All electric VFR help?

[Caveman]

Guys,

I could use some help with my thought process on my panel lay out.

Background:
VFR cross country, day night aircraft.
One Lightspeed crank triggered ignition and one mag.
One Plane Power alternator.
Single main battery. Nothing separate for the Lightspeed.

I've been studying the Aeroelectric book, etc.
Aircraft weight is a medium to high priority with me.
Here's the kicker... unlike most, I'm seriously considering no backup A.S. or altimeter.

I'm leaning towards fuses instead of breakers and going with a Piper 140 style basic electrical system. I've got probably 800 hours in these planes and I just don't see the need for the complexity of multiple busses. I've been through 2 alternator failures, one was a thrown belt, the other, bad diodes. I just switched off what I didn't need and went on my merry way.

My AFS 3500 order includes a battery back-up and my G496 will of course have battery back-up. In addition I have a Lowrance 1000 that I may panel mount on the co-pilots side just for something for them to play with.

I've got an ADI Pilot II on order for horizon reference if the AFS goes tail up.

I'll have an SL-40, GTX-327, and PS 3000 in the panel with a handheld comm for radio backup.

I do fly at night more than most. Probably 200 hours so far. It is unlikely I'll get an IFR rating or convert the airplane to IFR.

What say ye? Am I insane?

p.s. One more question. What do you recommend for a compass and where should I mount it. A S.I.R.S. Navigator mounted on the tipper glareshield?

 

[frankh]

Not at all

In fact I would be tempted to say that what you are proposing is more than you need.

Except that the night can sometimes be with poor visual reference so I think some form of reliable attitude idicator is wise, so the ADI will certainly give you that.

But even then, I had 200 hours of night in my old zodiac and was quite comfortable with an ADI, altimeter and handheld GPS (with battery backup).

Your engine systems are not electically dependant (I have 3 electric fuel pumps only and no mechanical pump) so ther is nothing to stop your engine running if your alternator dies and your battery power will run your instruments and lights for quite some time.

Put it this way I fly IFR and with my twin electric pumps the only additional thing I have is an SD-8 backup alternator which will run a pump and pretty much all my instruments in IMC.

Oh and I still don't have a compass...even for IFR.

I think you'll be fine with what you propose


Frank

 

[frankh]

OOPs

That should be 2 electric fuel pumps and mechanical pump
Frank

 

[frankh]

OOps 2

I would however consider a steam guage ASI and altimeter in case your electronic box went blank.

You need soem kind of backup for primary flight instruments...I could be a seperate electronic box (provided a single failure like a blown fuse won't take out both units). But personally I would not tolerate a single point of failure leaving with with no ASI or ALT.

FWIW

Frank

 

[flyeyes]

I think you're fine for VFR, but I would add 2 things at minimal to modest additional cost.

First, and most important, I would add a backup way to determine angle of attack in the landing configuration. GPS altitude and GS are close enough for cruise, and normal power settings and pitch are enough to keep you from overspeeds without ASI.

You might get in trouble trying to land without an airspeed indication. This wouldn't likely be a problem lightly loaded at your home field, but if you happen to be heavily loaded and/or at high density altitude you could get a nasty surprise. This has killed a lot of RV pilots.

You really only care about approach speed as a proxy for angle-of-attack. If you have one of these instruments an electrical failure should hold no terror for you.

Second, and much cheaper, I would add a small diode-isolated battery to run your electronics during engine start. This lets you have everything turned on, and also gives you a modest backup power source if you lose the main electrical system.

 

[Sam Buchanan]

I'm leaning towards fuses instead of breakers and going with a Piper 140 style basic electrical system. I've got probably 800 hours in these planes and I just don't see the need for the complexity of multiple busses. I've been through 2 alternator failures, one was a thrown belt, the other, bad diodes. I just swithed off what I didn't need and went on my merry way.

