From: Bud Yerly<mailto:budyerly@msn.com>
Sent: Saturday, March 10, 2018 2:59 PM
Subject: RE: [europa-committee] RE: Europa-List: Re: Vertical Power VP-X Pr
o
Mike and all.
Here I go again, keep in mind I have a love hate relationship with every co
mponent in an aircraft.
One piece of advise, be an amp zealot!
40-60 amp alternators are necessary on some pieces of equipment. Like a mo
tor home, yacht, or like my neighbor kids car with incandescent lighting (h
e likes the warm glow I guess) power everything, and his wonderful stereo h
e shares with everyone around him. Just kidding.
The Europa is a light simple aircraft. Today our aircraft for IFR really p
ush the 18 max amp Ducati VR beyond its capacity.
The main, and frankly the only hi amp item needed today, is the pitot heat
in a solid state IFR aircraft. That is where a 40 amp alternator, which is
belt driven, is necessary; because in the pattern, doing 80 knots at 4000
RPM the Ducati is barely keeping pace on a VFR day with normal radios/trans
ponder and the like (Rotax says it supplies 13.5 volts at 18 amps at 4000 b
ut don=92t count on it). If you have a 914, each pump is 2-3 amps and the
TCU and servo another .2. Add Pitot heat, electric gyros, autopilot, 5 wat
t radios, old 2.5 amp transponder, encoder, incandescent 100,000 candle pow
er landing light, and incandescent Whelen Strobes, you will need 30 amps a
nd a robust battery just to drive all that. Of course you will need the 60
amp if you add your heated seat cushions, electric snow suit, dual iPads a
nd stereo system. But you will be =93stylin=94.
Problems with the Belt Driven Alternator is you must change the cowl, add a
spacer to the prop drive lugs for the pulley flange sometimes, deal with n
oise from the alternator (magnetic and electronic from the alternator) and
of course the weight. If it is a low power belt drive alternator, you may
need to split the main bus into two and add a bus tie in the event of loss
of one alternator. Wiring designs for switching alternators/bus ties and s
ystem degradation (if the main or aux alternator is lost), is necessary. B
een there, done that! Time consuming, but necessary documentation, and it
works.
Pitot Heat: I=92ve installed Angus, Dynon, old Piper units and they all dr
aw 6-10 amps when on at full blast. Nice thing about the new ones is they
have thermostats so unless cruising in severe icing, they only draw a coupl
e amps. But that initial turn on and cruising in sub freezing temps will g
et you back up to the that max of 6-10 amps. No one has figured out anti-i
cing for the wings and prop to date. I=92ve commented on the backup static
source recently.
Consider this:
Led Lighting (high power landing light is 2.5 amps, and wing lighting is .
6 amps with continuous strobe)
Interior lighting of LED post lights (I know they are not sexy) is negligib
le).
Modern solid state radios pull .5 amps. Trig is one, and they do not requi
re cooling air.
(Cooling fans draw a max of .5 amps and if a unit needs one, it draws too m
uch power.
Mode S transponders today are all digital and pull .5 amps max.
Gyros are a thing of the past. A solid state EFIS is all that is necessary
. It pulls only about .6 amps if you are a frequent button pusher. Leave
it alone and it drops to .1 amp.
Engine monitors are built into the EFIS systems and pull next to zero.
Autopilots draw a max of 2 when working hard and .5 at cruise.
Ipads tend to draw about 2 amps when working as a nav device. More if need
ing a charge and working hard.
Aux boost pumps adds 2-3 amps when under load, so figure 4 amps at 4000 RPM
in a 914 on downwind with both on.
Trim and flaps are momentary draws so I=92m not counting them.
Batteries are now stronger and longer lasting, and even I am warming up to
the Li ion batteries. Heck, put in two.
At night in the weather, with idle RPM you are on the battery only normally
so if the battery was down a bit and on landing roll out you key your old
Garmin radio, expect the incandescent lights and radio to cut out, leaving
you dark and quiet on the runway.
So the amp draw is in the range of 9-10 amps until you turn on the pitot h
eat and landing lights then you are at 18-20. If you want a fully IFR Euro
pa to meet the required equipment for IFR, you must have a belt driven alte
rnator at this time to provide the necessary amps at lower RPMs. Until the
extra alternator coil gets approved on the back of the Rotax, you are stuc
k with the mods I discussed above.
