421 down in Alabama

:(...
 
I see a number of 300-400 series turbo'd Cessna twins come through the local shop each yearmany of which are undergoing pre-purchase inspections. The condition of the exhaust system on some of them is scary beyond description.
 
I got a call about this last night, they were people from the neighborhood where I grew up. They used to buy their cars from us...:(
 
This is very sad! A friend of my wife was actually a close friend of this family. They were headed to the airport that is a half of mile from my house! (DTS)
 
Horrible indeed!:(

Sounds like it flew on one fan for a bit. I guess that single engine operations in a twin on Take off and landing are really a thin margin kind of thing.
 
at gross the 421 is not exactly a hot performer on two engines let alone one, especially with the heat they had down there yesterday. very unfortunate accident.
 
tonycondon said:
at gross the 421 is not exactly a hot performer on two engines let alone one, especially with the heat they had down there yesterday. very unfortunate accident.
Click to expand...

Definitely not 'peak performance' kind of weather down here recently.

Very sad.
 
Think about what you just wrote. Why should any airplane be hard to land with 50% of power available? The most-common problem with en-route failures is that the pilots overcompensate and find themselves too high and too fast on the approach. Faced with either an over-run or a go-around, they make a bad decision.

AdamZ said:
Horrible indeed!:(

Sounds like it flew on one fan for a bit. I guess that single engine operations in a twin on Take off and landing are really a thin margin kind of thing.
Click to expand...
 
Adam: the critical point in a twin is on departure between lift off and blue line (single engine best rate of climb). Once past blue line, assuming under gross weight and in CG, the plane should climb; albeit, slowly. In cruise, as Wayne said, it should maintain altitude until at single engine ceiling.

I'm sorry for the loss; seems many folks here knew the folks. I'm afraid unless we find out more was wrong with the plane, it will come down to proficiency and judgement of the pilot. To early to tell.

I might also add, we and investigators will never actually know all that went on. Investigators will do their best, but no one actually knows or will be able to determine what was actually going on in the plane.

Sigh,

Dave
 
Last edited:
What seems disturbing to me is that the crash apparently happened around 6:30pm about 2 miles from the field, but they didn't locate the wreckage until around 2 in the morning and by then everything was burned beyond recognition. You'd think folks would have seen the fire.
 
wabower said:
Think about what you just wrote. Why should any airplane be hard to land with 50% of power available? The most-common problem with en-route failures is that the pilots overcompensate and find themselves too high and too fast on the approach. Faced with either an over-run or a go-around, they make a bad decision.
Click to expand...

I'm not multi rated so I'm not sure what the critial speeds or phases of flight are on one engine. The reason I thought it might be a tighter margine is the that the center of thrust would be off to one side, and when you start adding flaps and gear etc to the equation It would just seem to me to be a narrower margin of controlability. But again I'm not multi rated so can't say for sure

Dave Siciliano said:
Adam: the critical point in a twin is on departure between lift off and blue line (single engine best rate of climb). Once past blue line, assuming under gross weight and in CG, the plane should climb; albeit, slowly. In cruise, as Wayne said, it should maintain altitude until at single engine ceiling.

I'm sorry for the loss; seems many folks here knew the folks. I'm afraid unless we find out more was wrong with the plane, it will come down to proficiency and judgement of the pilot. To early to tell.

I might also add, we and investigators will never actually know all that went on. Investigators will do their best, but no one actually knows or will be able to determine what was actually going on in the plane.

Sigh,

Dave
Click to expand...

Thanks Dave.
 
AdamZ said:
I'm not multi rated so I'm not sure what the critial speeds or phases of flight are on one engine. The reason I thought it might be a tighter margine is the that the center of thrust would be off to one side, and when you start adding flaps and gear etc to the equation It would just seem to me to be a narrower margin of controlability. But again I'm not multi rated so can't say for sure
Click to expand...
Think about it this way. The thrust is most asymmetrical at high power settings but you land with lower power settings.

Years ago before I was even multi-rated a pilot was letting me land a Twin Commander. One of the engines quit on short final and I didn't realize what it was nor did I feel much unusual force. The thing I remember most was the immediate way-out-of-sync sound from the props. The real pilot took over and landed and when I asked what happened he said, "the engine died". Sure enough. Good thing we were taking it to a shop to get it worked on when that happened.

