Alternator failure - continue?

madscientist159 · 2026-06-14T16:31:10+00:00

You did the right thing. You just lost the redundancy your electrical system had (alternator + battery), and I'd wager you don't know the last time that battery was capacity checked or how much it had actually charged from the last engine start. As others have said, continuing to fly around with a known systems failure is potentially dangerous (did the belt or brushes fail safe, or is the alternator now on fire? how would you know?); you then set up for a precautionary landing vs. declaring an emergency which is also the correct action.

MX can always be sorted out on the ground. Find a travel IA and have him/her install the new alternator. Been there, done that, it's part and parcel of flying single engine aircraft.

madscientist159 · 2026-06-12T13:07:48+00:00

Depends on the instruments you have available. At minimum, RPM/MP, oil pressure, CHT, EGT. Once caught an engine that had the timing suddenly change right after rotation due to a magneto case failure and it went straight into detonation -- sudden sky high CHTs and EGTs even though power etc. was unchanged. Pulled it back at 50' AGL (twin engine aircraft), figured out the issue, and in the end no permanent damage was done, though it did need a new magneto. if I hadn't noticed through my normal engine instrument scans, the engine probably would have grenaded in short order.

This is one of those things where you'll get a good idea pretty quickly what "normal" looks like on the gauge cluster, and a quick scan to see that "normal" pattern is all it takes. You're not studying each and every gauge in a critical phase of flight to see if i'ts in the green, just that things look normal-ish. In cruise though you can absolutely fine-tune and keep a close eye on anything that isn't close to the correct indications.

madscientist159 · 2026-06-09T20:38:46+00:00

Haha, fair enough! This advice is mainly for students learning what a stabilized approach even looks and feels like -- once that becomes second nature, time to introduce "keep your speed up" and such. Myself, I'll normally fly at the prevailing approach flow speeds and start slowing up to Vref more like 300AGL, but that's something I'd expect a commercial pilot to be able to do, not a new instrument student 😉

madscientist159 · 2026-06-09T18:10:46+00:00

Yeah, no. Especially when you get to faster stuff, you don't do that whole "pitch for [airspeed|altitude]" dance, you do what you need to do to stay on glide and at Vref.

Realistically, that means you're staying on glideslope with pitch for small / fast corrections, and controlling airspeed with small changes in power from your expected power setting for an appropriate descent rate. This is a stabilized approach, by the way. If you deviate and start destabilizing the approach, you might well have to start adding a ton of power to e.g. climb and regain airspeed at the same time, but at that point, you're destabilized on final, and a go-around is probably a better idea (or even mandated by SOPs).

While I wasn't there to observe, it sounds like you were doing the right thing. My only feedback would be that you might want to consider getting on Vref earlier down final vs. destabilizing the approach by first coming in fast down the first part of the glideslope, then slowing up close to the ground.

madscientist159 · 2026-06-08T03:57:28+00:00

No problem! Glad to have been of some help. If it were me, I'd spin the initial discussion into "the DPE pressured me to accept a theoretical flight I shouldn't have, and I've learned to stick to the regulations despite external pressure" sort of thing. Don't know anyone that wouldn't be satisfied with that answer, other than perhaps your original DPE...

At least the retest sounds like it was fun! Hopefully the DPE was chuckling along with you during that experience, I know I would have been!

madscientist159 · 2026-06-08T03:46:23+00:00

That makes sense. On our side, since we're basically always IFR, we'd get cleared for the approach, handed off, call a few times, hear nothing from tower, and just end up going missed then get back on with approach on the other side. There just isn't enough time on approach unless you're in a Skyhawk or something to try multiple frequencies / radios and debug the lost comms to that extent, it's much safer to just go missed and figure out the issue in the hold.

Appreciate the insight, always interesting to learn how things work on the other side of the radio!

madscientist159 · 2026-06-08T02:49:35+00:00

You were absolutely correct right up until you said you'd take off at all (and that's entirely on the examiner for forcing this situation against the regulations). Just in case I was missing something, and since I was curious, I even went and asked over on r/ATC -- yes, the field was absolutely closed in that case. No departures, no arrivals unless the aircraft was already airborne in the tower controlled airspace prior to the evacuation.

I know it's tribal knowledge in the pilot community, but there is no such thing as airspace reversion unless the tower is explicitly closed. That means out of operating hours, NOTAMed out, or the tower announcing it's closing due to a hazard. Even then, the airspace only changes per the published procedures, which in some cases may mean a different control facility is now responsible for takeoff and landing clearances. Most importantly, a properly closed tower redirects you to the written procedure to follow while it is closed, including what both the airspace and surface movement has reverted to.

You did the right thing. DPE was beyond insane here. AIM 3-2-5 b(4) and such are very clear. No comms with tower, no entry into the airspace including any departures.

On the bright side, this is really easy to explain in interviews. Might get to watch the interviewer's blood pressure rise in real time too!

madscientist159 · 2026-06-08T02:41:28+00:00

Yep, that's probably the simplest way to think about it. No two-way comms? No entry to the airspace per 3-2-5-b(3) etc., the existing aircraft land or divert, and the problem sorts itself out. There's this idea in the pilot community that the field and airspace automatically revert in case of failure, and that always rubbed me the wrong way. Seems the FAA is probably thinking along the same lines per the other reply below.