In Europe, you do have the new guys: FLYGAS who have reportedly added a sec
ond set of coils and rotors to the back of the Rotax 9 series. The prototy
pe was clean and neat looking last time I looked.
Circuit design is fairly easy for dual alternators, even if you split the b
uses. You can review Bob Knuckles and go from there. I haven=92t put cust
omer circuits I design on my website but I=92m available to send copies.
In the use of Vertical Power and other so called easy plug and play wiring
units, I am mixed on them. To save panel space or extensive panel mods to
enlarge the panel face for circuit breaker panels, I have used the very ine
xpensive and reliable circuit board made by EXP. I do not use their face p
late. I install my own switches and relays where I want them. I also moun
t it securely, fab a cover panel (I don=92t need some loose nut falling int
o a circuit board) and apply cooling air as PTCs do warm up which affects t
heir tripping point. I do not like the EXP annunciator panel but it works
(except for amps) and it has a built in surge protector. Weight is .6 pou
nds with my cover and D sub plugs.
I spoke to Vertical Power at Sebring last month. The unit weighs in at 2 p
ounds, and their power hook up box is 1.6 pounds (from memory) The boxes a
re large (so where to put them is a problem) and their supplied wire bundle
s with D subs are heavy as sin and use straight connectors so the wire bund
le bending as well as box placement must be planned very carefully. A spor
t aircraft is already 5 pounds of crap in a 3 pound bag so I just don=92t h
ave room for these huge boxes.
Remember, if a system is automatic, you have lost control. As with power p
anels, don=92t try to isolate one circuit to test during the build without
planning your plug circuits to allow a bypass of all the rest of the circui
ts. If all wired direct, it is all hooked up or nothing.
I prefer to teach my clients how to wire, the tools and wire necessary to d
o the job right. Try to make everything serviceable inside the panel and t
he panel a breeze to remove (of course nobody but me wants to do it as it i
s plugs and screws.) I have also found, if it is convenient and automatic
it is also expensive, heavy, and seems to always require extra support. So
metimes dumb simple systems, well documented, are the least troublesome. T
he client understands and knows his panel, and in the event of a problem, i
s more comfortable with troubleshooting. Remember, if you plan it to be se
rviceable, it will never fail.
Just my opinion.
Bud Yerly
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Window
s 10
From: Mike Gregory <m.j.gregory@talk21.com>
Sent: Saturday, March 10, 2018 5:40:15 AM
Cc: 'Bud Yerly'
Subject: RE: [europa-committee] RE: Europa-List: Re: Vertical Power VP-X Pr
o
David,
Yes of course you may pass that on to Alan ' I don=92t think I=92ve said
anything libellous about VP, and the points made on the AeroElectric list a
re open to all who care to subscribe. I believe very much in careful consi
deration of factors such as reliability and maintainability before installi
ng anything that has not a track record for application to the Europa. Whil
e cost/benefit is also a consideration, I would be much more concerned abou
t ease of fixing to get home if anything went wrong when far away from spec
ialist support.
I am copying this to Bud Yerly, and would welcome any comments from him, es
pecially if he has fitted such a packaged system to a Europa.
Best wishes,
Mike
Dr Mike Gregory
+441480 451655
+447885 355765
From: 'Peter Jeffers' via europa committee [mailto:europa-committee@googleg
roups.com]
Sent: 10 March 2018 09:40
Cc: europa-committee@googlegroups.com
Subject: [europa-committee] RE: Europa-List: Re: Vertical Power VP-X Pro
Hi David ,
I did suggest a while ago that he contact the LAA wrt his proposition rathe
r than receive unverified information from club officials.
Pete
From: davidjoyce@doctors.org.uk [mailto:davidjoyce@doctors.org.uk]
Sent: 10 March 2018 08:48
Cc: 'Peter Jeffers'
Subject: RE: Europa-List: Re: Vertical Power VP-X Pro
Mike, Are you happy to pass that on to Alan? Might save him some bother. Da
vid
On 2018-03-10 00:32, Mike Gregory wrote:
Hello David,
I had a discussion with Francis some years ago about the EXP-Bus, which you
no doubt are aware was an earlier system providing an integrated solution
to electrical control and distribution. We agreed that it was not somethin
g we would wish to encourage for permit aircraft, as such a system has the
potential to give trouble that would be difficult to diagnose and fix if th
e software or hardware went wrong.
