I learned a few things recently that I want to share with PA30 owners. How to re-install a nose bonnet on a PA30 the right way, and how to diagnose an electrical problem caused by a failed alternator (presumably).

I also want to discuss the risk factors of the flying I’m currently doing by identifying them, and then outlying how each was addressed.

While this may be intuitively obvious to many of you, these are things I had to relearn in the course of my busy life. Maybe you’ll learn something too.

Let’s recap how I have gotten to this point….

FlightSafety: I spent most of the month of January in Dallas, completing my sim qualifications that enabled me to provide initial and recurrent simulator instruction in the G280. My mechanic was traveling for his flying job and I was traveling for mine.

I was asked by FSI to stay in Wilmington for all of February to provide training in the Astra Jet. The implication is that i’d be spending open days doing self-study in preparation for getting qualified in initial classroom instruction in Savannah. I jumped at the chance to be home all month, and was able to spend quality time with my Beverly.

The first 3 weeks of the month were lost due to Paul’s schedule. He wanted to be home for the first flight of N833DF, and I was trying to accommodate that.  Finally I got tired of waiting and went with his very professional assistant – Ralph. So much time lost to schedules – his and mine.

I had been mentally preparing for this first flight for weeks. There is a plethora of advice out there for each of the things with which I had to contend. I read engine books, watched videos, and talked with people I trust to develop a plan of action. Everyone I consulted is confident in their advice, and no one shows any signs of doubt. Not many agree either, and the details of how to actually do what they propose are often sparse. I am alone in my checkbook and alone in my cockpit. It is on me to decide how to proceed.

Meanwhile, the clock was ticking on my departure to Savannah and I still didn’t feel like I knew what I was doing. Time spent with my airplane was time I wasn’t working to get ready to instruct. I desperately wanted to fly myself there, but I needed to get 10 hours and an oil change done before I felt I could do that. Paul’s schedule and my own was making that maddeningly difficult. I was rushed, agitated, and generally stressed. Risk identified.

The engines and the workmanship are a thing of beauty. I am very happy with the outcome there at this point. Given that every single system has been touched or disturbed in the process, I did my best to lay out a plan of action for a complete or partial engine failure of either side or both. I even thought about what I’d do if I had an abnormal temperature or pressure indications, including which of the instruments would be believed. Precautionary shut-downs were a possibility. I was ready for anything – or so I thought.

Complicating the matter considerably was the fact that I had to rush each flight by design – to avoid ground run time. Maybe rush isn’t the right word, but it was the result. Increasing the pace of your flying in an airplane you haven’t flown in some time is problematic. Risk identified.

Breaking in new engines dictates that you minimize ground time, and change your flows and process. Do not cycle the props as you normally would, leave the cowl flaps open for the entire flight, alter the mag check, and learn to include new instruments in your scan. The new electronic ignition system could actually cause a nasty backfire if performed incorrectly. Finally, the EDM 760 engine monitor with all of the bells and whistles was new to me. It would be essential for this flight, and would require significant attention.

Mistakes were made; I think I mentioned that on the very first flight, the one that carries more risk than most, I allowed myself to be distracted and left the gear down for some time. I had to remember not to close the cowl flaps, so that interrupted my cruise flow to begin with. Fuel pressure on the right engine was normal on takeoff, but the left showed that it was far too lean. I momentarily considered an abort against continuing. The investment I’d made was a factor. I had to do this right.

On the roll, fuel flow on the old instruments were 8 gph versus 12 gph on the right (as it should be).  If that old gauge was correct, the left engine would burn up if I continued. I was working hard to decide, until I found and focused on the new engine monitors. Button pushing on the roll wasn’t helping. By leaving it alone it finally confirmed that both engines were pulling 12.4 gph. This confirmed that the old indicators were junk by the time I was level in cruise. I was far behind the gear up part of my flow by now, and they stayed out for a while.

Had an engine failure occurred climbing out, I can only hope I would have reacted appropriately and brought the gear up then. If not, I certainly would have landed straight ahead and trashed a perfectly good airplane. I’d have lived, but what a dumb ass. Move on and learn from it.

Level in cruise now, the autopilot didn’t work in any mode. It appeared that the work Paul had done adding the new engine monitor had completing disconnected the autopilot. Nothing was working there at all, except heading mode. I’d spent time and money getting it just right last year, and now it was dead when I could really use it. Not good!

It wouldn’t be until the third flight that I realized the autopilot pitch mode was the only part that stopped working, and I’d had issues with that before. What made me believe that the entire systems was disconnected was that I’d forgotten how the complex system worked. I’ll get pitch mode fixed later, but I started realizing that IMC was a risk I didn’t want to take until I got my act back together in this airplane. Significant risk identified, at least for the proposed flight to Savannah.

With all that going on, my performance under these conditions disappointed me. I imagined being wired tight and ready for anything. The skill safety margin was not as broad as I imagined, and the luck bucket contributed a bit on the first takeoff.

