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Tecnam P2008 Turbo


markmn

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115hp 'monster'???

 

I fly behind a 914 on a regular basis, how about you? It buys you views like this, that the 912 can't deliver on.

 

post-6-0-42618700-1357131733_thumb.jpg

 

Putting a 914 turbo in a 1300 lbs airplane is a power to weight ratio that would result in flying faster, PERIOD.

 

Some SLSA use 180hp engines so the speed issue can be dealt with. A 15% increase in power will only buy you 3.75kts in additional speed, that would likely be offset by extra weight.

 

FD has already designed the CT to fly with the 912 in a perfect balance of performance and weight, so why screw with it?

 

In Aviation there is no such thing as perfect design, or perfect balance. What does perfect balance of performance and weight mean?

 

we are talking about the rustic and half-grafted design of the Tecnam

 

 

Rustic?

P2008_side1a.jpg

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. . . "The 914 turbo is a 115hp monster. It will give more speed, more torque AND give you the ability to exceed LSA standards. Its overkill for the carbon fiber CT no question. the 912i is already the optimal engine for the airframe. Putting a 914 turbo in a 1300 lbs airplane is a power to weight ratio that would result in flying faster, PERIOD.

 

FD has already designed the CT to fly with the 912 in a perfect balance of performance and weight, so why screw with it? Oh, thats right, we arent talking about the CT, we are talking about the rustic and half-grafted design of the Tecnam." . . .

 

115hp 'monster'???

 

I fly behind a 914 on a regular basis, how about you? It buys you views like this, that the 912 can't deliver on.

 

Putting a 914 turbo in a 1300 lbs airplane is a power to weight ratio that would result in flying faster, PERIOD.

 

Some SLSA use 180hp engines so the speed issue can be dealt with. A 15% increase in power will only buy you 3.75kts in additional speed, that would likely be offset by extra weight.

 

FD has already designed the CT to fly with the 912 in a perfect balance of performance and weight, so why screw with it?

 

In Aviation there is no such thing as perfect design, or perfect balance. What does perfect balance of performance and weight mean?

 

we are talking about the rustic and half-grafted design of the Tecnam

 

Rustic?

P2008_side1a.jpg

 

CT,

 

You should know better by now.

It is a total waste of time trying to convince that guy of anything. :)

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CT,

 

You should know better by now.

It is a total waste of time trying to convince that guy of anything. :)

 

I don't know about that, recently he advocated closing the throttle for touchdown and yesterday agreed with a poster that said landings work at 50-55kts with as much as 30° flaps. That is a lot of change from the usual 30° and 55 kts is risking stall or worse.

 

I worry when the last word is delivered with such authority and isn't backed up. I think when you make bold assertions that you should be prepared to provide a source or logical reasoning that gets you there. So I try to discuss such things.

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. . . "I worry when the last word is delivered with such authority and isn't backed up. I think when you make bold assertions that you should be prepared to provide a source or logical reasoning that gets you there." . . .

 

Totally concur with you.

That's the whole problem with this guy.

Besides what you just stated, when someone asks him a follow up question, with regard to his bold assertions (BS), he refuses to answer and withdraws from further discussion. Something isn't right there.

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...

As far as flying it we are regularly seeing 12-1500 ft of climb. It easily makes 120kts but the main advantage is being able to maintain that indicated airspeed at higher altitudes which translates to higher TAS. We are still testing props but there is clearly something to the "constant speed effect" propeller. It is not going to perform like a real constant speed prop but we are seeing that some props definitely "unload" much faster at high altitudes than others.

We have and will continue to test several props from different manufacturers who are making props specific to this application. As of now a new sensenich is performing very well but we will approve other brands if it outperforms the sensenich.

...

 

Mark

 

Mark,

 

It sounds as though you are selling the almost constant speed technology but are settling on a traditional prop. If there is clearly something to the technology what is the issue keeping it from getting employed?

 

What altitude do you optimize your pitch for?

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The 914 could be a benefit to the CT, but maybe not so much in the US as other parts of the world. We have a speed limit, weight limit and prop limitations which could hinder the full potential of the 914 CT match up. In many other parts of the world speed isn't an issue and you are allowed an in flight adjustable prop. All these people could benefit from a 914 and of course where you live can play a part too. Do you live in Death Valley, CA or Leadville, CO. type environments. It really all boils down to personal choice and your personal use and then of course government regs.