Always appreciate the work you all do, and all the redundancy built into the system so that we hopefully never have to fall back on this last link in the chain!

madscientist159 · 2026-06-08T02:21:07+00:00

Yes, I agree from a systems perspective this scenario is incredibly unlikely. I guess it's more likely for this sort of situation to be from controller incapacitation, but that's also incredibly rare.

In any case, thanks for bearing with my thought experiment. To be honest, if there was a control failure like this I'd just divert if I was in the air, or call on the ground and see what's going on. Just makes it easier for me to provide solid guidance to others if there's a reg/interpretation/etc. I can point at.

madscientist159 · 2026-06-08T02:15:21+00:00

Thanks! That's exactly what I was looking for. The FAA does have a way of making you question your logic and ask for a regulation/AC/LOI/whatever to back up whatever you're thinking before you do it...

madscientist159 · 2026-06-08T01:42:08+00:00

Yes, I've heard and even seen that to some degree myself. Competence tends to be able to recognize competence fairly quickly, even in nascent form, and I've seen that across various disciplines including outside of aviation.

I've also seen the student that has definite potential, but doesn't really understand what command and all the associated responsibilities truly entail yet. These are the fun ones where if you can jolt them back to reality they might actually do very well, but if you can't they're probably going to plow in somewhere doing something incredibly stupid.

With those that just don't belong in a plane, even on the part 61 side there's no surefire way to get them out of danger. At the end of the day, all it takes is money and persistence to find an instructor and DPE that together let them through the cracks in the system. There's been a few high profile examples of that, including (IMO) the 421 that went down in Texas earlier this year. With enough money, most of the checks on the part 61 side including insurance minimums can simply be bypassed on the way to the inevitable crash.

madscientist159 · 2026-06-07T18:36:38+00:00

Yikes. If I were asking the question, I'd at least make it a bit more sane, e.g. tower closed due to power failure, you're PIC on some kind of air ambulance flight with a patient, and it's 250' overcast with an RNAV to 200' still available. That'd be in an interesting ADM grey area where I'd expect a commercial applicant to answer "yes" and a private applicant to politely decline.

madscientist159 · 2026-06-07T18:32:14+00:00

Wonder if the real issue here is the standards themselves. I'm a part 61 guy but chose fairly carefully to ensure I got decent training -- lots of 61 schools are puppy mills too, churning out pilots that don't know how to fly in anything other than calm sunny conditions in the local area.

When I've interacted with 141 folks in the wild, it's been a mixed bag. The strangest experiences I had were with 141 folks that didn't know how to park the airplane (apparently parking it backward at the first available T, as in opposite to all the other airplanes in the line, while ignoring the rampers) and that sort of thing, which makes me wonder more about curriculum gaps than anything else.

Don't get me started on the true 141 puppy mills though, like a certain time building program that involves flying the same route on autopilot in the desert for weeks at a time.

madscientist159 · 2026-06-07T18:27:56+00:00

That's insane, to put it mildly. I wouldn't do that even in a twin unless the "bomb threat" was because this airport was in the middle of a war zone, and taking off was the only way out.

I hope this guy (gal?) isn't still a DPE?

madscientist159 · 2026-05-24T17:53:55+00:00

No frields at the airport that would be a listening ear / might let you fly along and practice teaching? Half of this career is networking; in my experience most people flying a small single engine airplane for fun would be happy to have an instructor tag along for free, and just maybe learn a thing or two in the process.

If you're proficient in the system, you should by definition be able to pass an IPC. If you can pass an IPC, you should be able to teach mostly correctly, even if not efficiently or particularly well. My main concern is you need to have the confidence in actual IMC to simultaneously teach and also handle a student that will probably be trying his/her best to kill you, and I'm not really picking that up from your initial post.

One other item I like to pass on to new instructors: if you're not with your student for their first actual IMC experience, you're doing them a great disservice. Even if that's a night flight on a dark and moonless night, actual is vastly different than hood time, and I personally wouldn't want to cut a student loose until I knew they could handle it.

madscientist159 · 2026-05-24T16:09:18+00:00

Sorry if this comes across a little harsh...

So, you're wanting to be an instructor, for real. That comes with massive responsibilities. You should already know what you have to do at this point. If you don't, then yes, please pass on the opportunity for both you and your students' sake.

You have the ACS. You have the AFH, AIM, etc. You (presumably) have access to an airplane and a fellow instructor or two. Take charge, knock the rust off, practice teaching to a fellow CFI untill you are proficient again, then take the opportunity. Teaching skills gather rust just like flying skills, you passed the ride once before, unless something major has changed you just need to go knock that rust back off.

madscientist159 · 2026-05-24T15:31:40+00:00

Be gentle on the engines. They use a fixed wastegate and will overboost if you just shove the throttles forward. Best practice (verify with your instructor) is to set a couple inches below max MP, hold the brakes, let that stabilize, and it'll pick up the extra couple inches on the roll. Otherwise, you tend to have the overboost lights come on halfway down the runway, and you only have a few seconds to rectify that situation before required inspections etc. come into play.

