At 10:54 AM 31/07/2010, you wrote:
Hi Mike
These guys are doing really well at the Worlds so far, this could be the new
glider to beat.
According to the PDF document linked in your email they say that ..
"The size and geometry of the extractor lower the pressure level inside the
cockpit to ambient levels..."
I read that as meaning the cockpit pressure is neither higher nor lower than
the outside air, so probably no effect therefore on the accuracy of the
flight recorder pressure altitude.
ROSS
_________________________________________________
However if that is true it won't prevent air leaks out of the canopy
frame as the pressures there will definitely be lower than
ambient(static) pressure.
The article also says the vent"sucks air out of the cockpit" and
"depressurises" the cockpit so I think the article may just be poorly worded.
DG reckon the Mandl vent reduces the pressure considerably below
static pressure. Several (maybe 5)HectoPascals below static at 100
knots or so. One Hpa is about 27 feet. So you could be reading 135
feet high on your flight recorder pressure altitude. This could cost
you all points for a day. The pilot who lost all points at Benalla
about 18 months ago on one day had had a Mandl type vent installed
not long before. As it is installed under the fuselage near the
trailing edge of the wing the Mandl vent may not be as effective as
the new Jonker vent which may cause even more suction.
Mike
Borgelt Instruments - manufacturers of quality soaring instruments since 1978
phone Int'l + 61 746 355784
fax Int'l + 61 746 358796
cellphone Int'l + 61 428 355784
email: [email protected]
website: www.borgeltinstruments.com
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