grumman aa-5 stall warning delay

[H@mst3r]

Hi all

why does the grumman aa-5's stall warning have a delay of about 5
seconds? Is this normal or is there something wrong with the aircraft?

Thanks

H@mst3r

[[email protected]]

H@mst3r > wrote:
> Hi all
>
> why does the grumman aa-5's stall warning have a delay of about 5
> seconds? Is this normal or is there something wrong with the aircraft?
>
> Thanks
>
> H@mst3r

My AA5B doesn't have any such delay nor have I ever seen a report of
such in all the info from the American Yankee Association.

During preflight, do you make sure the vane moves freely and isn't
gunked up?


--
Jim Pennino

Remove .spam.sux to reply.

[H@mst3r]

no, it moves freely and has just been rebuilt by our AMO.

Brand new case for someone to investigate

[[email protected]]

H@mst3r > wrote:
> no, it moves freely and has just been rebuilt by our AMO.
>
> Brand new case for someone to investigate

The stall warning on Grummans is a spring loaded vane screwed to a switch.

When the airflow where the vane is mounted starts flowing up, the
switch closes and the alarm sounds.

It is impossible for there to be a delay between the switch closing
and the alarm sounding.

That leaves either the vane being bent, positioned incorrectly or a
too stiff of a spring, thus requiring being deeper into the stall before
the switch closes.

I would question how the switch could be "rebuilt" locally as the switch
is proprietary and not generally available as a part.


--
Jim Pennino

Remove .spam.sux to reply.

[vaughn]

"H@mst3r" > wrote in message
...
> Hi all
>
> why does the grumman aa-5's stall warning have a delay of about 5
> seconds?

What? You have a stall warning that you can actually hear? Be thankful!

The rental Cessnas that I fly were all made before headsets were commonly
used. Add the attenuation of that headset to my natural "old man's" high
frequency hearing loss, and those crappy "penny whistle" stall alarms are
totally out of the picture for me.

No big loss, the plane has all kinds of ways to warn me of a stall.

How about other folks?

Vaughn

[[email protected]]

On Jan 5, 11:45*pm, wrote:
> H@mst3r > wrote:
> > no, it moves freely and has just been rebuilt by our AMO.
>
> > Brand new case for someone to investigate
>
> The stall warning on Grummans is a spring loaded vane screwed to a switch..
>
> When the airflow where the vane is mounted starts flowing up, the
> switch closes and the alarm sounds.
>
> It is impossible for there to be a delay between the switch closing
> and the alarm sounding.
>
> That leaves either the vane being bent, positioned incorrectly or a
> too stiff of a spring, thus requiring being deeper into the stall before
> the switch closes.
>
> I would question how the switch could be "rebuilt" locally as the switch
> is proprietary and not generally available as a part.
>
> --
> Jim Pennino
>
> Remove .spam.sux to reply.

Most likely it's the buzzer. Some of those were a small
electromechanical horn, which uses a small coil, a diaphragm and a
switch on the diaphragm that opens the coil's supply when it's
displaced. The resulting oscillation makes lots of noise. When that
switch gets dirty, it might be a few seconds before the diaphragm gets
around to moving enough to start the oscillation. Probably need a new
horn. The other possibility is a bad connection somewhere in the
circuit, most likely the ground connection at the horn.

Dan

[[email protected]]

wrote:
> On Jan 5, 11:45Â*pm, wrote:
>> H@mst3r > wrote:
>> > no, it moves freely and has just been rebuilt by our AMO.
>>
>> > Brand new case for someone to investigate
>>
>> The stall warning on Grummans is a spring loaded vane screwed to a switch.
>>
>> When the airflow where the vane is mounted starts flowing up, the
>> switch closes and the alarm sounds.
>>
>> It is impossible for there to be a delay between the switch closing
>> and the alarm sounding.
>>
>> That leaves either the vane being bent, positioned incorrectly or a
>> too stiff of a spring, thus requiring being deeper into the stall before
>> the switch closes.
>>
>> I would question how the switch could be "rebuilt" locally as the switch
>> is proprietary and not generally available as a part.
>>
>> --
>> Jim Pennino
>>
>> Remove .spam.sux to reply.
>
> Most likely it's the buzzer. Some of those were a small
> electromechanical horn, which uses a small coil, a diaphragm and a
> switch on the diaphragm that opens the coil's supply when it's
> displaced. The resulting oscillation makes lots of noise. When that
> switch gets dirty, it might be a few seconds before the diaphragm gets
> around to moving enough to start the oscillation. Probably need a new
> horn. The other possibility is a bad connection somewhere in the
> circuit, most likely the ground connection at the horn.
>
> Dan

If it were a bad connection somewhere, it would likely not work at all.

