Marc,
The Canadair Regional Jet has a three static sources. They are
selectable from normal to alternate. This usually cross connects the
Captains to the F/O and vice versa. The third one is independent for the
Mach speed transducer and the Cabin Pressure Acquisition module.
It would be safe to assume that if one or more of the static port was
taped over for painting then all of them were taped over.
Our Turbo Props do not have a selectable static source. They do have
selectable Air Data computers though.
Michelle

Marc Lattoni wrote:

Last night on Discovery Channel there was a story of a Peruvian 757 that
went down because the two static ports had been taped over for cleaning and
not removed. As you might imagine, the airspeed indicator and altimeter gave
erroneous readings and fed the onboard computers erroneous data; after a
series of bizarre warning messages (zero airspeed and "over speed warning"
from the computer) the pilots attempted to correct for contradictory
information and multiple warnings and the plane crashed into the ocean

Do modern airliners not have an alternate static source as on my 172?

Marc





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Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity