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Deathtrap MU-2 BANNED

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The MU-2 dozen’t handle ice particularly well, but neither do a lot of other airplanes
Sorry Sled, I know you Have experience in the airplane but I would second the post from ATC700, I have loads of heavy icing experience in the NW without any problem, they once thought the horizontal stab was icing up and losing lift at slow speed, only to find out the exhaust was not allowing ice to form.
 
Say Again Over said:
Sorry Sled, I know you Have experience in the airplane but I would second the post from ATC700, I have loads of heavy icing experience in the NW without any problem, they once thought the horizontal stab was icing up and losing lift at slow speed, only to find out the exhaust was not allowing ice to form.
I'm sorry if my speeds were "dated" - it's been 20 years since I last flew the MU-2 and a lot of water has passed under the bridge if you know what I mean. We played around in a lot of ice in the airplane, as well, in the mountains of Utah, Idaho, Wyoming, Montana, and Nevada. Personally, I came into the MU-2 from 400 series Cessnas and Cessna 340s - airplanes that also aren't particually known for their ability to carry a load of ice. When they told us at school that we needed to keep our speed up in ice, I took them at their word and just did it. I never had any problems with the airplane, but one of our guys did. He let it get a little slow one day on approach into SLC and ended up getting a real load. I'll never forget his face when he came into the office - he was white as a ghost. It had taken full power to drag it to the runway. He said that he thought that he wasn't going to make it. (For what it's worth, we looked at the airplane and there wasn't any ice on the horizontal stab - you're right, the engine exhaust keeps it pretty clean - but there was ice just about eveywhere else the boots couldn't reach.)

ACT700 said:
I'm sure there are outfits out there that want you to "have read the manual over the weekend to do a checkride by tuesday"!
Be careful about generalizing. That's like me saying all asian carriers are unsafe.
I'm sorry, but I have no problems generalizing when it comes to MU-2s and initial and recurrent training. Granted there may be the occassional exception to the rule, but that's just it, the occassional exception to the rule. The question that I was answering was posed by someone without MU-2 experience. It's guys like him (good pilot) that the MU-2 will eat for lunch without the proper training. Unfortunately, there's all too many operators out there that only look at the bottom line. Maybe your outfit was one of the exceptions.

The MU-2 isn't an airplane to be feared, just respected.

LS
 
Look at a plane like the Beech 18. The average pilot these days would have a hell of a time finding any company to insure the thing. If someone with 1000-2000 hours and say 500 tailwheel called them, they'd probably tell them 'sorry, but we just can't insure you.' If a pilot with say 5000 hours and 1000 tailwheel calls 'em, they'll probably be able to get the insurance, but they best have DEEP pockets.

Why? The Beech 18 is an airplane just like any other airplane. If you have basic conventional gear skills and a head on your shoulders, it is operated just as safetly as any other airplane...and insurance treats it accordingly. Operating it is basic stick and rudder (and instrument) skill...not rocket science. It's just an airplane.

The MU-2, on the other hand, is more myth than fact in the public eye. Over the years, the number of MU2 accidents has roughly paralleled the number of King Air accidents...the difference, of course, being that there are far more King Air's out there than MU-2's. The MU2 has been blamed for having an extremely high wing loading, but truth is, in landing configuration, it's lower than a King Air 350, and clean, within ten pounds/sq' of a King Air 200.

Some say the spoilers for roll control kill lift. They don't. The reduce wing efficiency, but they don't kill lift. There is a difference.

Last year, three FAA teams flew 60 hours in the MU2 as part of a Flight Standardization Board to look into the MU2 as part of all the political fallout. They did it over eleven days, and in the end came to the conclusion that "with reasonable training, an average pilot can operate the MU-2 safely if opeated within the AFM guidlines." Go figure.

During research on the MU-2, with 214 total fatal accidents (since 1968), a researcher remarked that within a 90 day period five fatal B737 accidents occured, resulting in over 500 fatalities...more than the MU-2 in over 30 years. Was anybody prepared to ground the B737 for review? Of course not even though more people died in a few accidents in that airplane than in all the MU-2 accidents combined. Obviously the total number of deaths isn't the key to the picture...but to some degree I believe he makes a good point. Conversely, he notes that fatalities attributed to the MU-2 have included such things as a lineman running into the propeller of a MU-2 on the ground, and this being recorded as a fatal accident. Somewhat grasping at straws, there.