This is easy to test:

1. Turn on master switch.

2. Press on vane with finger.

If the horn sounds, everything is electrically OK.

As to what the noise maker is, I would have to look in the maintenance
manual, which is at the hanger.

According to the AYA Maintenance Compendium, the switch in the assembly
is only available from the assembly manufacturer and can only be
"rebuilt" by the manufacturer, which leads me to believe if the assembly
was "rebuilt" locally, then a switch was used that happens to fit
mechanically but has the wrong spring tension, thus delaying switch
closure.


--
Jim Pennino

Remove .spam.sux to reply.

[Jon Woellhaf]

I know someone who told me about someone who repaired an intermittent
electrical stall horn by resoldering a cold connection. It's worked fine
ever since -- so I hear. <g>

> wrote in message
...
On Jan 5, 11:45 pm, wrote:
> H@mst3r > wrote:
> > no, it moves freely and has just been rebuilt by our AMO.
>
> > Brand new case for someone to investigate
>
> The stall warning on Grummans is a spring loaded vane screwed to a switch.
>
> When the airflow where the vane is mounted starts flowing up, the
> switch closes and the alarm sounds.
>
> It is impossible for there to be a delay between the switch closing
> and the alarm sounding.
>
> That leaves either the vane being bent, positioned incorrectly or a
> too stiff of a spring, thus requiring being deeper into the stall before
> the switch closes.
>
> I would question how the switch could be "rebuilt" locally as the switch
> is proprietary and not generally available as a part.
>
> --
> Jim Pennino
>
> Remove .spam.sux to reply.

Most likely it's the buzzer. Some of those were a small
electromechanical horn, which uses a small coil, a diaphragm and a
switch on the diaphragm that opens the coil's supply when it's
displaced. The resulting oscillation makes lots of noise. When that
switch gets dirty, it might be a few seconds before the diaphragm gets
around to moving enough to start the oscillation. Probably need a new
horn. The other possibility is a bad connection somewhere in the
circuit, most likely the ground connection at the horn.

Dan

[B A R R Y[_2_]]

vaughn wrote:
>
> How about other folks?

The electric stall horns on all the Warriors I trained in, my Sundowner,
and the C182 I just bought, work great and are easily heard. This is
true even through headsets and at higher power settings during departure
stalls and dirty slow flight.

I've recorded video in the Sundowner and the horn is easily heard on the
recordings.

[Mike Noel]

Are the Warriors different from the Archers? My 74 has a light but no horn.
Perhaps the Warrior wing gives a more abrupt stall? My constant chord wing
gives plenty of warning without a horn.

--
Best Regards,
Mike.

http://flickr.com/photos/mikenoel/

http://photoshow.comcast.net/mikenoel


"B A R R Y" > wrote in message
...
> vaughn wrote:
>> How about other folks?
>
> The electric stall horns on all the Warriors I trained in, my Sundowner,
> and the C182 I just bought, work great and are easily heard. This is true
> even through headsets and at higher power settings during departure stalls
> and dirty slow flight.
>
> I've recorded video in the Sundowner and the horn is easily heard on the
> recordings.

[B A R R Y[_2_]]

Mike Noel wrote:
> Are the Warriors different from the Archers? My 74 has a light but no horn.
> Perhaps the Warrior wing gives a more abrupt stall? My constant chord wing
> gives plenty of warning without a horn.
>


I didn't think so.

The Warriors I flew ('78,'78, & '79) were newer than your Archer, which
might be the reason for the horn.

[Dave[_19_]]

My 76 Warrior has a horn.

VERY difficult to stall tho..

Wle instaled Art Mattisons VGs and gap seals and we can fly around
easily with the horn blowing. (They lowered our stall speed by about 4
- 5 knts)

At lighter loads, we don't even have a departure stall. It just flies
along with the VSI steady, full power, 15 deg of bank and the yoke
full back.

Almost temped to rewrite the POH... :)

Dave


On Wed, 7 Jan 2009 16:06:20 -0700, "Mike Noel" >
wrote:

>Are the Warriors different from the Archers? My 74 has a light but no horn.
>Perhaps the Warrior wing gives a more abrupt stall? My constant chord wing
>gives plenty of warning without a horn.

[John Godwin]

"vaughn" > wrote in
:

> What? You have a stall warning that you can actually hear? Be
> thankful!

Earlier Pipers I've flown (e.g. Comanche 260B) had a light; other
aircraft didn't even have a stall warning.

--