Fine example of Tarver Engineering release for service

Tarver Engineering wrote:


The sole reason for using a static port is so the guts can be removed from
the pitot tube, in order to improve reliability. A pitot port produces no
static pressure datum.


Just as an example, when the aircraft is sitting still on the ground -
airspeed = 0. Since the pitot and static ports are in the same state,
doesn't that imply that static pressure is present at the pitot port?

MAH

mah wrote:

Tarver Engineering wrote:


The sole reason for using a static port is so the guts can be removed from
the pitot tube, in order to improve reliability. A pitot port produces no
static pressure datum.


Just as an example, when the aircraft is sitting still on the ground -
airspeed = 0. Since the pitot and static ports are in the same state,
doesn't that imply that static pressure is present at the pitot port?

MAH

Sure it's there, but it's there only until the a/c starts to
move. It's then no longer 'static pressure' because it's been
raised by the ram effect of the movement.

That's why you now need a 'static port' to supply the static
pressure to use as a reference. Is it really that difficult to
see?!?
--

-Gord.

Tarver Engineering release for service
From: "Gord Beaman" )
Date: 3/2/2004 11:53 AM Central Standard Time
Message-id:

mah wrote:

Tarver Engineering wrote:


The sole reason for using a static port is so the guts can be removed from
the pitot tube, in order to improve reliability. A pitot port produces no
static pressure datum.


Just as an example, when the aircraft is sitting still on the ground -
airspeed = 0. Since the pitot and static ports are in the same state,
doesn't that imply that static pressure is present at the pitot port?

MAH

Sure it's there, but it's there only until the a/c starts to
move. It's then no longer 'static pressure' because it's been
raised by the ram effect of the movement.

That's why you now need a 'static port' to supply the static
pressure to use as a reference. Is it really that difficult to
see?!?
--

-Gord.

Should we tell tarver static ports existed before pitot tubes were used in
aircraft?

From my experience most aircraft have static ports separate from the pitot
tube.

Dan, U.S. Air Force, retired

"Gord Beaman" wrote in message
...
mah wrote:

Just as an example, when the aircraft is sitting still on the
ground -
airspeed = 0. Since the pitot and static ports are in the same
state,
doesn't that imply that static pressure is present at the pitot port?

MAH

Sure it's there, but it's there only until the a/c starts to
move. It's then no longer 'static pressure' because it's been
raised by the ram effect of the movement.

That's why you now need a 'static port' to supply the static
pressure to use as a reference. Is it really that difficult to
see?!?

Apparently.

The CO

"Gord Beaman" ) wrote in message . ..
mah wrote:

Tarver Engineering wrote:


The sole reason for using a static port is so the guts can be removed from
the pitot tube, in order to improve reliability. A pitot port produces no
static pressure datum.


Just as an example, when the aircraft is sitting still on the ground -
airspeed = 0. Since the pitot and static ports are in the same state,
doesn't that imply that static pressure is present at the pitot port?

MAH

Sure it's there, but it's there only until the a/c starts to
move. It's then no longer 'static pressure' because it's been
raised by the ram effect of the movement.

That's why you now need a 'static port' to supply the static
pressure to use as a reference. Is it really that difficult to
see?!?


where are the mud bees?

(running with scissors)
Date: 3/2/2004 5:18 PM Central Standard Time
Message-id:

"Gord Beaman" ) wrote in message
...
mah wrote:

Tarver Engineering wrote:


The sole reason for using a static port is so the guts can be removed
from
the pitot tube, in order to improve reliability. A pitot port produces
no
static pressure datum.


Just as an example, when the aircraft is sitting still on the ground -
airspeed = 0. Since the pitot and static ports are in the same state,
doesn't that imply that static pressure is present at the pitot port?

MAH

Sure it's there, but it's there only until the a/c starts to
move. It's then no longer 'static pressure' because it's been
raised by the ram effect of the movement.

That's why you now need a 'static port' to supply the static
pressure to use as a reference. Is it really that difficult to
see?!?


where are the mud bees?

Shacking up in the pitot tubes.

Dan, U.S. Air Force, retired

"mah" wrote in message
...

Just as an example, when the aircraft is sitting still on the ground -
airspeed = 0. Since the pitot and static ports are in the same state,
doesn't that imply that static pressure is present at the pitot port?

Sure, unless:
1) The aircraft is moving
2) The wind is blowing
3) Either 1) or 2)
4) Both 1) and 2)

At that point the pressure is no longer static - so you need a static
port.
IIRC in fact, for an aircraft to be certified for IFR it has to have an
alternate
static source *as well*. Pitot pressure ceases to be equal to static
pressure
once the air is in motion relative to the port.
Whether the air moves on its own or the plane moves
through it is irrelevant.

The CO

MAH

Can you point to a reg tht says that? I don't think it is true. Mine was
IFR certified when I bought it, and it did not have alternate static (I've
since added it). Also the FAA materials for the IFR written mention several
times that breaking the VSI glass is the way to get alternate static on an
airplane that doesn't have a valve. I wouldn't think they'd make such a big
deal about it if an alternate static source was requried for IFR cert.

The CO wrote:

IIRC in fact, for an aircraft to be certified for IFR it has to have an
alternate
static source *as well*.

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

Ray Andraka wrote:

Also the FAA materials for the IFR written mention several
times that breaking the VSI glass is the way to get alternate static on an
airplane that doesn't have a valve. I wouldn't think they'd make such a big
deal about it if an alternate static source was requried for IFR cert.


It should be mentioned here that this trick only works on an
unpressurized a/c. You won't get much activity on the VSI needle
if you try this with a pressurized aircraft!.

--

-Gord.

"Ray Andraka" wrote in message
...
Can you point to a reg tht says that? I don't think it is true. Mine
was
IFR certified when I bought it, and it did not have alternate static
(I've
since added it). Also the FAA materials for the IFR written mention
several
times that breaking the VSI glass is the way to get alternate static
on an
airplane that doesn't have a valve.

That might work if the cabin was unpressurised, depends on whether the
guage face
was vented to the static side of the pressure balance.

I wouldn't think they'd make such a big
deal about it if an alternate static source was requried for IFR cert.

Ah, in Australia mate. I can't quote the ANO/R off the top of my head
but
to be certified for Class 1 it needs an alternate static source IIRC.
I'll see if
I can find the ANO/R somewhere.
(ANO= Air Navigation Order ANR= Air Navigation Regulation)

I can't speak for the FAA, so if they don't require alternate static
source for
Class 1 IFR I'm rather surprised, but I guess it could be the case, I
don't know.

Class 4 IFR (NVMC) doesn't require it in Oz.

The CO