Apparently not all Aztecs can fly on one engine

[AdamZ]

Apparently this Aztec didn't know it could fly on one engine. Tell em Ted
http://news.yahoo.com/s/ap/20100823/ap_on_re_la_am_ca/cb_bahamas_plane_crash

 

[Ted]

Not knowing the full details, it wouldn't surprise me if the following combination of events took place:

- The plane was at (or over) gross
- It was a really frickin' hot day
- The plane was at low altitude when the engine failed, not providing much time for reaction
- The pilot didn't respond properly

With full fuel, I can still put 1200 lbs in my Aztec. 6 people and luggage pretty easily meets or exceeds that (when we've done 6 people, I was the only male in the plane). The plane will not climb particularly well at that weight on hot summer days, and you'd need to be at around Vy to get a good climb rate. If they were over gross on a hot day at a relatively low airspeed and not much above ground, I could easily see their result happening.

I rarely fly near gross. Even when I did my Mexico trip and had three humans, luggage, survival gear, and 9 dogs heading to Colorado, we were a couple hundred pounds under gross, improving as fuel burned off. I have tested and, if flown properly, my Aztec will maintain altitude just fine with the left engine dead and the airplane clean at gross at or below about 6000 ft MSL on a hot day. However if one had failed on me right after taking off from Cozumel while I was still at low altitude, low airspeed, and climbing, it would definitely be work to get me back to the airport. I'd first fly out over the ocean to try to regain some altitude, then come back in. It'd be doubly hard if it was the left engine and that meant I lost my hydraulic pump and would have to pump down the gear manually (fortunately in that case I had a co-pilot who could have helped).

While this isn't the Aztec below, piston aircraft CAN cruise on one engine if flown properly. The below picture was taken on a hot day with full fuel, although still well under gross. I landed it with the prop like that. It was only a problem once I landed as that particular plane didn't want to taxi on the right engine only (Aztec will) and I had to mess to restart a feathered engine on the ground before continuing.



One more point: I do a good sum of single engine training in twins I fly and am a big believer in it. While I generally don't actually feather the engines, I will pull the power back on one engine once a safe altitude has been reached and do my various maneuvers to remind myself how the plane flies in the degraded mode. My takeoffs are done with the assumption that an engine WILL fail at any point in the process, and so I take precautions to give me the best chance of success when that happens. Will it work? Beats me, I hope to never have to test it.

 

[Jim Burns]

As a fellow Aztec owner/pilot and an MEI, I'd echo Ted's words. Low and slow, heavy and hot with one on death's door would be a tough spot to find yourself. I find our Aztec will maintain altitude below 6000 and fly at around 135mph with one engine idled and the other deafening.

Drag demonstrations are real eye-openers. I again agree with Ted's idea to fly the airplane, get the gear up, climb in a safe manner back to pattern altitude, then head back to the airport. A climbing turn back towards the airport on one engine while heavy and hot with the gear hanging in the wind might very well eliminate the "climbing" part of that notion.

 

[Lance F]

Under Part 23 certification the FAA doesn't require a light twin that weighs under 6000# or has Vso speed under 61 kts to demonstrate ANY single engine climb performance.

Hot and heavy, the pilot really has to do it right and even then it may not be enough.

Buy a jet

 

[jesse]

It'd be doubly hard if it was the left engine and that meant I lost my hydraulic pump and would have to pump down the gear manually (fortunately in that case I had a co-pilot who could have helped)

Perhaps you'd be better off leaving the gear up and pranging it into the runway? Seems like pumping the gear down manually could put you into a situation where that was more drag then you wanted and now you can't make it to the airport. I suppose that decision would depend on how heavy you were but something definitely worth considering.

 

[Jim Burns]

Correct. If the gear is up when the engine fails, the gear stays up until on final.

 

[Aztec Driver]

Immediately after takeoff, full fuel, two people, and a dirty configuration will not allow you to fly off.

Hence, this damage.

 

[Ted]

A climbing turn back towards the airport on one engine while heavy and hot with the gear hanging in the wind might very well eliminate the "climbing" part of that notion.

Yes. Fortunately the Aztec is docile enough that you wouldn't likely get into a stall/spin unless you really tried, but getting to a safe altitude is a much better idea first.

Perhaps you'd be better off leaving the gear up and pranging it into the runway? Seems like pumping the gear down manually could put you into a situation where that was more drag then you wanted and now you can't make it to the airport. I suppose that decision would depend on how heavy you were but something definitely worth considering.