Between 1996 and 2005, 41 MU-2 accidents occured, 18 of which involved fatalities. 15 of those 18 fatals were pilot error involving a failure of basic piloting skills. 16 of those 18 involved pilots with no simulator training (FTD), who had all their training with their emplyer/operator. Some had no training, and two attended FSI but didn't complete the program. In comparing King Air accidents to MU-2 accidents, 80% of the King Air and 72% of the MU-2 accidents were pilot error. This alone, is telling. What we do not have here is a bad airplane. What we have here are bad pilots.

Bad pilots? For whatever reason, be it lack of training, lack of judgement, lapse of attention...whatever, we have pilots crashing the airplane. Not the airplane crashing pilots. Without doubt, some cases have occured in which the airplane got the better of the pilots, but overwhelmingly, most of the accidents, particularly the fatal accidents, have been lapses in basic airmanship and piloting. To blame the airplane would be a poor carpenter blaming his tools.

One of the airplanes I fly is a very unstable airplane, or can be, as airplanes go. It's suited for it's role, and it's lack of traditional stability, especially in certain configurations, is a necessary part of it's existance. Years ago, a pilot flew the airplane and returned to land. He climbed out and walked away, saying he was afraid of it and would never fly it again. This individual had the insight and wisdom to recognize his own limitations and abide by them, and there's nothing wrong with that. He made a good choice. Is he incapable of flying the airplane? I doubt that, he just lacked experience in type, and mission experience. I firmly believe that with more exposure and experience, he might have changed his mind...but it's mute point; he made a good call, and he's alive as a result. Others who didn't make the same choice since that time have since been killed in the same type airplane.

Is the airplane unsafe? No. Are the pilots incompetent? No. The dead pilots are not incompetent, just dead; they allowed or placed themselves into situations which while not necessarily beyond their means as pilots, was beyond their means as pilots in that airplane at that time. Conversely, those who continue flying the airplane...are they incompetent or guilty of improper decisions? No. There's nothing wrong with the airplane; like a computer it only does what it's made to do. It's a tough airplane; I can attest to that personally. And those who have experience in it almost universally agree (myself included) that it's got one of the better wings out there for aircraft of it's kind...point is that this airplane, like the MU-2, is just a machine. It's flyable by people of ordinary ability (such as myself) with the proper training and mindset to take things one step at a time, take the time to learn the airplane, and who will operate it conservatively.

Far better to walk up to the edge of a cliff and stop short, than to run to it, stop too late, and get a good view. One can always buy the postcard. Pushing one's limits or delving into a project with which one has inadequate training and experience is running to the cliffs; any time one approaches the edges of the envelope (be it the aircraft performance envelope, or one's own training and knowledge envelope) one has gone too far, much like the edge of the cliff. For that we can never blame the cliff, and we can never blame the airplane, only ourselves.

Soapbox over.
 
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avbug said:
During research on the MU-2, with 214 total fatal accidents (since 1968), a researcher remarked that within a 90 day period five fatal B737 accidents occured, resulting in over 500 fatalities...more than the MU-2 in over 30 years. Was anybody prepared to ground the B737 for review? Of course not even though more people died in a few accidents in that airplane than in all the MU-2 accidents combined. Obviously the total number of deaths isn't the key to the picture...but to some degree I believe he makes a good point. Conversely, he notes that fatalities attributed to the MU-2 have included such things as a lineman running into the propeller of a MU-2 on the ground, and this being recorded as a fatal accident. Somewhat grasping at straws, there.

Soapbox over.

25% of MU-2's have been involved in accidents. What % of B737's have
been in an accident?

Like I said:
Wing seperates from airplane. Pilot fails to compensate for loss of wing.
Pilot Error.

CE

Just sayin'
 
What a ridiculous way to cloud the issue. Nobody ever tried to correlate a wing failure with pilot error, nor incude a wing failure in the pilot error statistics. A wing which separates might be construed to be pilot error if it were the result of something the pilot might have found during a preflight, or if the pilot elected to fly through a thunderstorm. However, when we speak of pilot error and issues involving basic airmanship skills we're not speaking of wing separations.