But if your master contactor goes belly up, you will have no electrical power unless you have an essential bus that is tied directly to the battery. The rational for the essential bus is the capability to bypass the entire contactor problem. Since there is very little complexity to adding the e-bus, I think it is a great addition to your system and gives you the option of easily completing the flight in the event of the entire electrical system going down.

 

[vlittle]

I had the same criteria is designing my electrical system (VFR Night and VFR OTT).

The EFIS, GPS and handheld nav/com all have battery backup, so in the event of a catestrophic electrical failure in flight, I still have full primary flight, nav and engine instruments available. (BTW this has happened to me).

I did add an ASI for the reasons detailed by others.

Extras I could do without: Stall vane (Dynon AoA works well and the ASI is the backup), TBI (Trutrak), Hobbs.

Extras I would never do without: Monroy traffic monitor, discrete voltmeter.

I do have a heated pitot for VFR OTT (plus the required current gps database and alternate nav (VOR in my handheld) instrument), and I installed an alternate static source in case I ever upgraded to IFR. Since I installed my O2 system, I'm finding that many of my flights over the mountains involve climbing above clouds for brief periods. I consider it safer than scud-running at lower altitudes through the valleys.

One piece of advice: When you set up your fuse panel, don't run similar instruments or critical instruments off the same circuit. If you trip a fuse, you don't want everything to go black.

Next time, my panel will be even simpler.

 

[Caveman]

Great feedback gentlemen! Just what I was needing.

Sam, I know of a C150 based here that just suffered a battery contactor failure. I'd considered the backup batteries in the GPS's and EFIS sufficient to handle that possibility. I would be reduced to just the mag unless I ran the Lightspeed direct from the battery, though. I would have to land within an hour or two and make repairs before the backup and main batteries died on the EFIS / EMS and GPS's. Maybe the E-buss is the way to go.

Vern, I appreciate the VFR OTT comments. I don't do that at night but have been known to do it in rare occasions in daylight if the weather is fine below the cloud deck with reasonable ceilings. Also, the things you would and would not do without were great. I hadn't thought of the O2 opening up more possibilities. One question though, why the extra voltmeter when both gps's as well as the EFIS / EMS have volt readouts?

Flyeyes and Frank, your asi comments were expected. I reasoned that gps ground speed with wind information and a little mental math would be enough to keep me out of trouble on approach. Perhaps I should revisit that. I'm still not convinced another backup battery is necessary.

For a VFR airplane's altitude I considered the dual gps altitude sufficient. I half expected someone to comment "What if you lose GPS signal"? That is what prompted the compass question.

It will probably take an extra $1200 to $1500 to add the ASI and a decent altimeter. I was hoping to follow Verns lead and add traffic watch down the road.

My airplane is over budget and getting heavier by the minute. But safety first. I was hoping to use the standard tipper panel and save weight. There won't be much height for the back up instruments.
We all have our comfort levels. I just have find a balance between money, added weight affecting performance, and risk probability.
I've got some more pondering to do!

 

[vlittle]

Why a discrete voltmeter?

I have 4 voltmeters in my airplane:
-engine monitor
-efis
-traffic monitor
-van's voltmeter
-and probably one more in the gps

The problem with all of the voltmeters is that they don't always agree. They are all attached at slightly different points off the main or avionics bus, and reflect voltage drops due to system loads.

The engine monitor (RMI) needs me to push a button to read it. The efis (Dynon) wants me to configure the screen to display it instead of other more useful data. The traffic monitor only displays volts when it has no other information to display (although it has a cool voice alert when over/under voltage). Finally, the GPS alerts me only when power fails.

The solution? A nice, dedicated voltmeter upstream of most loads! I calibrated a Van's one in my lab, and installed it last May. Very useful to detect overloading the alternator and general bus condition. Works when everything else is turned off.

V

 

[az_gila]

Not that many $$$$

.....
It will probably take an extra $1200 to $1500 to add the ASI and a decent altimeter. I was hoping to follow Verns lead and add traffic watch down the road.
.....

It shouldn't be that much...

