Plane Crash in Savannah

MikeD said:
It can be done crew-wise, but to do so it has to be briefed as a possibility, with both crewmembers knowing and understanding their instant role(s) in the event of occurrence. No different than something like a V1 cut with regards to the same idea.
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That's the only way it'll work. Plus some trust the equipment will do it, and the other guy follows instructions.
 
SpiraMirabilis said:
It bleeds off variable Py air from the FCU to reduce power if Torque exceeds 44.3(I think?). In practical terms it means you can just shove the power control lever to the wall if you were so inclined. I tend not to do that though.
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Except you can still exceed ITT/Ng limits, right? Why does everyone speak as if Torque is the only limit? [emoji851]


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mshunter said:
That's the only way it'll work. Plus some trust the equipment will do it, and the other guy follows instructions.
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Agree. It's not something that can just be done on the fly......I mean, it can, but chance of succesful outcome is low.

It's one of those things that you had to have practiced/simulated either at an altitude with a hard deck, or in a simulator that can model it highly accurately; in order to establish an "attempt/no attempt" altitude (with a sufficent padding of X feet applied for technique, ham hands during emergency, delay in response, etc), where you know that "ok, at this altitude, I can make a 180. At this altitude I can make a 90 degree turn. Below that, I'm limited to an approximate +/- 45 degrees in front of me......essentially from my 10 to my 2 o'clock".

It's not impossible at all, but it does take planning, finesse, and some expectation that its about to occur.....ie-expect the worst. And the 180 turn may not even guarantee a runway, it may only guarantee a taxiway, grass, or at least a clear spot on the airport, if nothing else is available.
 
Wardogg said:
And CFR.
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Agreed. What I was referring to was some people I talk to who say "but there's no guarantee you'll make the runway"; which I agree....there are no guarantees. But getting back to the field itself is often better than some alternatives out there, even if you do land on grass/dirt/taxiway only. In an urban area, it may be the only open area available. So if you have the known altitude to make it, it's better than the alternative.
 
Roger Roger said:
"Failing TTL" or wiring/control failure that is easily bypassed by switching the SRL switch off?
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Having had a TTL valve fail on takeoff, the SRL off instantly returned power. Just have to make sure the power lever isn't buried to the stop or it will over torque one the power returns. It should be an ingrained reflex if the engine goes wonky.
 
RedBaron2000 said:
Except you can still exceed ITT/Ng limits, right? Why does everyone speak as if Torque is the only limit? [emoji851]


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No, because it reduces fuel flow into the combustor. Torque is just the end result, but it's also going to keep temps from going high.

Also, it's not instantaneous, and during my initial training I discovered that while the PCL lever in the Simcom FTD is pretty well instantly-responsive, if you try to just throw the lever forward in the real airplane, you will bump it over the torque limiter and it takes a moment to recover. That's why there's a 63.3 or some somethingish for 5 seconds limit on the torque gauge. But I never saw it get that high, and it never went that long. Also, I've only taken off from APA twice in the summertime, first time without ECS on, second time with ECS on. We self-limit our takeoff roll to 36.9 PSI unless it's absolutely necessary to use full power, and on both rolls through the initial climb, until I could gain a bit of airspeed, the temperature was in the 730/740 range. The only real difference the ECS made was when I turned it on during the climbout it bump-dropped the cabin altitude even though I set the cabin altitude to 10k, because I didn't want the bump and wanted to bring it in gradually, but I can't have nice things. So the second time I just kept the ECS on.
 
gotWXdagain said:
No, because it reduces fuel flow into the combustor. Torque is just the end result, but it's also going to keep temps from going high.

Also, it's not instantaneous, and during my initial training I discovered that while the PCL lever in the Simcom FTD is pretty well instantly-responsive, if you try to just throw the lever forward in the real airplane, you will bump it over the torque limiter and it takes a moment to recover. That's why there's a 63.3 or some somethingish for 5 seconds limit on the torque gauge. But I never saw it get that high, and it never went that long. Also, I've only taken off from APA twice in the summertime, first time without ECS on, second time with ECS on. We self-limit our takeoff roll to 36.9 PSI unless it's absolutely necessary to use full power, and on both rolls through the initial climb, until I could gain a bit of airspeed, the temperature was in the 730/740 range. The only real difference the ECS made was when I turned it on during the climbout it bump-dropped the cabin altitude even though I set the cabin altitude to 10k, because I didn't want the bump and wanted to bring it in gradually, but I can't have nice things. So the second time I just kept the ECS on.
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Torque in psi lolwut. Pratts are weird rabble rabble.
 
gotWXdagain said:
No, because it reduces fuel flow into the combustor. Torque is just the end result, but it's also going to keep temps from going high.

