Author: "tshrem2003" <tshrem@...> Time: Mon Mar 8, 2004 3:17 pm PST Link
Ship,
The simple question you never answered is: Does anyone (Unison, any
prop maker, etc) prohibit or recommend against the use of Lasar on
any certified engine/prop combination? The answer to this question
will quickly prove or disprove all of your theories.
By the way, the LASAR is not "classified as electronic ignition" it
IS electronic ignition. The only thing mag-based is the redundant
back-up system.
Tim
--- In vansairforce@yahoogroups.com, shiprv8@a... wrote:
> sort of incorrect
> PMA has nothing to do with props or vibrations; PMA represents the
paper
> trail -- on every nut, bolt, casting, batch, etc. -- on the
manufacturing side of
> FAA certification meaning that the certified unit is manufactured
in
> compliance with FAA FAR standards on manufacturing.
>
> editorial comment: PMA is a nightmare when you're certifying an
entirely new
> engine design!!!
>
> Anything that is FAA certificated must also have a PMA at the
manufacturing
> level. In some cases (like entire engines, for example) PMA is
actually more
> difficult to achieve than the certification itself. Anyone
manufacturing a
> Certificated part must also have a PMA (manufacturing)
authorization from FAA.
>
> Superior and ECI got all of their clone technology as PMA
manufacturers for
> Lycoming components. Perfectly legal.
>
> Re LASAR applications on 320, 360, etc.:
> -- each of those engines would've been tested and listed as a
certified
> installation by Unison.
>
> Re prop/LASAR combinations:
> Although LASAR is a mag-based system, it is classified as an
electronic
> ignition. Any **approved** engine/prop/LASAR combinations would
have had to be
> tested and certified under FAR by the prop manufacturer for that
specific
> installation.
>
> Bottom Line:
> A quick call to Hartzell or any other certified prop vendor can
tell whether
> LASAR is approved, restricted, etc. for any of their props. For
> experimentals, we're on our own as always.
>
> ship
> [Non-text portions of this message have been removed]
Author: shiprv8@... Time: Tue Mar 9, 2004 4:39 pm PST Link
In a message dated 3/8/2004 6:09:26 PM Eastern Standard Time, tshrem@... writes:
> The simple question you never answered is: Does anyone (Unison, any
> prop maker, etc) prohibit or recommend against the use of Lasar on
> any certified engine/prop combination?
if you mean "electronic" generically, the answer is "yes"....the older Hartzell prop is placarded on EI; the Whirlwind says "no EI" for the 150 series props.....it's always a case-by-case basis....if you want a given prop, find out what ignitions it can handle and vice versa....a quick call to the respective vendors will answer the question
> The answer to this question will quickly prove or disprove all of your theories.
what "theories"? are you referring to prop testing and the impact of EI on propeller stresses?
> By the way, the LASAR is not "classified as electronic ignition" it IS electronic ignition. The only thing mag-based is the redundant back-up system.
LASAR is "electronic-over-mags" ....."classified" refers to FAA's terms on prop testing, not mine....it's an excellent unit but it's still has mags, and mags fire all the time....the L" in LASAR stands for "Limited" as in "Limited Authority Spark Advance System"....it's "limited" b/c it's not possible to fully control the spark timing due to the mags firing sparks on fixed timing all the time....LASAR is a compromise driven entirely by the FAA's desire to have engine redundancy if total electrical failure....it was the only way to get LASAR approved for installation on certified MAG-BASED engines without requiring full re-certification of the entire engine.
ship
Author: David Domeier <davidd010@...> Time: Tue Mar 9, 2004 5:53 pm PST Link
re"....LASAR is a compromise driven entirely by the FAA's desire to have
engine redundancy if total electrical failure....it was the only way to get
LASAR approved for installation on certified MAG-BASED engines without
requiring full re-certification of the entire engine." ship
Ship,
And while it is an attractive system, there may have been a certification
issue with Cessna and LASAR/Lycoming in the 172.
