Marc Zeitlin

Originally posted by LargePrime

It would seem a composite over foam core duct would lose much less heat than any other standard duct material.

Maybe, but the duct length/surface area is MUCH larger.

 

I havent found any recomended way to upgrade the stock system.

There are MANY ways. Electrical heaters, oil heaters, blowers in the stock air duct, etc. See the COZY mailing list archives. See the CSA newsletters.

 

Leaking should be only around the front gear and the canard holes right? (not counting vents).

 

Should be, but there are many other leak points. The landing brake actuator hole, for instance. The canopy seal, for another. There are ways to seal these, but none are in the stock plans.

 

The offset canard controlls dust showed me should elimanate the canard leak.

 

The offset in the canard torque tube helps, but it hardly seals the hole. There are a number of ways of sealing the 1/16" space that you BETTER have around the torque tube, but again, none are in the stock plans.

 

I would guess dust and cliffords front gear cover should mostly eliminate that leak. With these leaks plugged would the stock system be adequate?

IF you plugged ALL the holes, and sealed the canopy well, as well as ensuring that the stock heating system was working at full efficiency, I'd estimate that you'd be able to keep the cabin at 35F to 40F above ambient temperature on a cloudy day. Right now, I'm getting 25F above ambient in my COZY MKIV, and I've still got lots of work to do to seal holes. This is perfectly reasonable down to 25F or so (ambient temp), but in the winter up high, it gets a LOT colder than that, even with a lot of clothing on.

 

Carl Denk swears he flies all year in his Classic in his shirtsleeves, so it should be possible.

 

Does Nat or the Cozy Community have a recomended procedure for increasing the heat output for high/northern fliers?

Other than what I've pointed out? Just wear a lot of clothing :-).

Originally posted by dust

since when is minnesota the desert??

Tell me where Mojave is, and who designed the heating system in the V.E./L.E. that Nat leveraged. Then tell me when Nat moved to Arizona, and/or how much he modified the original heating system (from the standpoint of moving large quantities of hot air from the back to the front).

Originally posted by LargePrime

I would think that a canard is warmer than a typical spam can.

When the sun is out, you bet. Other than than, it's about the same.

 

So are they colder than your typical spam can? If so why?

They're colder in some cases (with the stock heating system) for a couple of reasons. They tend to leak more than the typical spam-can that's well maintained (although I've certainly flown in a few 172s/warriors that were made of swiss cheese from an air infiltration standpoint), plus the heating system is a lot further away from the heat point. It's about 2 - 3 feet from the heat muff in a 172 to the heat outlets, and about 8 - 10 feet in a canard. More flow resistance, less flow, more heat dissapation within the duct rather than into the cabin.

 

You've got to remember that the V.E./L.E./COZY families were designed by guys that live in the freaking desert and only fly north in the summer :-).

Originally posted by JakeC

Thanks for the info Mark. Cozyaircraft.com was the first place I looked for the VNE but they have left it off the spec sheet for some reason.

I apologize - neither web site specifically calls out Vne. It has been discussed numerous times, but you'd have to search the COZY mailing list archives to know that.

 

Do you know of anyone that is modifying their cozy in order to raise the VNE? It seems that with some of the higher HP installations going on that it would be pretty easy to exceed that number with the Cozy. Is this even an issue at cruising altitudes?

I know of one person that was going to use an O-540 that had done extensive mods on structure and airfoils, but he is no longer pursuing his project and it never flew. Other than that, no. Since we've never gotten a good answer from Nat regarding the limiting factor in Vne (structure, flutter, etc.), it's hard to know what to modify without doing a full analysis, which very few of us are capable of doing.

 

The way I understand it the higher you go the lower your indicated airspeed. You have to forgive my ignorance in this matter. I'm not yet a pilot and I may have a skewed view of what is possible with indicated vs. true airspeed at higher cruising altitude.

To a rough approximation, TAS is higher than IAS by about 2% per 1000 ft of altitude. So, at 10k ft, add 20% to your IAS to get TAS. The issue for Vne is IAS. I can indicate ~160 mph at 10,000 ft (no wheelpants yet) on about 65% power (117 HP). With Vne at 220 mph, I'd need 2.6 times (220/160)^3 as much power (304 HP) to get there. You won't get that out of an O-540.

 

At low altitudes, where IAS~=TAS, yes, there will be a problem - you'd easily be able to exceed Vne.

 

Does this help?

Originally posted by JakeC

Speaking of that, what is the VNE for the Cozy? Thanks in advance.

Jake

These numbers are available on the www.cozyaircraft.com web site, as well as the www.cozybuilders.org web site. Vne for the COZY MKIV is 220 mph IAS.

Originally posted by Daryl Lueck

For all you flyers out there... where did you mount your intercom jacks????

For the front seats, my jacks are on the top of the front seatback in between the two headrests. For the rear seats, they're just below that in the vertical section of the center console. The wires live between the shoulders of the pilot/copilot, and in the rear, drape over the legs.

 

This way, all the wires to all four jacks are about the same length and go to the same place in one bundle.

 

Works for me.

