Hi Kingsley,
I am not an aerodynamicist, so this is my uninformed explanation why the
trim tab deflection is desirable:
1. Nose down trim is commanding the tailplane to provide lift, this
slightly reduces required wing lift along with wing induced drag, so
it=99s a good thing.
2. If you move the CG forward and tailplane lift required is
reduced, the wing induced drag (to maintain level flight) will
consequently increase - not desirable.
3. To produce the desired tailplane lift without tab deflection
would require an internal trim spring or reduced counterweight and now
you=99re the test pilot!
Interestingly some Jodel models have all flying tails that are only
partially mass balanced, so reducing that lump of steel might work, but
I won=99t be trying it.
Cheers,
Roger
> On 28 Dec 2021, at 01:52, Kingsley Hurst <kingsnjan@westnet.com.au>
wrote:
>
> Hello Pete,
>
> I=99m at a loss to understand how the tailplane incidence can be
set with a fully flying tailplane. Is there an explanation please?
>
> Best regards
> Your antipodean cousin
> Kingsley
>
> Sent from my iPhone
>
>> On 27 Dec 2021, at 9:10 pm, Peter Jeffers <pjeffers02@gmail.com>
wrote:
>>
>> =EF=BB
>> Just remember that during build you are allowed a tolerance of round
about 1 degree in the tail plane incidence. This is enough to change
your trim settings for any particular situation. It will also explain
differences between various aeroplanes.
>> Pete J
>>
>> On Sun, 26 Dec 2021, 13:53 Bud Yerly, <budyerly@msn.com
<mailto:budyerly@msn.com>> wrote:
>>
>>
>> Get Outlook for Android <https://aka.ms/AAb9ysg>
>>
>> From: Bud Yerly <budyerly@msn.com <mailto:budyerly@msn.com>>
>> Sent: Saturday, December 25, 2021, 7:35 PM
>> To: europa-list@matronics.com <mailto:europa-list@matronics.com>
>> Subject: RE: Europa-List: Trim setting question
>>
>> As Tim said.
>>
>> Most do not trim in slow flight or stalls to notice the up trim.
=46rom takeoff to cruise it is all down trim.
>>
>>
>> Your CG is a bit farther aft so more down trim is needed in some
cases as the incidence of the wing is roughly 2.5 degrees nose down trim
is needed as speed increases
>>
>>
>> Happy Holidays,
>>
>> Bud Yerly
>>
>>
>> From: owner-europa-list-server@matronics.com
<mailto:owner-europa-list-server@matronics.com>
<owner-europa-list-server@matronics.com
<mailto:owner-europa-list-server@matronics.com>> On Behalf Of Pete
>> Sent: Saturday, December 25, 2021 4:27 PM
>> To: europa-list@matronics.com <mailto:europa-list@matronics.com>
>> Subject: Re: Europa-List: Trim setting question
>>
>>
>> Thx Tim, its good to know im not alone :)
>>
>>
>> That said, the tab is neutral, with the stab in line with the fuse
moulding, with the indicator also at neutral - so it appears the stab is
not lined up with the fuse moulding in flight. I find that odd.
>>
>>
>> Cheers and Merry Christmas!
>>
>> PeteZ
>>
>>
>>
>>
>> On Dec 25, 2021, at 4:21 PM, timward <ward.t@xtra.co.nz
<mailto:ward.t@xtra.co.nz>> wrote:
>>
>> =EF=BBHi Pete,
>>
>> I have exactly the same issue but can live with it. Altering it is a
real gymnastic exercise with space available and spanners!
>>
>> Cheers,
>>
>> Tim
>>
>> Sent from my iPad
>>
>> Tim Ward
>>
>> 12 Waiwetu Street,
>>
>> Fendalton,
>>
>> Christchurch, 8052
>>
>> New Zealand.
>>
>> ward.t@xtra.co.nz <mailto:ward.t@xtra.co.nz>
>>
>> 021 0640221
>>
>>
>>
>>
>> On 26/12/2021, at 8:49 AM, Pete Zut <peterz@zutrasoft.com
<mailto:peterz@zutrasoft.com>> wrote:
>>
>> =EF=BB
>>
>> Curious: My CG is a reasonable 60.86" yet I find that my trim is
generally set quite far down in most phases of flight (and never nose up
trim).
>>
>>
>> Is this what other folks are seeing?
>>
>>
>> Cheers and thx,
>>
>> PeteZ
>>
>> C-GNPZ classic 912S
>>
>>
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