Keep moving forward. For the second flight, I vowed not to make that same mistake ever again. Therefore, I’d made some entirely new ones! This time, I left the door unlatched on takeoff. I caught it in time for the climb out, however, and properly secured the door before it popped or the speed prevented it from closing. There goes a perfect flight, and in comes a distraction that led me to leave the fuel pumps on after takeoff.

The sound from the pumps led me to believe that the door still wasn’t sealed after I leveled off, even though it was. That led me to decide to terminate the flight short of the one hour recommended break-in flight length. I landed at my hangar after only 45 minutes of run time. Safety dictated I do that, but when I realized during the descent flow that the pumps were already on, my ego was further deflated. My luck bucket level is going down. What a dumb ass.

Clearly, I needed some time to figure out the new engine monitor and learn to fly the airplane again.

Still, I hadn’t thrown in the towel regarding my plans to fly myself to Savannah! It should have been obvious at this point that I couldn’t get it done safely. Preparing for my class – the first one I’d be doing and one that would last a full 9 days; getting in 10 hours of break in flying; arranging an oil change and the associated vehicle logistics; and then launching for Savannah with a failed autopilot and no recent instrument practice in this airplane. I just wanted the damn engine project done and I couldn’t see beyond that!  It had taken too long and I wanted my airplane back! I didn’t want to fly commercial if I did not have to!

Launch time: It is a beautiful VFR day with winds that were actually light for the season. I had picked up my new battery minder from Paul’s wife yesterday, and connected it last night. The engine and cabin heaters I’d purchased last year were keeping everything warm. Oil temp was in the mid-50s before I started up this morning. Things looked pretty good.

Bev had packed me a lunch, and my goal was to get a 3 hour flight in today with no mistakes. I am thrilled to have the airplane in its hangar and to have control over the flying again. The rust is beginning to come off, and I’m feeling better. I’ve re-learned how to use my autopilot and the only single squawk on the airplane is that the autopilot isn’t sending pitch trim signals. It won’t hold altitude, but I can live with that until I get it fixed in the spring.

Startup is immediate with these new ignitors. I’m ready in no time, even though I still don’t understand what the engine monitor is doing most of the time. The information I need eventually surfaces on the display, and that will have to be good enough for now.

Yesterday I requested a short taxi and immediate takeoff for the engines. Paul tells me I’m being overly conservative, so today I accept the longer taxi to hold short of 32 on foxtrot.  The warmup time will do them good, and it won’t take too long,

Holding short of 32, I do the modified runup for the engines and props, and then do the specific mag check. All is well and I contact the tower.

Tower clears me for takeoff, but at that time I see a flashing BAT on my EDM. I verify low voltage with the older voltmeter, and they agree. Something is wrong.

My incorrect attempt to diagnose and remedy the situation begins with turning off both of the alternators, then restoring them one at a time. Voltage was dropping into the 11-12v range, and neither alternator was coming online. I tried this several times, and then told tower I’d have to return to my hangar. They cleared me to taxi and I informed them I’d be shutting down my electric system and continue to taxi without comm.

What could have happened?  The only thing that changed in this perfectly running electric system was the battery minder. I had ordered this and dropped it off while the engines were going in. It was possible that I’d been given the wrong charger, so my first thought was to take the nose bonnet off and visually confirm what battery I had. My logbooks were in Paul’s shop, so physically looking was the best way.

I removed 100 (maybe 30) stainless screws and the bonnet. Next I removed the safety wire from the battery box and lifted the lid. There I found the Concorde RG-35A 12V SLAB.  Next I looked at the Battery Minder/charger-desulfator Model 128CEC1-AA-SS 12V-8A device. There was a number for support written on it, and I had the chance to speak with an engineer there by the name of Steve. I described my situation, and he quickly confirmed that I had the correct charger for the battery I was using. He went further and gave me his opinion that based on my description, my battery was most likely fine.

At that point I re-installed the battery box lid and safety wire, and attempted to put the nose bonnet back on. I began to re-install the bonnet at this point, but became incredibly frustrated trying to line up the screw without stripping them. The worry over ground runs, frustration over the systems failure and yet another delay, and the increased pressure of trying to get all these things done that I’d mentioned were simply too much.

I threw in the towel at this point. I just had a total electrical failure in my airplane – the one with dual alternators and new engines, and that is what it took for me to realize I was trying to do too much too soon. I’m tired, pissed, and frustrated. Let’s slow everything down.

I let Paul know that I had trouble with the bonnet and that the new screws sucked! I also told him the charger and the battery were good, so that wasn’t it. His point was that a voltage dropping into the 11v – 12v range was abnormal. I know better – it is entirely normal for a loaded SLAB battery to drop voltage linearly and then recover when unloaded. I did the right thing shutting the system down when I did. Look elsewhere for the issue. I had an attitude and it was leaking through.

Leaving the hangar before I started stripping screws out was the best idea. I closed up and went home for a few days, declaring that I would not be flying my airplane to Savannah. Instead I’d refocus my efforts on FlightSafety and do my best at getting ready to run a classroom full of experienced aviators.