100% of the MU-2's could be involved in accidents...and this still wouldn't make it a dangerous airplane, seeing as the overwhelming majority of accidents and fatalities are the result of pilot error. This would make it a field of dangerous pilots...which not conincidentally is the leading causes of why the King Air crashes, too. Further, 100% of the MU-2's could be involved in fatal accidents and still not brush the fatalities caused from the wreckage of B737's.

Nobody argues that the B737 is dangerous, despite the number of fatalities. Yet the MU-2, frequently involved in fatalities when flown by untrained, inexperienced pilots with a common identifiable thread of deficiencies in background and experience, causes a sensation.

This web board was dominated for a time with the last spat of MU-2 fatalities, lorded over by wives and sisters of the deceased. Not experienced individuals who had a clue whence they spake, but by people who were presed by emotion and not knowledge or understanding. These same individuals were responsible for the lobbying that has lead the FAA to once more set it's political foot forward to "investigate" the airplane.

Three separate panels of FAA investigators examining the airplane, it's history, it's accidents, it's everything, and putting 60 hours of flight testing on the airframe last year, and the official observation that "with reasonable training, an average pilot can operate the MU-2 safely if operated within the AFM guidlines." One might reasonably infer that either the MU-2's involved in accidents were being operated overwhelmingly by below average pilots, that average pilots had less than average training, or that average pilots (some better than others) failed to adhere to the AFM guildelines. Perhaps a combination thereof.

Assumption that the majority of the pilots are below average is a stretch. A given is that training by and large, particurly statistically among those involved in fatal accidents, is inadequate. That pilots have failed to adhere to AFM guidelines is also often borne out in accident investigations. Obviously far more flights are conducted successfully by pilots who are adhering to the aircraft manufacturer's guidelines than not, else we'd see a higher percentage of losses. Here we have everyman's airplane that really shouldn't be flown by every man...but legally can be until newly mandated training takes place.

As proper training and oversight is mandated, a decrease in the accident rate and record is inevitable; this is exactly what we shall see. Again, there's nothing wrong with the airplane; it's a poor carpenter that blames his tools.

All things mechanical can fail. As pilots, much of our training is spent not learning to fly operating equipment, but to deal with the failures. And therein, so said Sir William, lies the rub.
 
avbug said:
The MU-2, on the other hand, is more myth than fact in the public eye. Over the years, the number of MU2 accidents has roughly paralleled the number of King Air accidents...the difference, of course, being that there are far more King Air's out there than MU-2's.

Right, and while comparing the number of existing airframes as you did tells some of "the rest of the story". however it too can be skewed by differing utilization rates. The best comparison is the accidents per 100,000 hours of flight. According to the linked article that comparision is quite unfavorable.

Overall, its five-year accident rate from 2000 to 2004 was 3.17 per 100,000 flight hours, compared to 1.73 accidents per 100,000 flight hours for that time frame among other popular turboprops, according to Robert E. Breiling Associates. During the same five-year period, the Mitsubishi's fatal accident rate was 1.66 per 100,000 flight hours, or more than triple that of popular turboprops.

When the accident rate per adjusted for hours flown is almost double, and the fatal accident rate adjusted for hours flown is more than triple, something is going on. We can argue whether the something is a dangerous plane or poorly trained pilots, and I don't have a strong opinion one way or another. However, assuming the numbers are accurate, it's hard to argue that nothing is happening.

avbug said:
The MU2 has been blamed for having an extremely high wing loading, but truth is, in landing configuration, it's lower than a King Air 350, and clean, within ten pounds/sq' of a King Air 200.

True, but it's not particularly meaningful to say "the wing loading is only 10 lb./ sq-ft more thn a XXX"

A more telling comparison is a percentage comparison. The MU-2B has a loading of 50 lb/sq ft. while a Marquise has a wing loading of 65 lb/sq ft.

The MU-2B wing loading is 47 percent higher than the KA 90 and about 20 percent higher than the KA 200. It's starting to get close in the 300/350 series which are 45 lb/ sq ft and 48 lb/ sq ft respectively, which places then at the high end of the spectrum for turboprop wing loading. The wing loading of the Marquise is well above that of any of the King Air series (35 % higher than the 350)

It's not inaccurate to say that the wing loading is more typical of a jet. on the low end, the MU-2B has the same wing loading as the Beech Premier, and the Marquise has the same wing loading as the Lear 45.