Vans airspeed - with markings $195

Altimeter from Vans $249

Less than $450 total from Vans - E-bay, used, etc. cheaper...
All of the plumbing exists, so nothing extra in that area...

I'm going to go this way (alt and asi) with a Dynon 180, but I already have the instruments... but want to buy some YT gyros?....

gil in Tucson

 

[gmcjetpilot]

By George I think you got it

It sounds like you know what you are doing and understand risk, mission, weight, cost and time to build equation. Electrical gurus are not plane designer and may not focus on weight. You are on the right track, wiring for the mission, such as your logic is telling you, correctly. One good battery, one good alternator, good connections and grounds.

As far as no back up Airspeed or Altimeter is fine. Lets say the EFIS dies. You have your GPS which gives ground speed and track. Even if you had nothing, you can look out the window and be able to approximate your altitude and airspeed by the seat-of-the-ol-pants. Land.

I'm have no Airspeed/Altimeter backup for with a Dynon EFIS and the day/night VFR mission. Lets say on a long X-C the dynon died? I would land. BTW I do have a wing leveler/T&C autopilot if it was a dark moonless night. Now what? What happened when the Vac pump died on planes in VFR in the old days? Land

My concern is not safety, but will I get stuck away from home. Getting on the ground is easy, but what happens on a X-C. I land. With EFIS and Engine monitors we have LOTS of eggs and instruments in one basket.


Now on the ground with no EFIS, I'd be grounded, using my personal rules. Why personal rules? BECAUSE (here is the kicker) for Day VFR an experimental does not NEED altitude or airspeed! True story. If you don't believe me call the EAA. Would I keep flying? Day VFR with gps ground speed and alt, may be but probably not. However I'd be legal to do it. Of couse if something happened that would be another story.


The electronic all-in-one engine monitors is harder to deal with because it has RPM/MAP/FP/OT/FUEL LEVEL, but guess what, its not required by FAR's either! It is experimental. (Don't try to make sense, these are regs not common practice or necessarily a good idea.) To try and back up the Engine monitor with discrete back-up mechanical gauges would be tough and a waste IMHO. It's probably better to get dual redundant engine monitors and EFIS I suppose. However cost & weight goes up. Thank goodness these items are very reliable and hope if it fails, its local.

This is NOT RECOMMENDATIONS FOR BEST PRACTICES, only legalities. Ever fly a Piper cub with no electrical or hand held battery powered gps/com? Planes fly fine with out EFIS and engine monitors. Get the map out and do some pilotage.

I'm not suggesting you fly X-C with out at least one of these instruments installed and working, but getting on the ground is all I worry about. VFR is VFR, however these items ARE required for NIGHT VFR. You can back up and get redundant crazy. If I wanted to get redundant I might consider carrying a spare EFIS and Engine monitor in a fly away kit for a cross country. Just land and plug and play. As far as battery and alternator, they are very reliable if you do it right. Even if the alternator fails, as you say you turn it off and go on battery your merry way.

Compass? You don't need a compass if the AFS 3500 is what I am thinking. The AFS 3500 has a mag heading. Also in a pinch you have the battery powered GPS that gives you TRACK! What more do you want. I'd rather have track than heading any day.

Really the FAA will (must/should) accept the EFIS mag direction for a compass. No compass back-up, jelly jar or vertical card, is needed. Also per the above discussion guess what? A compass is not needed for day VFR. The only thing needed, As Required, is the ELT or transponder, but those are not needed, depending on airspace and how far you fly from home base.

When you think of the capability, redundancy and information you have in your panel its mind boggling. Many jets and most GA planes even today are flying around with way less redundancy. Cheers G

Guys,

I could use some help with my thought process on my panel lay out.

Background:
VFR cross country, day night aircraft.
One Lightspeed crank triggered ignition and one mag.
One Plane Power alternator.
Single main battery. Nothing separate for the Lightspeed.