They started production with LASAR and then it was discontinued. Current
172's have 2 mags, no LASAR.
It would be interesting to know exactly why this happened.
dd
[Non-text portions of this message have been removed]
Author: "mahlon_r" <mahlon_russell@...> Time: Wed Mar 10, 2004 6:37 am PST Link
There seems to be some confusion, miss-information and half truths
regarding the discussion of Unison LASAR system. These are the facts
as I believe and am pretty sure them to be true.
LASAR stands for L-imited A-uthority S-park A-dvance R-egulator. It
is not a full authority FADEC system. The LASAR system electronically
generates a variable energy and variable timed ignition event for the
engine that uses the system, by monitoring MP, RPM & CHT and using
pre-programmed software program in the regulator. This LASAR generated
spark is the distributed mechanically through the distributor in the
LASAR mag as it would be with a conventional mag. The systems back up
is, that if the LASAR portion of the system fails or if you lose
electrical power the LASAR mags revert to being able to generate
normal standard magneto ignition and distribution. The system is
approved for use on many, many aircraft and engines through the STC
(supplemental type certificate) process. There are no restrictions in
any of the STC documents, installation instructions or user manuals,
for propeller installations, RPM restrictions or any other operational
restrictions, in addition to what any OEM installation had before the
LASAR system is installed, except that a LASAR equipped engine must
use 100LL Min fuel. The document that shows all of the STC approvals
for both aircraft and engines and has the installation instructions
for the LASAR system is SL1-96 and is available at unison's website
at: http://www.unisonindustries.com/news/service_documents.html
scroll to the LASAR section of the page and look for SL1-96.
The FAA approved Flight Manual Supplement( P/N FMS1-96) for any
Certified LASAR equipped aircraft and engine combination also says, in
the limitations section, that there are no changes in regard to engine
or propeller operational restrictions due to the installation of the
LASAR, except for the need to use 100LL min. fuel. This document also
give a very good description of how the system works in laymen's' terms.
I hope this helps.
Good Luck,
Mahlon
--- In vansairforce@yahoogroups.com, shiprv8@a... wrote:
> In a message dated 3/8/2004 6:09:26 PM Eastern Standard Time,
tshrem@c... writes:
>
> > The simple question you never answered is: Does anyone (Unison, any
> > prop maker, etc) prohibit or recommend against the use of Lasar on
> > any certified engine/prop combination?
>
> if you mean "electronic" generically, the answer is "yes"....the
older Hartzell prop is placarded on EI; the Whirlwind says "no EI" for
the 150 series props.....it's always a case-by-case basis....if you
want a given prop, find out what ignitions it can handle and vice
versa....a quick call to the respective vendors will answer the question
>
> > The answer to this question will quickly prove or disprove all of
your theories.
>
> what "theories"? are you referring to prop testing and the impact of
EI on propeller stresses?
>
> > By the way, the LASAR is not "classified as electronic ignition"
it IS electronic ignition. The only thing mag-based is the redundant
back-up system.
>
> LASAR is "electronic-over-mags" ....."classified" refers to FAA's
terms on prop testing, not mine....it's an excellent unit but it's
still has mags, and mags fire all the time....the L" in LASAR stands
for "Limited" as in "Limited Authority Spark Advance System"....it's
"limited" b/c it's not possible to fully control the spark timing due
to the mags firing sparks on fixed timing all the time....LASAR is a
compromise driven entirely by the FAA's desire to have engine
redundancy if total electrical failure....it was the only way to get
LASAR approved for installation on certified MAG-BASED engines without
requiring full re-certification of the entire engine.
>
> ship
Author: Walter Tondu <walter@...> Time: Wed Mar 10, 2004 10:21 am PST Link
I hate to throw more fuel into the fire, but those of you with
non-standard compression engines will want to check with the prop
manufacturers because some of them will have limitations based
upon this as well. If you combine high-compression with electronic
ignition you may find that this is a combination some prop
manufacturers don't like.
--
Walter Tondu
http://www.tondu.com/rv7