Cirrus Alternator Failure

A Cirrus is an electric airplane.  There are no vacuum pumps and therefore no vacuum driven instruments. The Klapmeier brothers did this on purpose, trying to make it a modern airplane.  No vacuum systems means no vacuum pump failures, hence there is a lower likelihood of instrument failures in IMC.

What Cirrus did instead was put a lot of electricity producing and storing devices in the airplane.  All SR20 and SR22s are equipped with 2 engine driven alternators and 2 backup batteries.  Alternator 1 is a 28 volt alternator (the amperage varies based on whether or not you have an air conditioner) while Alternator 2 is a 28.5 volt alternator.  There are 2 24 volt backup batteries, as well.  Battery 1 is also used for starting.

In traditional airplanes that have 1 alternator, an alternator failure can affect a lot of things.  Depending on how many electronics are in the airplane, the battery can get depleted quite quickly.

The Cirrus electrical system is quite ingenious.  It’s a little bit different based on whether you have an Avidyne Cirrus or a Garmin Perspective Cirrus.  I will discuss that further below.

The main goal of this article is to talk through what happens in the event of a #1 Cirrus Alternator Failure (an Alternator 2 failure actually isn’t a big deal at all, though Alt 2 is required for IFR flight), the procedure for trying to fix it, and a technique I have developed that makes the pilot’s job easier.  First, let’s go through the #1 Cirrus Alternator Failure procedure.

Alternator 1 Failure

In either avionics configuration, the Cirrus Alternator Failure procedure is the same.

  • Check and reset the circuit breaker for Alternator 1 (Reset only once)
  • Cycle the Alternator 1 master switch
  • If Alternator 1 doesn’t come back online, leave the Alternator 1 master switch off and shed load on the battery

Avidyne Entegra

The Avidyne Entegra has 2 busses, the Main Bus and the Essential Bus.  Alternator 2 isn’t set to come on until the engine RPM reaches 1700.  While on the ground, Alternator 1 runs both the Main and Essential Buses.  In the air, Alternator 1 runs the Main Bus and Alternator 2 runs the Essential Bus.  Since Alt 2 is 28.5 volts, the higher voltage won’t allow the power from Alt 1 to cross over and run the Essential Bus.  There are also 2 one-way directional diodes that prevent the voltage from Alt 2 to cross over and run the Main Bus.

Having said all that, when Alternator 1 fails, Battery 1 is now running the items on the Main Bus.  There are a significant number of items on the Main Bus which causes the 24 volt battery to quickly lose it’s charge. This precipitates the need for shedding load.  Items like GPS 2, the air conditioner and aircraft lights can all be turned off.

In the above scenario, Alternator 2 is running the Essential Bus still that has all the Essential items on it.  Those include:

  • The PFD
  • Flight Instruments and associated Avidyne computers
  • Engine Instruments and associated Avidyne computers
  • GPS 1
  • Com 1
  • Nav 1
  • Autopilot
  • Stall Warning
  • Charging Battery 2

Note 2 important items that are not on the Essential Bus:  the flaps and the landing light (which is very handy at night).  Those two are only on the Main Bus, which Battery 1 is now powering.

Let’s further enhance our scenario.  You are flying over Nevada (quite remote and not a lot of airports) at night, 30 minutes from the nearest airport when your Alt 1 fails.  When you get to the airport you are planning on landing at, you want to have your flaps and your landing light, but we don’t know how long Battery 1 will last.

The solution (this is where my technique comes in):  Turn off the Battery 1 master switch.  This is an easy solution to ensuring you have battery power to use your flaps and landing light.  Instead of going through and shedding load, simply turn off the source.  You’ll still have all the above items on the Essential Bus, which is all you need to keep safely flying.  Then, when you get to your landing airport, turn Battery 1 back on to utilize your flaps and landing light.

Garmin Perspective

Cirrus wired the Garmin Perspective plane a little bit differently.  There are now 2 Main Buses along with the Essential Bus.  Alternator 1 runs Main Bus 1, while Alternator 2 runs Main Bus 2 and the Essential Bus. Both Alternators are running all the time.  The Alternator 1 Failure procedure remains the same.

The cool thing that comes along with the second Main Bus in the Perspective is the amount of items you still have available to you in the event of an Alternator 1 failure.  The only items you lose will be:

  • Yaw Damper
  • Landing Light
  • Air Conditioner and associated components
  • EVS Camera
  • 12 Volt power supply in armrest

Everything else is powered off of Alternator 2.  That’s not much.  The only item you really want on the above list is the landing light if you are going to be landing at night.

