On the B727, the Captain's or F/O's static sources are selectable from
Normal to "Alternate", which would provide the static instruments with
static air which is used for the Mach Airspeed Warning and Pressurization
systems

"Marc Lattoni" wrote in message
news:c3%hc.1386$2q2.192@edtnps84...
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