REFLECTOR: glide

[Don Johnston]

IIRC. Twin props operate opposite from single props. That is, no oil
pressure and the prop goes to course (feather).

From: Mark Magee <edjonesbrady at gmail.com>
To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
Cc: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
Date: Wed, 20 Jun 2012 10:05:56 -0500
Subject: Re: REFLECTOR: Reflector Digest, Vol 87, Issue 124
Hi Kevin,
FULL FEATHER is best case scenario for any propeller driven aircraft that
has lost power. We don't see it available so much in GA because it can
require a hydraulic pressure reservoir. With a dead engine the windmilling
is now the power source that turns the oil pump that controls the prop
pitch. As pitch approaches FEATHER prop drastically slows down, as does oil
pump, as does oil pressure required to continue pushing the blades to
FEATHER. With no oil pressure reservoir (large and heavy) getting that
blade those last 20-50 degrees to FEATHER becomes impossible as their is no
more oil pressure left to push the hub. This is all assuming you haven't
bled out your oil. Commercial turboprops will most likely have a hydraulic
reservoir to get to feather, which will be the least drag/best glide or
single engine performance profile.

Mark B. Magee
N34XL XLFG
Sent from IPhone 4
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