Diesel aircraft

[vpjr 18]

I am waiting for some info from Thielert about Time Between Replacement ,ie Overhaul (TBR), and Life Limited Components. I dont think part 91 ops will have to comply with the TBR but will have to comply with Life Limited Components. I need to know the times and cost of replacement to determine the engine reserve cost per flight hour. That will tell us a lot toward getting this thing off of the ground for skydiving.

[vpjr 18]

Talked to the US Thielert rep and he says that the installed weight increase for the 4.0 Diesel in the naturally aspirated 206 is 200 lbs. That would limit a 206 to 5 jumpers and pilot to stay under gross. I havent even tried to calculate the empty weight cg after the jumpers leave. The installed cost vs the gross sales per hour could still work but it is disappointing

[ZigZagMarquis 9]

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Talked to the US Thielert rep and he says that the installed weight increase for the 4.0 Diesel in the naturally aspirated 206 is 200 lbs.

Wow. That kinda sucks. And there isn't too much more you could strip off of a 206 set-up for jumping to buy back some weight... is there? Maybe the paint? But that would only get you, what, 20 to 40 lbs? I've heard rumors that at some point in the future Av-Gas is just plain going to go away... don't know if that's fact or fiction or when, but if it does, you wouldn't have much choice. Although, I'd think that aircraft engine mfgr's would come up with a lighter weight Diesel engine... maybe??

[ZigZagMarquis 9]

Hey Jr... thought of another question... if you convert said 206 to a Diesel engine, is it still air cooled or does it now become water cooled? If "yes", is that where all the weight hit comes from? If "no", where does all that weight hit come from??

[DJL 235]

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If I wanted black, greasy smoke, I would go back to jumping the DC-3.

But with diesel, you also get a pilot with a ten-gallon hat, 6x9 inch belt-buckle, cowboy boots, and the plane comes equipped with a CB-radio in place of the NavCom.

And with Bio-diesel you get Al Gore.

"I encourage all awesome dangerous behavior." - Jeffro Fincher

[Zing 2]

Yep, all the real cowboys I know now wear sneakers ... they got tired of being mistaken for truck drivers.

Zing Lurks

[RMURRAY 1]

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Hey Jr... thought of another question... if you convert said 206 to a Diesel engine, is it still air cooled or does it now become water cooled? If "yes", is that where all the weight hit comes from? If "no", where does all that weight hit come from??

the Thielert Centurion 4.0 is turbocharged V8 350HP diesel so is not really a direct replacement for the 206 engine. Diesels have a very high compression ratio so everything needs to be "beefy". The 4.0 is liquid cooled. for more info on diesels for aircraft check out dieselair.com - very interesting stuff....

rm

[ZigZagMarquis 9]

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...Diesels have a very high compression ratio...

Really?

[riggerrob 643]

A 200 pound increase in empty weight really cuts into pay load.
My suspicion is that diesels only have an advantage on long distance flights, where their lower fuel burn compensates.
This would be most advantageous on long out-and-back flights with no refuelling facilities at the turn-around point.

[ZigZagMarquis 9]

I think its that folks are getting interested in putting Diesel engines in piston powered aircraft that traditionally ran on Av-Gas because they could then run the plane on, well, Diesel, or kerosene, or JetA would probably run too and one wouldn't have to worry about dickin' with getting Av-Gas... especially like say places like Africa.

Rumor out of control, I know, but depending on who you listen to, Av-Gas isn't long for this world, even in the U.S. Its like 1/10th of 1% of the production of fuel... or something like that.

Anyway, the 200 lb. weithg hit Junior points out to convert a 206 to Diesel is surprising, but when you think of it, makes sense. Trouble is, there isn't much more you could strip off of a 206 set-up for jumping to buy any of that back, besides the paint. If he does it to one of his planes, guess he'll have to restirct his ops to skinny jumpers, no weight belts, tiny rigs only, maybe only haul Japanese jumpers... no fat Americans...

[billvon 2,998]

> A 200 pound increase in empty weight really cuts into pay load.

Only if max gross weight is not increased as well. Are you sure this is not the case? In some of the Soloy 206 conversions, the MGW is increased 200 pounds as well.

[ZigZagMarquis 9]

Well... too... like Junior said, I'd like to see what it does to the CG when near empty weight... i.e. low fuel and just the pilot left after say 5 jumpers just left the 206 with said Diesel conversion... I can't imagine that it would put the CG in front of the forward limit, but it would be interesting to see what the numbers crunch out to be. Hopefully he'll wander back by and post what he came up with. I don't have all the right Datum, numbers, etc. to run the numbers myself.

[riggerrob 643]

Usually you need to modify the wing to legally increase the gross weight.
For instance when Soloy converts a Cessna 206 to turbine power, they also modify the wings for STOL, installing triangular vortex generators and other gadgets.