As far as the accident in this thread goes, it's hard to say what happened. Maybe the airplane couldn't maintain altitude on one engine or maybe the pilot lost control.
 
Last edited:
Everskyward said:
As far as the accident in this thread goes, it's hard to say what happened. Maybe the airplane couldn't maintain altitude on one engine or maybe the pilot lost control.
Click to expand...

Exactly - just not enough details right now. About all we know is that they lost an engine in cruise and diverted to Demopolis. At some point between cruise flight and the airport they crashed.

The Flightaware track is interesting - last reported altitude is 17400':
http://flightaware.com/live/flight/N692TT

Take a look at the track log:
http://flightaware.com/live/flight/N692TT/history/20110709/1958Z/1H0/KDTS/tracklog

They were cruising at FL210. Just before the radar track ends, you see the altitude decrease to 17,400' where it ends and the speed increases from around 195 to 234 then cuts off. Could have been just a normal emergency descent or catastrophic loss of control and the plane fell out of the sky.

Could be alot of things....could have been a much bigger emergency than the loss of one engine.....could have been an inflight fire.....could have been that they were high on the approach to Demopolis and lost control on a single engine go around....more questions than answers at this point.
 
TangoWhiskey said:
I count six kids in the family picture the dad has on his profile:

http://www.facebook.com/teutenfw?sk=info

Anybody know if one wasn't on board?
Click to expand...

I think it is still pretty fuzzy - someone posted on PPW all the names and ages of those killed and the total number was 8. All of the news stuff and press releases only refer to the parents and 5 kids for a total of 7. I think the details are still coming - apparently the remains were burned pretty bad could take a while before any more details come out.
 
Oldest daughter was from Mom's prior marriage and lived with her father in St. Louis. She wasn't on the plane.
Fearless Tower said:
I think it is still pretty fuzzy - someone posted on PPW all the names and ages of those killed and the total number was 8. All of the news stuff and press releases only refer to the parents and 5 kids for a total of 7. I think the details are still coming - apparently the remains were burned pretty bad could take a while before any more details come out.
Click to expand...
 
wabower said:
Oldest daughter was from Mom's prior marriage and lived with her father in St. Louis. She wasn't on the plane.
Click to expand...

Okay, that explains why she had a different last name....thought it might have been a nanny.
 
wabower said:
I see a number of 300-400 series turbo'd Cessna twins come through the local shop each yearmany of which are undergoing pre-purchase inspections. The condition of the exhaust system on some of them is scary beyond description.
Click to expand...

Very true. I saw a Navajo recently that had similarly bad exhaust on pre-buy inspection. You don't want to have that on any airplane, but especially not on a turbocharged one.

wabower said:
Think about what you just wrote. Why should any airplane be hard to land with 50% of power available? The most-common problem with en-route failures is that the pilots overcompensate and find themselves too high and too fast on the approach. Faced with either an over-run or a go-around, they make a bad decision.
Click to expand...

Absolutely correct.

Dave Siciliano said:
Adam: the critical point in a twin is on departure between lift off and blue line (single engine best rate of climb). Once past blue line, assuming under gross weight and in CG, the plane should climb; albeit, slowly. In cruise, as Wayne said, it should maintain altitude until at single engine ceiling.
Click to expand...

Also absolutely correct. We know that a 421 can fly on one engine (if nothing else, there was the posting in "Lessons Learned" about that recently, and the pilot successfully landed the plane. My guess is the plane was pretty heavy given the load. The trick is being calm, cool, and collected - which is going to be exceedingly difficult when your family is on board and you just lost an engine.

If the pilot either had too much speed coming in and couldn't bleed it off (that can be a problem in the 310 - never flew the 421) or alternately came in too slow and hit a Vmc issue (or handled it properly but ran out of altitude), either one could cause a problem.
 
Ted DuPuis said:
If the pilot either had too much speed coming in and couldn't bleed it off (that can be a problem in the 310 - never flew the 421) or alternately came in too slow and hit a Vmc issue (or handled it properly but ran out of altitude), either one could cause a problem.
Click to expand...