I don't think that it's unreasonable to suggest that the wing loading may be a contributing factor in some of the loss of control accidents.
 
I would guess (don't know) that the wing loading of the Piaggio Avanti is probably greater than that of the MU-2. Comparing the MU-2 to the King Air 90 isn't really a fair comparison, but comparing it to a King Air 200 or larger might be. I mentioned wing loading because it's one of the arguements that many cry about when they scream bloody murder regarding the MU-2.

We can argue whether the something is a dangerous plane or poorly trained pilots, and I don't have a strong opinion one way or another. However, assuming the numbers are accurate, it's hard to argue that nothing is happening.

I don't think anybody is arguing that "nothing" is happening. However, the question does exist as to w(h)eather this is a pilot issue, or an airplane issue.

I don't know that the statistics with respect to /100,000 flight hours are particularly meaningful, especially in light of the fact that whereas considerable training regimes exist for comparative aircraft for the King Air (and are used heavily), the same availability does not exist, or more exactly, is often not used, for the MU-2. Accordingly, when we see numbers that indicate 16 our of 18 fatal accidents occured when flown by pilots with little or no training, including pilots who washed out of recognized training programs, the crux of the problem comes into light.

The fact that the FAA has reviewed the airplane on multiple occasions, and the best that anybody can come up with is a need for better pilot training, tells us something.

The aircraft is derided by emotional relatives, and the legislation and politics are wrought by...politicians. The FAA, even after convening multiple panels of pilots and experts to examine the airplane it's training, it's operation, it's maintenance, it's characteristics...can only come up with a need for better pilot training. That says something...coincidentally the same thing that the accident history of the airplane says.

Is the airplane demanding in a single pilot instrument environment with an emergency in progress? Certainly it can be, but does this mean it's a dangerous airplane, or just that pilots need to be better trained to handle it? I say the latter, and reiterate that a poor carpenter blames his tools every bit as much as poor pilots blame the airplane for their shortcomings.

Certainly mechanical failings can occur. One poster has cited a wing loss...but I've known other aircraft that lost wings, too. Recently we saw an Airbus lose it's vertical stab. Airliners have dropped engines, lost wing panels, lost pieces of the gear and decended in flames...these things happen. What we don't see are MU-2' raining down due to wing separations and other structural failures that are inherent to the design. We see problems with pilots not flying the airplane, flying it where they ought not. Flying it beyond it's design envelope, and so forth. Yes, mechanical failings do occur, but the majority of the accidents, and particularly the fatal ones, are not the result of a design failure...but a pilot failure.

If indeed the design fails three times as much, statistically speaking and in terms of crashes, accidents, incidents, and fatalities, on a comparative basis to other light or medium turboprops, what we have is a failure of pilots in the type design that's three times greater, or more, than other similiar or comparitive designs. No matter how it's sliced, it's a pilot issue that needs addressed.
 
CrimsonEclipse said:
25% of MU-2's have been involved in accidents. What % of B737's have
been in an accident?

Like I said:
Wing seperates from airplane. Pilot fails to compensate for loss of wing.
Pilot Error.

CE

Just sayin'
Do you think that it could have anything to do with the fact that because of the "reputation" of the airplane the price is cheap, allowing unexperienced pilots who should not be flying it, own one?
 
avbug said:
I would guess (don't know) that the wing loading of the Piaggio Avanti is probably greater than that of the MU-2.

And you'd be right. The Avanti is 67 lb/sq ft. THe Beech starship is also around in the 50's. I think the point should be taken thoughthat thes planes occupy the higher end of the scale, compared to the smaller King Airs, the Conquests, and the Cheyennes



avbug said:
I don't know that the statistics with respect to /100,000 flight hours are particularly meaningful, especially in light of the fact that whereas considerable training regimes exist for comparative aircraft for the King Air (and are used heavily), the same availability does not exist, or more exactly, is often not used, for the MU-2.

That's a good point, it would probably be accurate to say that more king air operators put thier pilots through more frequent simulator training than do MU-2 check haulers.



avbug said:
The aircraft is derided by emotional relatives, and the legislation and politics are wrought by...politicians.

well, we have to consider the source there. I posted the news snippet to stir the pot a little and get some discussion going, not because i agreed with the Senator.


avbug said:
No matter how it's sliced, it's a pilot issue that needs addressed.


