If you fly enough hours in a small airplane, you're bound to have an alternator failure. Between Bobby and Wally, they've experienced a few alternator failures between them. The guys swap stories and give some great tips on what to do if your alternator ever decides to take a little break while you're in the air!
You're cruising along enjoying your flight... when all of the sudden you notice the low voltage light on the panel is flashing. You glance over to the amps gauge and sure enough, it's showing a discharge. What do you do? How much time do you have? Is it even an emergency?? All that and more on this week's episode of Behind The Prop!
Clear prop! Number two following twin traffic on 3 mile final. JB using runway 25 on a 4-mile final.
This is Behind the Prop with United Flight Systems owner and licensed pilot, Bobby Doss. and it's co-host: major airline captain Designated Pilot Examiner, Wally Mulhearn. Now let's go behind the prop!
What's up Wally. Hey bobby how are you. I'm great another episode and this week is going to be about a system. It's going to be part of a system. And I’m sure as many have done check rides with you. You're fan of the electrical system. I remember it electrical conversation happening in my check ride with you. And today We're going to let everyone hear us talk about an alternator failure. How many alternator failures have you had in your aviation career. I have had I've had two alternator failures. One was in a multiengine airplane you have two so It's not as big of a deal One was in a single engine airplane which resulted in a total electrical failure It can be a big deal Maybe not such a big deal You know the alternator basically is a battery charger so we deal with this on a daily basis in our personal life and we don't even really know it but pretty much every one of us in our pocket has a cell phone and at some point that cell phone gets plugged into the wall and gets charged and then when we leave our house or our office wherever we unplug that cell phone and we are walking around with our cell phone without without being charged so in essence we are walking around with our cell phone having experienced alternator failure and we we learned to manage that Using our cell phones. We know if we're gonna be out for let's just say twelve hours using Your phone without the ability to charge it. You might do things with the phone. You may shut apps down. You may turn off Features on the phone. That use a lot of electricity. I know my iPhone actually even warns me and it pops up when I get the ten percent says would you like to go to low power mode. Yeah, absolutely absolutely. It does that and so We kind of deal with this every day. But when I get in a briefing room on a check ride and we talk about this it seems like just such a foreign concept You know if if you and I Bobby Go to a baseball game and I looked down at my phone at you know we're in the sixth inning and on down to six percent on my phone I’m probably gonna send The people that I care about that. I'm in touch with a message saying hey I’m about to lose Power on my phone If you really need me contact Bobby. Here's his number. So I’ve established kind of an alternate means of of Of contact. We do that all the time. We do that without even thinking about it. It's just part of our day life. I don't want to take it for granted but but we both have a little bit of experience and a lot of people. I remember when I was a newly student pilot And I was. I've openly said. I was pretty scared of flying. Not afraid afraid but timid and appreciative of what was going on right were a couple thousand feet in the air right. There's a big fan blowing in front of us Man if I thought about then what I felt like if the power went off the if the plug came undone, I’m panicking. I'm I’m really freaking. Let's talk about what all is happening to the aircraft until the electrical system when that alternator stops charging what would put this the immediate effect to the end user. The pilot were aircraft as that alternator stops producing energy. Yeah, initially the the result is is nothing. Nothing I mean. Everything is still working we we just were not getting charge to the battery so we have started a time. Clock the the clock that most people will will answer me would When we're when we're talking about check rides is, they'll say well. We have thirty minutes of battery life. Well the fact is we don't know how much battery life we We might we might have two hours. We may have ten minutes I I. We don't know but we use the cell phone example. We've all had a cell phone with crappy battery. The yeah probably needed to be plugged in a lot more each day. There are some trainers out there. That probably need a little bit more juice everyday right right so we don't know but we do know that we are limited and at some point. That battery is to fail and we will then have a total electrical failure. One thing that. I was demonstrated fairly early on in my training Was to go out to the practice area and my instructor Master switch off. And and after I caught my breath, I mean you can read all day that that the engine is still gonna run. But you know when when when he reaches over there and reaches across your lap and hits those two little red switches and flips them down You know after I gasp and realize that. Well he's right. The engine does continue to run and we flew around for few minutes just for the heck of it and he actually demonstrated that. Okay look all your flight instruments the ones that you really care about your pitot Static instruments airspeed altimeter vertical. Speed your gyroscopic instruments.
