Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Tue, 07 Oct 2003 23:01:16 -0400
Message-ID: <redirect-2628036@logan.com>
From: Dan O'Brien <danobrien@cox.net>
Subject: Re: Prop for the Super ES
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Dan Newland requested passing on any information learned from Tim Ong about 
the numbers for the three props tested on the factory's Super ES.  I spoke 
with Tim today, and while he didn't have all of the numbers handy, here is 
the information that he shared.

1. In high cruise (25-squared), the Hartzell was roughly 3 kts faster than 
the MT and the Aerocomposites.

2. In climb, the MT and Hartzell were about the same, and both did better 
than the particular Aerocomposites prop that was tested.  However, the 
Aerocomposites prop that was tested did not develop 2700 RPM on the 
take-off roll because it was not optimized for the ES.  Tim saw no reason 
to believe that the Aerocomposites would not perform as well as the others 
if adjustments were made to allow it to develop 2700 RPM.  His 
understanding was that these adjustments would not be difficult to make 
(consistent with Eugene Long's post in this thread).  (It is not difficult 
to believe that the Aerocomposites would perform well on a 2700 RPM 
take-off if the reports about its take-off performance on the IV and the 
Legacy are accurate).

3. The Hartzell is roughly 23 lbs heavier than either composite.

4. There is a noticeable reduction in nose-heaviness when flying with one 
of the composites rather than the Hartzell.  However, this can be offset 
by: i) putting batteries and if needed other accessories aft; ii) a bigger 
trim tab; or iii) putting about a 5 lb lead weight way back in the 
tail.  Given two planes that are identical except for the prop, the plane 
with the Hartzell will be about 28 lbs heavier because of the heavier prop 
and the 5 lbs of ballast in the tail.  But the two planes will feel about 
the same.

5. The Hartzell is more durable than the composite props, and probably 
requires less frequent repair on average.  However, the Hartzell may be 
more costly to repair.  As Pat Weston noted in his post on this thread, 
little dings in his MT are builder-repairable (apparently a little glass, 
some sanding, and paint), so the potential for an increased incidence of 
"dings" that have to be repaired doesn't have to break the budget.  It 
seems that the composite props need repairs more often than the aluminum 
prop, but the repairs on the composite prop tend to cost less.  Take your 
pick.  The Aerocomposites claims to be more durable than other composite 
props because of its nickel leading edge.  Tim did not have the data to 
evaluate this claim.

I note that every person who responded to my question about props for the 
Super ES is happy with his prop choice.  All three props were 
represented.  Seems to me like we have three good options to satisfy 
different preferences. :)

Dan O'Brien
Lancair Super ES