There was a lot of discussion on the AeroElecric list in 2016, typified by
the contributions copied below from Bob Nuckolls and Peter Pengilly, two pe
ople whose advice I respect.
I share the summary view expressed by Peter Pengilly at the end of his pie
ce:
"So we have a device of unknown quality passing data to a second device of
equally unknown quality to control a function that we really need to work c
orrectly all of the time. That is rather too much trust to put in people I
have never met and who are unwilling to describe how they ensure their desi
gn goals are achieved in their products.
"However good a VPX is at managing an electrical system, from my perspecti
ve this type of function is taking unnecessary risks for very little gain.
It is also expensive when a few fuses will carry out the same job."
If someone wants to spend the money, then no doubt they could get LAA appro
val to install such a system, but even with this newer system I still would
n't encourage it ' and certainly not if the reason for adopting it is tha
t the builder doesn't understand electrics and wants to "simplify" his elec
trical build.
Best wishes,
Mike
Dr Mike Gregory
01480 451655
07885 355765
From: davidjoyce@doctors.org.uk<mailto:davidjoyce@doctors.org.uk> [mailto:
davidjoyce@doctors.org.uk]
Sent: 09 March 2018 15:23
Subject: Fwd: Europa-List: Re: Vertical Power VP-X Pro
Mike, Do you have the time to offer an opinion on this? David
-------- Original Message --------
Subject:
Europa-List: Re: Vertical Power VP-X Pro
Date:
2018-03-09 10:19
From:
"alan_hunter1664" <alan_hunter1664@yahoo.co.uk<mailto:alan_hunter1664@yahoo
.co.uk>>
To:
europa-list@matronics.com<mailto:europa-list@matronics.com>
Reply-To:
europa-list@matronics.com<mailto:europa-list@matronics.com>
.co.uk<mailto:alan_hunter1664@yahoo.co.uk>>
I'm going to send this to my inspector but I would be grateful of any comme
nts on the attached prior to this. Does this look reasonable as an avionics
installation for a Europa? there will be a standby altimeter & ASI which i
sn't shown on the diagram, also I haven't numbered the cables yet either
Thank you in advance
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=478518#478518<https://nam02.s
afelinks.protection.outlook.com/?url=http%3A%2F%2Fforums.matronics.com%2F
viewtopic.php%3Fp%3D478518%23478518&data=02%7C01%7C%7C880426fb54d54775280
f08d586734faf%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6365627521746021
81&sdata=4YVX8JvUDneFObv2k1GQxPxREaIZb4F7WgMymhrn%2Feg%3D&reserved=0>
Attachments:
http://forums.matronics.com//files/electrical_wiring_diagram_413.xlsx<https
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ics.com%2Ffiles%2Felectrical_wiring_diagram_413.xlsx&data=02%7C01%7C%7C88
0426fb54d54775280f08d586734faf%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7
C636562752174602181&sdata=DQ41JzPKJEqM%2By%2F2If6TIDq8AVMs7sfo%2BEioh9Dn6
TA%3D&reserved=0>
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ics.com%2Ffiles%2Felectrical_wiring_diagram_151.xlsx&data=02%7C01%7C%7C88
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C636562752174602181&sdata=WuKEJ5WExlfI%2B6vcO8oDI%2BC%2B7KpXCyrwQhoCWcq2U
A4%3D&reserved=0>
From: owner-aeroelectric-list-server@matronics.com<mailto:owner-aeroelectri
c-list-server@matronics.com> [mailto:owner-aeroelectric-list-server@matroni
cs.com] On Behalf Of Robert L. Nuckolls, III
Sent: 26 March 2016 20:53
Subject: Re: AeroElectric-List: Re: Vertical Power X-VP Pro or Sport
At 10:11 AM 3/24/2016, you wrote:
I have wondered about 2 issues w/ VP systems:
1. The all-your-eggs-in-one-basket issue. If the unit fails the aircraft i
s down and you, the owner, cannot fix it.
2. The system adds several layers of complexity & cost to the relatively si
mple task of power distribution.
I'm curious if owners of the system share those concerns and how they addre
ss them.