I've been studying the Aeroelectric book, etc.
Aircraft weight is a medium to high priority with me.
Here's the kicker... unlike most, I'm seriously considering no backup A.S. or altimeter.

I'm leaning towards fuses instead of breakers and going with a Piper 140 style basic electrical system. I've got probably 800 hours in these planes and I just don't see the need for the complexity of multiple busses. I've been through 2 alternator failures, one was a thrown belt, the other, bad diodes. I just switched off what I didn't need and went on my merry way.

My AFS 3500 order includes a battery back-up and my G496 will of course have battery back-up. In addition I have a Lowrance 1000 that I may panel mount on the co-pilots side just for something for them to play with.

I've got an ADI Pilot II on order for horizon reference if the AFS goes tail up.

I'll have an SL-40, GTX-327, and PS 3000 in the panel with a handheld comm for radio backup.

I do fly at night more than most. Probably 200 hours so far. It is unlikely I'll get an IFR rating or convert the airplane to IFR.

What say ye? Am I insane?

p.s. One more question. What do you recommend for a compass and where should I mount it. A S.I.R.S. Navigator mounted on the tipper glareshield?

 

[Caveman]

I'm leaning your way

It shouldn't be that much...

Altimeter from Vans $249

I'd read here on DR's site that these were made by Falcon instruments and most people dismissed them as unreliable. Not true? Good enough for vfr back-up?

I've also been following the threads on the smaller 2 1/4" instruments. And have been considering those as well. Once again, altimeter cost was an issue.

I can make all this stuff fit in the standard panel. It may not go where I'd prefer. I have the map box and was going to use it. I can add a subpanel for switches if needed.

Thanks Gil!

George, your comment, "My concern is not safety, but will I get stuck away from home". This is one I hadn't considered except in passing. AOG on a long cross country would not be good and I've done several 1200 nautical mile CC's. No telling how long it would take to get a replacement EFIS / EMS. Great point. That may be the deal breaker.

We'll see. I'll play around with panel planner some more and cushy up to the financial officer. I may fly around with the plane in the buff per the Dan C. method for awhile and put off the paint.

 

[N941WR]

It shouldn't be that much...

Vans airspeed - with markings $195

Altimeter from Vans $249

Less than $450 total from Vans - E-bay, used, etc. cheaper...
All of the plumbing exists, so nothing extra in that area...

I'm going to go this way (alt and asi) with a Dynon 180, but I already have the instruments... but want to buy some YT gyros?....

gil in Tucson

This is exactly what I did plus a slip ball and I bought a compass but never installed it. My thought was that between the battery backup in the Dynon and the 496, I was covered as far as a direction indicator.

Here is a picture:


I've found that I tend to fly it in this set up (but with the GPS plugged into the Airgizmo.):

 

[Sam Buchanan]

Here's the kicker... unlike most, I'm seriously considering no backup A.S. or altimeter.

In my RV-6, the Dynon D10A is backstopped by the RMI uEncoder. But the ultimate airspeed backup is the totally independent (no electrical power needed, separate pitot system) LRI angle of attack indicator. Since this is my primary instrument on every landing anyway, it is always there regardless of whether or not the electrons have taken a lunch break. I would not hesitate to initiate a day VFR flight if this was the only operational "airspeed" indicator in the plane. It provides all the info needed for safe takeoffs and landings, and airspeed indication in cruise is unnecessary for day VFR ops.

 

[SteinAir]

Good on ya Sam! I was wondering if no-one learned to "fly the wing" anymore?!?! Backup ASI's and ALT's for a VFR airplane? Come on...you're new Citabria/Pitts/Maule/Cub/Husky, etc.. don't have 2 of each when configured for VFR.

If you can't fly your airplane (after a number of hours) without using an airspeed indicator, then it won't matter if you've got 10 of them in the plane...you're headed for bigger problems from a pure pilotage standpoint - but that's just my opinion.

I wonder how many people have landed their RV's without an airspeed indicator? Let's say you do something stupid like leave the pitot tube cover on (just for discussion purposes here) These RV's aren't that difficult to land without an ASI.....

