Angle of Attack
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Angle of Attack
Comments please. I think the aircraft is great. I love the AOA device.
https://www.youtube.com/watch?v=2wlvpJLcf-A
https://www.youtube.com/watch?v=2wlvpJLcf-A
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100% agree!!
The Wright Bros understood the importance of AOA from the very beginning.
My landings in the 727 greatly improved when I started using the Honeywell Fast/Slow AOA indicator that was equipped on some of our planes.
It proved, often, that our zero fuel weight, as provided by load planning was, indeed, incorrect.
The Wright Bros understood the importance of AOA from the very beginning.
My landings in the 727 greatly improved when I started using the Honeywell Fast/Slow AOA indicator that was equipped on some of our planes.
It proved, often, that our zero fuel weight, as provided by load planning was, indeed, incorrect.
Last edited by wanabee777; 8th Jan 2016 at 00:30.
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Totally agree and surprised at the lack of AOA in light GA also that A5 looks a great little Sea plane and a lot of fun.
We have an AOA on the Citation and you could disregard the ASI and just fly the gauge for more accurate speeds and approach.
My only concern without reference to another instrument is if the AOA instrument failed or false read which could land you in a dangerous mess
So I would still want an ASi and preferably 2 separate AOA to cross reference
Pace
We have an AOA on the Citation and you could disregard the ASI and just fly the gauge for more accurate speeds and approach.
My only concern without reference to another instrument is if the AOA instrument failed or false read which could land you in a dangerous mess
So I would still want an ASi and preferably 2 separate AOA to cross reference
Pace
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I've been banging on about this on here for decades! AoA is what the wing knows - there is NO SUCH THING as stall speed, only stall angle. Yet every time the tired old responses come back supporting use of air speed in stall avoidance.
The GA world does NOT think AoA. The airliner world is obsessed by 'speeds', and the only airliner I know with an AoA indicator is Concorde!
As the video says, the military know better. They always think AoA, just as the aeroplane does.
I've said it before, and here it is again.... I'd trade just about any instrument on the Chipmunk's panel for an AoA indicator!
There's been a problem to date with fitting them to prop singles - the propwash mucks up AoA measurement using conventional sensors. One wonders if it's significant that the aeroplane in the video is a pusher?
The GA world does NOT think AoA. The airliner world is obsessed by 'speeds', and the only airliner I know with an AoA indicator is Concorde!
As the video says, the military know better. They always think AoA, just as the aeroplane does.
I've said it before, and here it is again.... I'd trade just about any instrument on the Chipmunk's panel for an AoA indicator!
There's been a problem to date with fitting them to prop singles - the propwash mucks up AoA measurement using conventional sensors. One wonders if it's significant that the aeroplane in the video is a pusher?
I'm a big provisional fan of AoA. Provisional because I think that for GA there are a bunch of best practice issues still to be sorted out and, whilst clearly you can do without AoA, you can't actually do without airspeed - if only to determine the rotate point. You also need speed or altitude in the cruise, as reference solely to AoA is a recipe for phugoids.
The military don't use AoA exclusively - they do usually use it for approaches and some combat manoeuvring in fast jets. For various other things they also use IAS and/or IMN.
Testing out IAoA instrumentation and developing some best practices has surely to be an ideal use of the new CAA E-conditions?
G
The military don't use AoA exclusively - they do usually use it for approaches and some combat manoeuvring in fast jets. For various other things they also use IAS and/or IMN.
Testing out IAoA instrumentation and developing some best practices has surely to be an ideal use of the new CAA E-conditions?
G
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Most light GA types don't have a 'rotate point'. They fly when they are ready!
Used to break my heart to watch the Manchester-based flying school PA 38s doing circuits at bumpy Barton - hammering down the runway up to and beyond the point the aeroplane would happily fly, elevator firmly down, nose leg having seven sorts of sh*te kicked out of it, until some mythical 'rotate speed' was achieved, way too far down the runway, and the little Tommy gave a prayer of thanks as it left the ground like a cork out of a champagne bottle, at last allowed to take to its natural element!
