Author: "Cary Rhodes" <rhodeseng@...> Time: Mon Mar 1, 2004 7:10 am PST Link
Question?
Have you any experience with flying or more important landing with
the trim in either extreme position??
Or has someone experimented with stall characteristics with extreme
trim positions??
Motor failure or switch failure or some other gremlin could cause
this.
These thoughts occured to me this weekend installing and wiring the
trim servo.
cary rhodes
Author: "Ross P. Hauck" <ross@...> Time: Mon Mar 1, 2004 8:37 am PST Link
You can easily overpower the trim in slow flight. I really like the
electric trim, especially with the hat switch on top of the stick grip.
Ross
-----Original Message-----
From: Cary Rhodes [mailto:rhodeseng@...]
Sent: Monday, March 01, 2004 6:27 AM
To: vansairforce@yahoogroups.com
Subject: [VAF Mailing List] Electric Trim
* Question?
Have you any experience with flying or more important landing with
the trim in either extreme position??
Or has someone experimented with stall characteristics with extreme
trim positions??
Motor failure or switch failure or some other gremlin could cause
this.
These thoughts occured to me this weekend installing and wiring the
trim servo.
cary rhodes
[Non-text portions of this message have been removed]
Author: Gregory Bitzer <gbitzer@...> Time: Mon Mar 1, 2004 8:38 am PST Link
Cary,
I've done some testing in this area. The trim tabs are relatively small and
I didn't have any trouble overcoming the force when in the extreme
position. I investigated this after I discovered that a runaway elevator
trim on my A-36 Bonanza was very difficult to over power (the Bonanza has a
large elevator with 2 large trib tabs). I'm using electric trim outboard on
my left aileron and inboard on the left elevator.
Hey, do you still want to get some time in my 6?
Greg
gbitzer@...
RV-6 (400 hrs) Atlanta, GA
At 02:27 PM 3/1/2004 +0000, you wrote:
>Question?
>
>Have you any experience with flying or more important landing with
>the trim in either extreme position??
>
>Or has someone experimented with stall characteristics with extreme
>trim positions??
>
>Motor failure or switch failure or some other gremlin could cause
>this.
>
>These thoughts occured to me this weekend installing and wiring the
>trim servo.
>
>cary rhodes
>Online help on this group at:
>http://help.yahoo.com/help/groups/
>
>Yahoo! Groups Links
Author: "Jeffrey Hall" <jhallrv4@...> Time: Mon Mar 1, 2004 10:14 am PST Link
As I have no trim indicator, I will occasionally takeoff with the trim in landing position. At takeoff it's no big deal, it becomes obvious early after liftoff that I've done it again, but I just push the coolie hat forward as I accelerate, no big deal. However, the forces increase dramatically if I don't retrim. At lower speeds, there is no problem, but I can imagine that at cruise speed the force needed would be significant. So, if for some reason the trim ran away and you were slow to stop it, you would have to slow down quite a bit to comfortably fly the plane. I have done demonstrations at cruise, to a couple of passengers, having them hold the stick, then applying trim, and it's quite dramatic. The trim tab on the RV is very effective.
Now you have me curious. I'll have to try it at cruise with full trim, if I can get there.
Jeff
"Toucan"
[Non-text portions of this message have been removed]
Author: "Larry Perryman" <larry-perryman@...> Time: Mon Mar 1, 2004 1:55 pm PST Link
Cary,
On the 9 it is damn hard to hold even if it is not fully one way or
the other. Never have gone all the way but even part way is hard.
Regards
Larry Perryman
> Have you any experience with flying or more important landing with
> the trim in either extreme position??
Author: "Larry Perryman" <larry-perryman@...> Time: Mon Mar 1, 2004 1:56 pm PST Link
Cary,
On the 9 it is damn hard to hold even if it is not fully one way or
the other. Never have gone all the way but even part way is hard.
Regards
Larry Perryman
> Have you any experience with flying or more important landing with
> the trim in either extreme position??
Author: Randy Richter <richterrbb@...> Time: Mon Mar 1, 2004 4:26 pm PST Link
No experience flying an RV in an out-of-trim condition, but I've
experienced it demoed in the USAF crates I've flown and it's a handful.
About correcting a suspected o-o-t condition, somewhere in the FARs it
says something about the trim control circuit breakers being within
reach of the pilot. I imagine this just applies to certified acft, but
that's the way my -7A is going to be configured, as I'm installing
electric elevator and aileron trim. For an electric-only acft, the
CB/switch won't correct the condition, but it can keep it from worsening.
It occurs to me that runaway aileron trim might actually be worse than
elevator, just because the effect is so far off of the "straight up" and
"straight down" axis.
Bear in mind that as airspeed decreases, so does control effectiveness,
so not only do you lose primary (i.e., just the elevator or aileron
itself) flight control authority, the trim tab also loses authority, so
it's pushing less hard against your inputs, hence, easier to control.
You'll still have a slight net loss of authority, due to the small area
of the trim tab working against the rest of the primary flight control,
but it seems to me that at approach speeds, it should be (relatively)
controllable. In fact, in one acft I flew, there was discussion in the
flight manual concerning runaway CG change (due to draining fuel to
different tanks) and one way of maximizing up-elevator authority that
was mentioned was to trim full nose DOWN, causing the trim tab to move
to a position that would impart maximum nose UP authority with maximum
aft yoke (I know, "yoke" is a four letter word in this forum, but it's
just the way things were back then).
I don't think I could recommend to anyone to explore this realm, but I'm
sure there are adventurous souls out there who have or have experienced
it in the NS (No S_ _ t) world.
I'd also be very interested to read anyone else's experience with this
in an RV.
.002
Randy
Cary Rhodes wrote:
> Question?
>
> Have you any experience with flying or more important landing with
> the trim in either extreme position??
>
> Or has someone experimented with stall characteristics with extreme
> trim positions??
>
> Motor failure or switch failure or some other gremlin could cause
> this.
>
> These thoughts occured to me this weekend installing and wiring the
> trim servo.
>
> cary rhodes
--
Randy Richter
richterrbb@...
-7QB Kit in hibernation
[Non-text portions of this message have been removed]
Author: "Chuck Stratman" <Pilot93434@...> Time: Tue Mar 2, 2004 5:31 am PST Link
Jeff,
Curious why you have no trim indicator? Jeff I don't know your background, you might be a former Blue Angle, but be careful testing full trim at cruise. The word OVERSTRESS comes to mind.
Take care
Chuck Stratman
N118JR
----- Original Message -----
From: Jeffrey Hall
To: vansairforce@yahoogroups.com
Sent: Monday, March 01, 2004 10:16 AM
Subject: Re: [VAF Mailing List] Electric Trim
Now you have me curious. I'll have to try it at cruise with full trim, if I can get there.
Jeff
"Toucan"
[Non-text portions of this message have been removed]
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