Correct. If the gear is up when the engine fails, the gear stays up until on final.

I'd definitely use zero flaps for landing.

Adding gear would depend on a lot of things, especially temperature and weight. One of the advantages the Aztec has is that it has three methods of getting the gear down - hydraulic pump on the left engine, hand pump, and a CO2 cartridge. So if you really can't get it down in time with the hand pump, pull the CO2 cartridge.

When would I put the gear down? The POH says it'll take 50 pumps with the hand pump, and that will take a while. If I was VMC I'd probably make a high downwind (the Aztec is a world class leader in losing altitude) and put it down then. IMC is a lot more interesting. A co-pilot definitely helps. I wouldn't hesitate to use the CO2 cartridge if necessary.

 

[AdamZ]

Immediately after takeoff, full fuel, two people, and a dirty configuration will not allow you to fly off.

Hence, this damage.

Whew I remember that day!

 

[gismo]

Yes. Fortunately the Aztec is docile enough that you wouldn't likely get into a stall/spin unless you really tried, but getting to a safe altitude is a much better idea first.





I'd definitely use zero flaps for landing.

Adding gear would depend on a lot of things, especially temperature and weight. One of the advantages the Aztec has is that it has three methods of getting the gear down - hydraulic pump on the left engine, hand pump, and a CO2 cartridge. So if you really can't get it down in time with the hand pump, pull the CO2 cartridge.

When would I put the gear down? The POH says it'll take 50 pumps with the hand pump, and that will take a while. If I was VMC I'd probably make a high downwind (the Aztec is a world class leader in losing altitude) and put it down then. IMC is a lot more interesting. A co-pilot definitely helps. I wouldn't hesitate to use the CO2 cartridge if necessary.

One of the nice things about the Baron is that the gear can be lowered in 3-4 seconds regardless of which if any engines are running, just by moving the gear selector switch. And BTW, I was under the impression that it's possible to add a second hydraulic pump on the other engine of an Aztec to provide the same capability. Have you considered that?

 

[Gmaper]

One of the nice things about the Baron is that the gear can be lowered in 3-4 seconds regardless of which if any engines are running, just by moving the gear selector switch. And BTW, I was under the impression that it's possible to add a second hydraulic pump on the other engine of an Aztec to provide the same capability. Have you considered that?

I also heard about the second hydraulic pump option. How expensive is that? Also, flaps are hydraulic and if extended when the pump fails they will come up to trail without pumping but if you want them all the way up you have to pump? Do I remember this right, Ted?

When I took my multi check-ride in an Apache back in the dark ages the examiner had me doing a simulated single engine landing with the left engine at zero thrust. I had to demonstrate how to pump but didn't really have to do that. No flaps for single engine landings. When I was on about 1/4 mile final he said if an airplane pulls out on the runway what are you going to do? I said we're landing anyway. He said "good answer".

 

[Ted]

One of the nice things about the Baron is that the gear can be lowered in 3-4 seconds regardless of which if any engines are running, just by moving the gear selector switch. And BTW, I was under the impression that it's possible to add a second hydraulic pump on the other engine of an Aztec to provide the same capability. Have you considered that?

Of course, if you had an electrical failure, you'd have to put the gear down manually, and I don't know what that's like in the Baron. When I had my electrical failure, I was happy to have the hydraulic gear. However if I had a hydraulic failure or a left engine failure, I'd probably wish I had electric gear.

You can add a second hydraulic pump, either to the right engine or as an electric pump. I have no idea what it costs, and it's not been a particularly big worry. Since the Aztec already has three means of getting the gear down, that's sufficient as far as I'm concerned.

I also heard about the second hydraulic pump option. How expensive is that? Also, flaps are hydraulic and if extended when the pump fails they will come up to trail without pumping but if you want them all the way up you have to pump? Do I remember this right, Ted?

That's a good question, and I honestly don't know the answer. My understanding was that when the hydraulic pump quits, the gear and flaps stay in whatever position they're in, and you have to then manually extend or retract them. In the case of the flaps, I want to get those things up as soon as the engine fails. As Jim pointed out, a drag demo is very enlightening. You will lose altitude at quite an alarming rate.