Originally posted by marbleturtle

Carter Copters are spiffy... but the time frame looks like 6 years plus, and its only a two seater.

The Cartercopter seats five.

Originally posted by Daryl Lueck

My a&p doing my inspections says to run a line out the cowling. He says that the vent line is incase the pump builds too much pressure. Would this be dumping fuel?

I don't know whether the pump is the same on the carbureted and injected version of the O-360, but I DO know that there's a vent on the carbureted one. I put a right angle tube fitting on it and ran a hose from there to the bottom cowling flange. I drilled a hole in the flange and siliconed the tube in place, with clearance in the bottom cowl flange to clear it.

 

It would, in fact, dump fuel overboard if the pump overpressures, but I've never actually heard of that happening, so it'll be pretty rare. Also, better OUT of the cowling than IN it.

Originally posted by John Slade

Perhaps I'm missing something here. It's my understanding that the airworthyness certificate you get clears you to fly VFR within 40 mile radius, or whatever it is. When flight testing is complete YOU sign the plane off and away you go.

This is almost correct, and you ARE missing something. When you get your certificate, it says nothing about operations. The thing that does is the "Operating Limitations" document, and it has two parts - one for the 25 or 40 hour restricted period, and one for everything else. There are different operating limitations for both, and the DEFAULT is VFR day only. If you want VFR night or IFR after your restricted period is up, you need to ask for it and have it explicitly called out in the op. limits, which is written BEFORE the inspection.

 

Now you're airworthyness cert specifically says "not approved for IFR unless properly equiped or some such wording". Therefore, by default, the airplane IS approved for IFR once it IS properly equiped.

The airworthiness certificate says nothing on it about equipment or restrictions. The op. limits are written by the FSDO/DAR, and must be approved during the inspection. You can ASK for IFR approval, but they don't have to write it in or give it to you if they don't like the equipment. The DEFAULT is VFR only - everything else is by request and approval. Since you haven't been through this process yet, I'm not sure you should hold yourself out as an expert on what happens or how the process works.

 

I think that comes down to what's "required for ground equipment in use". If you're not using any ground equipment because you have a GPS, then there's no equipment required in the plane to make it IFR ready.

91.205 (d) (2) states "Two-way radio communications system and navigational equipment appropriate to the ground facilities to be used".

 

In theory, you can use your plane for IFR without any radios or nav equipment if you're not going to land at a controlled airport or by using VOR/ILS/DME/etc. equipment. I'd almost guarantee that you'll never get a DAR/FSDO to approve your op. limits for IFR operation without appropriate radios and nav equipment, however. GPS (per the BMA URL listed above) is only approved for IFR navigation as SUPPLEMENTAL equipment, meaning that you've got to have some OTHER form of NAV available to you in order to use the GPS.

 

Given these things, you may be able to convince some DAR/FSDO to give you IFR approval in your op. limits with just a BMA or homegrown system in your plane and nothing else - it is at least in theory not illegal for them to approve it (except for the GPS as "supplemental" part), but personally, I wouldn't spend the time and money on installing those things unless I was SURE I'd get approval, because if you don't, you're just going to have to get the IFR approved equipment anyway. Feel free to be the guinea pig - many will thank you if you get it approved and lead the way.

Originally posted by John Slade

I think this is the loophole, Marc. BMA and others don't offer IFR equipment. They offer VFR eqipment. Once we have it in our planes we can use it under IFR without breaking any rules.

In theory that might be the case, but in fact, you will need to get your installation approved by your DAR or FSDO for IFR use - it's part of your operating limitations for ex. am. built and there's no way around it.

 

Basically, if you can convince the FSDO/DAR to give you IFR approval for your installation, be it BMA, Dynon, chewing gum and paper clips, or whatever, then you'll be legal. If you CAN'T convince them, then whatever loopholes you think there might be will get you a cup of coffee, if you happen to also have a couple of bucks.

Originally posted by marbleturtle

Is it required that you use Certified Instruments to fly IFR even if our planes are NOT certified? Anybody know?

So, prompted by this question, I searched the web, talked to Garmin, and finally called AOPA. While the answer that I got from AOPA is not canonical (in that it was not provided by the FAA's legal department) here's what they (AOPA) told me:

 

There is NOTHING in the FAR's that speaks to the issue of manufacturing qualifications for IFR equipment in ANY aircraft. However, in order to be able to SELL equipment for aircraft usage, the equipment (at least the navigational equipment) must meet TSO requirements, and for GPS's, it's TSO C-129.

 

So, if BlueMountain Avionics (or Joe Blow's Bargain Basement GPS's) wanted to SELL GPS equipment for use as IFR navigational devices, they'd have to meet the TSO standards (which are self-certified by the manufacturer, but are subject to inspections by the FAA and are more stringent than non-TSO'd equipment).

 

Since you cannot manufacture your own equipment to use in your NON-EXPERIMENTAL certificated aircraft, you are restricted to using equipment from a manufacturer, and since they must meet these TSO standards to claim IFR usage, there's no leeway.

 

Similarly, if I wanted to purchase a navigational device for use in my experimental amateur-built aircraft, it would have to meet the TSO requirements (since the manufacturer must meet these standards in order to sell it).