The 914 is a good engine. The CTLS with the 912ULS was a great plane too, but Rotax not FD introduced a new engine so FD incorporated that into the mix. It will be a great plane until someone comes along and introduces something new again.

 

You know what all the CT's will always be good planes especially if you own one. If you're happy then that's all that counts in my book. :)

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For every 8% increase in power you realize a 1% increase in speed, we are talking about less than 4kts, this is not about speed. The 914 isn't a racing engine it is a low compression 912 with soft starts and stops built in.

 

120kts @ 17,000' = 160kts

 

Practical ceiling becomes 18,000'

 

Those are the motivations high TAS and clearing high mountains.

 

It all becomes practical with a prop that can really unload at altitude, until then the LSA rule makes it far less practical.

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If the 914 was good for the CT FD would be offering it. Talk to real experts from FD on the airplane. The FD CT will fly past the specs with a simple prop pitch change, but why do it? The LSA speed limits are already maxed in the plane, and its gas mileage makes it a sweet proposition.

 

Why stick a racing engine into a VW beetle? No reason if your purpose is to fly LSA and to fly with practicality. The entire point is simple. If you want to juice up your flying speeds, fly experimental, build your own pile of junk, or get a small jet.

 

The 914 is not about just the extra power, it is about having that power all the way up in altitude where the air is thinner and the airplane can have a higher true airspeed. Flight Design did offer a 914 in the high lift version of the airplane called CTLS HL. Along with the 914 it also had a longer wing like will be used on the new C4. I don't think any were brought to the states, but there are used in europe for towing gliders.

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I think you'll find it isn't so much your specs, but rules/regs, cost (an $18K engine verses $31K) and marketing. Not to mention all MFG's learn as they go. They are not all knowing and can't test for everything. FD has evolved because of its customers. You became a tester and evaluate and they based their marketing, cost and new product decisions on that.

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Interesting conversation here.

I only have 50 hours in the 914 so I certainly don't know it all.

 

What happens is that the 914 can easily over rev many props as soon as you go up say 3000 feet in elevation. Others you can go up say 5000 feet before the engine will easily over rev and thus allows the aircraft to maintain a higher IAS at a higher elevation. Certainly not a constant speed propeller but being able to maintain a higher indicated airspeed at a higher elevations is what I understand "constant speed effect" to mean.

The 914 cost is about $5000 more than the 912is and weighs about the same as the 912is. That is the disadvantage.

The good part is that it will easily climb out at 12-1500 feet per minute with a very smooth and low vibration engine. It can legally fly higher true air speeds at higher elevations where the air is usually smoother also. It sure feels like more than 15 more horsepower. I have heard this from others who have flown the 914. Maybe it is conservatively rated.

 

Mark

 

 

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It sure feels like more than 15 more horsepower. I have heard this from others who have flown the 914. Maybe it is conservatively rated.

 

 

No experience with the 914, but...

 

...other than at SL, it will be more than a 15 hp difference.

 

Disregarding the fact that the way most of our props are pitched keep us from ever developing full power, a 912's 100 hp begins to fade as soon as a climb above SL begins. The whole point of turbocharging (or turbonormalizing) is to maintain a given rated power throughout the climb and at altutude. So, that 15 hp delta should increase as altitude increases.

 

Right?

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No experience with the 914, but...

 

...other that at SL, it will be more than a 15 hp difference.

 

Disregarding the fact that the way most of our props are pitched keep us from ever developing full power, a 912's 100 hp begins to fade as soon as a climb above SL begins. The whole point of turbocharging (or turbonormalizing) is to maintain a given rated power throughout the climb and at altutude. So, that 15 hp delta should increase as altitude increases.

 

Right?

 

With the adjustable prop we get good power from the 914 from TO to 18,000' but it is not an LSA. As soon as your are faced with a fixed pitch you have to pick an altitude to optimize for. If you take advantage of the turbo and optimize for say 16,000' your TO performance would be degraded.

 

I would pitch as coarse as I could and still have acceptable TO that way I would have best cruise somewhere up high. The 15hp delta wouldn't exist, I would likely have a penalty instead but as I climbed the delta would appear and grow.

 

If you had a DUC prop and it truly unloaded at altitude that would be a different ballgame.