Similarly, my boss is considering installing wing tip extensions on all of his Cessnas (182, 205 and 206) to increase the LEGAL gross weight. It seems that the average skydiver has gained weight since he bought those airplanes back in the 1970s???

[vpjr 18]

I wanted the diesel for the increased hp, faster climb times, increased time between overhaul, cheaper and lower fuel burn per head, and single lever operation that a low time pilot couldnt screw up. I wanted to turn the plane in 20 minutes to 13K agl so I could get an exp load in between tandem loads. Tired and slow tandem masters take up to 15 minutes to get back in the plane. The 550 with all the mods is doing 6 jumpers to 13K and back in 30 minutes. Too long for the DZO and tandems to wait.

[vpjr 18]

Thanks to Antoinette for your post picture.

[ZigZagMarquis 9]

Understand. Thanks.

So, if I'm understanding right... you can get that... "...I wanted the diesel for the increased hp, faster climb times, increased time between overhaul, cheaper and lower fuel burn per head, and single lever operation that a low time pilot couldnt screw up. I wanted to turn the plane in 20 minutes to 13K agl so I could get an exp load in between tandem loads...... but the trade-off will be with the weight hit, you'll only be able to haul 5 jumpers + pilot vice 6 jumpers + pilot... again, if I'm following you right... what do you think you'll do?

Will you go diesel and take what that gets you ... or am I missing something... and you'll stay with what you've got??

[ZigZagMarquis 9]

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Thanks to Antoinette for your post picture.

Shhhh! I don't think she knows.

[diablopilot 2]

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Understand. Thanks.

So, if I'm understanding right... you can get that... "...I wanted the diesel for the increased hp, faster climb times, increased time between overhaul, cheaper and lower fuel burn per head, and single lever operation that a low time pilot couldnt screw up. I wanted to turn the plane in 20 minutes to 13K agl so I could get an exp load in between tandem loads...... but the trade-off will be with the weight hit, you'll only be able to haul 5 jumpers + pilot vice 6 jumpers + pilot... again, if I'm following you right... what do you think you'll do?

Will you go diesel and take what that gets you ... or am I missing something... and you'll stay with what you've got??

How are you figuring that a 206 is good to haul a pilot and 6 jumpers?

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You're not as good as you think you are. Seriously.

[ZigZagMarquis 9]

I've seen 6 jumpers and a pilot in a 206. From a jumeprs perspective, not my favorite mode of transportation to altitude and one that I'll usually pass on these days (6 jumpers in a 206 that is)... but... As long as its not over gross nor out of CG and there's enough seat belts... what could possibly go wrong?

[vpjr 18]

6 jumper seats is the happy medium. When selling tandems skydiving operators want to say this. Yes we can take both of you in the plane at the same time, Yes we go all the way to 13K and you get 1 minute of free fall time, Yes if you both want video you can jump at the same time. No way around it tandems keep most dzs running. some do handy cam so a 182 will do.

[ZigZagMarquis 9]

So it sounds like you don't want to covert to Diesel because that would drive you back to just being able to take 5 jumpers? Sorry, I'm being thick.

[diablopilot 2]

Hmmm....maybe there is other information I'm missing......

Cessna reports the 206 Model H to have a useful load of 1360lbs. That's before gas.

Maybe the interior that get stripped and the cargo door being removed is enough to make up the difference, but you'll be REAL light on gas to make 6 legal if they are big boys or tandems.

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You're not as good as you think you are. Seriously.

[vpjr 18]

As per the POH each seat belt attach point in the aircraft is rated at 250lbs for the C models. Just have enough Hooker Harness Tag line belts. The stock airplane has a 3600lb gross weight, and my stripped planes weigh under 1900lbs. = 1700lbs. useful load. Pilot 180, 6 jumpers at 220, = 1500lbs and 40 gals of fuel only weights 120lbs. Under gross and with the large horizontal tail of the C models the CG stays in full and empty.

[vpjr 18]

Also check the price of the H model. I dont think to many of them flying skydivers.

[diablopilot 2]

Wow. How do you strip 1700lbs?!

And I understand about the H model, but even then the older modes give at best 100lbs more before modification.

I figure worst case scenario 2 tandems at 900 to 1000 lbs, 2 camera men at 400 to 450lbs and a pilot at 200lbs. If you can strip that much weight I can see that it's possible.
Edit: mis-read what you were saying. In reality you've stripped a 2400lb aircraft down to 1700 lbs. Makes more sense. I did notice your fuel weight was off. 40 gal should weigh 240 lbs. So 6 looks like it's doable but there's not much of a margin!

Thanks for the help.

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You're not as good as you think you are. Seriously.