Assuming there wasn't a much greater emergency, those are the most likely possibilities - either got too low and slow on the approach or was too hot and high and botched the missed/SE go-around.

I'm really curious to know why the radar track stops so suddenly though. From some posts on PPW, another pilot was in the area at the time talking to the same controller, but on a different freq, so he was only hearing the controller's side, but said it sounded like a normal divert.
 
Fearless Tower said:
Assuming there wasn't a much greater emergency, those are the most likely possibilities - either got too low and slow on the approach or was too hot and high and botched the missed/SE go-around.
Click to expand...

You end up having only one opportunity to get it right. Doing a SE go-around is typically a particularly bad idea, and you're best off just landing even if it's not an ideal landing. If I had the option, I would try to get to an airport that had a long runway for the plane I was flying. If not, I'd better get it right the first time.

This is also why it pays to do single engine practice. In a 421, recurrent sim training is probably the best idea for that. If I have to go to Navajo School, you can bet that I'll be doing lots of V1 cuts and coming in for a landing on one.
 
Ted DuPuis said:
This is also why it pays to do single engine practice. In a 421, recurrent sim training is probably the best idea for that. If I have to go to Navajo School, you can bet that I'll be doing lots of V1 cuts and coming in for a landing on one.
Click to expand...
That's another thing that seems suprising about this - flying a 421, I'm sure he would have had some kind of re-current as part of his insurance requirements. Losing an engine at FL210 doesn't seem like a major event.
 
Fearless Tower said:
Exactly - just not enough details right now. About all we know is that they lost an engine in cruise and diverted to Demopolis. At some point between cruise flight and the airport they crashed.

They were cruising at FL210. Just before the radar track ends, you see the altitude decrease to 17,400' where it ends and the speed increases from around 195 to 234 then cuts off. Could have been just a normal emergency descent or catastrophic loss of control and the plane fell out of the sky.
Click to expand...

So here's a question for 421 experts: is the cabin pressurization derived from one engine or both? If you lose a blower, will you also lose pressurization?
 
From both engines if system is operating properly.
wsuffa said:
So here's a question for 421 experts: is the cabin pressurization derived from one engine or both? If you lose a blower, will you also lose pressurization?
Click to expand...
 
I attended FSI 421 school (same sim covers 421, 414 and 340, depending on instrumentation and computer settings) on six-month intervals for 5 years. During S/E drills, the 421 is well-behaved at medium weights, not real sprightly when heavy. My worst sim experience was trying to land on the carrier. Never touched the boat. Navy pilots must know something I don't--like how the hell you're supposed to do it.

Ted DuPuis said:
You end up having only one opportunity to get it right. Doing a SE go-around is typically a particularly bad idea, and you're best off just landing even if it's not an ideal landing. If I had the option, I would try to get to an airport that had a long runway for the plane I was flying. If not, I'd better get it right the first time.

This is also why it pays to do single engine practice. In a 421, recurrent sim training is probably the best idea for that. If I have to go to Navajo School, you can bet that I'll be doing lots of V1 cuts and coming in for a landing on one.
Click to expand...
 
wabower said:
I attended FSI 421 school (same sim covers 421, 414 and 340, depending on instrumentation and computer settings) on six-month intervals for 5 years. During S/E drills, the 421 is well-behaved at medium weights, not real sprightly when heavy.
Click to expand...

That sounds about what I'd expect, and also what I'd expect from the Navajo (since that's all I have time in for planes of that size).

My worst sim experience was trying to land on the carrier. Never touched the boat. Navy pilots must know something I don't--like how the hell you're supposed to do it.
Click to expand...

:rofl:
 
Everskyward said:
Think about it this way. The thrust is most asymmetrical at high power settings but you land with lower power settings.

Years ago before I was even multi-rated a pilot was letting me land a Twin Commander. One of the engines quit on short final and I didn't realize what it was nor did I feel much unusual force. The thing I remember most was the immediate way-out-of-sync sound from the props. The real pilot took over and landed and when I asked what happened he said, "the engine died". Sure enough. Good thing we were taking it to a shop to get it worked on when that happened.

As far as the accident in this thread goes, it's hard to say what happened. Maybe the airplane couldn't maintain altitude on one engine or maybe the pilot lost control.
Click to expand...

