The pressure inside of the fuselage at speed will always be lower than the ambient outside air pressure. A ram air
source out on the wing and away from the engine compartment can provide fresh air, but a little muffin fan will not do
it. Does everyone have a CO monitor on board?



"Morgans" wrote in message ...
:
: "Montblack" wrote
:
: I know many planes are leaky ...but if you do have a somewhat tight
: cockpit, would a (small) fresh air feed, slightly pressurizing the cabin
: (perhaps with a small computer type fan), be good insurance against CO gas
: intrusion?
:
: Somewhat tight is the key phrase. I don't think most are tight enough for a
: muffin fan to be able to create positive pressure.
:
: Add to that, fan blade type fans are very, very poor at creating pressure.
: Squirrel cage blowers are used where pressure is needed. That is why house
: air handlers (furnaces) have squirrel cage blowers, as do heater blowers in
: cars.
:
: Still, a fresh air blower will not help where the cause of the CO is a
: cracked heat exchanger. (muff)
:
: The other problems are fixed by sealing off the leaks, especially in low
: pressure areas, but you knew that.
: --
: Jim in NC
:
: