Cloud Nine's New Plane

Ted DuPuis said:
I also just realized that, using the fun panoramic photo feature of the iPhone, I could actually start off with one engine shut down, do a restart and shut down the other engine, and do a photo that looks like both engines are feathered.

(no, I'm not actually going to do that)
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Chicken. :)

LOL.
 
Just a guess, but the pilot door STC might induce significant sticker shock. I imagine cutting into the pressure vessel would not be cheap. Is it worth two extra crates?
 
Ryanb said:
Nice landing Ted!
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Thanks! I'm getting the hang of it and getting to where the mains are touching down more smoothly. As you probably noticed, as soon as the mains touched down, the nose comes down fast. The plane has a very forward CG. Part of this is because one of the two 85 lb batteries is located in the nose. There's an aft battery conversion which I intend on doing. That helps landings (and CG issues) quite a bit.

Although the plane's max gross is 9920 lbs, if you're at the forward CG limit it goes down to 9149 lbs. Now realistically, you have to try really hard to get to the forward CG limit. The only way I've found to do it is to put two 300 lb pilots in up front. For the normal

Greg Bockelman said:
Just a guess, but the pilot door STC might induce significant sticker shock. I imagine cutting into the pressure vessel would not be cheap. Is it worth two extra crates?
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That's why I said I would look into it. I also expect it would likely cost a great deal, plus it creates another source of pressurization leaks. If it's what I think it will cost, then it's a no way. But it's worth a few phone calls.
 
Nice one Ted!

The Commander and yours with the -1's are very similar in that regard - they kinda lose poop around FL200. These are ideally 16000-FL230 kind of planes, although as you said they can be nursed up higher in ideal conditions. The MU-2 has better cabin diff, so is better suited for comfort up high.

I seem to burn around 60-62gal/hr at 17500ft doing about 240-245kts, which is about 10kts slower than you at same altitude. As would be expected, the smaller wing has less drag. I've not gone higher than that yet, but I expect to see the fuel drop to about 58gal/hr up there. As for economy, that's on par per mile in cost with just about any higher end piston twin.
 
stratobee said:
Nice one Ted!

The Commander and yours with the -1's are very similar in that regard - they kinda lose poop around FL200. These are ideally 16000-FL230 kind of planes, although as you said they can be nursed up higher in ideal conditions. The MU-2 has better cabin diff, so is better suited for comfort up high.

I seem to burn around 60-62gal/hr at 17500ft doing about 240-245kts, which is about 10kts slower than you at same altitude. As would be expected, the smaller wing has less drag. I've not gone higher than that yet, but I expect to see the fuel drop to about 58gal/hr up there. As for economy, that's on par per mile in cost with just about any higher end piston twin.
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I think the MU-2 also has a smaller cabin than the Commander and thus less associated drag. The smaller wing has less drag, but that also hurts the altitude performance as you get higher. I'd be curious as to what you find your performance to be once you get above FL200. Weight especially makes a difference here, as does OAT. Going west with the dogs, FL200 was really the optimal altitude. We ended up at FL220 on the first leg (filed FL240) but it just ran out of steam up there with that temperature and weight. Coming home with just fuel and the two of us, FL230 worked.

One thing I do wonder about is how the MT props would make a difference in my situation. People have mostly said that they aren't seeing a performance improvement with the 5-bladed props on MU-2s, but in my operations (long trips) it makes sense to go up high. Higher altitudes are where the MT's blade design really shines. I doubt we can justify it, it's more of a thought experiment.
 
Does this mean my $100 donation for the 414 overhaul will get automatically forwarded to the HSI fund??? :)
 
The props are $100K... Frankly, doesn't make sense on -1 plane, mainly for the -10's. But the guys who have done it on the Commanders love it. Say the vibrations are much less, better climb, much more quiet. But no real speed gain.

