Lancair Live!

J.C. Peterson wrote: ↑Fri Oct 20, 2023 4:02 pm

I am far from an aerodynamicist, but my observations are the MT blades nearly always have a substantially thicker airfoil profile. In comparison, the 5 blade composite Hartzell on Evos and Epics is actually thinner than the metal alternative. Those composite props are also the most efficient props in every metric tested. It’s a very generalized summary, but thinner airfoil designs seem to be better.

All the MT props I have looked at are essentially wood props with a protective layer or glass. Technically still 'composite' but not the same as carbon on a foam core. The wood core construction methods limits your options in terms of airfoil type and thickness. Thinner isn't always better, but it certainly opens up many more design options that can be exploited

It’s been doing this for awhile. It was getting better as it is a long story. But it’s back down to 1qt per 1.5 hours of flight. Been using AVblend. I am going to stop using it and go back to no additives.


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I’m about a quart per 4-5 hours. It seems to blow out anything over 4 indicated, which is actually 5 in the sump (I measured), with much of that quart seemingly blown on the belly,, which is annoying. If you read the COPA list, they have the same issue. I’d like to find a way to stop blowing oil on the belly.

Dan O'Brien wrote:I’m about a quart per 4-5 hours. It seems to blow out anything over 4 indicated, which is actually 5 in the sump (I measured), with much of that quart seemingly blown on the belly.

I keep 6 on the dipstick and add at 5. I have some belly misting, but it isn't too bad. Anything over 6 goes right to the belly in mine. Engine is IO-550N.

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I sold my Mooney Rocket in 2018, after my Lancair IVPT was completely finished, with new paint and interior and I wasn't flying it anymore. The guy that bought it had an unfortunate "Gear Up" landing the day he took delivery, in Denver, CO. I recommended he replace the prop with an MT, since the Rocket conversion is essentially the engine/prop combination found in a C414, the Continental TSIO520NB with a McCauley Full feathering 3 blade prop. The extra engine size and larger prop made that Rocket Conversion very nose heavy, enough that dual batteries are mounted as far aft as possible in the tail cone, and lead weights were added just in front of the rudder.

He installed the MT 4 blade prop (very sexy) and after my unfortunate demise of my IVPT on Xmas day, 2021, I begged him to sell me my Rocket back as an interim plane to fly during my IVPT rebuild (my only chance to get me wife flying again after our exciting Xmas day adventure; put her back in a plane she flew over 17 years with me in and feels like an old shoe). Anyway, my first notice is the MT paint issue, which THEY PROMISED WAS FIXED DURING the sale, was peeling paint. The second issue, when I pulled the engine to have the Continental Prop Strike SB complied with, we found a couple rags still stuffed in the end of the crankshaft oil passage from before the prop was installed. Mind you, the US MT Rep insisted on being at the shop (at the expense of First Class Round Trip Airline tickets to Denver, and other frivolous expenses) and later claimed he DID NOT observe the installation, washing his hands of any responsibility of this massive error. The plane had flown for 3 years with those paper rags deteriorating in the end of the crank and sending this fabric all around the engine, fortunately mostly caught by the oil filter.

I got MT involved, and after MONTHS of back and forth emails, they proposed the extent of their support would be I send the prop back to Germany, my cost each way, and they would repaint the blades and flush the prop hub and prop governor. Needless to say, the freight cost would far exceed me paying a US Shop to handle everything.

Now, with enough hours on the Rocket, and a new Garmin Glass instrument panel and A/P, I'm finally getting a feel for my TAS's at the different altitudes, and comparing them to my "Pre-MT Prop" performance numbers. I am CLEARLY SEEING A MINIMUM OF 15 KNOTS in decreased cruise speeds at my normal power settings. The paint on the prop is terrible, after several attempts by me and a good paint shop to get paint to stick on the tips. I have an appointment with MT in Deland FL in later January for the prop to be repainted (requires removal of all 4 blades, a "special prep and paint process", and reassembly), which they WOULD NOT perform without an overhaul if it was one day over 5 years old. I'm hopeful I will gain back some speed with good paint on the blades, but fully realizing if I want my original cruise speeds again, I will be looking at a prop swap back to McCauley unless there is another "VALID OPTION". At this point promises from Prop manufacturers on speed expectations are completely suspect to me!!

As for MT; just realize once you right the check, YOU OWN THE PROP. Don't expect these people to step up to ANYTHING like you would normally see with U.S. Companies!

Tom

Tom, that sucks. I also am not impressed with MT's durability. The prop runs very smooth (3 blade) on my IO-550, but with only 450 hours and always being hangared, the prop looks pretty weathered. The rubber boots are dry rotting and the leading edge metal has lots of small pitting (nothing outside spec). The paint is not shiney and starting to chip. I called MT USA and they told me since it is over 12 years, my only option is for a full rebuild north of 6AMU. I'm probably going have to eat that vs switching to McCauley or Hartzell at the cost of 20 AMU. I do fly in rain, which I think is accelerating the weathering of the paint.

I do see 182 TAS running ROP which is pretty much standard ES speeds.