Follow the Alternator 1 Failure procedure, then do my technique again.  Turn off Battery 1 to save the battery power in order to use the landing light when needed.

Cirrus did a great job creating an all electric airplane with plenty of backups in case something fails.  I focused mainly on the Alternator 1 failure here.  If Alternator 2 fails, the system is wired for Alternator 1 to run everything while still charging Battery 1 and 2.  No big deal.

In my experience, turning off Battery 1 to conserve battery power is just a simpler solution when shedding load in the event of a Cirrus Alternator Failure.

Similar Posts

  • Hold Anywhere

    The latest Garmin software version on the Garmin G1000 and Cirrus Perspective by Garmin has a really neat feature.  It gives the pilot the ability to create a hold at any fix, VOR, NDB, or even airport.  If the point is in the GPS database, a hold can be created over it.

    How does it work?  Here are the steps.

    Let’s say ATC tells you to hold over an intersection on a Victor Airway that you are already on.  Since you are tracking the airway already, the airway should be in your flight plan complete with all the waypoints on it.

    Bring up your flight plan and highlight the waypoint to hold at.  Press the menu key.  Using the big knob, scroll down to highlight the hold at waypoint option at the bottom of the bottom of the menu.  Press enter.

    garmin-holding-pattern

    Now you can build the hold.  You select what the inbound or outbound course will be.  Select a timed hold or a distance hold.  Then select left or right hand turns.  You can even input your expect further clearance time.  Press enter and now you have a hold as a waypoint in your flight plan.  Assuming you have a WAAS unit, the autopilot will fly the hold for you.

    If you are ever told to “Hold Present Position,” Garmin has you covered.  Simply press menu on the flight plan page, scroll down to Hold Present Position, then follow the prompts on the screen to build a hold at your present position.

  • Garmin Perspective Missed Approaches

    Are you a Cirrus pilot with a Garmin Perspective?  Still can’t figure out the use of the go around button?  Read on!

    When it comes to flying an instrument approach, we as pilots are assuming we are going to land.  Most of the time, we won’t even take off if the ceilings or visibilities are below the minimums for an approach.  95% of the time, we do land.

    There is the other 5% of the time when something unexpected happens, whether we get a full scale deflection, or we don’t see the runway at the published minimums, and we have to perform a missed approach.

    When instructing, missed approach procedures are actually what I see the most deficiency in when instructing an instrument rated pilot.  It’s not necessarily configuring the airplane for a missed approach procedure, it’s the button pushing involved in setting up the GPS properly.  When a pilot isn’t proficient in the button pushing, that button pushing distracts the pilot from actually flying the airplane, which can lead to a dangerous situation.

    I am going to spend a few articles on flying a missed approach with different GPS and different autopilot configurations.  Today, I will be addressing the Garmin Perspective with a GFC 700 Autopilot, which is what all Cirrus Aircraft after 2009 are equipped with.

    The Garmin Perspective Missed Approach Procedure

    Once the decision to execute a missed approach has been made, here is the step by step procedure:

    • Full Mixture and Full Throttle
    • Simultaneously push the Go Around button on the underside of the throttle.  This does the following:
      • Sets the Garmin Perspective Flight Director to Go Around Mode (7.5 degrees pitch up and wings level)
      • Takes the Garmin Perspective GPS out of Suspend Mode
      • Switches the CDI back to GPS mode if it is in a different mode
      • Garmin Perspective with GFC 700 Autopilot stays on
    • Flaps up
    • Confirm airplane is climbing
    • Set altitude bug for missed approach altitude (assuming it isn’t there already)
    • Set NAV mode and IAS mode on the Garmin Perspective GFC 700 Autopilot

    Garmin perspective

    That’s it.  When Garmin and Cirrus got together to create the Garmin Perspective with the GFC 700 Autopilot, they tried to make as simple but robust system as possible.  Once you have the procedure down for the right buttons to press, then the procedure is relatively straight forward.

  • Garmin 530/430 Missed Approaches

    Flying a missed approach can be stressful enough.  When you haven’t done one in a while and your GPS isn’t showing you how to get to the missed approach point and you can’t remember which button to press, that adds a lot more stress.  Recipe for disaster?  Quite possibly!

    No need to fear, we are here to help.  The procedure for getting a Garmin 530 or 430 to give you missed approach guidance is actually simple and straightforward, if you know what to do!

    Note: Because of the variety of different autopilot configurations in different airplanes, this article will focus solely on the GPS.

    What the GPS is Thinking

    The way Garmin designed the Garmin 530 and Garmin 430 is to be as helpful to pilots as possible.  Their thinking was, 95% of the time, a pilot will make a landing on an instrument approach.  This is pretty accurate as most of the time, this is what happens.  Most general aviation pilots don’t fly approaches to minimums all that often, thus negating the need for a missed approach.