We've had discussions about these kinds of systems on numerous occasions
over the years that began with relatively innocuous products like the EXP-
Bus
http://tinyurl.com/jucvcar
<https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Ftinyurl
.com%2Fjucvcar&data=02%7C01%7C%7C880426fb54d54775280f08d586734faf%7C84df9
e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636562752174602181&sdata=Epd3nNylaA
fg%2Fa78kaavhj%2BbifeUsy6nqDzzwilsxz0%3D&reserved=0> and sort of reache
d an apex with the Vertical Power products. Based on my experience in the T
C aircraft world, I've always assessed such offerings from two perspectives
:
Cost of ownership: Over the lifetime of the airplane . . . from the day
you plunk down your credit card to order the product until the time you se
ll or scrap the airplane, what is the $service-value$ when compared to the
$acquisition/maintenance value$?
Part of that cost of ownership has to include cost to acquire and instal
l the system. Our airplanes are not very complex. A review of the Z-figures
describes a range of complexity from ultra-lights to a Lance Air 4P. If o
ne chooses to wire up fuse blocks and flip switches purchased at the hardwa
re store, the cost of acquisition can be quite nominal . . . but the number
of tinker-toys is greater and they are not combined into plug-n-play modul
es.
However, no single component is very expensive hence easily and cheaply
replaced when it reaches end of service life. Further, nothing is 'automati
c' . . .
we are encouraged to be technically cognizant pilots, not appliance oper
ators. Even when you consider the totality of automation offered by any air
plane super-system, what percentage of your block-to-block trip time is con
sumed doing those operations yourself?
Once you've deduce the demands on your time and attention for manual ope
rations, how much are you willing to pay to have those things done for you?
The other side of the coin begs the question for how much understanding
and in-flight cognizance is discouraged or even denied to you when you let
the software do it for you?
I am reminded of a line from "The Right Stuff" attributed to Deke Slayto
n of the original astronauts after discovering that they were being selecte
d to be mere passengers on the first US manned space flights.
Deke Slayton: What Gus is saying is that we're missing the point. What Gus
is saying is that we all heard the rumors that they want to send a monkey u
p first. Well, none of us wants to think that they're gonna send a monkey u
p to do a man's work. But what Gus is saying is that what they're trying to
do to us is send a man up to do a monkey's work.
Us, a bunch of college-trained chimpanzees!
Animals had been used in aeronautic exploration since 1783 when the Mont
golfier brothers sent a sheep, a duck and a rooster aloft in a hot air ball
oon. We've come a long way since then . . . we KNOW that high speed motion
at altitude is not inherently
hazardous . . . we also know that MOST unhappy days in the cockpit have
roots in lack of knowledge, skill or just inattention.
I started the AeroElectric Connection in 1988 based on an observation at
OSH suggesting that the electrical system was the least understood compone
nt of the OBAM aircraft.
The 'Connection grew out of the notion that the whole universe runs on s
tone-simple-ideas in physics. All creativity is a study in properties of ma
terials and management of energy. Ergo, if you can learn to make bread or
repair your lawn mower, you can also learn to how to craft and operate a ma
chine that would have scared the socks of the Montgolfier brothers with les
s risk than their first living passengers might have been exposed to.
If Goggle has their way, self flying airplanes are right on the heals of
self-driving cars. No doubt there will be customers for those products. Do
n't know why everyone else likes to fly but I do it because I'm a pilot wit
h an intense interest in how and why the machine works while maintaining it
with a minimum of interference, cost and down time for repairs.
Probability for electrical system malfunctions being root cause for bent
machines and/or people are vanishingly small. Yet many of our brothers 'wo
rry' about the electrics for what I'll suggest are two primary reasons. Lac
k of understanding combined with the relative frequency of 'dark n stormy n
ight' stories in the aviation rags that speak to electrical systems issues
while illuminating the pilot's ignorance.
If installing a 'push-button' electrical system is attractive, then do s
ome soul searching for the motivation If it is a ploy to avoid a need to u
nderstand . . . or just a love of technological bells and whistles. If mone
y is no object and having and airplane with lots of nice displays is a goal
, then by all means. But if money is tight but you're worried about the art
ful combination of simple-ingredients in a recipe for success, then allow m
e to suggest that the learning curve is steep and not difficult. If push-bu
tton utility is the goal, then know that virtually ALL products ranging fro
m EXP-Bus to Vertical Power do perform as advertised.
Choice of products is all about how large the bells-and-whistles bucket
is.
