Re: Break the VSI?

Date:         22 Nov 96 05:48:05 
From: (Peter Gugerell)
Organization: Customer of PING - Personal InterNet Gate
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  or MIME structure (MiDiBu) wrote:

| One of the oldest tricks that a pilot learns is that if the static
| ports are clogged up, one breaks the glass on the vertical speed
| indicator (VSI).  Before you see the problem with this I would like to
| address two things:
| ...
| But, the reason that I'm posting this is - Could the pilots of a 757
| break the glass on the pitot/static instruments and undo the damage
| done by the ground crew/bad walkaround?
| Mike Weller

Hi Mike,

Yes, they could break the glass. No, it wouldn't help. There are no
conventional barometric instruments on most modern jet aircraft. The
data from the static ports and the ram air probes goes into an "air
data computer". This computer provides an electrical signal that
drives the instruments. The altimeter and the VSI are not self-contained
instruments; they only display computer-generated data.


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