    Garmin Missed ApproachGarmin designed their software with this in mind.  When an airplane crosses the missed approach point, the GPS will go into what’s called suspend mode (a SUSP annunciation appears above the OBS key).  It will keep the missed approach point as the active waypoint because it assumes the pilot is going to land.

    This can be confusing to pilots.  This is what happens when software engineers and pilots come together. Engineers often believe they are smarter than pilots! (See the Airbus fly by wire roll out)

    The Procedure

    In the case of a missed approach, the button pushing on the GPS is actually relatively simple.  There is no SUSP key to take the GPS out of SUSP mode (thanks Garmin!).  Instead, you press the OBS key.  This will take the GPS out of SUSP mode, making the first waypoint on the missed approach procedure the active waypoint.  Your GPS will now give you guidance on the missed approach procedure.

    If you are going missed off an ILS, LOC, or VOR approach, then there is one more key you’ll have to press. Your CDI needle (whether it is digital or analog, an HSI or just a CDI gauge) will be reading off the NAV radio and your CDI indication on the GPS will be VLOC.  After you press the OBS key, press the CDI key on the GPS so you will start getting course guidance from the GPS again.

    That’s it.  Button pressing on the different autopilots will vary, but if you are familiar with yours, you’ll be able to tell it to follow the GPS and climb to the proper altitude.

  • Cirrus SR20 vs. Diamond DA40

    Note:  For this article I am comparing a 2008 Cirrus SR20 G3 and a 2008 Diamond DA40 XLS.

    Aircraft shopping can be a tedious process.  First, a buyer needs to know what the mission is.  How far will flights typically be, how many people will be on board, and how fast does the airplane need to be.  Then, the buyer has to figure out what the budget is.  Finally, a prospective owner needs to figure out how much airplane he or she can handle.

    Two very good airplanes for newer pilots transitioning from a flight school 172 who need a faster airplane to build experience in, but also want to experience a glass panel, are the Cirrus SR20 G3 and the Diamond DA40 XLS.

    Cirrus SR20 G3

    The 2008 Cirrus SR20 G3 is a good airplane.  The G3 is equipped with the 6 cylinder, Continental IO-360-ES, 200 HP engine.  Performance-wise, an owner can expect 135-140 knots true at 9 GPH (Lean of Peak) or 145-150 knots true at 11.5-12 GPH (Rich of Peak).  The 3 blade propeller equipped models have better takeoff and climb performance than the 2 blade propeller equipped planes, especially in high density altitude conditions.

    Cirrus SR20 Comparison

    The airplane is equipped with the Avidyne Entegra EX 5000 glass panel system.  Most models out there will have Avidyne’s CMAX (Chart View) and all will have the Avidyne EMAX (Engine Monitoring).  All came from the factory with the STEC 55x autopilot (though a handful will have the STEC 55 SR, which doesn’t have glideslope functionality).  They also came from the factory with dual Garmin 430s. Most units have been upgraded to WAAS.

    Some owners have upgraded the autopilot to the Avidyne DFC 90, which is a nice upgrade.  The STEC 55x is a rate based autopilot which takes it’s commands from a hidden turn coordinator that is behind the instrument panel in front of the co-pilot’s seat.  The STEC has some crosswind limitations on approaches where the pilot can actually fly better than the autopilot.

    The DFC 90, however, is an attitude based autopilot that  takes it’s commands from the attitude indicator on the Primary Flight Display (PFD).  It also adds a Straight and Level button as well as an Indicated Airspeed hold button, adding safety and functionality.  It does much better in crosswinds on an instrument approach then the STEC.

    A select few SR20s have been upgraded to a single (or dual) Garmin GTN 650 touch screen GPS unit.  The GTN 650 is a very nice upgrade.  The Garmin 430 is a great unit, but the learning curve with the GTN 650 is much less.  The touch screen setup makes a little more sense to the new user.

    Values on the 2008 SR20 G3 with 1,000 hours or less run somewhere between $220,000-$260,000, depending on total time and equipment.

    Diamond DA40 XLS

    A handful of 2007 XLS DA40s were made, but not many.  Most XLS models you will see are 2008 and later. These are equipped with the Lycoming IO-360, 4 cylinder, 180 HP engine with the Powerflow Exhaust STC. Due to the Powerflow Exhaust, the performance is equal to the SR20.  At 6,000-8,000 feet, you will routinely see 140 knots true at 10-10.5 GPH.  Higher altitudes will give slightly better performance and lower fuel burn.  Like the SR20, the Diamond DA40 XLS comes with either a 2 blade or 3 blade prop.  Go with the 3 blade as the takeoff and climb performance is much better.