You're heading indicator your attitude indicator are working. Just fine now. You know you're probably going to lose. fuel gauges Most airplanes you can lose your turn coordinator. Obviously, you're going to lose your radios all your avionics One thing People always tell me is They're gonna they're gonna squawk seventy-seven hundred with an electrical failure and and you know I pointed out. Well okay good. Good luck doing that It's it's pretty obvious on the newer transponders would with a digital readout. Because you won't see anything to read out so you. It's it's pretty obvious that the transponder is not working but as far as airplane flying a day VFR are you know the VMC conditions Really the airplane is flying. Just fine art there. Some plays out there that may be crop dusters. Whatever that don't have a battery and then the you hand prop and they don't have any power. Yeah, I mean the the early early airplanes don't even have electrical system battery to to charge or no alternator right always having an alternator failure right the one thing that that I think I thought about. My instructor did the same thing for me. They went to the practice area. I was nervous in talking about. We're gonna fall out the sky. And he reached over to the same thing and I panicked. I think the most shocking thing to me was how freaking loud got right. We we no longer had our headsets. We weren't talking so he was screaming at me. See nothing happened. Nothing did happen. The plane kept flying as normal. The electrical system and the battery do nothing to create the spark. Once the magneto turning so the planes should keep running without the battery or an alternator for for as long as you have fuel that that's correct and that is That's excellent point about it getting louder. Most airplanes that we fly nowadays have an intercom system and the intercom is an electrical Component and so with a total electrical failure. You are gonna lose the electrical system so you might as well take the headsets off and and as you said scream at each other because you're not gonna have that ability and and. I encourage instructors to do that with students on a flight. Just get out of The practice area in Show them Demonstrate what it sounds Like with the headsets off. and You know most airplanes have a hand mic how would we actually Communicate with ATC if we just had a A failure of the intercom system. You know do We have the ability to have a speaker in the airplane? How do we turn the speaker on? And I know we're getting off on a tangent a little bit and not really talking about alternator failure but that's something to think about what. What is it like in airplane with with an intercom system failure?
Yeah, that example was a really good example and and quite frankly when the master switches off, That's exactly the the scenario of the alternator failing and then that battery losing all of its power. The aircraft can act just like it Would some five to twenty to thirty minutes later, Whatever that timeline would ultimately be for that battery, You're in the same scenario. So I asked before we started recording. Alaskan again are you. Are you having an emergency at that point?
and the answer is it just depends. Dave EMC I would say no You're not; Imc I would say yeah You probably are. Night that's debatable You know obviously if you're using an electronic form navigation gps, Be or anything like that You would You lose that with a with a total electrical system failure. But if you're very familiar with where you are which she should be if you're flying VFR You should be okay. You really should be okay and have some contingency plans maybe. Do you want to continue an extra fifty miles. It may take you another thirty minutes. I don't know I can answer that. The one thing That when I when I bring this up in In check ride scenarios is The applicants usually pretty good about talking through shedding unnecessary electoral electrical equipment. If you've got a number two radio a number two nav com shut that off. Certainly if you have some sort of iPad or something plugged in To usb port or the cigarette lighter unplug that to prevent a drain on. They're pretty good about mentioning that. Sometimes they're not really that good about Saying I’m going to refer to a checklist and that is really Where we want to go on this because if we have a systems failure in an airplane and we have a checklist The talks about or addresses a system spell you that that's what we want to do. because in most of these airplanes again the airplanes that I’m most of the time flying in our four place Pipers, warriors, archers, that sort of things and Cessna one seventy Twos. that's mostly what.
I'm flying in to check rides. The checklists by and large are going to try to troubleshoot. And try to fix the problem. And gonna try to do a reset of their relay. And it's going to try to get that alternator back for you and that's the ultimate the ultimate goal. Gee, It quit working. Let's try to make it work. There is a process in place. And it's right in the checklists. All you do is read it and be able to follow the checklist. and you know there are I know in in our airplane are one seventy-two if we pull the power back for doing slow flight or power off stalls Sometimes our alternator Does drop off line and just following the procedure and the checklist. We can get right back and it turns into a a nonevent right.