Another consideration is cost of ownership for the fielded system. When
it breaks, what are your options for getting it back in service, at what co
st and down time on the airplane? There's a cost of competence and confiden
ce when the root cause of failure is not understood and remedy is beyond yo
ur control. A situation that seldom occurs when your recipe for success is
a collection of simple components from the hardware store.
The second benchmark speaks to failure mode effects analysis and mitigat
ion that asks the following questions:
1. How many ways can this part fail?
2. How will each failure affect system operation?
3. How will I know it failed?
4. Is the failure pre-flight detectable?
5. Is failure of this part, in any failure mode, likely to create
a hazard to flight?
6. Will failure of this part be likely to overtax my piloting
skills for comfortably terminating the flight?
When you're looking at a nice touch-screen with lots of pretty colors, m
ost of the answers to the above are not known to you. On the other hand, a
small box of fuses, switches, relays, terminals and wire has no secrets . .
. and allows the builder to comfortably asses all the above and the import
ant SEVENTH question:
7. Is there any failure with effects that influence more than one system?
Having good answers to the above is foundation for a failure tolerant, l
ow maintenance, minimum cost of ownership product with minimized risk. That
's how we built Beechjets and Bonanzas . . . machines I like to think of as
airplanes for pilots.
Bob . . .
From: owner-aeroelectric-list-server@matronics.com<mailto:owner-aeroelectri
c-list-server@matronics.com> [mailto:owner-aeroelectric-list-server@matroni
cs.com] On Behalf Of Peter Pengilly
Sent: 26 March 2016 00:08
Subject: Re: AeroElectric-List: Re: Vertical Power X-VP Pro or Sport
--> AeroElectric-List message posted by: Peter Pengilly
--> <peter@sportingaero.com<mailto:peter@sportingaero.com>>
That's a rather angry post, let's try to take the emotion out of this discu
ssion.
Looking at the flap and trim control only. The VPX is a software driven mac
hine. It takes switch inputs, recognises the pilot has requested a certain
action and switches power to a service. The logic is executed by software.
I do not know what standard was used to design, code and test the software.
The VPX has full control of the flap and trim motors and can drive them to
full deflection at any time it chooses, either would be rather bad news in
most aircraft, particularly at cruise speed . If that were to happen at a
slow rate I believe the only way to stop it would be to shut down the whole
VPX - I'm not even sure if that is possible. I hope there are some protect
ions built into the VPX to prevent un-commanded movement, but I don't know
as I cannot find that data in the public domain. Therefore we only have the
assertions of the designers that motor run-aways will not happen.
EFISs are also software driven machines, all of the common uncertified EFIS
s are in the same boat - I have asked the manufacturers how their software
was written, they have declined to answer.
So we have a device of unknown quality passing data to a second device of e
qually unknown quality to control a function that we really need to work co
rrectly all of the time. That is rather too much trust to put in people I h
ave never met and who are unwilling to describe how they ensure their desig
n goals are achieved in their products.
However good a VPX is at managing an electrical system, from my perspective
this type of function is taking unnecessary risks for very little gain. It
is also expensive when a few fuses will carry out the same job.
Peter
On 25/03/2016 20:35, Kelly McMullen wrote:
> --> AeroElectric-List message posted by: Kelly McMullen
> <kellym@aviatingcom<mailto:kellym@aviatingcom>>
>
> Your assertion that the flap and trim in the VPX is dependent on EFIS
> is flat incorrect. It only uses the airspeed to control how fast the
> trim motor runs or to prevent exceeding flap airspeed limit, which is
> something other systems don't do. You apparently missed that I have
> independent power backup to EFIS should something fail in the VPX. I
> also have an independent EFIS that isn't dependent on ship's power at
> all, which has battery life close to fuel range of the aircraft.
> The likely problems a failure of the VPX would cause is same as loss
> of alternator. I suppose a circuit could go crazy, so you turn the
> master off. I don't trust the VPX any more than I do the alternator or
> traditional power layouts. I've seen the failure of voltage regulators
> and overvoltage systems and the havoc they cause. If you have planned
> correctly, there is no more risk than a traditional fuse and circuit
> breaker design. Asserting there is more risk has no demonstrated basis
> that I have seen. If you have evidence, please educate us.
