Twin Commander

General Category => Engines => Turbine Commander Engines => Topic started by: donv on December 13, 2019, 05:27:26 pm

Title: 7000 TBO
Post by: donv on December 13, 2019, 05:27:26 pm
If I get my -10s overhauled now, will I have a 7000 hour TBO?

Alternatively, if I get an (admittedly expensive) hot section, can I extend my engines to a 7000 hour TBO?

I'm going to ask my service center about this as well but interested to hear what fellow members have to say.
Title: Re: 7000 TBO
Post by: SKYFLYER on December 13, 2019, 06:50:42 pm
Judging by the Honeywell document below you would have to be a "commercial" operator to get the 7000hr TBO... But as with all things I seem to recall there being a way to extend the -10 to the magical 7000hr TBO.

I am not sure if it was a commercial operated aircraft sold to an individual and continued on with the maintenance intervals as shown in the logs, but there is a valid way to extend to 7000.

https://aerospace.honeywell.com/content/dam/aero/en-us/documents/learn/products/engines/infographics/A40-1868-000-001-TPE331TurbopropEngine-ig.pdf?download=true
Title: Re: 7000 TBO
Post by: donv on December 13, 2019, 08:40:20 pm
Interesting! I can put the airplane on a 135 certificate easily, if that is what it takes.

I've actually thought about doing a bit of charter before, but my main concern is that my interior wouldn't hold up to it for long.
Title: Re: 7000 TBO
Post by: Adam Frisch on December 14, 2019, 02:38:23 am
Steve B used to have his on 7000hrs and a program, I think, but dropped down to 5000hrs. The TPE programs are not very cost effective.
Title: Re: 7000 TBO
Post by: Steve binnette on December 14, 2019, 08:30:07 am
I used propulsion international, when I overhauled my engines.  They were done at EAM.

I did the price guarantee overhaul. Which gave some protection in the event there was something crazy expensive during overhaul.

That program required me pay an hourly.after overhaul. There were multiple plans.  I choose the cheapest.  My total cost for both engines was around $85/hr.

I had my engines overhauled to the 7000hr specs and got a letter from FAA allowing the extension as long as I stayed on the plan.

My engine log says 7000hr overhaul, but the FAA letter says I needed to stay in the program?

The benefit was I got a guaranteed  not to exceed price for my overhauls and I was in the program for the first 350hrs.  I think the likelyhood of something going wrong is right after the overhaul, so I liked that coverage.

Ultimately I dropped out of the program as soon as I was able. The numbers just did not work for me and my 125hr a year flying schedule.  If you fear having a unexpected engine problem then the program might work.  The thought of using this program as a way to save money for the next overhaul did not really pencil out for me.  The plan I was on did not completely cover the cost of an overhaul, you needed to bump up to a more expensive plan.

I don’t feel the value of the airplane will be impacted that much by being on the program.  Depending on how close to overhaul you are.  My engines were zeroed out.  It will take many years before the program adds value to my plane.

Here is a old article by Chad Ahrens he owns propulsion International and is a nice guy.  It is a sales pitch but has some good info.

https://www.flightlevelsonline.com/issues/summer12/article/pi-engine-maint.html

Here is a link to his website, give him a call and run some numbers.

https://propulsioninternational.com/tpe331-commercial-fleet/


Title: Re: 7000 TBO
Post by: donv on December 14, 2019, 12:23:02 pm
I thought I had heard that he was no longer taking new enrollments?

The bigger question is whether your engines are still 7000 hour engines, or did they revert back to 5000 hour engines?

Personally, I'm unlikely to fly 5000 hours in the time I own the airplane, or even 2500 (although I suppose there is some possibility of that). The value of the longer TBO would be purely resale value of the airplane. Also, if I'm doing an overhaul anyway and could get that feature without much additional cost, it seems like it would be smart to go for it.

If there were a way to upgrade my engines during hot section, that would be a real benefit to me. My engines will be due for hot sections in about 200 hours, and if I do the hot section, they will only have about 700 hours to go until overhaul. But if they were 7000 hour engines, they would have 2300 hours, which is a big difference.

So even if I had to spend some extra money at hot section, but short of an overhaul, that would seem worthwhile.

I'm going to talk to Aero Air about it and have them do some research-- in the end, that's the definitive answer, but it's useful to know if it's even a possibility.
Title: Re: 7000 TBO
Post by: Steve binnette on December 14, 2019, 02:26:09 pm
I think it is up to the shop doing the 150hr inspection.  If the engine log is good enough then they sign you off.

For a buyer from outside the states my engine would likely be considered a 7000hr engine without question.

Who knows!!
Title: Re: 7000 TBO
Post by: Bruce Byerly on December 17, 2019, 12:44:03 pm
If the logs say 7,000 hours, who’s to say they are or aren’t? If it is on a 135 and then it comes off, does it revert?  Where is that process outlined? Are overhauls mandatory for part 91? Are they prudent on 30 or 40+ year old engines? Lots of gray area and questions to which answers and opinions vary.  YMMV as they say.

 I brought in a 1000 a few years ago. The logs said they were configured for the 7,000 hour TBO period. I asked the question, the chief inspector gave me that look. Like a gift horse.

But the trouble now is that fully complying with the latest SB for that TBO option can approach an overhaul so it may not be worth it given the long TBO and extra costs associated with compliance plus the technical side of the commercial operator provisions the Mfg outlines.
Title: Re: 7000 TBO
Post by: donv on December 17, 2019, 12:51:44 pm

But the trouble now is that fully complying with the latest SB for that TBO option can approach an overhaul so it may not be worth it given the long TBO and extra costs associated with compliance plus the technical side of the commercial operator provisions the Mfg outlines.