And I we talked about your failure. I had a failure with Devin miller. Who was on the show really early on. He can be found online @FamilyPilot. Devin And I were outshooting Practice approaches at nighttime. Both instrument rated pilots Making sure we're staying current proficient and on our last approach back into this airport, Devin noticed that the alternator light The levels was on and then that we were. The alternator was at zero was not producing any charge anymore. And we were probably on a long final probably ten miles out from the airport Pre-COVID the tower was still open. And we were talking. I think to atc. When I noticed it and we were switched over to tower shortly after we alerted ATC. Atc look we're not having any other issue other than we notice our alternators not producing charge. we're having no issues but we may lose communication with you When you talk about the steps that she would take of course we pulled out The checklist did our checklist. But what other Actions like alerting, Atc we've talked about turning some things off would you consider In a number of different scenarios? and throw a few obvious ones out at to what for have landing gear, What are you thinking about as a professional pilot, while he would be your Assuming it's obviously electrically powered landing, will be thinking about Flaps? we'll be thinking about the flaps and how we would manage our flaps. You know if we're on ten-mile final long final into here And we thought the battery was starting to go do we do we go and put them out or not? Let's talk about. I guess. Those two scenarios first flaps than landing gear. Would you be thinking if you were, Obviously we were in an archer so no powered flaps we have a handle; But let's assume assessment we have powered flaps. What are you gonna do?
Yeah, and as I thought about this. I've actually had three alternator failures. I had forgotten about this. This other one's trying to show me up now. He's got three now. yeah, one was in a bonanza. I was by myself Vmc conditions. Wasn't a cloud in the sky so whether it was not an issue at all as about fifty miles from my death my destination and So about twenty minutes. Maybe twenty to twenty-five minutes out. And I got an indication of an alternator failure So I immediately pulled out the checklist in went through the troubleshooting and I was not able to get the alternator back so here I am working on battery Power. and Did address shutting off on necessarily electrical equipment and in in this case it was daytime. So I shut off all the lights that I had on. I shut off my number two Nav com Left my Gps going which in this particular airplane The gps had its own internal backup battery Being charged to the electrical system. But I knew that. If I had a total electrical failure, I would still have that available to me. But anyway about fifty miles out I called up approach control was going to an airport that had a tersa And so I was out of their Radar coverage. But I but I called them up and told him I was fifty miles out and I was coming in that. I had an electric an alternator failure. And that I may lose my ability to communicate with them so Immediately they cleared to land. I'm fifty miles out. Twenty-five minutes out. I was heading northeast. And they cleared me to land straight into runway 4. I am going into manure Louisiana. A said kay. You're cleared land runway 4 and So I did a couple of things I also. I asked him what the phone number was for the tower and they gave me the phone number and I it in my phone so I knew okay if I get down low enough and I really need to communicate with them. I can call him up on my telephone. I have a you know Bluetooth headset. So I could speak to him through the headset My next thought was all right, What about my gear? I've gone electric driven gear I want to make sure the gear is down.
But I knew I have the manual gear extension ability but the thing that I really wanted to get was I wanted to get a green light before I lost my electrical system. so I made the determination that about thirty miles out. I was going to go ahead and lower the gear. My thought processes. Was I probably still had enough power at that point and it would give me enough time to Do a manual gear extension and still aimed toward the airport. So about thirty miles out. I went ahead and extended the gear. And I got I got green lights. So I was happy that that the gear was down. And then I you know my thought was well, What about flaps? well I went ahead and put the flaps down and made a normal landing using the normal flap setting and lo and behold. I never lost anything. I taxi. Did it with the Being able to talk to tower and talk to ground it was ended up being a nonevent. But I had all these things in my back pocket. Had I needed them.
The one thing that We see on checkride is You know if we do have total electrical failure, Obviously it's in an electrically flap driven airplane. It's going to be a flaps up landing. the older airplanes quite frankly anything before about 1980. There is probably no data in the performance Section that addresses no flaps. If you look at the newer one seventy twos. And I say newer. I'm talking ‘81. ‘81 and newer There is if you go to the short field landing distance chart which is the only landing distance chart that is in in there. It's a short field landing this chart. There's a note. There are actually four notes on the bottom. If you look the older airplanes there are three notes but about 1981. There's a fourth note. The fourth note says For no flaps at thirty five percent landing distance and add between seven and nine knots to your approach speed. so you know most people Most of these airplanes call for about sixty-one to sixty-three knots. somewhere in there and most people probably fly more like sixty-five. So according to this book is telling you to come in about seventy knots and at thirty five percent to your distance and few when you look at The landing chart at sea level the landing distance is is usually some six hundred feet so adding another thirty five percent. You're still below thousand feet but it is something to consider Especially you get into multi engine airplanes. You get into a beech baron or something and you have a total electrical failure. And you're going to have to land with no flaps. How much more runway or we're going to need to. I want to go into that Thirty-five-hundred-foot runway with flaps in this airplane? Well that might be in a situation where you might want to consider the airport down the road. That's got seventy-five hundred feet rather nearly thirty-five hundred feet.
