A question on Airbus landings

Thomas Borchert wrote:
I've heard that in FBW Airbuses, if your sink rate on finals is low for
whatever reason, the computers might not consider it to be a landing at
all, and might actually prevent reverser deployment and even inhibit
brake application on the landing roll?


You may be referring to the accident in Warsaw some years back.

Yes Thomas, I was.

It was the gear switches that didn't report landing, IIRC. It makes absolutely
no sense to connect landing detection to sink rate on final.

Pardon my ignorance but aren't the two connected, in the sense that
you'd touch down lightly if your sink rate is lower?

Ramapriya

Pardon my ignorance but aren't the two connected, in the sense that
you'd touch down lightly if your sink rate is lower?


Yes, but if you are down, you are down, i.e. the gear is compressed by
the weight of the plane. The problem in Warsaw was that the wheels
didn't start spinning because of aqua planing.

And just to make sure the point gets across: The Airbus 300 and 310
(the early models) are not FBW. The 320 and its derivatives, as well as
the 330 and 340 (and 380) are. As is the Boeing 777.

--
Thomas Borchert (EDDH)

The switch on a main gear strut is called the "Squat Switch". It's
position is used for lots of things on airplane. Pilot can by pass the
"squat" switch if needed in cockpit, ie bypass the "Squat" switch to
pull the gear up on the ground.

Haven't seen the wiring diagram but would guess that reverse thrust
would not be available until you had activation of "Squat" switch, ie
no reverse thrust until you are on the ground.

All the current birds have ASB. Failure in that system (very rare)
prevents any braking.

Lots of what ifs.

Big John

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On Mon, 10 Jul 2006 13:46:20 +0200, Thomas Borchert
wrote:

I've heard that in FBW Airbuses, if your sink rate on finals is low for
whatever reason, the computers might not consider it to be a landing at
all, and might actually prevent reverser deployment and even inhibit
brake application on the landing roll?


You may be referring to the accident in Warsaw some years back. It was
the gear switches that didn't report landing, IIRC. It makes absolutely
no sense to connect landing detection to sink rate on final.

As for the incident in Russia yesterday, the A310 is not FBW.

Big John wrote:


Haven't seen the wiring diagram but would guess that reverse thrust
would not be available until you had activation of "Squat" switch, ie
no reverse thrust until you are on the ground.


It doesn't sense wheel spin up?

The,

It doesn't sense wheel spin up?


On the 320, it does.

--
Thomas Borchert (EDDH)

That was my point.

Thomas Borchert wrote:

The,


It doesn't sense wheel spin up?



On the 320, it does.

"Beavis" wrote in message As a result of that accident, I wouldn't be
surprised to see the
factoring of the TRs into the data removed or reduced. (The 737-300,
for example, doesn't include the TRs in its landing data.)

That landing data calculation was allowed by Ops Specs, which have been
revoked at most carriers.

D.

If your sitting on ramp in a 320 and put the gear handle in the up
position will the gear retract? (No wheel spin)

Wheel spin up might be used to prevent reverse thrust being applied
while airborne??? If so, how can reverse thrust be used to back the
aircraft into a parking spot?

I'm asking questions, not critizing.

Many thing have changed snce my last hands on on heavy iron.


Big John
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On Wed, 12 Jul 2006 10:39:31 -0400, The Visitor
wrote:

That was my point.

Thomas Borchert wrote:

The,


It doesn't sense wheel spin up?



On the 320, it does.