And this video isn't calling for the abolition of 'speeds', only 'stall speed', which doesn't exist as an absolute.
Used to break my heart to watch the Manchester-based flying school PA 38s doing circuits at bumpy Barton - hammering down the runway up to and beyond the point the aeroplane would happily fly, elevator firmly down, nose leg having seven sorts of sh*te kicked out of it, until some mythical 'rotate speed' was achieved, way too far down the runway, and the little Tommy gave a prayer of thanks as it left the ground like a cork out of a champagne bottle, at last allowed to take to its natural element!
And this video isn't calling for the abolition of 'speeds', only 'stall speed', which doesn't exist as an absolute.
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There's been a problem to date with fitting them to prop singles - the propwash mucks up AoA measurement using conventional sensors. One wonders if it's significant that the aeroplane in the video is a pusher?
I am no electronics person and have little faith in the stuff, but a simple rheostat switch that can move a needle to represent zero to seventeen degrees over an actual needle movement of forty five deg can't be beyond the wit of mankind, at a sensible price?
I wouldn't utter the words "stall speed" in close proximity to SSD as that would equate to invoking the wrath of Khan! I've tried in the past!
Are the AOA indicators on GA aircraft calibrated to the cruise or landing config ?
This is obviously independent of configuration, and is usually set to show the AoA of the wing with a 'clean' aircraft, but this can be modified by sensors on the flaps, gear, and other adjustable devices, to take into account configuration changes.
MJ
Ps. Some students just don't seem to be able to visualise the AoA thing at all, and I find that a length of bamboo cane, with a piece of wool on the end, taped to the underside of the outboard section of the wing, and protruding far enough in front to be clear of the effect of the wing on the airflow, works sufficiently well as a crude alpha indicator to get the point across.
Last edited by Mach Jump; 7th Jan 2016 at 22:02. Reason: Added Ps.
I guess I'm the odd man out, I just don't see the point. If you understand basic pilot-level aerodynamics, it's all obvious. And if you don't, all the fancy gauges in the world won't help you. Hence it wouldn't have helped with AF447, because those guys were just totally lost and in tunnel-vision panic mode, to do what they did. (And ditto the recent Air Asia accident). If it isn't obvious to you that keeping the stick hard back while descending at 5000+ fpm is a bad idea, one little instrument among many won't help.
I've been yelled at on here for daring to utter the phrase "stall speed", but actually it's a pretty useful concept. It's extremely rare to try and land (or take off) in a 60 degree bank, never done it myself. And if you can remember some very simple math, the airspeed indicator makes a pretty decent AoA susbtitute assuming you're not trying to do loops.
I've been yelled at on here for daring to utter the phrase "stall speed", but actually it's a pretty useful concept. It's extremely rare to try and land (or take off) in a 60 degree bank, never done it myself. And if you can remember some very simple math, the airspeed indicator makes a pretty decent AoA susbtitute assuming you're not trying to do loops.
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I hope this doesn't degenerate into a screaming "stair head rammy" (Scottish expression) over stall speeds. Let's just agree that we all are aware of AoA.
SSD, I too would trade a few instruments for such a device, ASI being one of them. Although it may be of some use for Nav in the event of GPS failure.
The wooly stick ahead of the wing? Ok but a little crude. For GA light stuff I don't think sensors on flaps or other configuration changing devices is necessary.
It needs to be neat, tidy, and do a reasonable job on a clean a/c. If it were to read "stall" when clean and the flaps are down it is erring on the safe side.
If such a device could be built at a sensible price I think it would be taken up, especially if it could be retrofitted to anything. An expensive box of electronic junk costing an arm and leg to be certificated will not be.
My daft idea of lashing a fuel gauge tank sender unit wind vane thing to an u/c leg reading to a fuel gauge with instant read out is still on the drawing board, my a/c being permit powered I may try something this summer just for fun if nothing else. Any advice gratefully received.