What would you do with no Pitot input?

Just my 2 cents as usual, but for VFR this whole discussion kind of makes me chuckle. Sure backups are nice, but if you're only flying on nice CAVU days, why are we discussing "backups" at all - what's the point?! Remember the golden Van's formula; SIMPLE=CHEAP=LIGHT=FAST!!

Cheers,
Stein.

 

[videobobk]

Unusual partial panel

While I totally agree on the B/U ASI and altimeter, and have both in my plane, I learned why that isn't always the answer. Or at least, not something to stake your life on. On takeoff from OSH a couple of weeks ago, with pretty heavy traffic, I got to what I thought was T/O speed and started to rotate. A quick glance at the ASI yielded ZERO! I was in no position to abort, so went ahead with the T/O. I knew I could land without the ASI and considered it the safest option, all things considered.

My AOA is also tied into the pitot, so no AOA. The bug cleared the pitot about 30 miles later, so no big deal. Didn't have to stop and troubleshoot. BUT it did point out a backup isn't always the answer. I have known several people who have picked up bugs in flight. Know how to land without the ASI in case you have to.

Bob Kelly

 

[Caveman]

The goals

O.k. let's get specific and narrow the mission. I do 2 or 3 long cross countries per year of 500 to 1200 nm. We go see the kids at school say 8 times a year, 150 nm. We fly into the Dallas metroplex once or twice at about 200 nm. I'm not "just" a CAVU flyer. I have weather limits but I do serious cross countries. Sometimes the shorter ones are in "just above marginal vfr plus a personal safety margin" weather. Plus... I want to out run and out climb all of you guys!

Seriously, when Bruce took me for the demo ride in the RV-7A and I was pushed back into the seat on take-off and the old feelings of my hopped up '68 440 Magnum Dodge Charger came rushing back from my youth, I swore then and there, that if I could make my RV-7 perform as well as the demonstrator, I would be happy for life. That's the goal guys. Keep the weight manageable so I can best the demonstrator and keep us safe in "legal vfr" not CAVU, and not IFR.

Now you know why I went with the engine and prop that I did. (lightweight 195 hp parallel valve engine). My one concession to weight has been the autopilot. I've cut all the lightening holes. I've used primer sparingly since I live in the near desert. I plan on occasional gentleman's aerobatics. This is also why I was leaning toward a single EFIS/EMS lightweight radio stack with handheld gps's and comm for back-ups. I've got a lowly thousand hours or so of pic all in low powered spam cans. I received the pilot's certificate in 1979 so I'm a bit old school with the map and compass. I still pull out the sectional on trips I'm not thoroughly familiar with.

The question, and yes I know only I can answer it, is:
Does the above instrumentation safely fit the mission profile!
You guys have been awesome!

 

[frankh]

And would agree but

Good on ya Sam! I was wondering if no-one learned to "fly the wing" anymore?!?! Backup ASI's and ALT's for a VFR airplane? Come on...you're new Citabria/Pitts/Maule/Cub/Husky, etc.. don't have 2 of each when configured for VFR.

If you can't fly your airplane (after a number of hours) without using an airspeed indicator, then it won't matter if you've got 10 of them in the plane...you're headed for bigger problems from a pure pilotage standpoint - but that's just my opinion.

I wonder how many people have landed their RV's without an airspeed indicator? Let's say you do something stupid like leave the pitot tube cover on (just for discussion purposes here) These RV's aren't that difficult to land without an ASI.....

What would you do with no Pitot input?

Just my 2 cents as usual, but for VFR this whole discussion kind of makes me chuckle. Sure backups are nice, but if you're only flying on nice CAVU days, why are we discussing "backups" at all - what's the point?! Remember the golden Van's formula; SIMPLE=CHEAP=LIGHT=FAST!!

Cheers,
Stein.

The specific mission was for a lot of night flying. For day VFR, sure...look out the window!

