, and perhaps I was stretching my knowledge of AoA indicators a bit. Logically, though, shouldn't the true angle of attack remain constant, probably around 0 degrees (depending on the airframe and wing), as you accelerate on the ground? In other words, I would assume that the angle of attack would be similar on the ground at 20 knots and in level cruise at 120 knots. Perhaps it's taking more into account than I realized.
Edit -- Ok, I looked up the Alpha Systems product. Do you have what they refer to as a "reserve lift indicator?" It seems like it takes two pressure readings and uses the difference to generate something similar to an angle of attack. I wonder if that explains why it's different on the takeoff roll when the plane really isn't flying yet, even though the angle of the wind creates a low angle of attack.
From Ted
No, it's not. Angle of attack is what keeps the plane flying and the wing developing lift. If you want to "measure" that by airspeed, and fly based on a set of safe airspeeds, fine, but you need to have some understanding of what keeps that wing flying. I fly by a set of speeds too, and I don't have an AOA indicator, but I understand what is really happening to that wing, and how airspeed and attitude relate to the AOA the wing is experiencing.
But then Ted why my plane over the runway at 20kts and AOA in no stall indication does not get off the ground when I pull on the yoke. But I know that as soon I reach 80kts I can pull on the yoke and it will get airborne. You may have notice that the POH never mention AOA but airspeeds. And then how come you don't have an AOA indicator?
José
Logically 20 on the ground and 120 in the air would both seem the same. I'm still not sure how that works. Maybe it reads the diverted air off the leading edge instead of strictly the oncoming wind.
Yep, I think all the Alpha Systems are considered reserve lift indicators, and the probe has two holes, as you describe.
... they do it in a controlled training environment they will without question be able to do it when it matters most....
....What you describe in their abilities is just what I did, what my students have done, and what most others have. It's nothing special. We've all done it.....
.... How much actual experience do you have doing real flying? It's obviously low, and you've dodged the question when I've asked before. ....
Thanks. I wonder how it would display on a "big jet."
Okay...I'll say what everyone else wants to...
You
Should
Not
Be
Flying
A) all training is done in a controlled environment, sim engine failures to lost procedures, that's just training
B) BS! you are trying to tell me MOST sudden pilots practice full spins and revocover on heading!
C) I don't recall you ever asking me that.
I have over 3000hrs at this point, flew floats and Tailwheel in the PNW, so yea did the weather thing, flown 200seres from coast to coast and back, half of which IMC, flown AG, flown turbine, gold seal CFI a few times over, did photo work, flown DZ work, flown.....
Log about 100hrs a month on average, own my own plane too
How bout you champ?
The more that people trot out their "merits," the more it shows their shortcomings.
Exactly. People manage to crash doing things in reality they did fine in training. So, doesn't it make sense to have extra safety nets? The rest of the industry thinks so.
Sorry, not what I was trying to imply. Stalls and other seat of the pants "fly the plane" stick and rudder skills is what I was getting at.
WRT the spins and recover on a heading, the stats on that were pretty clear that it was far more useful to recognize and recover first than to know how to recover from a spin since you'll be too low to recover once you're in.
Now I get it. My initial impression was that you were sub-500 hours. But your hours also explain your attitude - I see mostly stick-and-rudder flying listed in your credentials, and if you fly 100 hours a month on average, then you probably don't remember what it's like for many people who don't fly that regularly and might not have that same level of proficiency and capability. What surprises me is that you don't see what happens to pilots who don't get to fly as much. That was the biggest thing instruction taught me. And while we seem to be in agreement that people should be doing stick and rudder exercises, your clearly macho attitude regarding other safety nets is where we differ.
2000+ hours, about 1600 multi almost all in piston twins with about 50 hours in a Cheyenne and Commander 690. Long XCs - 8-10 hours on the hobbs is a common day for me, so is ending up in a different time zone/climate/country from where I started. My trip to Canada last month was 11 in a day going to middle of nowhere uncontrolled airspace in Quebec. See the map in my signature. Why check the weather, I'm going anyway kind of trips. Ice, storms, low approaches to mins, etc. Used to be 500 hours a year in a combination of planes (last year I had 7 different planes I flew regularly), now down to 100ish. Really don't use the autopilot much, and most of my flying has been single pilot IFR.
And the biggest thing I've learned is that, while my insurance broker has told me that pilots like me they don't worry about crashing, I know I am human and can make mistakes like all the other people who've crashed before me. I don't need all the shiny gismos, but I do like having them since one day they might help me not me a statistic should I screw up.
Guess that makes me a wimpy pilot for acknowledging what the rest of the industry realized a long time ago.![]()
You're Billy Bad Ass Pilot, you should be able to figure it out with all your spouted credentials.