And let's assume you you're in a Cessna and there's still far but it is a really short runway and you're concerned about distance. Would you put ten out or would you would use all of it if you had some battery left? He did in your example. I'm just curious. What would the guidance be for a student or a private pilot if they had a short field that they really get. Would you use ten because you could go round with ten. I honestly wouldn't go ever twenty in. That can scenario because I could be stuck at twenty need. Go round and have a real problem.
That that's the thing is that When you when you put the flaps out of the flat mode or is a fairly high draw item on the electrical system. And if you're going to drain a battery it's gonna drain when you're putting a draw on it. So by putting the flaps out you're taking the chance that You may lose the total electrical system after the flaps are out and now you can't retract them. so A consideration especially if you're having to doing an instrument approach a where you think you may have to go around and go to an alternate. I know we're talking about a really bad day. An electrical failure going around having to go to an alternate airport That that definitely classifies as a bad day but you know a consideration may be. I'm just going to do a preemptive strike. And I’m just going to make this whole flap landing again You know even know flaps a one seventy-two for a sea level airport. Sort of a standard just a little bit warmer than a standard day. Still looking at less than a thousand feet. and most of us aren't flying into airports with less than a thousand-foot runway.
And I I've heard it. I've heard in the hallways; I’ve heard people say to me. The initial thought process is land as soon as possible. I got to get on the ground. This is in a follow sky. We talked about you. Flying another fifty miles. I might not go two hundred miles. I might not go fifty
I might not go fifty miles There's all kinds of scenarios we could say varies. But the think you need to divert and land right away? is that the first thing you're gonna be thinking?
no. It's not the first thing. The first thing I’m going to be thinking about is trying to get that alternator back and That's what the checklist will probably have You lead you into. basically a reset process a reboot. I mean we going back to our cell Phones are cell phones. Start doing weird things. First thing we do is rebooted and start over again and most of the time that fixes the problem. But the checklists most of the checklists will say land as soon as practical. So what does that mean? Well if I’ve got an airport that's my if my destination is thirty miles away and my divert airport is twenty-five miles away And I’m familiar with my destination airport. And maybe I haven't been there but I’ve familiar with what runways I've got all the frequencies written down on my flight plan for it. I'm familiar as familiar as I can be with that airport. So going to an airport That's just five miles shorter I you know. Every situation is different but. Don't be predisposed to having to divert to the nearest airport. That most checklist do not say land as soon as possible. They say land as soon as practical.
So that's a great probably best practice a couple of other best practices. Obviously, we think about batteries and other sources when we're probably flying nighttime where we know We don't have another way to see something. We should have flashlights headlamps at nighttime all the time, but this is a time where I think we definitely want different data. Extra batteries ever want to be able to take the iPad out of the console and put it into another source. What other things would we consider That might be helpful to us in in a in a situation where we're losing the alternator?
well you know the one thing that that is. I think is important is to keep your stuff charged. I've I. I fly a lot of people and I’ll maybe they're using an iPad and I look over there and I see I say you know how's your, What's your battery? Oh we're good. I'm at I’m it Fifty one percent in I think well why wouldn't if we have the ability to charge in the airplane. Why wouldn't we be keeping that charged? because a one hundred percent iPad is going to last longer than a fifty percent iPad. So just be prepared. Keep everything charged. You know as well as you can. I think most of us would rather take off with full fuel rather than half fuel. You'll even though half you'll may get us to our destination and plenty you know with plenty of fuel plenty of reserves and safely. But I think most of us would say I prefer full fuel. We'll think of think of the chargeability of all your devices as fuel if you can keep it full. Let's keep it full yet.
You made me think of a lesson I learned from one of my searchers which was never use less than the full runway right? Why would I ever take off with Fifty one percent of the runway available right when I just go down there and get one hundred percent of it. so Good pilots don't use fifty one percent of their batteries and they don't use fifty one percent of the runways. Right. Either way, so hopefully enjoy this episode all about the alternator failure and while he's had three, I’ve had one. It's going to happen to you probably in your flying career if you fly planes with electrical systems at all And there's not a reason to panic. There's a reason to use good judgment. There's a reason to have a plan and implement the checklist usage. And then that plan to make sure you make a good decision on whether you divert turn go back. A land of as fast as possible practically possible. so Hopefully, you took something away from today's episode. as always, fly safe and stay behind the prop.
Thanks for listening. Thanks for checking out the Behind The Prop podcast. be sure to click subscribe and check us out online at BehindTheProp.com behind the prop is recorded in Houston, Texas. Show creator and host is Bobby Doss. Co-host is Wally Mulhearn. This shoe is for entertainment purposes Only. and not meant to replace actual flight instruction. Thanks for listening and remember: fly safe!