GumpAir wrote:Take good notes as I'm sure thinking of trading the Cessna for a CH750.

No time today Gump. He had a list about a mile long and some of those folks were well ahead of me. Anyhow, they have a CH750 for rent and instruction at Carson. I'm headed down this week sometime to take a much longer flight. It's got a Continental 0-200. I saw one other CH750 at Cloverdale with the Continental and one on anphibs with a built O-320. It's a one person with 1/3rd fuel airplane at this point but they are working with the factory to up the gross weight to #1650 using Normal G limits instead of Utility limits. It's really a better looking airplane on floats. The demonstrator has the Jabiru 3300 and it seems like a pretty good performer but I gotta tell you; nothing like the CH701 for getting off quick or getting in short. There was a CH750 in the last 90% phase of construction there in the shop with the UL250is on the nose. It's a fantastic looking engine but I wonder why he didn't just go to the UL350is and get some real juice to work with. There's not much difference in price and by the looks of his glass panel he's not short of cash.

I had an eyeball meet with Joey and never did find Woody though his airplane was displayed front and center. It had the canopy cover on and he must have been off doing something or another.

I'll post some pictures as soon as I get them downloaded. Probably tomorrow.

EB

VCBZenith wrote::( Emory, what up man? Neither Joey nor I saw you.

I saw Joey just before he took off. He was easy to spot because his airplane is kinda famous on the net you know. I was there today until about 1PM when I took off to meet my self imposed schedule to get back home. I was the skinny geek with the tan BCP long sleeve T and hat and the fuzzball beard. Honest I was there!

EB

Emory Bored wrote:

and a just flat out weird rudder. When you pull the power back on the 701 it makes the Tri-Pacer seem like a sailplane. Seriously. You land this thing with power. It's still on my list but I'm looking forward to the 750 flight today.

EB

The 750 APPEARS to have everything good the 701 does, a couple of things the 701 needs, and not as many of the bad things.

During research, I learned that there was a mod approved by Chris Heintz himself, to add one more rib bay's worth of span to the 701. This is because the original 701 from 1986 was lighter by far than the current ones. To compensate for the higher weights of the later airplanes, additional wingspan/area/aspect was proposed. For reasons I do not know, that mod was approved by CH, but not incorporated into the later revisions of the 701. POSSIBLY because he was going to incorporate the longer wing into the upcoming 750?

So it is possible that as the 701 gained weight and gained power, the takeoff/climb performance stayed the same, but the glide and slow-speed capability got worse. As a guess, knowing that a new design optimized for LSA class was in the works, they shelved the wing upgrade for the 701, and just threw it into the 750.

Now the interesting bit is that the 750 also has a lot more room in it for people and baggage, and a firewall/fwd. fuselage that was stronger and could handle more weight and power. If you look thru the Zenair website, you will eventually see a brief mention that the 750 can handle a light, no-frills O-320.

It makes some sense that a 750, with a LIGHT O-320, and no frills, no extra weight, no heavy radio stack, and no "foot deep" paint finish might have as good or better power to weight ratio than the 701, yet you would still benefit from the extra comfort and longer wing.

Reducing the weight of the O-320 also opens some interesting doors. Losing 20 pounds of magnetos and adding 3 pounds of LSE electronic ignition will give you a 10% bump in HP/torque, at the same time as a very significant reduction in fuel usage. There are now light weight starters, but a big secret is that with the LSE ignition you can hand start the engine easily and safely because it automatically retards the spark until after TDC. So you could actually not have a starter.

The EXP alternators built off of a small Kubota tractor alternator will save more weight. With the iPad and tablet GPS gizmos they have today, and LED lights, you simply do not need 30 or 40 amps.The composite propellers are lighter and work well. Much less stress on the crankshaft, gyroscopic forces, etc.

So you stand a very good chance of having a 160-170HP engine, that is a real airplane engine, that runs on car gas, that falls within the acceptable weight range of the 750. It is likely that the performance would be better than the 701.