Right, but if I'm overhauling anyway, wouldn't it make sense to try to get the extra time, really for resale value only?

In my unique case, it might be worth it to try for it during my next hot section, if that's even possible. My problem is that after hot section, my engines will only have about 700 hours until the 5400 hour overhaul time. If they were 7000 hour engines, that would be a major change in the picture.
Title: Re: 7000 TBO
Post by: SKYFLYER on December 17, 2019, 12:59:24 pm
I just got this from Honeywell marketing. A couple areas clearly saying 7000hr TBO's

https://aerospace.honeywell.com/en/learn/about-us/blogs/2019/07/four-ways-our-tpe331-engine-elevates-performance?utm_source=email&utm_medium=email&utm_campaign=19_godirect&utm_content=direct-to-newsletter&mkt_tok=eyJpIjoiTkdWbVlqTXpNVFV4WXpabCIsInQiOiJEOFIwNTJcL25DWE53eEFOalwvV2NSaUVwQWhyVDhcL2x4YStuR20xb2l0MVwvRkEyODYwdCtWblphV3F0M1lcL0lYRVNWYXFKbWZ0dENlR0lIUDJVYU9HNXhTSnE0R0hWbTZnaUFzb0VqNDVPMHNJMmMwNENBT1plNVNGTEEzY1wvek9JVSJ9
Title: Re: 7000 TBO
Post by: Bruce Byerly on December 18, 2019, 10:50:54 am

But the trouble now is that fully complying with the latest SB for that TBO option can approach an overhaul so it may not be worth it given the long TBO and extra costs associated with compliance plus the technical side of the commercial operator provisions the Mfg outlines.

Right, but if I'm overhauling anyway, wouldn't it make sense to try to get the extra time, really for resale value only?

In my unique case, it might be worth it to try for it during my next hot section, if that's even possible. My problem is that after hot section, my engines will only have about 700 hours until the 5400 hour overhaul time. If they were 7000 hour engines, that would be a major change in the picture.

Maybe, but if it cost an extra $200,000 to get there, does it make sense then?

Don, in your case, I suggest complying with everything that would be required to run 1800 hours and add the new combustors, tighten up the compressors, and enjoy your 310 knot 980 until the next hot is required.  ;D
Title: Re: 7000 TBO
Post by: donv on December 18, 2019, 06:46:21 pm
So you would skip the overhaul, Bruce?
Title: Re: 7000 TBO
Post by: Adam Frisch on December 19, 2019, 12:35:18 am
Do they really do 310kts? Is that for the 1000-model? Seems to be 295-300kts in the 980 whenever I've taken a ride in Steve's.
Title: Re: 7000 TBO
Post by: donv on December 19, 2019, 12:40:46 am
Honestly, 300-305 is about as fast as I see. Not because it won't go faster but because I don't like to run it over the barber pole. Or even right on the barber pole-- I prefer to have a couple of knots of cushion.

Do they really do 310kts? Is that for the 1000-model? Seems to be 295-300kts in the 980 whenever I've taken a ride in Steve's.
Title: Re: 7000 TBO
Post by: donv on December 19, 2019, 02:42:29 pm
I should add that, generally, a 980 will be a little bit faster than a 1000 under the same conditions, because a 980 weighs less yet still has the same power, wing, etc. However, the 1000 has a higher MMO and so where the 980 might be limited by the barber pole at cruise, the 1000 will not.
Title: Re: 7000 TBO
Post by: Bruce Byerly on December 21, 2019, 12:25:40 am
So you would skip the overhaul, Bruce?

Don,

I would never say skipping recommended overhaul intervals on any component “just because you can” is the right thing to do but, depending on the engines, I think it may be a real option. Given the value of the planes and our stage in the life cycle, it may be an attractive option if the engines are solid late model, regularly flown high SB status engines. If, for example, the engines are 40 years old and have never been overhauled.   then I’m guessing those engines are due.

I looked at a plane this week with props 19 years since overhaul. Legal? Yes. Smart, no. IMHO.
Title: Re: 7000 TBO
Post by: donv on December 21, 2019, 10:59:53 pm
Well, my engines are 40 years old and have never been overhauled!
Title: Re: 7000 TBO
Post by: Bruce Byerly on December 23, 2019, 03:27:28 pm
Well, my engines are 40 years old and have never been overhauled!

At least they are “the devil you know”  :P

Pretty good testament to the engines I suppose.  Just saw a $400k hot section on a 1300 hour TBM.  Gotta love those 331’s!
Title: Re: 7000 TBO
Post by: donv on December 23, 2019, 03:31:18 pm
$400k hot section? Ouch! I'll have to remember that if I ever get tempted by a TBM or PC12!

In my case, I think it's a testament to having been flown consistently 100-150 hours per year, every year, and never having been maintained anywhere other than a service center since new.
Title: Re: 7000 TBO
Post by: SKYFLYER on December 23, 2019, 04:34:14 pm
400K... I hope it was still under warranty
Title: Re: 7000 TBO
Post by: donv on January 09, 2020, 12:16:24 am
Now I'm also seeing a couple of -5 Commanders advertised with 6000 hour TBO and 3000 hour hot section interval. What's the deal with that one?
Title: Re: 7000 TBO
Post by: donv on November 14, 2020, 03:38:30 pm
I've seen the service letter, and the gotcha appears to be that they want you to fly 800 hours per year, or do the overhaul within 9 years-- which is basically the same thing.

It's really aimed at airline customers. I thought those guys were on condition in the first place, but maybe not.