I couldn't get higher because my left power lever travel was hitting against the stop, even though it was not temped out yet. We've turned the top fuel up a little since then on the fuel controllers to change this, but not had a chance to test it yet. But from what I saw, from around 17000ft the climb rate drops down to around 500ft/min or so (this was a hot day), so to get to FL250 would need some patience and a cold day...

Is your ceiling FL280?
 
Velocity173 said:
Does this mean my $100 donation for the 414 overhaul will get automatically forwarded to the HSI fund??? :)
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Yes! In fact, we renamed the engine fund campaign accordingly. :)

stratobee said:
The props are $100K... Frankly, doesn't make sense on -1 plane, mainly for the -10's. But the guys who have done it on the Commanders love it. Say the vibrations are much less, better climb, much more quiet. But no real speed gain.

I couldn't get higher because my left power lever travel was hitting against the stop, even though it was not temped out yet. We've turned the top fuel up a little since then on the fuel controllers to change this, but not had a chance to test it yet. But from what I saw, from around 17000ft the climb rate drops down to around 500ft/min or so (this was a hot day), so to get to FL250 would need some patience and a cold day...

Is your ceiling FL280?
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What I've observed with the MTs on the 414 is that the climb is a lot better and the cruise is better at altitude, with it becoming more obvious as the air gets thinner and even a few extra kts indicated make a more noticeable difference on true airspeed or more noticeable climb improvement. So really, as the performance of the engines gets weaker, that's where the MTs seem to shine. To that end, I think the -1s might benefit from it, but who knows. One person I know who flies a Cheyenne 400LS said the MT props made a big difference in RVSM world. Although the ceiling of the plane was always FL410, those upper altitudes actually became usable with the props.

Like I said, for now it's a thought experiment anyway. With the 414 the justification was pretty clear. With this plane, not so much. At least not at this point.

The ceiling on this one is FL250.
 
I dropped the plane off for the HSI on the right engine on Saturday. I was impressed with the shop (Arkansas Turbine). They're supposed to get started on it this week and hopefully have it completed in time for the Mitsubishi convention next month (April 18-20). Saturday was my first flight in the plane without another pilot right seat (well, I brought my 5 year old along). I feel comfortable in the plane, but I also don't wear it like a suit. That'll come with experience. Most notably, even at flight idle the plane doesn't slow down quite as much as I'm used to (the 414 with 4-bladed props really would come down like a brick) so it's just getting used to the plane.

I'm enjoy the performance and economy of the plane. I took off from my airport with 156 gallons of fuel in, which is pretty light - max is 366 - and the two of us. Time to climb when you remove the step was about 13 minutes to FL190. Once there we were truing out at 270 on 68 GPH combined. Basically similar MPG as a Cheyenne at that point. If I'd realized how quickly we'd get to altitude I probably would've filed for FL210.

At this point my plans for the plane to optimize it are pretty well figured out, basically get rid of as much weight as I can plus remove some unnecessary antennas. I expect that'll help with the FL230-250 performance, where the engines run out of steam.
 
68GPH combined for a twin turbine is quite impressive!
 
Ryanb said:
68GPH combined for a twin turbine is quite impressive!
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Going down to Houston it was down to 56 GPH for 250-255 KTAS. I think I can do better.

The biggest thing about the fuel burn is how quickly it decreases after takeoff. You start off at around 110 GPH combined on takeoff, but it's down to 80 or so by 10k feet (roughly 5 minutes after takeoff) and 68 GPH by FL190. Basically 75 GPH for the first hour and then whatever your cruise burn is after that.
 
The plane has been at the shop for its hot section for 2.5 weeks now. I talked to the shop on Monday and they had the engine off and completely disassembled. I don't have photos yet, but here are the big notes:

- 3 of the 8 EGT probes were burned away
- Combustor is cracked
- Stage 2 turbine wheel is in bad enough shape that they didn't bother trying to send it out for repair
- Stages 2 and 3 stators are pretty bad as well

This engine has about 4200 hours on it total and has a bit of an odd history that I haven't been able to fully put together. It was bought as a used engine that was put on the plane about 6 years and ~300-400 hours ago. The man who owned it 3 owners ago owned the plane for about 30 years. Then when the next person bought it, the right engine (which was timed out) was replaced with this engine (which was less timed out). Because of that, I have no idea how well it was run or taken care of, and it could've been run hot quite a bit causing the damage.