So how do you address it? require all the check haulers to put thier pilots through simulator based training twice a year? It's good to say we need better training, but it's a lot more difficult to acheive better training, especially among shoestring operators who view training as something to be dispensed wth as cheaply and quickly as possible.
 
avbug said:
Assumption that the majority of the pilots are below average is a stretch.
I'd say probably half of them are below average.
 
I think Lead was pretty much right on with his description of the airframe idiosycrises of the MU-2. If I may expand on that a bit, lets look at the differences with the Garrett engine.
I have over 3,000 hours with a TPE in a King Air. And never had any problems with it. But, it will not windmill and sometimes not "feather" automaticaly like most turboprops. It has a fine system called NTS, or Negative Torque Sensing, which if rigged and operating correctly will help drive the prop to about 88% feather, certainly helping alleviate a lot of the drag. But, if it is not working, or not handled correctly, you are driving THE ENTIRE ENGINE. No free turbine here. And, as opposed to a lot of multi-training, where we are taught to "test" the dead engine by slowly pulling the power back to idle, that only tricks the NTS into thinking YOU WANT TO GO TO IDLE!!! So, the NTS will then bring the blades back to flat pitch. Just look at the radius of those big 4 blades (or 3 sometimes) and imagine all that wing area cut off from airflow, and you are dragging that entire engine also. Just try spinning the engine by hand sometimes, you get the idea. So, picture this, the left engine is in flat pitch, killing lift on that wing, and to try to raise the wing you use the yoke instead of rudder, now you have raised the spoiler on the right wing and killed lift there too. The correct drill in an engiine failure is to push the failed engine power up full, not retard. And rudder, then trim.
I think little things like this, plus the spoilers have caused more than a few accidents out there. Still a great plane/engine combo, just needs to be learned and respected a bit better than most.

Hung
 
But, it will not windmill

Oh, it does. Trust me on that. I found out the hard way. I also use the braking effect to good advantage during steep descents down terrain faces...but it definitely does windmill. NTS at idle during steep descents will pulse in and out as the system seeks to put a load back on the blades. The governor is attempting to move the blades to flat pitch, whereas NTS is trying to move it out of flat pitch and toward feather to put a load on the blades.

I'd say probably half of them are below average.

Hard to argue with logic. One out of every ten are probably also in the top ten percent...

And you'd be right. The Avanti is 67 lb/sq ft.

Which begs the question as to w(h)eather the wing loading is particularly relevant to the accident record of the MU-2. The Avanti has a high wing loading (I believe the wing area is the same, or roughly so, as the Cessna 182...you're a lot better at math...you might know)...clearly this of itself isn't the defining factor. But it's often cited in arguements agains the MU-2.
 
avbug said:
Why? The Beech 18 is an airplane just like any other airplane. If you have basic conventional gear skills and a head on your shoulders, it is operated just as safetly as any other airplane...and insurance treats it accordingly. Operating it is basic stick and rudder (and instrument) skill...not rocket science. It's just an airplane.

That's just it.....I haven't had the privilege of flying in an 18, but everything I've heard on the Beech 18 bulletin boards is that the airplane is a relatively easy to fly and fairly dependable. Many who have flown it liken the old twin beech to a mini-DC-3. However, in recent years, the insurance rates for said airplane have gone through the roof and many pilots with less than 2000 hours time are finding it very difficult to get insured. Some say it's because of the tailwheel, others claim it has more to do with the twin 450 hp engines and still others claim it is related to the track record of freight operators. Regardless of the reason, the bottom line is that a low time individual owner operator is going to have some trouble getting insurance for the bird even though most pilots who have flown them find them very safe, reliable aircraft.

That MU-2 pilots don't seem to have the same trouble getting insurance seems to me to lend credibility to exactly what you are saying, Avbug: that the reality of the situation is that the plane isn't as dangerous as some would claim. I don't have the experience to say either way, but I find the subject rather interesting.
 