When I took my multi check-ride in an Apache back in the dark ages the examiner had me doing a simulated single engine landing with the left engine at zero thrust. I had to demonstrate how to pump but didn't really have to do that. No flaps for single engine landings. When I was on about 1/4 mile final he said if an airplane pulls out on the runway what are you going to do? I said we're landing anyway. He said "good answer".

One of the "problems" with the Aztec's design (if you can call it that) is that you can't see what it's really like to have to pump the gear down without either jacking the plane up and doing it on the ground or shutting down the left engine in flight. So as a result, you don't really have a good idea of what it's actually like until you do it. I know how to operate the hand pump, but I really don't know what operating it in a real emergency would be like.

 

[RotorAndWing]

FWIW on the PA23 series if the hydraulic pump has failed and the flaps are down all you have to do is raise the flap handle to up and the flaps will "blow back" to about the 10 degree angle.

 

[Gmaper]

One of the "problems" with the Aztec's design (if you can call it that) is that you can't see what it's really like to have to pump the gear down without either jacking the plane up and doing it on the ground or shutting down the left engine in flight. So as a result, you don't really have a good idea of what it's actually like until you do it. I know how to operate the hand pump, but I really don't know what operating it in a real emergency would be like.

Ted, if you haven't actually pumped the gear down you might try to get a chance to do that when your airplane is in for annual inspection. When I was the airport kid I sometimes performed that task when a PA-23 was in for a gear swing test which was done during 100 hr inspections.

FWIW on the PA23 series if the hydraulic pump has failed and the flaps are down all you have to do is raise the flap handle to up and the flaps will "blow back" to about the 10 degree angle.

Thanks for the detail. I didn't know how far back up they would come but I guess my memory about them coming up when the flap handle was raised was still good. At my age any correct memories are cherished. :wink2:

And for all you PA-23 operators I hope you don't have a hydraulic power pak leak because it makes a real mess of the carpet. Again going way back in the memory archives but I think the power pak is in the console right behind the gear and flap levers.

 

[Jim Burns]

Part of the annual or 100hr inspection should be to morph into a monkey, slide your head under the co-pilots panel and above the rudder pedels to look behind the power pac so you can check for leaks and to insure that the drain tube is inserted in the bottom of the catch pan below the power pack. Without the drain tube in the catch pan, you end up with the mess on your carpet rather than on the belly of the plane. You can also insure that the over flow/vent hose is attached to the top of the power pac. It helps if you remove the co-pilots seat, but not necessary if you're very flexible.

 

[gismo]

Of course, if you had an electrical failure, you'd have to put the gear down manually, and I don't know what that's like in the Baron. When I had my electrical failure, I was happy to have the hydraulic gear. However if I had a hydraulic failure or a left engine failure, I'd probably wish I had electric gear.

In the context of a single engine approach, the electric gear shines for several reasons, the chief one being that it's pretty much unaffected by a dead engine whether you are lowering or raising the gear. That means that if you find you put the gear down too early in the approach and need it up to make the runway that option is available.

You can add a second hydraulic pump, either to the right engine or as an electric pump. I have no idea what it costs, and it's not been a particularly big worry. Since the Aztec already has three means of getting the gear down, that's sufficient as far as I'm concerned.

How many means does it have for retracting the gear, especially if the engine with the pump isn't running? While a single engine go-around isn't a pleasant thought, there are times when it might be the best option but being unable to raise the gear kinda puts the dampers on that thought. The issue of raising the gear when you lose one on climbout seems even more serious. How do you handle that? Of course even in the Baron it's wise to simply land the airplane on whatever survivable terrain exists ahead if an engine quits before you get the gear up if you're heavy, but at mid weights it's not all that hard to fly away from an engine failure that occurs just as you break ground (on a short runway) and part of that procedure is raising the gear as soon as you have reason to believe you can stay in the air. Even if you guess wrong, you can get the gear back down if you've got 4 seconds before touchdown.

 

[Ted]

In the context of a single engine approach, the electric gear shines for several reasons, the chief one being that it's pretty much unaffected by a dead engine whether you are lowering or raising the gear. That means that if you find you put the gear down too early in the approach and need it up to make the runway that option is available.

