Jet A

If you want a turbine that comes remotely close to matching the airframe and you're willing to do it right, get an Allison 250. It will outperform the T-58 in every flight regime.

looks like it would be a great engine for a turbo prop, but not for a jet. It is not the same flow design setup as the t58.

 

Why do you say that this would be better for this application?

 

Did i mention it would be a cool turboprop?

 

Sooo, after re reading my last post, i realized that i may have come off as an arse...well more than usual. Looking back i could have been a little more diplomatic in my writing. it is hard to not get offended when you cant see exactly how it was intended. with that being said, i appologize for that. i will take Marc's post as helpful instead of an attack.

 

1) Need a turbine with a minimum of 250 - 350 lbs static thrust. (1/5 - 1/4 aircraft gross weight, minimum). I don't think the "Turbo-charger" turbines are capable of this magnitude of thrust.

A GE t-58 is more than capable of that. I was not saying i was going to use a "turbocharger turbine". I was mearly implying that i like JE and have built them.

 

Need long runways, i.e. 5,000 ft - 7,000ft (plus) for takeoff.

Why do you say that?

 

Speed brakes that can be deployed at any speed.

And the reason i opened this topic......

 

Vne 220 kts - need to be very careful as the airframe could EZ-ly exceed this. (Must perform stringent flutter testing to 1.2 x Vne)

 

Can you do this with your prop? or some other prop, RE engine combination? Yes, this is a responsibility thing.

 

Maybe i could program the JE to defuel when this speed is reached?

 

Money pit, WAG, $40 - $60 k for the engine and airframe modifications.

Intial engine price (7k-16k) military surplus - overhauled with 0hrs

Conversion from a shaft to a jet. 300$-1000$

Modifications to orginally airframe. Hard to say for an already built, but i will be building around this powerplant.

 

JetA, I'm with you, I love the smell of JP-4 in the morning. :-)

I love the smell all day long!

 

I will agree with you and most others that have spoken out. This is probably not a cost effective modification to this airframe. But that has never been my intention.

 

Turbines are cool, yes -- I agree, but you're getting valuable feedback here that your ego is preventing you from absorbing gracefully, if at all. Results with your approach may include "nah nah, I told you so", but don't forget "dangerous" and "disastrous". Personally, you'd be much better off with a dose of humility and respect as you go through the information gathering phase.

True, I was a bit quick to get defensive...I am now a sponge

 

Not even remotely. If you honestly, really think that - rethink building an airplane. You don't have the basic understanding needed to build and fly safely.

Richard, i can assure you that i am more than qualified make the necesicary safety precautions and design changes to make this airplane safe and reliable. I dont know everything, and i never will. But i can learn what i need to. When i made that statement, i am not entierly sure what i ment, but it wasnt what i wrote. regardless, sounds like you have 3 issues with this...going to fast, not being able to slow down and not enough fuel. I was trying to address one of those very issues.

while i appreciate your comments. how did me saying they are cool, lead into the conversation of safety? umm...ok well every jet pilot must be unsafe because they are using a jet engine..... would an f-16 or a raptor be cool with a prop? NOPE! But thanks, i am fully aware of the consequences of my actions. Now, while these before mentioned aircraft are designed around this paticular powerplant. i can think of a few canard style planes that are based around a jet engine as well. Are they unsafe? I never said i had any intention of breaking any Vne unless i have engineered other things to keep that in check. Do you have the impression i was going to build a plan designed for a RE with a 150hp and simply modify the motor mounts and drop in a 350lb jet engine will close to 850ftlb thrust? if that is the case then you are mistaken. Obvioulsy since i started the thread with the intention of learning about airbrake...somethink not equiped on the standard cozy, i must be doing some design changes?

What happens if i pass the critical mach number of the cozy? what happens if i just want the extra power to take of on my own personaly run way, that happens to be shorther than the average commercial runnway? i would say that a higher power to weight ratio would be a good thing. No where in my list did i say...cause i want to go faster than the prop cozy. So before you go ASSuming things, why dont you stop being my mom and be practical. Maybe i am a kid, maybe i am someone that knows everything, or maybe i am here just trying to learn more about this paticular aircraft.

 

I think your ranting was a bit premature. cool, you want to take your plane cross country...maybe i want to just fly around on 50 gallons of fuel and come back to the same airport i left. What does that matter. I think jet engines are COOL, and people that dislike my opinnion can go their (*)

 

Sincerly,

 

Another cozy builder <^>()<^>

Richard, while i respect your opinion, may i ask why you do not care for the turbine engine in this plane? you obviously made a point to mention it, and i would love to hear why.

 

Advantages of a turbine engine?

Ranked from most important

1. It is VERY VERY cool! (i am still a kid thats important)

2. Its sounds VERY VERY cool! (see above)

3. In the event of a mechanical failure ie. motor cuts out. you have a slightly better glide ratio due to no prop. Probably not much, but still an advantage.

4. I have an obsession with jet engines. I have built 2. the kind were you take a turbocharger off a diesel and make a jet engine out of it.

5. I have considered the costs of these engines. they are not much more than some of the rotarys that go in these.

6. there is less axuillary parts...these engines need fuel and air. less things to go wrong. I personally believe that turbine engines are more reliable.

7. i like taking the road less traveled and what better way to put my engineering skills to the test?

8. A much higher power to weight ratio than any reciprocating engine every thought about. --

9. operating costs.....maybe not really sure, i know they have a little (ok a lot) higher fuel consumption. but that is a factor of power. i would say hp for hp the JE has a better effeciency.

10...because it is so COOL!

I was scanning in chapter 6 to my computer last night....I like to have backup just in case....well i wasnt paying attention and spilt nail polish remover (not mine!) all over page 5 and 6 of chapter 6. I managed to get it cleaned up fast enough not to wreck any other pages, but now...no 5 and 6. Is there anyone that could possibly send me page 5 and 6..(private message). i would really appreciate it.

 

DP

Waiter, you rock. that website is lots of good info. thanks for that, gives me some more questions to ask some more people that have more familiarity with this. Is there anybody on this forum that is considering this conversion...jet engine?

I believe that is a berkut and i found them on a google image search a while a go. maybe i will try and refind them and see if they are contactable.

What design problems am i going to runinto with these? Obviously both of them will need to come out equal, with both sides. that is easly done with hydrualic flow valves. i like the accumulator idea. Should not be any problem with the brakes coming in quickly due to air pressure, but out will be another story. i would like to have a switch that allows them to come up about 1/2 of the way, and then another toggle that will adjust them down or up for the given situation. this will allow me to fine tune on the ground and in the air.

 

Anybody see any structural issues with this? looks maybe like that paticular design will cut into fuel area, or baggage area?, what about the strakes taking this load? as close as this is to the fuselage, i do forsee any problems with loading but i like to hear others thoughts.

Well thanks guys.

 

to anwsers a few of the comments...

I have no desire to sell my cozy, to many lawsuit possiblites.

Second i will be putting in a jet engine (t58 )and keeping it above idle on approach is optimal. That is good info on the landing brake, electric or hydraulic for me. here are some pics where my ideas orginated.

 

 

next question for wayne. how are both rudders applied...opposite directions? is there no mechanical linkage to keep them going the same direction?? or do they only operate one way, and when you apply both you get drag, with no turn? <---- new to aircrafts.....

newbie here.

 

Just wonding if the mark IV has airbrakes...if not how hard would they be?

 

Was thinking hydraulic actuator, airbrakes attached backside of strakes, by the fuselage.

 

Bad idea, good idea, read the plans, already there?

Let me have it.