Learning #1: The next day I returned to the scene of the crime with the bonnet still off. Paul walked me through the process for determining what was going on with the electric system. I started the left engine first. The alternator came on just fine, and the voltage bumped up to 14.2v on both indicators. Next, I started the right engine and both alternators were online. Wow – and ugly intermittent problem would not be good.

After only a few seconds, the entire electric system dropped off and I was back to Batteries once more. This is when Paul told me that the only way to reset the alternators for an over-voltage relay trip was to remove all volts from the bus. The master switch would have to come off.

I had already shut down the engines by the time this information came out. What we now knew is that the left alternator was fine longer than the right, so I’d restart the right engine, leave off all the avionics, and see what the voltage did.

Just what I wanted to do with brand new engines – diagnostic restarts!

With the right engine running you could see that the voltage started at 12v, but then rose to 15v; back to 12v; and finally to 16.5v where it tripped the voltage regulator.

Wow! This means that the right alternator is failed (maybe the voltage regulator0 and causing the voltage to spike, thus tripping BOTH alternator over-voltage relays. In flight – I’d would have had to diagnose this by turning off the master switch and resetting each alternator in turn. Just imagine me being this rusty and having to do this while flying an approach into Savannah!

Mystery solved!  It is worth noting that the only device that was carried forward during this engine project was the alternator that failed. I had directed it’s replacement, but Paul told me that he ran out of time and used it anyway.

Learning #2: After a few days went by and I addressed some of my other stressors, I tried to figure out a path forward with Paul to get the right alternator fixed and the bonnet back on. Communication is not his strong suit, for sure. I was convinced that the bonnet screws would be a problem he’d have to address, but nailing him down and getting him to come up and fix both issues was a problem.

Some background that might help you understand my frustration, which turned out to not be justified, will be helpful. Years ago, I had paid Paul to install quarter turn stainless fasteners in the bonnet, at his suggestion. Later he found them to be difficult to use, as did I. I had actually damaged some of receivers to the quarter turn fasteners myself, so I know they were a pain. When he asked me to change them once again to simple screws with back-plates, I agreed. He could do that while the airplane was down.

Now that I could NOT get the damn bonnet back on I was really pissed. After hearing many suggestions from Paul to get my airplane going again, and not seeing anything actually happen, I decided to go to my hangar and try to get the bonnet on one more time. I was calm now, having made progress at work and home. It would either work, or I’d stop trying until April when my travel was complete and I had more time to address it. If Paul wasn’t available then, I’d get it done in Wilmington.

It is ironic that I’m writing this on the first day of March, while sitting on the commercial airplane bound for Charlotte and eventually Savannah. I say eventually, because we taxied back to the terminal over an hour ago, and this broken bitch is still getting worked on. The very commercial trip that I was trying hard to avoid is biting me in the ass. It could be worse – but it is funny. Somebody farted an hour ago and I swear they were thinking about evacuating the aircraft.

Back at the hangar yesterday, the last day of February. The month I hate to fly anyway. I am calm, ready for Savannah (I hope), and appreciative of the fact that I now realize how much better it will be to get back to flying this complex machine at a measured pace.

The bonnet is resting in place with no screws. I take my time and test each nut-plate to ensure I haven’t already stripped or damaged any. They all appear good. Paul and his wife have been communicating with me this morning, since I told Paul I’m done waiting for him and trying to make this come together. Told him that I’d decided I’ll talk with him again in April, and if not then, I’d get it looked at up here.

That sparked a back and forth where the three of us tried to transfer hangar keys so he could do it while I’m gone. I considered it, but 2 hours of driving and another 2 of putzing around on the day before I leave would just tick me off further. I declined and continued working my the bonnet.

At that point Paul and I began texting again. I noted that half of the screws were smaller than the other half, and wanted to confirm where the short ones went. His instructions were as follows:

  • Use the short ones first
  • With the bonnet in position, start at the aft (top) center, then forward (bottom) center.
  • Think of it like putting a wrap on the nose, and work your way out from the center

I did it the way he described, and it went on smoothly and with no fuss. The nose bonnet is on and the aircraft is now flyable on one alternator.

We have a plan! To avoid any further ground run time, and to conform to the Penn Yan recommendation, I will launch the airplane for Paul’s airport and fly the break-in pattern for at least an hour before I land.  Paul will have a spare alternator, recently overhauled, ready to swap for the right side.

Depending on timing and weather, I may fly off the remaining 4 hours of the break-in time and get the oil changed while I’m there. That will give me 30 hours of free run time on mineral oil, just before I go to Dallas again. I’ll fly the snot out of it in April, and maybe get the autopilot pitch issue resolved during that time as well.

Fly Safe!


By fdorrin

Contract corporate pilot and experienced instructor in the Gulfstream 280; WestWind; and Astra aircraft. Own and operate a beautifully restored PA30 Twin Comanche. CFII; MEI; ME-ATP; SES. Typed in DHC-8, B-25, IAI-1124, IAI1125, G100, G280. Retired Electrical Engineer, software developer, and Project Manager. Retired engineer / executive - Delmarva Power, Conectiv Energy, and PEPCO Holdings, Inc.