Right thrust/Tower Apprentice

Right thrust/Tower Apprentice

Post by Stacy Smit » Fri, 21 Jan 2000 04:00:00



I have finished rebuilding a plane I crunched on its maiden flight...it
was a Tower Hobbies Apprentice, advertised as a first low-wing plane (I
built it as my second plane).  Although I crunched it due to my error, I
was fighting a persistent left roll tendency.  To fly straight, it
required constant and significant right aileron (I crunched it while
trying to trim it out).

I checked everything before the maiden flight and re-checked the wing and
tail after the crash (they were essentially undamaged except for small
wing tip ding) and the ailerons were/are straight and even, the wing not
twisted, lateral balance OK.  Trim levers on the radio and control
surfaces were centered.  So, I'm trying to figure out why it rolled left
so hard before I send it up again with it's rebuilt nose.

One thing I noticed is the plans call for 6 degrees downthrust and no
right thrust.  Seems to be the plane should have some right
thrust...anyone else have this plane who can comment?  Any ideas on what
to look for on a plane with a left roll tendency?

Thanks in advance for any ideas...
Stacy
(Remove NOSPAM from my address when replying by email)

 
 
 

Right thrust/Tower Apprentice

Post by Tom Fawce » Fri, 21 Jan 2000 04:00:00


It's doubtful that engine thrustline is the cause, I built mine
according to the plans and it flew straight and level.

Have you checked that the rudder is absolutely straight, in line with
the engine thrust line? A little left rudder will causewhat you
experienced, rolling to the left.

Other potential causes, the wing halves are not joined straight. If
the wing halves are not lined up perfectly it can insuce a roll
tendency.

My suggestion is to have a more experienced pilot do the first flight,
and make him aware that there is a left roll tendency. Also be sure
you have plenty of aileron throw to use correcting the roll.

TF

On Thu, 20 Jan 2000 13:09:25 -0500, Stacy Smith

Quote:

>I have finished rebuilding a plane I crunched on its maiden flight...it
>was a Tower Hobbies Apprentice, advertised as a first low-wing plane (I
>built it as my second plane).  Although I crunched it due to my error, I
>was fighting a persistent left roll tendency.  To fly straight, it
>required constant and significant right aileron (I crunched it while
>trying to trim it out).

>I checked everything before the maiden flight and re-checked the wing and
>tail after the crash (they were essentially undamaged except for small
>wing tip ding) and the ailerons were/are straight and even, the wing not
>twisted, lateral balance OK.  Trim levers on the radio and control
>surfaces were centered.  So, I'm trying to figure out why it rolled left
>so hard before I send it up again with it's rebuilt nose.

>One thing I noticed is the plans call for 6 degrees downthrust and no
>right thrust.  Seems to be the plane should have some right
>thrust...anyone else have this plane who can comment?  Any ideas on what
>to look for on a plane with a left roll tendency?

>Thanks in advance for any ideas...
>Stacy
>(Remove NOSPAM from my address when replying by email)


 
 
 

Right thrust/Tower Apprentice

Post by Paul McIntos » Fri, 21 Jan 2000 04:00:00


Absolutely!  It would surprise you how a very small misalignment can
cause quite a large roll effect.  If you really want to chaeck the
airplane, get a Robart incidence meter and check it ALL.

Quote:

> It's doubtful that engine thrustline is the cause, I built mine
> according to the plans and it flew straight and level.

> Have you checked that the rudder is absolutely straight, in line with
> the engine thrust line? A little left rudder will causewhat you
> experienced, rolling to the left.

> Other potential causes, the wing halves are not joined straight. If
> the wing halves are not lined up perfectly it can insuce a roll
> tendency.

> My suggestion is to have a more experienced pilot do the first flight,
> and make him aware that there is a left roll tendency. Also be sure
> you have plenty of aileron throw to use correcting the roll.

> TF

> On Thu, 20 Jan 2000 13:09:25 -0500, Stacy Smith

> >I have finished rebuilding a plane I crunched on its maiden flight...it
> >was a Tower Hobbies Apprentice, advertised as a first low-wing plane (I
> >built it as my second plane).  Although I crunched it due to my error, I
> >was fighting a persistent left roll tendency.  To fly straight, it
> >required constant and significant right aileron (I crunched it while
> >trying to trim it out).

> >I checked everything before the maiden flight and re-checked the wing and
> >tail after the crash (they were essentially undamaged except for small
> >wing tip ding) and the ailerons were/are straight and even, the wing not
> >twisted, lateral balance OK.  Trim levers on the radio and control
> >surfaces were centered.  So, I'm trying to figure out why it rolled left
> >so hard before I send it up again with it's rebuilt nose.

> >One thing I noticed is the plans call for 6 degrees downthrust and no
> >right thrust.  Seems to be the plane should have some right
> >thrust...anyone else have this plane who can comment?  Any ideas on what
> >to look for on a plane with a left roll tendency?

> >Thanks in advance for any ideas...
> >Stacy
> >(Remove NOSPAM from my address when replying by email)

--
Paul McIntosh
Desert Sky Model Aviation
(877) 311-3759 (toll free)
(602) 780-9005 (in AZ)
desertsky.goplace.com