Avbug:

I guess I was not clear on that. When I say "it will not windmill", what I was saying is it will not windmill like a PT-6. Not a free turbine type of free wheeling. Yes, it windmills, but as a very heavily loaded set of blades that are in very flat pitch and driving the entire engine.
Agreed that you can use that to very good purposes, like landing in a very, very short distance, or descend in ways that ATC can't believe. And,,, if properly adjusted, they should not pulse. But most are never adjusted that well.
But, if you are in a loaded situation with a bad engine, and allow it to go flat instead of towards feather,, well,, your just going from bad to worse.

Hung
 
Berkut said:
I'd say probably half of them are below average.


Well, no, half are below the median. It doesn't necessarily follow that half are below average.

Let's say you have 100 people. 99 are 4' 6" tall. the other guy is 7 ft tall. The average height is 4' 6.3". 99% of that group is below average height.
 
avbug said:
What a ridiculous way to cloud the issue. Nobody ever tried to correlate a wing failure with pilot error, nor incude a wing failure in the pilot error statistics. A wing which separates might be construed to be pilot error if it were the result of something the pilot might have found during a preflight, or if the pilot elected to fly through a thunderstorm. However, when we speak of pilot error and issues involving basic airmanship skills we're not speaking of wing separations.
Wow, someone takes themselves too seriously.
It's called SARCASM!

avbug said:
100% of the MU-2's could be involved in accidents...and this still wouldn't make it a dangerous airplane, seeing as the overwhelming majority of accidents and fatalities are the result of pilot error. This would make it a field of dangerous pilots...which not conincidentally is the leading causes of why the King Air crashes, too. Further, 100% of the MU-2's could be involved in fatal accidents and still not brush the fatalities caused from the wreckage of B737's.
Um, yes...it would.

avbug said:
Nobody argues that the B737 is dangerous, despite the number of fatalities. Yet the MU-2, frequently involved in fatalities when flown by untrained, inexperienced pilots with a common identifiable thread of deficiencies in background and experience, causes a sensation.
It's not the total, it's the number of accidents per flight hour, and it's
MUCH higher in the MU-2.

avbug said:
This web board was dominated for a time with the last spat of MU-2 fatalities, lorded over by wives and sisters of the deceased. Not experienced individuals who had a clue whence they spake, but by people who were presed by emotion and not knowledge or understanding. These same individuals were responsible for the lobbying that has lead the FAA to once more set it's political foot forward to "investigate" the airplane.
True, but doesn't change the facts.

avbug said:
Three separate panels of FAA investigators examining the airplane, it's history, it's accidents, it's everything, and putting 60 hours of flight testing on the airframe last year, and the official observation that "with reasonable training, an average pilot can operate the MU-2 safely if operated within the AFM guidlines." One might reasonably infer that either the MU-2's involved in accidents were being operated overwhelmingly by below average pilots, that average pilots had less than average training, or that average pilots (some better than others) failed to adhere to the AFM guildelines. Perhaps a combination thereof.
Of course, it's everythig BUT the airplane.

avbug said:
Assumption that the majority of the pilots are below average is a stretch. A given is that training by and large, particurly statistically among those involved in fatal accidents, is inadequate. That pilots have failed to adhere to AFM guidelines is also often borne out in accident investigations. Obviously far more flights are conducted successfully by pilots who are adhering to the aircraft manufacturer's guidelines than not, else we'd see a higher percentage of losses. Here we have everyman's airplane that really shouldn't be flown by every man...but legally can be until newly mandated training takes place.
The airplane requires MANDATED training but is not different from every
other airplane. Um, ok...:rolleyes:

avbug said:
As proper training and oversight is mandated, a decrease in the accident rate and record is inevitable; this is exactly what we shall see. Again, there's nothing wrong with the airplane; it's a poor carpenter that blames his tools.
Except my tools don't kill 10 at a time.

avbug said:
All things mechanical can fail. As pilots, much of our training is spent not learning to fly operating equipment, but to deal with the failures. And therein, so said Sir William, lies the rub.
Rub all you want, just look at the numbers.

CE
 
Waiting.......... for..................the................



"brightspark" comment that is sure to come.........
 
I hate to disappoint you, swass. Actually, that's not entirely true, but I'm going to disappoint you, and deal with the self-loathing, anyway. No sparks of brightness for you, today.

Agreed that you can use that to very good purposes, like landing in a very, very short distance, or descend in ways that ATC can't believe. And,,, if properly adjusted, they should not pulse. But most are never adjusted that well.

