New Vent!

On Dec 7, 7:20*pm, Kevin Christner wrote:
I have an exit vent in the lower aft area of the fuselage of both my
'27 and '28. With all the other stuff done sealing rudder hinge,
elevator drive, horn splitters, etc, it improved negative pressure and
flow and resulted in less noise. This vent is a huge ass ache to put
in with the associated nozzle, has significant structural implications
requiring reinforcement, and simply, is not for the faint hearted.
The new vent on top is in a low pressure area which helps a lot with
getting flow and reduced cockpit pressure. It also takes an hour and a
half to install instead of about 10 hr. It's structural implications
are minimal. It slightly reduces available baggage storage in the top
center 4 inches.
Both my gliders will have rear vents closed this winter and '28 will
get top vent.
FWIW
UH

What work needs to be done to fit these to other types? *Reglass the
cockpit scoop to fit the inside of the fuselage shell?

2C

One done so far is for '24/27/28/29. It is molded to follow the inside
contour of the fuselage which has a lap joint.
To make one to fit another type, outer shape needs to be matched and
inner shape needs to be matched. Long answer
to say it probably won't be right. Other ships may follow- we'll see.
UH/LX

On Dec 8, 5:48*am, wrote:

One done so far is for '24/27/28/29. It is molded to follow the inside
contour of the fuselage which has a lap joint.
To make one to fit another type, outer shape needs to be matched and
inner shape needs to be matched. Long answer
to say it probably won't be right. Other ships may follow- we'll see.
UH/LX

Any thought of making an extended baggage tray for the 28? There is
no reason it couldn't extend back like the 27 does. That would give me
back the forward of spar space that I would lose with the collector
plate. That forward of spar space is filled on my glider with 2 water
bottles, hand held radio, parachute bag, and canopy cover. (and the
essential landout deterrent - the stale peanut butter sandwich)

Maybe the reason my 28 is quiet is that all the space between my head
and the tail is stuffed full

What measurements have been done on performance gains? I'd like to
see data for your 28 pre vent and post vent for sink rate at 90kts. I
won't spend $500 to reduce noise level or increase ventilation but I
would for a significant reduction in the sink rate at high speeds.

Andy