Does any 'heavy metal' use AoA gauges?
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Does any 'heavy metal' use AoA gauges?
Hi learn'ed folk, I have seen several posts that suggest the universal panacea is to place the airplane in a pitch attitude of +15 degrees.
This is all very well if your original flight path is horizontal, but not so good if the flight path is -20 degrees or more.
Surely an Angle of Attack meter would be an asset, instead of the usual AI.
Do any large airplanes have these AoA gauges?
I think they may be fitted to some smaller executive jets.
After all the wing's Cl. is determined by AoA and not by Pitch Attitude.
This is all very well if your original flight path is horizontal, but not so good if the flight path is -20 degrees or more.
Surely an Angle of Attack meter would be an asset, instead of the usual AI.
Do any large airplanes have these AoA gauges?
I think they may be fitted to some smaller executive jets.
After all the wing's Cl. is determined by AoA and not by Pitch Attitude.
Last edited by phiggsbroadband; 22nd Dec 2013 at 13:09. Reason: typo
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It is a user option on the 737. The military customer seem to order that option, however i haven't seen it in an airline configuration yet. The space where it would be displayed on the PFD is often used for an analog RA display.
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Just turn the flight path vector on. Difference between pitch attitude and flightpath = AoA...
Big AoA user and "indicator" advocate here.
Military likes the display because of the operational requirements and the ability to nail approach speed/AoA after a rough calculation from the book for weight and configuration and ....
We also landed closer to the "limit" than the commercial heavies, and the nasal radiators used the "indexer" lights next to gunsight/HUD for their approaches to a rolling, pitching and short runway.
The AoA is most useful when close to max performance and landing approaches. The more current indicators ( figure 1980's and on) compensate for configuration. My first jet with a good AoA indication in the HUD did not! So one rainy night I bumped the flap lever and only had leading edge flaps down and about half the basic flaps down. So my approach speed with the "correct" AoA was about 20 knots too fast and I failed to do a good cross check of configuration and the rule of thumb approach speed. Almost slid off far end of the runway.
OTOH, the basic procedures used by the heavies in the commercial world are pretty conservative and safe. "x" degrees of pitch, and "y" amount of power will work about 99.9% of the time. Unlike AF447.
For the heavies, I would recommend a HUD with an inertial-based flight path vector and the pitch lines. AoA could be optional. Nothing like seeing where you will impact the ground/runway, huh? See Asiana crash.
Military likes the display because of the operational requirements and the ability to nail approach speed/AoA after a rough calculation from the book for weight and configuration and ....
We also landed closer to the "limit" than the commercial heavies, and the nasal radiators used the "indexer" lights next to gunsight/HUD for their approaches to a rolling, pitching and short runway.
The AoA is most useful when close to max performance and landing approaches. The more current indicators ( figure 1980's and on) compensate for configuration. My first jet with a good AoA indication in the HUD did not! So one rainy night I bumped the flap lever and only had leading edge flaps down and about half the basic flaps down. So my approach speed with the "correct" AoA was about 20 knots too fast and I failed to do a good cross check of configuration and the rule of thumb approach speed. Almost slid off far end of the runway.
OTOH, the basic procedures used by the heavies in the commercial world are pretty conservative and safe. "x" degrees of pitch, and "y" amount of power will work about 99.9% of the time. Unlike AF447.
For the heavies, I would recommend a HUD with an inertial-based flight path vector and the pitch lines. AoA could be optional. Nothing like seeing where you will impact the ground/runway, huh? See Asiana crash.
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A dual HUD is standard equipment on newer aircraft like the 787 and A350 onwards. On less recent ones it is optional, like the 737, CRJ and E-Jets as well as some turboprops like the Q400. Will be interesting to see if the 777NG will switch to a similar flightdeck layout to the 787.
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All FBW Airbuses (A320/330/340 etc.) have an AoA display on the PFD.
Not a "standard" presentation, and not marked in units, but with 3 defined bands
More modern ones have an additional AoA display in case of loss of airspeed indication...
Not a "standard" presentation, and not marked in units, but with 3 defined bands
More modern ones have an additional AoA display in case of loss of airspeed indication...
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Too many purchasers of airplanes (i.e., airlines ... and others) use the “expertise” of those they employ or others on their payroll in one manner or another. Often it is the additional expense of including a direct reading AOA indication, together with the “advice” provided by these “paid consultants” (some of whom don’t know their knee from their elbow and others often don’t want to “rock the boat) who generally advise that obtaining such an AOA indication would be “nice,” but it does cost more. Inevitably, a good share of these airplane purchasers decide to forego the “additional expense” since it would be merely “nice to have.” Anyone who has operationally flown airplanes with direct reading AOA indicators will tell you that it is a very cheap addition that provides a wealth of knowledge to the flight crews … but, unfortunately, the numbers of these folks is not growing and they are not usually in the chain of advisors.
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Cosmo / Cough. Depends which definition of alpha is in use (relative air flow to chord line only makes sense when considering isolated 2d airfoil sections). Often longitudinal axis to flight path is used for the whole aircraft and thus incidence is not a factor. In any event, target and limiting values can be expressed reference to either.
Plus, Cough, plenty of aircraft still around with no flight path vector.
Plus, Cough, plenty of aircraft still around with no flight path vector.
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...plenty of aircraft still around with no flight path vector.
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galaxy, maybe I wasnt clear..
the aircraft, at the same airspeed, will have a different AoA when heavier, than lighter...
I was also asking about landing conditions, especially weights, wont the AoA be different for the same GPA? Vref is +/-5 so there appears to be some associated AoA variable there..
I am just asking to see how many variables affect the AoA, and what is the range of the AoA as a result.
the aircraft, at the same airspeed, will have a different AoA when heavier, than lighter...
I was also asking about landing conditions, especially weights, wont the AoA be different for the same GPA? Vref is +/-5 so there appears to be some associated AoA variable there..
I am just asking to see how many variables affect the AoA, and what is the range of the AoA as a result.