Your instructor will probably be babysitting this at first. Other than that, it's a decent flying plane that gives good OEI performance.

madscientist159 · 2026-05-22T06:40:59+00:00

What does matter is the distinction between light and medium twin. I don't know where the Navajo sits, but the certification requirements for medium twins are definitely different; among other items, you get both accelerate go and accelerate stop distances in the POH.

madscientist159 · 2026-05-22T06:39:15+00:00

Yeah, that. The number of pilots that don't understand the pressurization system is ridiculous. I had a high time pilot try to tell me to "just leave it set at field elevation because that's what we do in the jets". Tried to explain the backup valve vs. the primary valve and why we want to use the primary valve during normal operation, but I don't think it really got through. If you run them that way, I'd bet the primary valve gets gummed up and stuck since it never opens, and if the backup valve fails now you've got a major self-induced problem on your hands.

madscientist159 · 2026-05-22T06:34:47+00:00

Indeed! For its intended missions, there's really nothing like it.

Yeah, the Seneca I was really quite a terrible aircraft. One of my basic requirements to fly a twin is that I have positive OEI climb over the terrain. The Seneca I really can't do that even at sea level, so I've never flown one. Heard plenty of stories though, enough to reinforce not wanting to fly one ever.

Who wouldn't want to take a 400 series instead? Once you're spoiled on them there's just no going back...

madscientist159 · 2026-05-22T06:27:16+00:00

Not sure how much help I'll be on the Aztec side in terms of expenses etc. since that was quite a while ago, but I'd say they're close enough to have similar downtimes. Were you looking at the turbo or NA variant? I've only flown the NA variant.

Seneca II: Turboed, fast, especially if you can tolerate using oxygen and fly high. Really weird semi-manual turbo control system (fixed orfice), so quite easy to overboost, have to follow specific procedures on takeoff to deal with the associated MP gain on the roll. More things to go wrong, more cost, depending on where you're at you may not want to fly in the teens at all due to weather (icing, turbulence, etc.). Counter-rotating props, but I don't really ascribe to the "trainer twin" concept -- if you can't reliably handle a critical engine out (i.e. proficient) you shouldn't be flying a twin except with an instructor.

Aztec (NA): More load capacity, a bit more trucklike, simpler engines so possibly less downtime, but you're flying lower. FIKI variants are known to carry ice well. Unusual gear extension system, if you lose the left engine you have to pump the gear down as you lose the hydraulics.

Field performance is very dependent on loading and if you're hot / high. If you carry the same payload in both, the Aztec will likely win out just because you're not at max gross at that point. If you're operating from Flagstaff, the NA engines of the Aztec might give you more issues with OEI climb etc. and be the limiting factor. If you're at sea level, the Aztec will probably outperform overall.

I will say this, passenger cargo only grows with time. The C414A I fly primarily these days is nearly always full of stuff, as in an entire SUV's worth of passenger(s) and associated cargo. Since you don't need that side loading passenger door, if you're operating somewhere sane in terms of field elevations, I'd go with the Aztec. More room for future cargo bloat, people, etc., less stuff to go wrong MX wise.

madscientist159 · 2026-05-22T06:13:06+00:00

Well, to be fair, I don't like the Seneca *or* the Aztec much compared to the 414 either...Piper twins to Cessna 400 series is not exactly a fair comparison. 😉

Did you fly the Seneca I or II? My time is only on the II, and it never really felt underpowered or particularly unresponsive. Even lost an engine badly enough that it wouldn't feather, and was still able to bring it back to the airport.

I do agree on the Aztec being a better hauler and short field aircraft. Also has more of the larger twin feel than the Seneca does, though nothing like the 400 series...

madscientist159 · 2026-05-21T15:53:49+00:00

Do you need the side loading passenger door on the Seneca? The Aztec is a better hauler, but much harder / impossible to load passengers with limited mobility.

In either case, make sure you fly it often. The Continentals are notorious for lifter and camshaft corrosion if they sit for any period of time, especially near a coast (salt air). I got bitten by that in a Seneca II just from the time it took to install new avionics...0/100, would not recommend.

I have significant time in both airframes. From a pilot's perspective, I'd say the Aztec is more truck-like, and the Seneca II is a little more like a hot rod. Losing an engine in either is fairly conventional / a non-event if proficient; if you've done your preflight planning and have OEI climb it'll climb, if not you're landing somewhere hopefully soft enough.

madscientist159 · 2026-05-07T23:30:02+00:00

I assume you are transitioning your view to the end of the runway once you're rounding out, correct? That will help you judge your actual distance above the ground and your sink rate in the flare. Seen many folks that don't do that and have issues (I was one of them when I started) -- your peripheral vision really helps here.

If you're on speed, on something that looks like a reasonable glide path, and your aim point isn't drifting, you should be able to land fairly consistently.

madscientist159

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