Still, at this point not necessarily too horrible. I think they said they had a combustor that could be used in-house and were looking for the other parts that didn't appear to be serviceable.

The shop said that with the 3 EGT probes burned away, they think the engine was likely reading a lot lower on EGT than it was actually doing. Given how closely matched the left and right engines were, that may be true, but I think it wasn't reading that far off. I think more likely is that the pilots in the past just ran that engine pretty hard over its life, at least for some period. As I've always said, limits are not goals. That applies to turbines as well. I know that the pilot who flew the plane for the ~30 years that it was owned by one individual flew it at 520C EGT (that's what he told me, anyway, and I believe him) without issue, so that gives good backing to running it conservatively.

I have flights that are commonly in the 1,000-1,350 nm range. While I didn't go into the MU-2 expecting to necessarily be able to fly those legs non-stop (at least not all of them) it seems as though that may be doable. One person I talked to on the MU-2 forum said that when he ferried F-models to New Zealand, they were able to routinely get 1500 nm legs in no-wind or tailwind conditions by doing step-climbs as appropriate. I also have some drag reduction that I think will help for those higher altitudes. So we'll see.

The plane has an odd W&B. It has 2 batteries, and originally the main battery was in the tail. As part of the "extended baggage mod" it was moved to the nose, which completely screwed up the W&B and made it too far forward. To help alleviate this, a 30 lb ballast was added in the tail of the plane. I hate having unnecessary weight. So, I'm probably going to look into removing that along with other unnecessary items from the aircraft for weight and drag reduction at its next inspection, which is due this summer. I have to decide which shop to use for that, haven't yet.
 
I hope the costs are in line with your expectations and you're back in the air soon. :cool:
 
Get the go fund me going! Sounds like some $$$. :(

520C sounds conservative but no idea the limits on an MU2. All the helos I’ve flown have a continuous TGT/MGT of well over 700C and we run them there a lot.
 
Velocity173 said:
Get the go fund me going! Sounds like some $$$. :(

520C sounds conservative but no idea the limits on an MU2. All the helos I’ve flown have a continuous TGT/MGT of well over 700C and we run them there a lot.
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If I’m remembering my Garrett training correctly the probes are in the back of the engine where temps are cooler. I’m sure Ted will be along to correct me if my memory is bad.
 
Tarheelpilot said:
Sounds like someone was not nice to that engine.
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I'm thinking you're correct. Like I said, I don't know much about the history of it.

3393RP said:
I hope the costs are in line with your expectations and you're back in the air soon. :cool:
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Thanks! We'll see where it ends up. I'm confident the shop will do what they can to keep the cost to a minimum for us. They know that we're a non-profit and like what we do. We'll see.

Velocity173 said:
Get the go fund me going! Sounds like some $$$. :(
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Actually, we have a crowdfunding going right now that anyone can donate to! See below:

https://poundwishes.com/donate/2473881/engine-overhaul

I haven't been pushing it as much as I should be on our Facebook page. But the general expected range is $50-90k. Yeah, that's quite a range. Fortunately we have the money from the sale of the 414, but we have other expenses looming including insurance (renewal just came back with a $5k premium - honestly I'm pretty happy with that), the first 100/200 hour inspections this summer, required ADS-B upgrades, and then I also have some optimization work to do to the plane that will cost money but pay dividends in terms of better efficiency. If I can get the plane to where it'll do non-stop legs then that saves on cycle count and ultimately reduces costs. So, we'll see.