    Diamond DA40 Comparison

    Where the DA40 XLS has a leg up on the 2008 SR20 G3 Avidyne is in the avionics.  Diamond got on the Garmin G1000 train a little sooner than Cirrus did and the XLS is equipped with the G1000 and GFC 700 autopilot.  The Garmin GFC 700 autopilot is the best GA autopilot I have flown with.  It is an amazing piece of equipment.

    Most, if not all, DA40 XLS models will have both WAAS and Synthetic Vision.  Cirrus didn’t get Synthetic Vision till they put the Cirrus Perspective by Garmin in their aircraft in the middle of 2008.

    The DA40 has great visibility due to the massive amount of glass surrounding the pilot.  The big glider wings give it excellent pop off the runway, but quite a different climb pitch attitude than most other piston single engine airplanes.  The airplane does like to float on landing if the pilot doesn’t get the speed right.

    Values on the 2008 Diamond DA40 XLS equipped with the Garmin G1000 are around the low-mid $200,000 range.

    Comparison

    Performance wise, the airplanes are about equal.  Rich of peak, the Cirrus out performs the Diamond, but uses more fuel.  Both have about 5 hour ranges (though the Cirrus has bigger fuel tanks, 56 gallons usable compared to the Diamond long range tanks of 50 gallons usable).  Useful load is slightly better in the Diamond due to the fact that the Lycoming engine has 2 fewer cylinders than the Cirrus.  The Cirrus does have a roomier back seat, a larger baggage area, and a side stick instead of a center stick, but the DA40 has a back door.  The Cirrus also has the CAPS system, though an owner has to do a $15,000 repack every ten years.  Airplane values are about the same.

    I give a slight edge to the Diamond, though, and here’s why.  For about the same price, a purchaser can get the Garmin G1000 system complete with the GFC 700 autopilot in the DA40 XLS.  The Avidyne and STEC system is great, but the Garmin system is definitely above and beyond.  To get the Garmin G1000 in an SR20, you’d have to look at the Cirrus Perspective by Garmin, which came out in late 2008, and you’d be paying $300,000 or more for a single engine piston with 200 HP (though you do get Air Conditioning!).

    So for my money, I would go for the Diamond DA40 XLS.  I believe you get a little bit more bang for your buck and you don’t lose anything with the DA40 XLS.  Don’t get me wrong, I love the Cirrus, but comparing the two, I think the Diamond DA40 XLS rates a little higher.

  • Avidyne Entegra Chart Updates

    Columbia 400 Avidyne Entegra

    There are a number of airplanes out there equipped with the Avidyne Entegra PFD and MFD system, most notably the Cirrus SR20 and SR22 models from the early 2000s and the Columbia 350 and 400 from the same era.  The Entegra is pretty simple and easy to learn, but doesn’t have the capability that it’s Garmin glass panel counterparts do (I have not, however, tried the R9, which could prove much more capable than it’s predecessor).  I have found that pilots master the Entegra a lot quicker because of the reduced functionality.

    One of the nice features of the Avidyne Entegra is the CMAX Chartview option.  With a yearly subscription, you can get all the Jeppesen approach plates and airport diagrams for the entire US on your MFD.  Just like your GPS, though, you have to update the charts monthly to keep them legal.  After a period of time when you don’t keep up with the updates (I believe it is 90 days), then the charts disappear.

    The update process is a little tricky if you don’t have someone to explain it to you.  Once you go through it a few times, you’ll have it down pat.  Here’s the process for the Avidyne Entegra Chart Updates.

    Jeppesen Subscription

    The first step in performing your Avidyne Entegra Chart Updates is to create an account with Jeppesen, who handles all the GPS NavData and MFD Chart updates for both Garmin and Avidyne.  If you already have a Jeppesen subscription, you can skip down to the next section.  To do that, simply go to jeppdirect.jeppesen.com, and then do the following:

    • Click on Avionics Data on the upper left hand side
    • Click “Purchase Avionics Subscription”
    • Then, click on “Create Account” in the new users section
    • Once you’ve created an account, login, then put in your aircraft information and select 1 update for the Avidyne Entegra EX500 EX 5000
    • Click Continue at the bottom and you can put in your payment information

    Software Needed

    There are two different programs depending on if you have a PC or a Mac.  If you have a PC, you need the Jeppesen Services Update Manager (JSUM).  If you have a Mac, you need the Jeppesen Distribution Manager (JDM).  Download whichever one you need, then login, and your updates will show up.