SSD, I too would trade a few instruments for such a device, ASI being one of them. Although it may be of some use for Nav in the event of GPS failure.
The wooly stick ahead of the wing? Ok but a little crude. For GA light stuff I don't think sensors on flaps or other configuration changing devices is necessary.
It needs to be neat, tidy, and do a reasonable job on a clean a/c. If it were to read "stall" when clean and the flaps are down it is erring on the safe side.
If such a device could be built at a sensible price I think it would be taken up, especially if it could be retrofitted to anything. An expensive box of electronic junk costing an arm and leg to be certificated will not be.
My daft idea of lashing a fuel gauge tank sender unit wind vane thing to an u/c leg reading to a fuel gauge with instant read out is still on the drawing board, my a/c being permit powered I may try something this summer just for fun if nothing else. Any advice gratefully received.
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Back in the '70's, we used the AOA indicator on the KC-135 to tell us our best range angle of attack, best endurance angle of attack, as well as our stall angle of attack.
I never understood why the airlines are so reluctant to incorporate such a useful instrument throughout their fleets.
I never understood why the airlines are so reluctant to incorporate such a useful instrument throughout their fleets.
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I assume most of the GA AOA gauges on the market do not have the config sensors, and are either on a fixed calibration for landing or cruise which could lead to some false interpertation at best or conversely encourage a pilot who was unsure of the setup and was flying close to the performance envelope to Stall while they correctly read a gauge that shows they are not near that point.
Oops. 
Yes there are:
Angle Of Attack Indicators from Aircraft Spruce
I think it's a safe bet that these accessory AoA systems do not take into account config. changes, so I imagine you can set them up to indicate correctly in whatever config. you like best, but only one.
As Genghis says, If they become a popular accessory, we will need to establish conventions for what the best config. for that would be, and I imagine that most would agree that calibration in the 'clean' config. would probably offer the safest compromise, in most cases.
MJ
Yes there are:
Angle Of Attack Indicators from Aircraft Spruce
I think it's a safe bet that these accessory AoA systems do not take into account config. changes, so I imagine you can set them up to indicate correctly in whatever config. you like best, but only one.
As Genghis says, If they become a popular accessory, we will need to establish conventions for what the best config. for that would be, and I imagine that most would agree that calibration in the 'clean' config. would probably offer the safest compromise, in most cases.
MJ
Last edited by Mach Jump; 8th Jan 2016 at 01:11.
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The Piper Cheyenne II I used to fly had AoA as a part of its type design, and you lived by it, but it was a slinky plane. That said, for GA aircraft, I tend to agree with
I liked the Icon video, and am intrigued by the aircraft. I greatly respect the philosophy and effort toward safety, but if industry makes planes too "safe" pilots may forget to take responsibility for the safety of the flight themselves. If a pilot learns on the super safe Icon, how safe would they be while piloting a more mundane GA aircraft? It might be like getting your multi engine rating in a Cessna 337, should you really have a multi engine rating applicable to the regular fleet?
I installed an Alpha Systems AoA system in a client's Cessna amphibian. I set it all up (which was quite easy), and it worked very well. I even mounted it well forward on the glare shield, so it was more "eyes out". After 60 hours of flying the plane, I could not think of a time I looked at it, other than to confirm it was working. I just had no sense of need.
I had an older "lift reserve indicator" (form of AoA - same function) in my 150 for a while, but found I never looked at it. If I were landing into a place so tight that I would actually need to refer to it, I was much too busy watching where I was going outside, to ever look at an instrument in the panel.
I know that aircraft stall at an AoA, rather than a speed. For me, the stall is warned in the seat of my pants, and I refer to the airspeed if I'm curious about it.