Ah thanks for the explanation Mari
 
Adam: they've killed an engine on me many times on an approach and I couldn't tell which was out at the low power setting. The procedure is to land normally. Now, if one adds power, the differential thrust immediately becomes apparent and must be addressed. So, one doesn't want to get below normal approach angle and drag it in. There is a point one commits to land--period. Go around in not desireable. In these conditions, probably wouldn't be an option low on the approach.

Best,

Dave
 
Everskyward said:
Think about it this way. The thrust is most asymmetrical at high power settings but you land with lower power settings.

Years ago before I was even multi-rated a pilot was letting me land a Twin Commander. One of the engines quit on short final and I didn't realize what it was nor did I feel much unusual force. The thing I remember most was the immediate way-out-of-sync sound from the props. The real pilot took over and landed and when I asked what happened he said, "the engine died". Sure enough. Good thing we were taking it to a shop to get it worked on when that happened.

As far as the accident in this thread goes, it's hard to say what happened. Maybe the airplane couldn't maintain altitude on one engine or maybe the pilot lost control.
Click to expand...

Maybe burned through the exhaust on the good engine...:dunno:
 
Fearless Tower said:
What do you mean?
Click to expand...

The exhaust systems on those planes is notoriously weak. There's even an AD that involves pressurizing the exhaust and checking for leaks. When you lose one engine, you are taught to go full power on the other. I wonder if when it got new engines if it got new exhaust? You would hope he didn't lose both engines to infant mortality...:hairraise:
 
Fearless Tower said:
I'm really curious to know why the radar track stops so suddenly though. From some posts on PPW, another pilot was in the area at the time talking to the same controller, but on a different freq, so he was only hearing the controller's side, but said it sounded like a normal divert.
Click to expand...

Maybe the real problem developed around 17,000 and he squawked 7700? Just a data thing, perhaps?
 
Henning said:
The exhaust systems on those planes is notoriously weak. There's even an AD that involves pressurizing the exhaust and checking for leaks. When you lose one engine, you are taught to go full power on the other. I wonder if when it got new engines if it got new exhaust? You would hope he didn't lose both engines to infant mortality...:hairraise:
Click to expand...

I see...are training centers like FSI still teaching people to firewall it/go full power for engine failures?
 
Ted DuPuis said:
We know that a 421 can fly on one engine (if nothing else, there was the posting in "Lessons Learned" about that recently, and the pilot successfully landed the plane. My guess is the plane was pretty heavy given the load. The trick is being calm, cool, and collected - which is going to be exceedingly difficult when your family is on board and you just lost an engine.

If the pilot either had too much speed coming in and couldn't bleed it off (that can be a problem in the 310 - never flew the 421) or alternately came in too slow and hit a Vmc issue (or handled it properly but ran out of altitude), either one could cause a problem.
Click to expand...

Don't know if the 421 is much different but if you're landing with gear and flaps deployed it can take near full power to maintain a 3 degree slope if you're near MGW on one engine. In any piston twin it will require a significant amount of power on the good engine and that does complicate things by making the airplane yaw every time you make an adjustment to the power. If you jockey the power much you can end up with the tail wagging back and forth radically.
 
I trained at FSI for several years and don't think they ever taught that procedure. Full power on a turbo'd engine is something in the neighborhood of 40" and simply not necessary for most phases of flight other than go-arounds, which would be iffy at best for a heavy airplane.
Fearless Tower said:
I see...are training centers like FSI still teaching people to firewall it/go full power for engine failures?
Click to expand...
 
gismo said:
Don't know if the 421 is much different but if you're landing with gear and flaps deployed it can take near full power to maintain a 3 degree slope if you're near MGW on one engine. In any piston twin it will require a significant amount of power on the good engine and that does complicate things by making the airplane yaw every time you make an adjustment to the power. If you jockey the power much you can end up with the tail wagging back and forth radically.
Click to expand...

Correct. That's why on twins that have any significant amount of flaps, I hit full flaps on final at some point - where depends on the specifics of the approach.

In the Navajo, for instance (assuming the 40 degree flaps), it takes an excessive amount of power to maintain straight and level. If you have only one spinning, that's a bad situation to be in.
 
You must log in or register to reply here.
Back
Top