hevansrv7a

hevansrv7a

Well Known Member
Is there a simple, practical way to meet this standard on a -7/7A with manual trim? Non-electric preferred but not essential. Thanks.
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Sec. 23.677

Part 23 AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES​
Subpart D--Design and Construction
Control Systems​

Sec. 23.677

Trim systems.

[(a) Proper precautions must be taken to prevent inadvertent, improper, or abrupt trim tab operation. There must be means near the trim control to indicate to the pilot the direction of trim control movement relative to airplane motion. In addition, there must be means to indicate to the pilot the position of the trim device with respect to both the range of adjustment and, in the case of lateral and directional trim, the neutral position. This means must be visible to the pilot and must be located and designed to prevent confusion. The pitch trim indicator must be clearly marked with a position or range within which it has been demonstrated that take-off is safe for all center of gravity positions and each flap position approved for takeoff.]
 
Part 23 AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES
Subpart D--Design and Construction
Click to expand...

Doesn't apply to aircraft with experimental airworthiness certificate.

You will quickly learn in a few hours where to set the manual trim for takeoff just by looking at how far the trim control is extended. I am not aware of a really simple way to rig an indicator for manual trim.
 
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Somewhere in 23 YEARS OF THE RVATOR there is an article on a way to index the manual trim. I'd search for you, but got to get to building! :D Good luck.
 
MARK THE SHAFT

When the trim is all set up and you have the travel that you want, before installing the cable, hook it up to the tab and screw the knob in or out till your trim tab is in neutral position. Then take a SHARPIE and mark the shaft at the friction knob. Remove the shaft from the cable and cut or file a grove in the shaft. Paint the grove with red or white paint. This will now be your referance mark for "0" trim. Also place a dot on top of the wheel at "0" trim so you know how far to turn for your tab to be in trim for take off.

My trim tab rides about 1/4" up all of the time. And adjustments from takeoff to cruse and then landing, I never move the knob more than 1/8 turn. I don't know if this is good or bad! All I know is I can take off with the trim that I landed with and it seems to be right on.

During the walk around, always look at the location of the tab. Like Sam said, you will soon know where it is right.

MANUAL trim is a good choice. And manual flaps are even more fun!!!
It's too bad people want swithces and motors to do everything with a push of a button.

YOU WILL NEVER HAVE A PROBLEM WITH MANUAL TRIM.....K-I-S-S ;)

Warren
 
If you're using Van's trim cable, I'd suggest that you remove the spring loaded center release button and associated hardware. This will prevent you from trying to trim by moving the cable in or out with a linear motion. WAY TOO FAST. The center button can be replaced with a plastic disc that is engraved with arrows showing "nose up" and "nose down" (don't recall where I got mine). Once in place, play around with the vernier to determine proper position for take off and note it in your pre-takeoff checklist. On my 9, I simply screw the trim full in and then back off four revoultions to get takeoff position. You can add a label to the trim bracket for this procedure if you wish.
Terry
 
Thanks

I should have anticipated that everyone would think I thought that I needed this to fly. Nope. I have 60 hours and have never missed having it. I agree with all that was said about not needing it, and that it is not required for Experimental category. I just thought it would be good to do if not a big deal. Marking the shaft sounds good; I'll see if I can do it with the trim already installed. I'm using Bill Repucci's marker button and have removed the fast method.
 
the knob is your indicator

Neutral trim position is two fingers out on my plane. simple, tactile, repeatable. RVs are so great any variation in trim tab position is not an issue anyway.
 
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