Stall Warning Adjustment

Tony_T · #1 07-31-2010, 12:48 PM

The Production Acceptance Procedure instructions say "If the warning comes on too soon then the vane should be adjusted up slightly. If the warning comes on too close to the stall, then the vane should be adjusted down."

In trying to visualize the airflow over the wing and vane, this seems backwards to me. Can anyone explain in simple terms how the vane works?

Tony

rvbuilder2002 · #2 07-31-2010, 07:02 PM

Quote:

Originally Posted by Tony_T

The Production Acceptance Procedure instructions say "If the warning comes on too soon then the vane should be adjusted up slightly. If the warning comes on too close to the stall, then the vane should be adjusted down."

In trying to visualize the airflow over the wing and vane, this seems backwards to me. Can anyone explain in simple terms how the vane works?

Tony

Looks like you found a typo that know one has mentioned...
It is backwards.

Geico266 · #3 07-31-2010, 08:31 PM

Good catch Tony.

I have not had to adjust it as it is right above stall "out of the box".

NinerBikes · #4 05-22-2020, 09:22 PM

Quote:

Originally Posted by rvbuilder2002

Looks like you found a typo that know one has mentioned...
It is backwards.

What is the correct phraseology, then, or the correction of the Stall speed indicator?

rvbuilder2002 · #5 05-23-2020, 11:27 AM

Quote:

Originally Posted by Tony_T

If the warning comes on too close to the stall, then the vane should be adjusted down."

Quote:

Originally Posted by NinerBikes

What is the correct phraseology, then, or the correction of the Stall speed indicator?

The opposite of what was originally stated..... replace the word down, with the word up.

NinerBikes · #6 05-23-2020, 03:57 PM

"If the warning comes on too close to the stall, then the vane should be adjusted Up."

So bending the warning tab UP will make the warning come on at a higher airspeed, ABOVE the stall speed?

In other words, it will warn you farther in advance, at a higher airspeed, before a stall occurs?

rvbuilder2002 · #7 05-23-2020, 04:56 PM

Quote:

Originally Posted by NinerBikes

"If the warning comes on too close to the stall, then the vane should be adjusted Up."

So bending the warning tab UP will make the warning come on at a higher airspeed, ABOVE the stall speed?

In other words, it will warn you farther in advance, at a higher airspeed, before a stall occurs?

That is correct.

Bob Y · #8 05-24-2020, 07:52 AM

What revision of the PAP are you guys referencing? Mine is revision 2, dated 11/15/18, and page F0-3 says "If the warning comes on too soon then the vane should be adjusted down slightly." Red text added by me.

NinerBikes · #9 05-24-2020, 08:19 AM

Quote:

Originally Posted by Bob Y

What revision of the PAP are you guys referencing? Mine is revision 2, dated 11/15/18, and page F0-3 says "If the warning comes on too soon then the vane should be adjusted down slightly." Red text added by me.

This is correct. Bending it down silences it until closer to, at, or below stall speed.

Stall horn comes on later when landing, less margin of warning before you stall, when you bend it DOWN.

Sportquattro · #10 03-15-2022, 10:22 AM

Quote:

Originally Posted by rvbuilder2002

That is correct.

I need to adjust my RV9A stall warner so that it sounds earlier than it does. As i understand it I therefore need to bend it up, can Scott or someone knowledgeable post the best method to use for the actual bending, and approximately how much to bend for say 5kts sooner activation of the warning.

At present mine is warning at the actual stall, and I'd like it at or just before the buffet. I don't want to excessively over bend it and then end up having to bend it back down, I appreciate it may need a slight tweak or two after bending though.

Many thanks in advance
Nige