The Garrett may be set up in many ways, and all may be proper. The design of the airplane, and the maintenance documents attached to it, enable it be set up not only for a particular installation, but for a particular operator.

Ours were set up such that bringing the power levers to idle nearly tossed you out of your seat; the airplane could be pointed practically straight down and nearly stall out...that much braking action. When I first got in the airplane I had been in the same type with a PT6 engine on it, and out of habit pulled the power lever to idle during the landing. The airplane fell out of the air. During an hour and a half introduction to the airplane, I did a record number of go-arounds as I tried to find the sweet spot on that power lever.

In that condition, which is properly set up for that application, in a very steep dive down a canyon or hillside, the airplane will be felt very strongly to pulse as the NTS pushes the blade angle toward coarse. The flip side of it was found when I flew an airplane that hadn't been rigged quite right. The fuel control and the underspeed governor were discovered to fight each other if the speed control backed off the forward stop at 100%. We had to readjust the speed control bottom end (underspeed gov) to 98% instead of 96% because it was fighting the fuel control and causing massive engine surges. This wasn't learned until a throttle quadrant developed some play and the speed control backed off in flight. Power rolled right back to idle then surged up again, and kept doing it in increasing cycles.

It was a definite attention-getter.
 
A Squared said:
Well, no, half are below the median. It doesn't necessarily follow that half are below average.
Hence the "probably"
 
Nts

I agree with the previous post that flight idle fuel flows can be set up to Pulse or not to Pulse, it's really an operator preference. As far as whether the system is working properly, it's very easy to check during start up, if you don't verify that it's working, you get what you get, I've turned engines off at a safe altitude without the system working properly and there is tremendous yaw, not something you'd ever want to see just after takeoff.
 
The Cessna 208 Caravan deserves far more scrutiny than any MU-2. Mr. Tancredo should look at the abyssmal accident rate of that thing first. IMHO, no single engine should be allowed in commercial service at night, IMC or in icing.
 
no single engine should be allowed in commercial service at night, IMC or in icing.

That would take out a lot of airplanes currently flying everyday in those environments. The 208s alone, number several hundred.

CE-208
CE-210
CE-207
PA-32
PA-46
TBM-700
PC-12
others
 
I agree with the previous post that flight idle fuel flows can be set up to Pulse or not to Pulse, it's really an operator preference.

The pulsing on descent is actually the Negative Torque Sensing (NTS) system, which isn't a fuel adjustment. It's the governor driving the prop to coarse to apply positive torque, or a load, to the driveshaft.

The fluctuations that take place due to the speed adjustment interference occurs when the bottom end of the low speed governor is set close enough that when the power is pushed up (and the speed lever set back to lower RPM), the prop governor tells the fuel control to pull the power back, and then causes a reduction in fuel flow. The fuel control senses this as going underspeed and applies extra fuel, and the surge is interpreted by the governor as an overspeed and it takes away even more fuel. The engine begins to surge. The simple soloution is to set the bottom end of the propeller governing range up a little.

Personally I think it's a poor design that's capable of getting to that point as a function of normal positioning of the engine controls...but it is possible, even within a properly adjusted engine set according to the manufacturer.
 
Once again, I understand about the fuel flows and the pulsing. I know it can be set up either way, and having flown at least one that was not set up well,,, oh yeah, it grabs your attention. Especially if one is a "hard" low pitch and the other is not. Talk about yaw!
But (and I am the first to defer to Avbug on this, because I am no mechanic) I believe Garrett or Mitts came out with a S/B on setting either the fuel flows or blade angles recently to help counter that.
Still,,,, a well seasoned and qualified pilot who knows the systems will be able to counter any rigging/setting/flow problem.
Just my .002 with a fair amount of Garrett time.

Hung
 
Well, if we put into our OPSPECS, as not allowed, it obviously cannot happen.
Why was this not thought of before????

Hung
 
As far as insurance goes. I have a '56 C-172 and a '54 C-170. Same exact airplane except for the position of the gears. Double the insurance. Lots of accidents in a C-170. It can be slightly tricky on occasion, but really when it comes down to it you just gotta steer and not let up on it. Probably the same way for the MU-2 in laymans terms. Problem is old habits die hard with the hold 3 degrees of bank etc into the good engine, according to what most people say your probably gonna end up in the dust.
 

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