Also, it's not instantaneous, and during my initial training I discovered that while the PCL lever in the Simcom FTD is pretty well instantly-responsive, if you try to just throw the lever forward in the real airplane, you will bump it over the torque limiter and it takes a moment to recover. That's why there's a 63.3 or some somethingish for 5 seconds limit on the torque gauge. But I never saw it get that high, and it never went that long. Also, I've only taken off from APA twice in the summertime, first time without ECS on, second time with ECS on. We self-limit our takeoff roll to 36.9 PSI unless it's absolutely necessary to use full power, and on both rolls through the initial climb, until I could gain a bit of airspeed, the temperature was in the 730/740 range. The only real difference the ECS made was when I turned it on during the climbout it bump-dropped the cabin altitude even though I set the cabin altitude to 10k, because I didn't want the bump and wanted to bring it in gradually, but I can't have nice things. So the second time I just kept the ECS on.
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Ok I'll take your word for it. Those Pilati are pretty fancy planes, at least the PC-12 is. I know of altitude/temps where any one of the three could be exceeded while the other two aren't, at least on Caravans and Kodiaks. We had an Ng exceedance at another base a few months ago on a higher time engine...torque and ITT were within limits though.
 
Roger Roger said:
Torque in psi lolwut. Pratts are weird rabble rabble.
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I believe the logic is that torque is read by measuring the oil pressure at the power turbine, where most manufacturers convert the readout to ft lbs, Pilatus skipped the conversion and the gauge reads out straight PSI.

Also, I was slightly incorrect earlier, in that it is possible to overtemp a PC-12 engine, but it's really difficult. Most likely time would be ignoring the temp limits and trying to maintain max torque whilst climbing to altitude. But you'd have to try really hard or be really dumb to overtemp the PC-12-mounted PT-6.
 
gotWXdagain said:
I believe the logic is that torque is read by measuring the oil pressure at the power turbine, where most manufacturers convert the readout to ft lbs, Pilatus skipped the conversion and the gauge reads out straight PSI.

Also, I was slightly incorrect earlier, in that it is possible to overtemp a PC-12 engine, but it's really difficult. Most likely time would be ignoring the temp limits and trying to maintain max torque whilst climbing to altitude. But you'd have to try really hard or be really dumb to overtemp the PC-12-mounted PT-6.
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Yeah, that's kind of dumb. 0-100% makes way more sense.
 
gotWXdagain said:
Around 1,000' in a -12 there is nothing impossible about the turn. As Boris said, lightly loaded or in cold temps where you climbed out quick, it could probably comfortably do it from 700-800. The bird can do some pretty impressive things. In my initial training we simulated one from 1,000' AGL off a 3200' strip, and with all the drag devices out I could I still am not sure I wouldn't have ended up off the far end.
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Have you ever considered a solid IMC departure? Like, let's say overcast at 400' and 1sm vis? Think you can still reasonably make that turn and know where you're going to end up?
 
Gonna take a wild ventured guess that the culprit was a failed CT Blade event. It's the most common PT6 failure, AFAIK.

Caravan I once flew had one on the -114A, and 7 months later on the -42A that replaced it. Both were CT blade failures. Blade creep is not your friend.
 
somewhereupthere said:
Gonna take a wild ventured guess that the culprit was a failed CT Blade event. It's the most common PT6 failure, AFAIK.

Caravan I once flew had one on the -114A, and 7 months later on the -42A that replaced it. Both were CT blade failures. Blade creep is not your friend.
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Yeah Pratt seems to be having some issues with that lately.
 
somewhereupthere said:
Have you ever considered a solid IMC departure? Like, let's say overcast at 400' and 1sm vis? Think you can still reasonably make that turn and know where you're going to end up?
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Our standard procedure when flying the PC12 was that the PM would tune in the ILS (or whatever approach available) for the opposite runway and have it active on takeoff. Anytime I did a LIFR takeoff we would brief a direction of turn based on wind, and hope to catch the LOC back towards the runway. Would it actually work in a real situation? Can't say for sure, but we were definitely briefed and prepared to make that turn in IMC if we had the altitude.
 
somewhereupthere said:
Have you ever considered a solid IMC departure? Like, let's say overcast at 400' and 1sm vis? Think you can still reasonably make that turn and know where you're going to end up?
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Think you'll reasonably know where you're going to end up going straight ahead either? Or even a slight check turn? The chance of a successful outcome in your scenario is definitely stacked against you any way you slice it.
 
MikeD said:
Think you'll reasonably know where you're going to end up going straight ahead either? Or even a slight check turn? The chance of a successful outcome in your scenario is definitely stacked against you any way you slice it.
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I agree with your statement. As far as reasonably knowing where you'll end-up going straight ahead, well, when it comes to an energy management standpoint, straight ahead gives me more time. As soon as I rotate my lift vector to make a turn I am giving myself less time.

But, perhaps it's better to crash on the airfield, especially if there is ARFF available on the field.

At any rate I'm not trying to judge the decision to make a turn. One never knows what exactly the reaction will be until the time comes.

But, I've never liked single engine IMC, which is why I will never find myself flying one in anything less than a 1000' ceiling and 1sm vis. I did it once, went against my minimums, under the pressure to get the airplane ferried back to base from mx. I departed in 400' ceiling and 3/4 vis. I didn't like it, but the boss had the screws on me and I compromised. 6.5 hours and 4 legs later, the boss was buying the Blackhawk -42A STC.

I told myself I'll never fly another single engine airplane, turbine or not, in anything less than my personal minimums, ever again. I didn't like the thought of the possible outcomes of losing that engine on the departure home, in 400'-3/4.

Never again.
 
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