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I agree with Eddie,

 

It isn't so much that it has an extra 15 hp, it's the fact that the 912 looses HP as it increases past standard sea level and OAT. More or less we (912) loose 3% for every 1'K (altitude and OAT affects us), but the 914 gets to keep its HP rating up because of the turbo. Without getting into all the calculations with temps and altitude the 912 or any natural aspirated air engine will loose approximately 30%-40% of its HP at 10'K. Many engine's and compressor output max ratings are hypothetical on paper and will never be seen by an end user because we will never use them without all the fittings required to run them or ever run them in absolute perfect conditions.

 

The HP gap would increase between the 912 and the 914 as altitude increases. Actually it would start on the ground. Using a ground adjustable prop verses an in flight adjustable prop on a 914 would be a major detriment, but people do it due to cost or rules and /regs.

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...

 

The HP gap would increase between the 912 and the 914 as altitude increases. Actually it would start on the ground. Using a ground adjustable prop verses an in flight adjustable prop on a 914 would be a major detriment, but people do it due to cost or rules and /regs.

 

The problem with have the delta begin on the ground is that you will over speed your engine at a low altitude. If you pitch coarse enough to remove the delta up to 5,000' than you won't over speed all the way up to 18,000' and have 160kt TAS available.

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FD has already designed the CT to fly with the 912 in a perfect balance of performance and weight, so why screw with it? Oh, thats right, we arent talking about the CT, we are talking about the rustic and half-grafted design of the Tecnam. 

 

If the 914 was good for the CT FD would be offering it.

 

You wouldn't say things like that if you flew up here where I do. I operate from 6200 to 14.5k ish and the CTLS with 2 people and fuel becomes basically a death trap. The SW does better, but it's still anemic. Nothing against FD, just the nature of the beast operating/living at high elevation. A 914 up here would be absolutely amazing!

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CharlieTango, when it's time for a new engine, are you going go ELSA and get a 914?  I'd love to see how that works out.  As ELSA you could do the DUC prop as well.

 

I flew for the first time at 10,000 feet last week, you can definitely see the performance loss.  I think my max rpm there was about 5200-5300 (normally I am at 5700-5750).  I was showing 96 knots indicated and 116 knots ground speed at about 5000-5100rpm.  This is all from memory, don't hold me to those rpm numbers.

 

The nice thing was coming back down with a tailwind and 1000fpm descent rate, I got 155 knots groundspeed at 122kt indicated.  :)

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Andy,

 

Ed can continue past his TBO and if proper maint. is done along the way should see any where from 3K-4K hrs. on the engine without issues.

But  for each of us allowing little issues to drag on for years or hundreds of hours can take it's toll.

 

A 914 will not fit in a CT cowl and if you think the 912 is tough to maintain just try a 914 and find a mechanic who knows what's going on.

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Andy,

 

Ed can continue past his TBO and if proper maint. is done along the way should see any where from 3K-4K hrs. on the engine without issues.

But  for each of us allowing little issues to drag on for years or hundreds of hours can take it's toll.

 

A 914 will not fit in a CT cowl and if you think the 912 is tough to maintain just try a 914 and find a mechanic who knows what's going on.

 

 

LOL, I bet that last statement is true.  I didn't mean CT would be doing this anytime soon, just wondering if he'd take the leap when the time comes.

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Andy,

 

It would be a fun project.  I think I would find an 80hp 912 and put a 120hp turbo kit on that then sell my 912.

 

An almost constant speed prop would be perfect if it actually worked otherwise and adjustable prop with adjustment not accessible in flight would be next best.  Leaving Mammoth I would optimize for 15,000' and leaving sea level for Mammoth I would have less benefit.

 

My best friend has a 914 and maintenance has been cheap and easy so far.

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Andy,

 

It would be a fun project.  I think I would find an 80hp 912 and put a 120hp turbo kit on that then sell my 912.

 

An almost constant speed prop would be perfect if it actually worked otherwise and adjustable prop with adjustment not accessible in flight would be next best.  Leaving Mammoth I would optimize for 15,000' and leaving sea level for Mammoth I would have less benefit.

 

My best friend has a 914 and maintenance has been cheap and easy so far.

 

What do you think the reliability and lifespan of the turbo 912UL conversion might be?  Would the turbo kit fit under the cowl or would you need to modify it?

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