Velocity173 said:
520C sounds conservative but no idea the limits on an MU2. All the helos I’ve flown have a continuous TGT/MGT of well over 700C and we run them there a lot.
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Tarheelpilot said:
If I’m remembering my Garrett training correctly the probes are in the back of the engine where temps are cooler. I’m sure Ted will be along to correct me if my memory is bad.
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Tarheel is correct for this engine, which is a -1. Really, you can't compare the numbers as equivalents because different sensor types and different locations are used, plus different materials. The TPE-331-1 (which is what's on the MU-2) uses 8 EGT probes that are located a couple inches behind the stage 3 turbine wheel. -5s and I think -6s use ITT probes which are located between the stage 1 and 2 turbine wheels, as I recall. That redline is something around 700C or so I want to say.

Because EGT is used instead of ITT, the temps are cooler. ITT is really the limiting temperature. However, the temperature limit is also variable dependent on which phase of flight you're in and the OAT, essentially how much secondary (non-combustion) airflow mixes with the combustion air to cool it by the time it gets to the EGT probes. So, using a constant number can result in you running over temp depending on OAT and the particulars of your phase of flight, and if you simply run up to the redline you're almost certainly going to be overtemp during some portion. So, who knows. These older engines didn't have any protections built-in to them so it's easy for someone to overtemp/overtorque if they're not careful.

Running conservatively will yield you better MPG which for us matters since we run long legs that I'm hoping to be able to do non-stop. But running at higher altitudes is also part of how we get that efficiency, so I will need to experiment to determine what the best combination of altitude/temp/airspeed etc. will provide what we're looking for.
 
Yesterday I picked up the MU-2 from the hot section. Ultimately there was more wrong than expected, but thanks to Arkansas Turbine doing a great job of finding good used parts and sponsoring Cloud Nine, the bill was still quite reasonable for the work done.

In the end, all 3 stators and the stage 1 and 2 wheels had to get replaced, as well as the combustor, EGT harness, and a few other parts. The EGT harness on the plane was bad and was reading lower than actual. This probably explained part of the good performance that this had for an F model with -1s. He also found a couple of issues with the left side EGT harness, but not quite as bad.

I got to see and take home some of the old parts. The stators especially were very noticeably bad, with a lot of obvious erosion just from the heat blast. The turbine wheels themselves didn't look as bad, but there are some holes that developed cracks beyond the serviceable limit, plus a cracked blade or two (which is not allowable). The leading edges of the blades also had erosion that may or may not have been serviceable. Ultimately once one item gets beyond limits, the part is scrapped.

There is a noticeable improvement in the right engine performance. More torque at less fuel flow. I only did the test flight home, so I haven't been able to evaluate total performance, but it definitely seems to be more efficient than previously. I did a few points to try to determine optimal efficiency (this was at FL200, so not very high), and doing 241 KTAS @ 56 GPH seemed to be the most efficient at that altitude, at 4.3 NMPG. The efficiency should actually get better as I go up to higher altitudes, and we also departed with full fuel because it was going to be cheaper than back home and thus there was more weight.

Tomorrow I'm going down to Florida for the MU-2 convention and will get to play with it some more. I imagine I'll file for FL230 or 250 and see how it does up there.

Part of the return to service for any TPE-331 aircraft that has had an engine removal is an "NTS test flight" to make sure the NTS system is working correctly. So you have to do an in-flight shutdown and restart. I posted a video if that that my friend and co-pilot took. You can see the video on the Cloud Nine Facebook page:

https://www.facebook.com/cloudninerescueflights/

I'm very, very happy with the end result and can't wait to get back to saving pups with it!
 
Ted DuPuis said:
Yesterday I picked up the MU-2 from the hot section. Ultimately there was more wrong than expected, but thanks to Arkansas Turbine doing a great job of finding good used parts and sponsoring Cloud Nine, the bill was still quite reasonable for the work done.

In the end, all 3 stators and the stage 1 and 2 wheels had to get replaced, as well as the combustor, EGT harness, and a few other parts. The EGT harness on the plane was bad and was reading lower than actual. This probably explained part of the good performance that this had for an F model with -1s. He also found a couple of issues with the left side EGT harness, but not quite as bad.