I hope that the generation of pilots who learn on hyped instrumented GA aircraft also learn to fly them well, when the instruments quit, or go kaflooey. The AF447 pilots (for two) seemed to have missed that lesson. We can't be training around basic flying skills, just because there is new tech!
If you understand basic pilot-level aerodynamics, it's all obvious. And if you don't, all the fancy gauges in the world won't help you.
I installed an Alpha Systems AoA system in a client's Cessna amphibian. I set it all up (which was quite easy), and it worked very well. I even mounted it well forward on the glare shield, so it was more "eyes out". After 60 hours of flying the plane, I could not think of a time I looked at it, other than to confirm it was working. I just had no sense of need.
I had an older "lift reserve indicator" (form of AoA - same function) in my 150 for a while, but found I never looked at it. If I were landing into a place so tight that I would actually need to refer to it, I was much too busy watching where I was going outside, to ever look at an instrument in the panel.
I know that aircraft stall at an AoA, rather than a speed. For me, the stall is warned in the seat of my pants, and I refer to the airspeed if I'm curious about it.
I hope that the generation of pilots who learn on hyped instrumented GA aircraft also learn to fly them well, when the instruments quit, or go kaflooey. The AF447 pilots (for two) seemed to have missed that lesson. We can't be training around basic flying skills, just because there is new tech!
Most so-called 'AoA' indicators for light SEP aircraft are nothing of the sort. They rely on pitot and static pressure sesnsors, from which they 'deduce' AoA - usually on an overcomplicated display unit, to give the impression that they're worth the cost.
The aircraft I've flown with real AoA gauges displayed 'units' on a simple dial and had either an audio tone system (Buccaneer) or simple visual warning display (F-4).
I wouldn't recommend one of the current GA 'AoA' devices until someone has found a way of directly detecting actual difference between chord line and relative airflow and displaying it on a simple indicator.
The Russians have an excellent performance indicator in some of their aircraft - a combined 'g' meter and AoA gauge. Pull to whichever value is the more limiting and you're at your best turning performance!
Another of their very sensible instruments is a combined turn and slip and VSI - excellent for standby instrument work.
The aircraft I've flown with real AoA gauges displayed 'units' on a simple dial and had either an audio tone system (Buccaneer) or simple visual warning display (F-4).
I wouldn't recommend one of the current GA 'AoA' devices until someone has found a way of directly detecting actual difference between chord line and relative airflow and displaying it on a simple indicator.
The Russians have an excellent performance indicator in some of their aircraft - a combined 'g' meter and AoA gauge. Pull to whichever value is the more limiting and you're at your best turning performance!
Another of their very sensible instruments is a combined turn and slip and VSI - excellent for standby instrument work.
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AOA indication in the million-dollar cockpit chez Smasher is my butt which also does sideslip. Bargain!
If my bum tells me my ship is languishing and the controls are labouring at the air (ok, my hands are in on this, too) then AOA is high. If my behind says the ship feels tight and buoyant, AOA is low and it's all good. I sense the aeroplane's motion, weight and response through my magic posterior which is absolutely art rather than science.
The further away you get from flying by the seat of your pants the closer you come to flying by numbers. By the time you reach jet fighters, airliners and tankers this justifies investing in a proper AOA gauge, one that gives you useful, calculated metrics like best range and endurance, rather than vague notions like "low" (aircraft feels firm beneath me), "high" (mushing around) and "dead" (clenched.)
If my bum tells me my ship is languishing and the controls are labouring at the air (ok, my hands are in on this, too) then AOA is high. If my behind says the ship feels tight and buoyant, AOA is low and it's all good. I sense the aeroplane's motion, weight and response through my magic posterior which is absolutely art rather than science.
The further away you get from flying by the seat of your pants the closer you come to flying by numbers. By the time you reach jet fighters, airliners and tankers this justifies investing in a proper AOA gauge, one that gives you useful, calculated metrics like best range and endurance, rather than vague notions like "low" (aircraft feels firm beneath me), "high" (mushing around) and "dead" (clenched.)