EZFlap wrote:

Emory Bored wrote:

and a just flat out weird rudder. When you pull the power back on the 701 it makes the Tri-Pacer seem like a sailplane. Seriously. You land this thing with power. It's still on my list but I'm looking forward to the 750 flight today.

EB

The 750 APPEARS to have everything good the 701 does, a couple of things the 701 needs, <snip>

So you stand a very good chance of having a 160-170HP engine, that is a real airplane engine, that runs on car gas, that falls within the acceptable weight range of the 750. It is likely that the performance would be better than the 701.

Or maybe stick the extra rib bay on the 701 wing and go back to the Simonini idea so you don't gain all that weight to begin with. Those guys that I talked to all were in the #650 neighborhood on the 701. None of those owners think much of the flaps and Doug even recommends that you don't touch the flap handle until you got 50 hours PIC in it. Honest to pete almost all those 701 I saw were loaded with heavy useless panels. Here's all the panel a guy needs:

Well this forum just happens to be honored to have among its members the one and only person on this planet who has personal experience with a Simonini powered 701. I hope he participates in this discussion.

You can certainly achieve JATO performance with a long wing 701 with that kind of power-to-weight ratio. But you will sacrifice the cabin comfort and payload advantages of the 750 if that is of any value.

For the record, if I had a 701 I'd be interested in the Simonini, but there will definitely be some reliability questions to be answered.

Ok, so the guy who made all the CH701 videos with this airplane;




Now drives this one around. I wonder why?



Here are photos of our intrepid C5A engineer making his getaway and leaving the airport ATA through the top.





This was probably best in show from a home decor viewpoint but I have an idea that all that paint and leather interior with Gulfstream III panel probably cost a bit of useful load. Owner is a former Marine Corps officer so I take all that back. Nice airplane.



Here's a CH750 under construction in the shop. Wings are done, UL 250is engine installed and super panel being wired. 4 months, one guy with occasional help.



Here's his tires next to a set of 600 x 6. They are apparently made for a 4 wheeler.



Here's the panel and unfinished interior. I'll betcha he could make it to the moon with all that stuff


Here's a bitchin float plane headed for Petersberg AK



Here's the one I flew with blimp tires on the mains and an 8:50 on the nose. That's QSP owner Doug Dugger holding the propeller on.



Here's a sweet Rotax 912ULS install. The guy who owns this airplane decided to go LSA after 30+ years in a Citabria GCBC. He likes it though he said it took him awhile to transition from an airplane that doesn't glide well to one that doesn't glide at all. Said with a smile.




I had a great time and haven't flown the CH750 yet because we've had all this convective stuff going on in these parts for the last couple of weeks and I want to spend some time unchallenged in the pattern. I suspect though that I'm going to need to fly to Texas and fly the Savannah too. My sources tell me that the Savannah VG is what the Zenith should have morphed into by now. Then there's that buy American thing that's in the way. We'll see.

EB

Interesting report. They would seem to be a very straight forward build, being all pre punched skins, just start clecoing. And I like how the owner pilots are upfront about it's power off glide! It must be pushing their buttons in enough good ways that overlooking that drawback is no big deal.

I'm in love with taildraggers, but I think one of those 750's would be a LOT of fun.

It's my guess that they glide better with a direct drive engine. The short field technique involves running enough engine power to overcome the propeller drag and maintain some sort of sensible glide slope. I'm told anywhere between 2000 and 3000 engine RPM with the 912. The one in Carson City is Continental powered. Might be a different animal.

EB

Emory Bored wrote:It's my guess that they glide better with a direct drive engine. The short field technique involves running enough engine power to overcome the propeller drag and maintain some sort of sensible glide slope. I'm told anywhere between 2000 and 3000 engine RPM with the 912. The one in Carson City is Continental powered. Might be a different animal.

