Cheyenne II vs. Commander 690B

[iflyabeech]

I have had my Cheyenne II at FL270 and it does great. Above that, RVSM realistically pretty much takes care of all of the older turboprops. Don't have to worry about the heater since I am in FL. You never have to mess with SAS system. Engine inlet heat works well. The dukes pressure controller sucks big time. Seats are normal sized and comfortable. Cabin is kind of small. I do not have a cargo door but door size is not a problem for pax. I have had passengers larger than any seat I have ever seen before.

 

[Lead Sled]

I would much rather fly with a good ol reliable PT6 than the garrett

FWIW, I've come real close a couple of times to having to shut down PT-6s in flight. I've never had any type of issue with the Garretts. I've got friends that have thousands of hours behind both engines and their my experience echos theirs as well. I think this whole thing about Garretts being troublesome goes back to the early days of the "pre-century" series engines; but that was what? 40 years ago?

'Sled

 

[jergar999]

Both engines are wonderfully reliable. With a PT-6 on the the MORE program, I believe you can go 8000 hours between major overhauls with a Hot Section Inspection at 4000 if you follow certain protocols and do oil analysis and some other odds and ends. The Garretts can go 5400 with a hot section at 2700.

I have flown both, and my first experience with the Garretts were -10s on a Metroliner with questionable maintenance. The operator was cheap on batteries and didn't have a battery cart or GPU, so it was common to see hot starts, and poor maintenance led to other problems with the SRL comp and fuel limiter. I now fly a Commander that gets new batteries every year and has major maintenance done at Eagle Creek, and I have yet to see an engine misbehave. The PT-6 has always been rock solid, the only thing I have ever had happen was a diaphragm in the P3 valve broke shortly before takeoff. I aborted the takeoff, and it was repaired. Overall, neither engine gives me pause.

 

[$$$4nothin]

Go with the Commander. They look so much cooler. STYLE counts.

 

[pilotyip]

How they look usually reflects how they fly. If they look sleek and fast they are normally neat to fly.

 

[rchcfi]

Thanks everyone for your opinions. I just returned from Flight Safety and have to say I am excited to get my hands on the real thing.

I do have a question for real world operations though. How many of you that have flown them did that Overspeed Governor check before taking the props off the locks? Seems to me as you would piss off about everyone within 5 miles with that test on the ramp. Is there a way to do it after taxiing away? I was told by some people that they never did it. I was wondering what other "real world" tricks you've used in general.

Thanks!

 

[pilotyip]

The overspeed gov't check is not like a mag check, it does not have to be done every flight. I can remember doing them, but I do not thing there was any set interval. Also I do not think you can taxi with props locked, they are in the zero thrust position.

 

[rchcfi]

Also I do not think you can taxi with props locked, they are in the zero thrust position.

After I posted that I realized I had answered my own question. Once you take the props off the locks, the only way to get them back on the locks is to shut the engines down. And you are correct sir, if you try to taxi with the props on the locks, you'll just be making a lot of noise.

 

[Lead Sled]

Also I do not think you can taxi with props locked, they are in the zero thrust position.

I didn't think you could do it either until I was sitting in the back of an old Horizon Metroliner on a flight out of Portland Oregon a few years ago. Everything seemed routine from where I was sitting, but I was half asleep and not paying much attention. Evidently we had been cleared for takeoff prior to getting to the end of the runway - the crew kept it rolling at a pretty good clip and brought up the power. The next thing I knew we were about 45 degrees to the runway centerline and heading for the weeds. The crew immediately aborted and taxied off the runway. As they were taxiing back to the approach end you heard them take the props into reverse three or four times. Evidently, they didn't catch it the first time around back on the ramp.

I would have thought that you could tell by the power required that something wasn't quite kosher. Someone once told me that you got something along the lines of 75 hp out the back of a -10. (The Metro's -11 is basically just a -10 with the inlet on top.) I would imagine that if you really wanted to, you could keep both props on the locks and run the power up. The equivilent of 150 hp ought to get something moving.

'Sled

 

[jergar999]

I didn't think you could do it either until I was sitting in the back of an old Horizon Metroliner on a flight out of Portland Oregon a few years ago. Everything seemed routine from where I was sitting, but I was half asleep and not paying much attention. Evidently we had been cleared for takeoff prior to getting to the end of the runway - the crew kept it rolling at a pretty good clip and brought up the power. The next thing I knew we were about 45 degrees to the runway centerline and heading for the weeds. The crew immediately aborted and taxied off the runway. As they were taxiing back to the approach end you heard them take the props into reverse three or four times. Evidently, they didn't catch it the first time around back on the ramp.

I would have thought that you could tell by the power required that something wasn't quite kosher. Someone once told me that you got something along the lines of 75 hp out the back of a -10. (The Metro's -11 is basically just a -10 with the inlet on top.) I would imagine that if you really wanted to, you could keep both props on the locks and run the power up. The equivilent of 150 hp ought to get something moving.

'Sled

I have a similar story, my first ride in a Metro I thought for sure would be my last. NWS was an afterthought so a nasty old joystick-like tiller had been added above the armrest on the left side. It was bitter cold, the taxiway and runway were sheets of ice, and to make it a trifecta the pilot had very few hours in Metros, one orientation flight and one 135 check/type ride. He hadn't finished IOE or anything, but this was a 91 maintenance leg. To make a long story short, he taxied the thing all over the short taxiway, made some checks, lined up, and the next thing I knew we were sideways at a high rate of speed. I remember thinking that had there been a single dry spot on the runway and had we found it with the wheels it would have been disastrous.

 

[some_dude]

You can taxi with one of them on the locks, though! Not fun when you go to takeoff, although if you are awake you will figure it out very early in the takeoff run, and you can just pull both back into reverse for a second and then push it up and go. At least that's what I've heard ;-)

As for the overspeed governor check, I believe on the 690 it's an every ten hour check. Of course, I always assume someone else did it, so I never do it except on maintenance flights.

On the other hand, I ALWAYS do the NTS check and the NTS valve check, even though they are technically first flight of the day. If the NTS system is not working, it could ruin your whole day.

Incidentally, I want to defend the nosewheel steering on the Turbo Commanders. True, it isn't the way I would have designed it, but once you know how to use it, it really works well and is quite reliable. And it is nice not having the steering connected to the rudder. It's difficult to learn, but before long it becomes second nature and really no big deal.

After I posted that I realized I had answered my own question. Once you take the props off the locks, the only way to get them back on the locks is to shut the engines down. And you are correct sir, if you try to taxi with the props on the locks, you'll just be making a lot of noise.

 

[Say Again Over]

The Overspeed Governor check is done at maintenance intervals, like Some Dude mentioned, the NTS check is easily accomplished before each flight (not like the SAS test), and from what I remember, the Cheyenne has terrible steering.