[NSRCA-discussion] Annhedral Stab

[Nat Penton]

I probably don't have all the answers. There are some, uh, intangibles. 
Nat
----- Original Message ----- 
From: "J N Hiller" <jnhiller at earthlink.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Monday, April 21, 2008 1:30 PM
Subject: Re: [NSRCA-discussion] Annhedral Stab


> Thanks Nat, I will need more actual application info.
> My past experience with scale aerobatic airplanes having the stab in the
> scale location usually quit high relative to the wing position all pitched
> hard to the belly but those with the stab lowered didn't have near the
> problem. I thought it was because of the high stab position but it may be
> due to something else. I guess I need to build a test airplane with a stab
> that can be mounted in several vertical locations, someday.
> Thanks for your thoughts on this.
> Jim
>
> -----Original Message-----
> From: nsrca-discussion-bounces at lists.nsrca.org
> [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Nat Penton
> Sent: Monday, April 21, 2008 10:42 AM
> To: NSRCA Mailing List
> Subject: Re: [NSRCA-discussion] Annhedral Stab
>
> It is my opinion wing/stab vertical separation is immaterial - other than
> for wing/stab interference considerations.
>
> The downwash is a tube the diameter of the wingspan, so one inch up or 
> down
> vertically with the stab is the same difference.                       Nat
>
> ----- Original Message -----
> From: "J N Hiller" <jnhiller at earthlink.net>
> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
> Sent: Monday, April 21, 2008 4:20 AM
> Subject: Re: [NSRCA-discussion] Annhedral Stab
>
>
>> Downwash:
>> I almost mentioned downwash earlier as a seemingly significant 
>> contributor
>> to flight trim / setup. Vertical positioning of the stab in the downwash
>> appears to be important when matched to aircraft weight and horizontal
>> flight speed.
>> Would it be safe to assume that having a flat stab in line with the wing
>> would produced a pitch to the canopy or dose running that deep in the
>> downwash just make it hunt?
>> Thanks
>> Jim
>>
>>
>> -----Original Message-----
>> From: nsrca-discussion-bounces at lists.nsrca.org
>> [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Nat Penton
>> Sent: Sunday, April 20, 2008 9:38 PM
>> To: NSRCA Mailing List
>> Subject: Re: [NSRCA-discussion] Annhedral Stab
>>
>> Jim
>> I used anhedral, about 5 degrees, on my Express because the wing/stab
>> separation is effectively zero. My fear was interference from the wing
>> shear
>> line and the idea was to have the stab operate in a broader range of the
>> wash.
>>
>> It is impossible to get the stab out of the downwash.
>>
>> I have experienced heart pounding rudder interference from forward fins
>> and
>> wanted to avoid those puzzling instances of "was that me or was that the
>> airplane".
>>                                        Nat
>> ----- Original Message -----
>> From: "J N Hiller" <jnhiller at earthlink.net>
>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>> Sent: Sunday, April 20, 2008 1:01 PM
>> Subject: [NSRCA-discussion] Annhedral Stab
>>
>>
>>> Can I open a discussion on why some designs have an annhedral stab?
>>> Was it to lower the effective flying height of the stab to reduce the
>>> wing
>>> to stab vertical offset and knife edge belly pitch, or is there some
>>> other
>>> reason?
>>> Jim Hiller
>>>
>>> _______________________________________________
>>> NSRCA-discussion mailing list
>>> NSRCA-discussion at lists.nsrca.org
>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>>
>>
>> _______________________________________________
>> NSRCA-discussion mailing list
>> NSRCA-discussion at lists.nsrca.org
>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>
>> _______________________________________________
>> NSRCA-discussion mailing list
>> NSRCA-discussion at lists.nsrca.org
>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>