How many means does it have for retracting the gear, especially if the engine with the pump isn't running? While a single engine go-around isn't a pleasant thought, there are times when it might be the best option but being unable to raise the gear kinda puts the dampers on that thought. The issue of raising the gear when you lose one on climbout seems even more serious. How do you handle that? Of course even in the Baron it's wise to simply land the airplane on whatever survivable terrain exists ahead if an engine quits before you get the gear up if you're heavy, but at mid weights it's not all that hard to fly away from an engine failure that occurs just as you break ground (on a short runway) and part of that procedure is raising the gear as soon as you have reason to believe you can stay in the air. Even if you guess wrong, you can get the gear back down if you've got 4 seconds before touchdown.

That would be a more compelling reason for having a second hydraulic pump, and a logical one. To get the gear up if you lose the left engine you'd need to use the hydraulic pump, which means it pretty much won't be happening.

I view it as a lesser concern, though. When I fly, it's take off, gear up when I'm out of usable runway, and then I'm going. The gear doesn't take long to go up (not quite 3 seconds, but still not slow), so if the engine has quit by the time I pull the handle up, the gear will most likely make it up before the prop stops turning. That's where I'm the most concerned about it. I really can't think of a time when a single-engine go-around is something that I'd attempt in the Aztec. It's just not something that would likely be very successful.

Still, I agree that it would be a good idea. Something I'll consider for the future.

 

[flyingcheesehead]

One of the nice things about the Baron is that the gear can be lowered in 3-4 seconds regardless of which if any engines are running, just by moving the gear selector switch. And BTW, I was under the impression that it's possible to add a second hydraulic pump on the other engine of an Aztec to provide the same capability. Have you considered that?

The Apache I did my multi in had a 2nd hydraulic pump that was electric. So, it had FOUR ways to get the gear down: Normal (hydraulic pump on left engine), left engine or primary hydraulic pump failure (use the electric backup hydraulic pump), Emergency (hand pump), and Oh $#!+ (CO2 blowdown system).

IIRC, in the event of any sort of failure necessitating the use of the hand pump, you could put both gear and flap handles down and just start pumping - It had a valve that would lower approach flaps first, then lower the gear, then lower landing flaps. I did pump the whole mess down by hand once, it wasn't particularly difficult.

One of the "problems" with the Aztec's design (if you can call it that) is that you can't see what it's really like to have to pump the gear down without either jacking the plane up and doing it on the ground or shutting down the left engine in flight. So as a result, you don't really have a good idea of what it's actually like until you do it.

Why not shut the engine down once to try it? Of course, at a safe altitude near an airport and with cooling in mind and all that... Or you could stop in the lower peninsula on your way to 6Y9 (AHEM!!!) and go up with Tom Brady in his Apache to do it. I didn't find it to be physically difficult or take an excessive amount of time, IIRC both gear and flaps took about 25 pumps or so, and the pump was much easier to operate than the primer in a Cessna.

 

[Ted]

Why not shut the engine down once to try it? Of course, at a safe altitude near an airport and with cooling in mind and all that... Or you could stop in the lower peninsula on your way to 6Y9 (AHEM!!!) and go up with Tom Brady in his Apache to do it. I didn't find it to be physically difficult or take an excessive amount of time, IIRC both gear and flaps took about 25 pumps or so, and the pump was much easier to operate than the primer in a Cessna.

I've thought about that, but I think it needs to be done carefully, otherwise that gets into the category of potentially creating an emergency.

As for 6Y9, see y'all next year... maybe.

 

[Gmaper]

I've thought about that, but I think it needs to be done carefully, otherwise that gets into the category of potentially creating an emergency.

Shutting down a perfectly running engine might be compared to jumping out of a perfectly good airplane

Ted, does your Aztec have unfeathering accumulators? Back in the dark ages we did shutdown and feather as a part of multi-engine training. Our PA-23s did not have accumulators which meant the engine pretty much had to start in order to get enough oil pressure to unfeather. If you have accumulators you are supposed to be able to unfeather without having to depend on the engine starting and presumably a windmilling prop will start the engine if anything will.

 

[flyingcheesehead]

Shutting down a perfectly running engine might be compared to jumping out of a perfectly good airplane

Ted, does your Aztec have unfeathering accumulators? Back in the dark ages we did shutdown and feather as a part of multi-engine training. Our PA-23s did not have accumulators which meant the engine pretty much had to start in order to get enough oil pressure to unfeather. If you have accumulators you are supposed to be able to unfeather without having to depend on the engine starting and presumably a windmilling prop will start the engine if anything will.

