Fwiw, the differential pressure ports can also be on the pitot tube, if it is
carefully
located out of the wing's interference. My homegrown pitot will be well
ahead of the wing. Dynon also has a differential pitot driving their aoa
display.
Cheers,
Pete
> On May 11, 2014, at 9:01 AM, Nigel Graham <nigel_graham@m-tecque.co.uk> wrote:
>
> 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
>
> <Lift Reserve Indicator.pdf>
|