EB

I have just (gulp!) purchased a completed CH750 with an IO-240 with a Whirl Wind prop, so this is of intense interest to me. I have zero stick time in this aircraft and have become concerned about comments like "glides like a refrigerator," etc. I have flown Tri-Pacers and Citabrias, for example, but wonder how the 750 in this configuration will glide in case of an engine failure. The engine has been bench-tested of course, but not flown. I'm wondering whether or not the prop (now set at 19 degrees) will windmill or stop at or near best glide speed, and at what speed the prop will stop--short of a stall, and the rate of descent I can expect under engine-out conditions, and how that compares with just pulling the power back to idle, with attendant prop drag. How does this compare to Kitfoxes and Highlanders, etc.?

My one ride in a 701 confirmed that the glide is indeed steeper than a Cessna or Cherokee. I have no Tri-Pacer experience to compare. I'm sure the 750 is very similar.

The reduced glide is, in my opinion, more than compensated by the much shorter landing roll. A steep glide is also very useful in short landing areas coming in over obstacles. So in an engine-out situation, you may even have more options in that airplane than a Cessna. But I think it is safe to say that you will have to learn the flight characteristics and develop techniques that are different than other airplanes.

Another thing in your favor is that you have a certified (or certified design) engine.

Congratulations on having an interesting and very capable back country sportplane.

Thanks for the reply EZflap. I guess I will find out about the glide angle and rate of descent first-hand fairly soon (in the next month or so, after the airplane is here and in place). I remember, having been flying Cessnas, the steep glide and engine-off (prop "windmilling" under idle power of the Tri-Pacer, and have long wondered myself about how much prop drag had to do with the descent rate versus wing loading--it would seem that it's like having a big disc on the nose, but I'm no expert on areodynamics. On the other hand, Cessnas have essentially the same disc and still float. I agree that a lower stall and touchdown speed with a short rollout will provide more options in terms of places to put it down, so a practice of continuously being aware of suitable landing spots as close as possible to my position--a good practice anyway, will be essential. I figure I'll just practice at altitude, note the descent rate and angle, and try to develop an instinct for how far I can glide and still have enough left to manage a good approach without power. I don't plan to practice dead-stick, so in the event the prop does stop and extend the effective gliding distance, that's just an additional fudge-factor.

I was trained in the spot-landing days, so I don't quite get the power-on approach idea, other than not scaring the poop out of your passenger, if any. When I was training for a commercial ticket, this was the approach to approaches, but I don't think it's safe to be at an altitude from which one can't make the field in case of engine failure.

I'll appreciate further comment, especially negative comment.

Twister wrote:

Emory Bored wrote:It's my guess that they glide better with a direct drive engine. The short field technique involves running enough engine power to overcome the propeller drag and maintain some sort of sensible glide slope. I'm told anywhere between 2000 and 3000 engine RPM with the 912. The one in Carson City is Continental powered. Might be a different animal.

EB

I have just (gulp!) purchased a completed CH750 with an IO-240 with a Whirl Wind prop, so this is of intense interest to me. I have zero stick time in this aircraft and have become concerned about comments like "glides like a refrigerator," etc. I have flown Tri-Pacers and Citabrias, for example, but wonder how the 750 in this configuration will glide in case of an engine failure. The engine has been bench-tested of course, but not flown. I'm wondering whether or not the prop (now set at 19 degrees) will windmill or stop at or near best glide speed, and at what speed the prop will stop--short of a stall, and the rate of descent I can expect under engine-out conditions, and how that compares with just pulling the power back to idle, with attendant prop drag. How does this compare to Kitfoxes and Highlanders, etc.?

I would think that you'll have no problem with the transition. The 750 is considered easier to fly than the 701 in the first place. Secondly, with that engine you will have substantially less drag at idle power than you do with a geared engine. You can always start your transition to type by dragging it in until you get a sense of the power needed to do that then gradually steepen your approach by using less power and reducing airspeed until you are landing essentially no power. Finally, you can get up to Carson City Nevada where you can get a few hours of dual with a Continental 0-200 powered CH750. My sense is that in landing configuration there will be no difference between that aircraft and your own.

EB

Thanks, EB--sounds like sound advice. Yes, I have talked to the CFI at Carson City, and think I may just go up there and get my BFR in their 750. Your suggested procedure sound spot-on (npi).