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Tim,
The creation of an AoA indicator does not need to be complex or
expensive. Unlike the military devices that you are used to working
with, a simple differential pressure gage can be made to measure the
change of the stagnation point as it moves up the leading edge of the
wing as its AoA approaches 16 degrees. It requires two carefully
positioned holes on the wing LE and cannot use the single pitot feed.
A few years ago, an enterprising company in the US began selling a
device called the "Lift Reserve Indicator". Shortly afterwards, the
attached document appeared on the internet.
Given a choice, I would endorse David's recommendation and plump for
Mark Burton's excellent "SmartAss".
Nigel
On 11/05/2014 12:09, houlihan wrote:
> Hi Graham.
>
> I agree with your comments about the availability of AOA indications,
> I have not looked in depth at this but my understanding is the systems
> available are both very expensive and difficult to install.
> During development of the Jaguar aircraft the test aircraft had vane
> sensors mounted well forward on the pitot boom these measured pitch
> and yaw and validated the fuselage mounted incidence gauge. This was a
> fairly standard device that had a tube with a pair of slots that
> rotates to equal the pressure and aligns with the airflow
> On a single engined piston plane anything mounted on the fuselage will
> be affected by propwash and other factors, if it is mounted on the
> wing then the results will be affected by the wing itself and vortcies
> and flow breakdown probably at critical phases of flight. how would
> you check if the installation is sound and reports correctly without
> having carried out elaborate flight testing first.
> I guess and its only a guess is that the pitot based versions are
> likely to have the same limitations as standard pitots with things
> like position error and other effects I expect these things are all
> able to be corrected out one way or another with clever computation.
> Why is nothing simple ?
>
> I stand by to be corrected
>
> regards
>
> Tim
>
>
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