Angle of Attack (AoA) Technology Comparison

[Frank JK]

Feature	Vane-Based System	Pressure-Ratio Based System
Primary Method	Mechanical Alignment	Pressure Ratio
Complexity	High (Mechanical components such as bearings and seals)	Low (No moving parts)
Installation	Requires a precision-cut hole in the aircraft’s skin and complex internal electronics	Can be bolted on or integrated into an existing plate, making it a much simpler retrofit for GA aircraft.
Accuracy	Accurate across all flight regimes.	Accurate across all flight regimes, except during significant slips/skids.
Maintenance	Requires thorough inspection for sticking, wear, and damage before every flight.	Low maintenance; primarily requires keeping the ports clear of debris.
Failure Modes	Mechanical jamming, bird strikes, icing, snow, or heavy rain; often fails without warning.	Blocked ports (ice/bugs) or water in lines, but includes built-in diagnostic warnings.
Weight/Size	Larger, heavier, and creates more aerodynamic drag.	Smaller, lighter, and creates lower drag.
Target Aircraft	Preferred for commercial airliners and fighter jets due to high sensitivity; typically 2 to 4 redundant units per aircraft.	Widely popular in General Aviation because they are lighter, cost-effective, and easier to install.

 

Summary

If you are flying a high-performance jet where precision at Mach speeds is critical, a redundant vane-based system is the industry standard. However, for those flying light piston or turboprop aircraft who want a reliable, low-maintenance safety tool to prevent stalls and loss-of-control accidents, a pressure-ratio system is usually the more practical and cost-effective choice.

Advanced pressure-ratio systems have the ability to sense blocked ports and produce appropriate cockpit warnings. Historically, fatal accidents resulting from relying on false indications from damaged vane-based systems have even forced some manufacturers of those systems out of business.

 

Edited 18 hours ago by Frank JK
Allignment Correction

[skippydiesel]

I have an AoA through my Dynon Classic - no other stall warning device.

Its satisfying to hear it sound, as I flair for landing - tell myself my speed was about right.

Have heard it, on rare occasion, in a tight turn, which is good, as it alerts me to keep my speed/power up.

The visual display, is way too small and below the glare shield (out of line-of- sight), so its of little use when landing. I guess I could set it to go off at higher speeds but then I may find I am too fast on approach.

Many "wax lyrical" about these devises as a landing aid - could be good for STOL, when there is a visual display up on glare shield/HUDS .

I wonder if relying on an AoA makes you less able to land without it and possibly airspeed as well ? - something I have had to do on three occasions (tiny little ants in my system).😈

[facthunter]

I have pointed out  advantages  but not linked to actual landing judgement. It's mainly the Indication/confirmation of stall  safety Margins in various configurations and weights and manoeuvres..  Very useful if you have a complex Flap /Slat retraction schedule.  It doesn't show overspeeds etc Just AoA related stuff.   Nev