    Downloading the Avidyne Entegra Chart Updates

    First, we’ll go through the process of performing the Avidyne Entegra Chart Updates process for a Windows computer, using JSUM.    You’ll need two 2 GB USB drives formatted to FAT 16.  Here’s how to format to FAT 16.

    • Go to My Computer after inserting the USB drive
    • Right click on the drive
    • Click on Format, then select FAT and press OK

    Once the USB drive is formatted to FAT16, open up the JSUM program.  Login and your updates will be displayed on the screen

    • You’ll need to set the Avidyne CMAX Key Code
      • Right click the Avidyne Electronic Charts Service and click Set Avidyne Key
      • To get the key code, visit MyAvidyne.com and create an account using your JeppView subscription number and your serial number for your Avidyne MFD (found on the AUX page) and your PFD serial number (displayed on startup when the PFD is warming up)
      • Once you get the Key Code, copy and paste it in the window and click OK
    • Click on the service and click Start
    • The program should automatically detect the drive (if it doesn’t, click browse and select the drive)
    • Click Continue and the charts will start downloading and automatically programmed to the USB drive
    • If you are updating NavData on the MFD as well, follow the same steps as listed above in order to update the NavData

    Next, we’ll go through the Avidyne Entegra Chart Updates process on a Mac, using the JDM program.  You’ll need two 2 GB USB flash drives formatted to FAT 16 (the easiest way to format to FAT 16 is on a Windows computer, using the process above).

    • Open the JDM program and login
    • Insert the first USB drive
    • You’ll need to set your Avidyne CMAX Key Code
      • Click Service Details under the Electronic Charts Service
      • Click Set Avidyne CMAX Key Code
      • Program automatically detects the USB drive
    • Click and drag the Electronic Charts service over to the USB and release
    • The service is downloaded and copied to the USB drive automatically
    • Eject the USB drive
    • Insert the second USB drive (or plug the USB drive in to your MFD, do the update, then reformat the drive) and follow the same steps for the NavData

    Updated the MFD with the Avidyne Entegra Chart Updates

    Avidyne Cirrus

    Once everything is programmed the your USB drives, the rest of the process is simple.  Just go out to your airplane, plug in the first USB drive with the Electronic Charts on it, turn your battery on and the avionics master, and the system will upload the information automatically.  Once it’s finished, turn everything off, pull the USB drive out, then insert the second USB drive and do the same thing.

    Now, you’re all updated!

    If you’d like to see a video on the process, Jeppesen has some very good videos on the updating procedure.  The links are below.  If you have questions, please contact Texas Top Aviation and an expert will help you through the process.

    JSUM USB Programming Procedure

    JDM USB Programming Procedure

    Avidyne Entegra Chart Updates Upload

  • Iridium Zoleo Allows In Flight Messaging

    Satellite communications company Iridium now has a really nifty little product called the Iridium Zoleo Satellite Communicator. Most pilots who fly newer Cirrus Aircraft will be familiar with the company name Iridium. Iridium manufactures the built in satellite phone that is an option in all Cirrus after 2012. The Iridium Zoleo brings messaging capability to any airplane in a cost effective and simple manner.

    The Iridium Zoleo is a device roughly the size of a walkie-talkie. It links up with the Iridium satellite network to send and receive messages and emails anywhere in the world (or air!). To make things easier, the Iridium Zoleo links with a phone via Bluetooth to a free app that allows the user to write a message directly from the phone and send through the device.

    The Iridium Zoleo is affordable at only $200. A plan has to be purchased in order to send messages, with 3 different levels of subscription offered: 25 messages a month for $20, 250 messages a month for $35, or unlimited messages per month for $50. Each plan offers a $6 upgrade to allow unlimited worldwide breadcrumbs and tracking.

    The Iridium Zoleo has a 200 hour battery life and is designed to be shock, dust, and water resistant. Plus, the device has a built in SOS that can be used anywhere in the world. So, you can take it rafting down the Grand Canyon, hiking in the Andes, flying over the Atlantic, or SOS if you are stranded in the middle of the Indian Ocean.

    Click here to read more about Zoleo and here to read more about the Zoleo plans.

2 Comments

  1. Hank, this sort of thing is very helpful. Simple and effective!

    Now a question— The good Gen Hostage and I are gonna need a biannual check in about 6 months. Is there a good tutorial(s) somewhere that would be good?

    See Ya!

    Joe D.

  2. Great info…. Thanks!

    Side note I believe that a failure of Alt 1 (and Battery 1) with Perspective you will also lose the MFD too (Foreflight makes a great backup to that)

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