[Dmadd]

Folks,
If you had to guess, what would you say the parked deck angle is on a short gear RV-4? I'm on the list to get an advanced copy of the RC Allen RC 2600 electronic attitude indicator, and they want to pre set the AOA for me. Not sure if it will be modifiable by me later or not.
I'm gonna go out to the cold hanger with an electronic level later this week, but what ball park figure should I see?

DM

 

[Mel]

Are you sure you are looking for AOA?

AOA (angle of attack) is the attitude of the airplane relative to the air flow.
I think on an attitude indicator, what they want is the instrument panel angle with respect to straight and level attitude. Sitting deck angle has nothing to do with AOA. And an attitude indicator has nothing to do with AOA.
Unless I misunderstand, I think the angle you are looking for should be in the neighborhood of 8 degrees.
Set the airplane up for level flight and measure the panel angle.

 

[jclark]

Mel is right (of course )

They want the panel tilt.

Measure angle of panel relative to aircraft being level. I would assume on the 4 it is the same as on the 6 and 7 ... relative to the side longerons.

I **THINK** they said that within 2 degrees is within their error.


James

 

[osxuser]

It sounds to me more like they want to know what the PARKED angle of the panel is for erecting purposes on the gyro.... But I don't know why they'd need that.

 

[Dmadd]

Yes, this is what I meant to say... Tail draggers are nose high when parked, and the gyro has to reflect that at start up...
Thanks
DM

It sounds to me more like they want to know what the PARKED angle of the panel is for erecting purposes on the gyro.... But I don't know why they'd need that.

 

[Mel]

I can't imagine what value this info has to the gyro.

When the gyro erects, it erects to "level" regardless of the attitude of the aircraft. Parked attitude doesn't matter to the gyro.

 

[Rick6a]

This may help:

As regards panel tilt:

It doesn't really matter if the aircraft happens to sport a nosewheel or a tailwheel. "Panel tilt" refers to the gyro's deviation from vertical (0°) in relation to the aircraft in level flight. In a mechanical AH gyro, the factory adjustment of the instrument to compensate for this difference is not made to the gyro assembly itself but rather to that part of the internal assembly that allows a full up and down range of travel above and below the horizon line via the adjustment knob the pilot uses to align the little yellow wings with the horizon. R.C. Allen gyros can be adjusted in a range from 0° to 14 degrees. Typically, AH gyros used in RV's are adjusted for 8° of panel tilt. What this means is if the gyro is set up for 0° of panel tilt and RV is resting level, the pilot would find that the adjustment knob would already be at (or near) one limit of full travel just to center the little yellow wings on the instrument.

Since the 2600 series is a newer solid state "gyro" instrument and does not have an adjustment knob, the above information may or may not apply. Check with the manufacturer.

 

[Dmadd]

Thanks Rick. Just when I thought I knew what I knew... LOL.
I should never have switched to de cafe... ;-) I get it now.
Sheesh... I made that harder than it was. <BG>
Dennis

This may help:

As regards panel tilt:

It doesn't really matter if the aircraft happens to sport a nosewheel or a tailwheel. "Panel tilt" refers to the gyro's deviation from vertical (0?) in relation to the aircraft in level flight. In a mechanical AH gyro, the factory adjustment of the instrument to compensate for this difference is not made to the gyro assembly itself but rather to that part of the internal assembly that allows a full up and down range of travel above and below the horizon line via the adjustment knob the pilot uses to align the little yellow wings with the horizon. R.C. Allen gyros can be adjusted in a range from 0? to 14 degrees. Typically, AH gyros used in RV's are adjusted for 8? of panel tilt. What this means is if the gyro is set up for 0? of panel tilt and RV is resting level, the pilot would find that the adjustment knob would already be at (or near) one limit of full travel just to center the little yellow wings on the instrument.

Since the 2600 series is a newer solid state "gyro" instrument and does not have an adjustment knob, the above information may or may not apply. Check with the manufacturer.