We still do shutdown and feather - It's in the Commercial PTS, Area of Operation X, Task A: Maneuvering With One Engine Inoperative. The following note is right at the top of that task, emphasis mine:

NOTE: The feathering of one propeller shall be demonstrated in flight, in a multiengine airplane equipped with propellers which can be safely feathered and unfeathered. The maneuver shall be performed at altitudes and positions where safe landings on established airports can be readily accomplished. In the event a propeller cannot be unfeathered during the practical test, it shall be treated as an emergency.

The exact same note appears in the Private PTS as well. IMHO, if the FAA requires it on a checkride, it can't be too unsafe!

 

[jxdrl]

I don't see anything unsafe about it over an airport. Without accumulators, it's up to the starter to spin the engine to start and then the engine will unfeather the prop and begin normal operation. In the air, I could assume it would be harder to spin the prop then if it was feathered on the ground? - there was some discussion about this on the red board recently. There it was talk of a prop feathering on shut down and most being able to come out of that with the engine or use of a paddle.


Is it "safe" without accumulators to depend on the starter? Up to the DPE? I haven't flown a twin yet (the twinkie had an unfixable at the time fouled spark plug on run-up the day I tried). From what I've heard though, it should be a non-issue with a functioning starter.

 

[gismo]

Shutting down a perfectly running engine might be compared to jumping out of a perfectly good airplane

Perhaps, but all joking aside IMO it's a very good idea to occasionally shut the engines down in flight (one at a time) so you know the props feather properly and have some experience with a stopped engine before it happens unexpectedly.

Ted, does your Aztec have unfeathering accumulators? Back in the dark ages we did shutdown and feather as a part of multi-engine training. Our PA-23s did not have accumulators which meant the engine pretty much had to start in order to get enough oil pressure to unfeather. If you have accumulators you are supposed to be able to unfeather without having to depend on the engine starting and presumably a windmilling prop will start the engine if anything will.

If they are functional, accumulators will indeed bring a stopped prop out of feather, forcing it to windmill and making a restart real easy. Without accumulators it is necessary to crank the engine with the starter to get it to start turning and sometimes that can take a while. When restarting that way it's important to carefully observe the starter's duty cycle lest you burn it out or shorten it's life. It's also a real good idea to only do a shutdown in good VMC and when the plane isn't loaded to MGW so it will be relatively easy to handle on one should it become impossible to restart.

 

[Ted]

It is still part of the PTS to shut down an engine and restart it. As part of instruction with my instructor, we also have shut down a good engine and landed the plane. It's a good practice to do, especially at Williamsport where there's much longer runways than you need for such an operation and nothing else going on.

Shutting down the left engine on the Aztec (which means you now have both the engine not spinning and your primary means of not getting the gear down missing), doesn't seem like something that's inherently the best idea. I like Jim's suggestion better of doing it while the plane's on jack stands.

There are a lot of failure modes on various aircraft that you don't practice the real thing. The emergency gear extension on the Comanche is one, because doing so actually disconnects the gear from the motor and then you have to do a service operation on the gear before flying it again.

Now, as to shutting down and restarting an engine as part of the PTS: the DE I took my multi ride with (who had something on the order of 8000 hours of Aztec time) thought it wasn't a valuable piece of the PTS, and did add some potential risk to the checkride. I can't think of a time when I'd shut down the engine and want to restart it outside of training purposes. If I shut it down, there was a darn good reason for it.

 

[Jim Burns]

No unfeathering accumulators on the Aztec. The props are brought out of feather by the starters.

One thing about restarts in the air in the Aztec, they beat the living crap out of your engine mounts. I'd prefer to practice restarts in somebody elses airplane. The first time will make you think that it's going to shake right off of the airplane.

I also did my initial MEL with Tom Brady in his Apache. No accumulators, the re-start on the checkride wasn't a big deal. If I remember correctly, his second hydraulic pump was electric.

I did my MEI in a Beech Travelair with unfeathering accumulators. I never remember the prop ever coming to a complete stop. Accumulator would bring the prop out of feather and it would windmill a little faster, restarts were pretty easy.

I won't shut an engine down that is producing power and oil pressure, even if it's only a little power. If I see oil pressure dropping, a shut down is inevitable and I'll re-verify/feather/shut down/secure while I still can. I can't think of any reason other than fuel exhaustion where I'd want to attempt a restart. An attempted restart assumes a certain amount of reasoning that it will be successful.

 

[Ted]

No unfeathering accumulators on the Aztec. The props are brought out of feather by the starters.