But if you fly from the coast to where I live in OR there is precious little in the way of a visual horizon at night...The first time it happed it was a most eerie feeling, no moon, OVC layer above and no lightss on the ground.

I felt pretty disorientated to be honest. Does it happen often?...No but.....

I'd rather have a useful VFR XC device i.e a Trutrack and a couple of steam backups for primary flight indication.

Of course, then with an IFR rating I tend to look at instruments as soon as things get fuzzy.

But thats just me..

Frank

 

[SteinAir]

O.k. let's get specific and narrow the mission. I do 2 or 3 long cross countries per year of 500 to 1200 nm. We go see the kids at school say 8 times a year, 150 nm. We fly into the Dallas metroplex once or twice at about 200 nm. I'm not "just" a CAVU flyer. I have weather limits but I do serious cross countries. Sometimes the shorter ones are in "just above marginal vfr plus a personal safety margin" weather. Plus... I want to out run and out climb all of you guys!

The question, and yes I know only I can answer it, is:
Does the above instrumentation safely fit the mission profile!
You guys have been awesome!

Thanks for the clarification. This makes things slightly more complex...mainly because if you do much X/C at all, it's not a matter of if you run into weather, but when. So...then some additional equipment makes sense. First and foremost I'd still push for an AP, then a GPS with weather on it (to avoid that pitfall to begin with), then perhaps some very basic backups..nothing too crazy.

I think you're on the right track and will have a pretty good setup for your intended flying.

Cheers,
Stein.

 

[Caveman]

Reality is setting in

I think you're on the right track and will have a pretty good setup for your intended flying.

Cheers,
Stein.

Thanks for the help Stein. Reality is setting in. I called Wentworth a few minutes ago and ordered a "used" United Altimeter. It will be the first used part I've put on the airplane. I'll also order the Van's airspeed indicator. I already planned on a TruTrak ADI Pilot II and it is on order.

With two kids in college I need to manage money carefully. Besides, the financial officer just bought a new front loader washing machine. I think she bought the G1000 IFR panel aviation version cause it cost triple what her old top loader did.

I am determined not to borrow money to finish this beast and I gotta have money to pay a DAR, pay taxes on it, buy insurance and get some training before she leaves the ground.

A couple of questions for anyone willing to respond. I'm halfway home with this back-up planning.

1. I still want a compass. Call me old fashioned. If anyone is having good service with one mounted on the glareshield, please let me know what brands to consider. If you know of some mounting pitfalls please let me know. I've heard some people have had problems with panel mounted units due to the metallic nutplates. Is that really an issue?

2. I'm now thinking about the loss of the EMS and George's point about being stranded. I'm not too worried about the loss of fuel info or CHT's EGT's, etc. I'm pretty good about timing fuel burn. Assuming George is correct about equipment requirements for homebuilts:

What I'm considering is a couple of stand alone panel warning lights not driven off my single EFIS / EMS. I think I can figure out how to do this and add very little weight or complexity. I could land, check the black box for problems and if they weren't repairable, I could "stick the fuel tanks" to verify level or top them off and fly back home with out being stranded, and I'd stay within my comfort margin. Anyone see a need for anything other than a low oil pressure light and a low voltage light? All this would be contingent on a daylight flight back home in excellent weather, of course. I wouldn't have a tach or manifold pressure. Bear in mind that I have zero time with constant speed props to date. I'd have to run the engine full rich or use the "lean till she chokes and then add a pinch back routine".

 

[grover]

aog support

". . . but will I get stuck away from home". This is one I hadn't considered except in passing. AOG on a long cross country would not be good and I've done several 1200 nautical mile CC's. No telling how long it would take to get a replacement EFIS / EMS.

I ran this by dynon when I was efis shopping. asked specifically what is their aog support. wasn't encouraged. I suggested they have a loaner/rental pool of instruments for this purpose. their response was "that's a good idea" but they had no intentions of implementing was the impression I got.