>
> On 3/25/2016 12:23 AM, Peter Pengilly wrote:
>> Flame suit is on and I stand by all of my comments. As VPX has
>> control of trimou and flap motor based on an input from the EFIS any
>> error in this chain could cause significant problems. With an IFR
>> aircraft it is just about essential to have an alternative power
>> supply to the attitude instrument(s), outside of the VPX.
>>
>> I have had 25 years experience working with airborne software
>> writers, I don't trust them as much as some here seem to!
>>
>> Peter
>>
>> On 25 Mar 2016 02:52, "Kelly McMullen" <kellym@aviating.com
>> <mailto:kellym@aviating.com>> wrote:
>>
>> --> AeroElectric-List message posted by: Kelly McMullen
>> <kellym@aviating.com <mailto:kellym@aviating.com<mailto:kellym@aviat
ing.com%20%3cmailto:kellym@aviating.com>>>
>>
>> Misconceptions from lack of familiarity.
>>
>> On 3/24/2016 4:15 PM, Peter Pengilly wrote:
>>
>> - The sales pitch is that designing electrical systems and
>> wiring up is
>> difficult and this box makes it easy. I don't agree with these
>> statements!
>>
>> Never perceived it that way. It does simplify the wiring.
>>
>> - It provides limited opportunities for expansion There are a
>> limited
>> number of circuits available, once these are used up any
>> additional
>> services will have to be protected by conventional fuses or
>> circuit
>> breakers - seems to make the box a little pointless.
>>
>> The Pro version is not that limited, is intended for full IFR panel,
>> which is what I have, with several pins available for expansion.
>>
>> - The box is expensive compared to fuses.
>>
>> Not when you have to physically install each, do the labor to
>> replace any that blow, etc. I had full hardware priced for CB &
>> fuses system...easily $500. Add 100 hours of labor to design, and
>> create panel of fuses/CB etc, and you are over price of VPX.
>> Advanced Flight Systems thought enough of the concept that they
>> designed their own box.
>>
>> - Combining many functions in one box means that any failure
>> becomes a
>> significant event rather than just an annoyance.
>>
>> AFAIK, unknown event so far.
>>
>> - The software is designed and coded to an unknown standard and
>> tested
>> in an unknown way, neither of which engenders confidence.
>>
>> Have had no issues, have been operating the system for about 3 yrs.
>>
>> - The standAFAIKards used to design, build and test the hardware
>> are not easy
>> to discern, leading to questions on the long term reliability.
>>
>> Theoretical, where is data of unreliability?
>>
>> - Using the box to control trim and flaps using an input from an
>> EFIS
>> places a huge amount of trust in the software writers where a
>> fault
>> risks potentially very serious consequences.
>>
>> Does not use EFIS for input beyond airspeed, only outputs trim/flap
>> position to EFIS. Position comes from trim motor or a position
>> sensor. Power goes to trim/flap motor. No extra boxes needed for
>> trim speed control, runaway protection, wig wag lights.
>>
>> - Those an have chosen to use this box can be very firm in their
>> support, and intolerant of those who present an alternative
>> view, flame
>> suit on!!
>>
>> Only intolerant of criticism generated by lack of knowledge, not
>> facts.
>>
>> On the supportive side, the designer (Marc Ausman) is a huge
>> supporter
>> of homebuilt aviation, and is a director of EAA. The real world
>> reliability seems to be reasonable.
>>
>>
>> Data behind that assertion???
>>
>>
>> My advice would be to start by listing all the electrical
>> functions you
>> want in your aircraft, then which are key to the safe completion
>> of a
>> flight. If you have (m)any of these are you content to
>> entrust the
>> operation of these functions to the VPX? If you are list the
>> cost of
>> using fuses against other means. Install equipment for as
>> reason!
>>
>> Peter
>>
>> No problem with your recommendations, but how electrically dependent
>> is you aircraft? How critical are items beyond engine ignition? If
>> critical, you need some independent backup. Are you not planning for
>> portable GPS and Com radio for back up?
>> You can't fly commercial activities, so how much pressure is there
>> to fly in solid IFR? Why would you design electrical system that is
>> critical to continued flight without independent dual systems?
>> The VPX offers a lot of convenience and flexibility without hardware
>> issues. want to switch an item from buss A to B? Just a software
>> reconfigure. Want to change landing lights wig-wag function? Just
>> software. Ditto for trim or flap limits. Have you flown an example
>> of your aircraft model? Do you know how trim dependent it is?
>>
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