Which is a pain.

I won't shut an engine down that is producing power and oil pressure, even if it's only a little power. If I see oil pressure dropping, a shut down is inevitable and I'll re-verify/feather/shut down/secure while I still can. I can't think of any reason other than fuel exhaustion where I'd want to attempt a restart. An attempted restart assumes a certain amount of reasoning that it will be successful.

Well, I can think of one situation...



While that's a Navajo and not an Aztec, if you throw a cylinder, I'd shut down the engine. My instructor's Aztec (when he had it) threw a cylinder on his left engine about 10 years ago.

However otherwise so long as it's producing enough power to not be a hindrance, I'd tend to agree.

 

[Jim Burns]

Yep, thus my qualifier to watch the oil pressure. Blown jug would probably cause a major loss of oil.

 

[Henning]

One of the "problems" with the Aztec's design (if you can call it that) is that you can't see what it's really like to have to pump the gear down without either jacking the plane up and doing it on the ground or shutting down the left engine in flight. So as a result, you don't really have a good idea of what it's actually like until you do it. I know how to operate the hand pump, but I really don't know what operating it in a real emergency would be like.

Next annual, be there when they do the gear swing and pump it down. When we did swings we always did one on the manual system, I'm sure they wouldn't mind you doing it.

 

[Ted]

Yep, thus my qualifier to watch the oil pressure. Blown jug would probably cause a major loss of oil.

As my instructor tells the story (which is humorous in hindsight), he heard a loud "BANG" and thought "I sure hope that was the alternator belt." Pointed his flashlight out the window, saw the cylinder dangling by the spark plug wires and the crankshaft spinning. He said to himself "Well, I guess it's time to shut that one down," and landed safely on one engine.

My guess is a few liberties were taken with the words used, but it makes for a good story, and he did land safely.

 

[flyingcheesehead]

There are a lot of failure modes on various aircraft that you don't practice the real thing. The emergency gear extension on the Comanche is one, because doing so actually disconnects the gear from the motor and then you have to do a service operation on the gear before flying it again.

In which case, I'd wait for the annual to do it, that way the A&P is right there ready to reconnect it. I'd still want to do it at least once - Probably on the first annual after I got the plane - Just to know how it worked and be sure it actually did work!

I can't think of a time when I'd shut down the engine and want to restart it outside of training purposes. If I shut it down, there was a darn good reason for it.

IMHO, learning exactly how the emergency extension goes beforehand counts as "training purposes." It's your plane, of course, so I'm not saying YOU should do it - Just that I probably would. I'm crazy that way.

 

[flyingcheesehead]

One thing about restarts in the air in the Aztec, they beat the living crap out of your engine mounts. I'd prefer to practice restarts in somebody elses airplane. The first time will make you think that it's going to shake right off of the airplane.

Really? I don't remember it being rough at all in the Apache - Or is it something peculiar to the Aztec that causes this?

I also did my initial MEL with Tom Brady in his Apache. No accumulators, the re-start on the checkride wasn't a big deal. If I remember correctly, his second hydraulic pump was electric.

Yup. And since that plane probably goes through a dozen inflight shutdown/restarts a week, I'm sure Tom has a pretty good idea that it's going to restart and all the backup systems will continue to work, so I'd certainly feel more comfortable doing it in his plane than in my own where I've never done it before - Hence, my alternate suggestion that Ted go try it on Tom's plane instead. Plus, I really wish Ted and Laurie were going to 6Y9!

 

[Jim Burns]

When I few with Tom, we never shut it down, it was only on the checkride. The Apache didn't shake on start up, but both the Aztecs I have time in sure did/do. Maybe it's a 4cyl low hp vs 6cyl high hp thing or the longer arm between the prop and the mount.

 

[Jim Burns]

Like pulling the CO2 bottle just to see if it works then finding out you need to pull all the struts and replace every seal.

 

[Ted]

When I few with Tom, we never shut it down, it was only on the checkride. The Apache didn't shake on start up, but both the Aztecs I have time in sure did/do. Maybe it's a 4cyl low hp vs 6cyl high hp thing or the longer arm between the prop and the mount.

I don't recall that on mine, but then again it's been a while since we did a mid-air restart.

Like pulling the CO2 bottle just to see if it works then finding out you need to pull all the struts and replace every seal.

Yep, that's on the lsit of "Things I don't practice."