I got to see and take home some of the old parts. The stators especially were very noticeably bad, with a lot of obvious erosion just from the heat blast. The turbine wheels themselves didn't look as bad, but there are some holes that developed cracks beyond the serviceable limit, plus a cracked blade or two (which is not allowable). The leading edges of the blades also had erosion that may or may not have been serviceable. Ultimately once one item gets beyond limits, the part is scrapped.

There is a noticeable improvement in the right engine performance. More torque at less fuel flow. I only did the test flight home, so I haven't been able to evaluate total performance, but it definitely seems to be more efficient than previously. I did a few points to try to determine optimal efficiency (this was at FL200, so not very high), and doing 241 KTAS @ 56 GPH seemed to be the most efficient at that altitude, at 4.3 NMPG. The efficiency should actually get better as I go up to higher altitudes, and we also departed with full fuel because it was going to be cheaper than back home and thus there was more weight.

Tomorrow I'm going down to Florida for the MU-2 convention and will get to play with it some more. I imagine I'll file for FL230 or 250 and see how it does up there.

Part of the return to service for any TPE-331 aircraft that has had an engine removal is an "NTS test flight" to make sure the NTS system is working correctly. So you have to do an in-flight shutdown and restart. I posted a video if that that my friend and co-pilot took. You can see the video on the Cloud Nine Facebook page:

https://www.facebook.com/cloudninerescueflights/

I'm very, very happy with the end result and can't wait to get back to saving pups with it!
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Ted, where is the MU-2 convention?
 
Kritchlow said:
Thanks.... I may take a visit. Not much to do over the next few days.
Is it just tomorrow or a couple days?
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People are arriving tomorrow, I plan to be landing around 5 PM. It goes through Friday, most people will be leaving Friday evening.

I'm not sure how much time at the airport people will be doing. The schedule is all at the hotel (Hilton Sandestin) without going to the airport. If you want to see me landing, you can follow on FlightAware (N228WP) or I can PM you my phone number.
 
Ted DuPuis said:
People are arriving tomorrow, I plan to be landing around 5 PM. It goes through Friday, most people will be leaving Friday evening.

I'm not sure how much time at the airport people will be doing. The schedule is all at the hotel (Hilton Sandestin) without going to the airport. If you want to see me landing, you can follow on FlightAware (N228WP) or I can PM you my phone number.
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I may be there. Always looking for a reason to take the Vette out for a stretch. That said, household management may have a different plan for me....
 
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Ted DuPuis said:
Destin FL. If anyone's going to be around (@N747JB ?), let me know.
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I am driving down to Destin tomorrow and back on Thursday. I traded pontoon boats, so I am swapping them Thursday morning. Do you need a car while your in town? I’ve got an F-150 at the airport you are welcome to use! Message me for the door code, keys are in it at the south FBO parking lot!
 
N747JB said:
I am driving down to Destin tomorrow and back on Thursday. I traded pontoon boats, so I am swapping them Thursday morning. Do you need a car while your in town? I’ve got an F-150 at the airport you are welcome to use! Message me for the door code, keys are in it at the south FBO parking lot!
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Or just post the code here - what could possibly go wrong with that? :D
 
Many thanks for letting me borrow your truck, John! Hope to get to meet you this evening. :)
 
Video one Facebook was cool...more we want more, we really like it, we want more
 
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Last week I flew the MU-2 to Florida for the convention and then back home. Heading down I went at FL250 and heading home at FL240. In both cases I was running the engines conservatively, but still saw 250 KTAS at 52-53 GPH. I'm really happy with the performance and economy I'm getting out of the plane, and I also know there's room for improvement. If I can get up to 260 on that same fuel burn, then I'll be ecstatic. I think it's doable - it basically comes down to needing to get another 6 KIAS at those altitudes. That's not insignificant, but I think I can get enough drag out to make that a reality. I'm also considering trying to work a deal on MT props, which helped on the 414 a great deal.
 
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