 

However, if I wanted to put together a navigational device for my own use in my experimental amateur built aircraft out of tablet PC's (or chewing gum and paper clips, if your name is McGyver), I can do so, and use it for whatever purposes I like, including IFR flight. It's not at all clear what the FAA might try to claim if you had an accident with such a system, but they'd be hard pressed to find a regulation that would have prohibited it.

 

This certainly contradicts at least part of my original statement on this matter - in our experimental aircraft, we have a LOT of leeway. The URL provided in the previous posting (from BMA) explains most of this in more (and different) detail - it's good to see that AOPA is pretty much on the ball.

 

Now, the INTELLIGENCE of doing such a thing with a homebrew system that you might be using in hard IFR is questionable at best, but it would be legal.......

Originally posted by John Slade

......I guess it's a toss-up between the Garmin 195, the Garmin 295 or the Ipaq running some nav software. I'm leaning toward the 195. Any opinions?

I've got a 195 - works great. Don't really need the color, although it would certainly be nice. You can get them cheap on EBAY now that the 196 is out.

Originally posted by JakeC

Here is one example of a Tablet PC that might make a good candidate......

This tablet PC uses a TFT display, which would be really great, as long as you only fly at night. You won't be able to see it during the daytime, in sunlight. Daylight readable displays are expensive - we've been trying to find one to put in our difibrillator, and it's not easy to find an affordable one. Ask Greg at BM what they use for a visible display, and how much it costs.....

 

Does an instrument like this need to go through FAA cert before it can be used IFR or is it the Software, or both? Thanks.

It's both, and it's not simple. None of the newer, smaller vendors (Blue Mountain, PC Flight Systems, Dynon, etc.) have tried to get approval because it's expensive and lengthy. You don't have a chance on a homegrown system. Sorry......

You guys are missing John's point. He wants an IFR capable setup. NONE of the homegrown units (including the BlueMountain Avionics one) are approved for IFR usage. John will HAVE to purchase an approved unit from one of the larger manufacturers. He seems to have found a used 300XL for a not unreasonable price.

Originally posted by John Slade

Yea. Affordable is a variable. Sorry. Let's say < 3k. Did I mention that I'd like it to have COM also? So far I have one ICOM A200.

 

I'll start off VFR, but I'd like to complete my IFR training in the plane, then use it IFR approach if necessary. Ideally it would be "expandable/upgradeable".

For less than $3K you won't get IFR. You could get a King KLX-135A GPS/COM for $2600, but it's not IFR and the moving map is crap. The cheapest IFR setup is something like a UPSAT GX-60 for about $5100, and the map is still crappier than the Garmin 195/196 See:

 

http://www.gulf-coast-avionics/

 

I guess what I'm looking for in the panel is a REALLY cheap Garmin 530.

Aren't we all.....

Originally posted by No4

I'm quite keen on the idea of retractable under carriage.

Is it possible on the Cozy?

It is definitely "possible", although Nat will recommend against it. Others have pointed out installations and web sites, although none of them are flying (yet).

 

I see aerocad sell a retract, and velocity, can their systems be integrated to the Cozy?

IIRC, the AC retract is the Infinity retract system (which, BTW, _IS_ flying on a number of aircraft, including SQ2000's and L.E.'s). The Velocity system is completely different - it mounts on the fuselage and retracts up and out, while the Infinity system mounts on the end of the spar and retract up and inward. The Infinity system is the only one that has so far been integrated into a COZY, although there's no TECHNICAL reason that a Velocity equivalent gearset couldn't be engineered into the COZY structure.

Originally posted by John Slade

How about some avionics advice? I'm looking for an affordable 6.25 wide panel mount moving map GPS system. Is there such a thing?

Depends on your definition of "affordable". If you're only going for VFR, I'd just get a handheld with a mount - you can still couple it to your autopilot (if you have one) and the maps are just as good (if not better, especially on the Garmin 195/196).

 

If you really need IFR, you have to decide whether you need approach or just enroute, as the price will increase substantially with increasing capability.

 

Confused enough? :-).

Originally posted by Aaron

Maybe it's just me, maybe I'm in a bad mood, but up until recently this forum had a pretty high signal to noise ratio.

It's not just you - even the imperturbable John Slade seems to be getting a bit bent. And I would have to disagree re: the historical S/N ratio.

 

Anyone coming in here for the first time is going to think there's nothing useful here and not stay long enough to contribute.

I would say that that's already occurred. Look at the last time that anyone with a flying aircraft posted or responded to any of the "discussions" that have been occurring. Even Nat Puffer, on who's server this forum resides, and who designed the plane that most of the discussions revolve around, has not posted in FOUR MONTHS. This is NOT because he's incapacitated or unavailable.

 

Where are all the hundreds of people flying COZY's, L.E.'s, V.E.'s, Velocity's, etc. who could be contributing? Do you think that when they see the type of discussions that occur here, vs. the ones occurring on other fora, that they think there's any reason to become a member?

 

In many other forums, you'd get one warning after something like this, and then Poof! you're off the island.

At least two, that I can think of.

 

Am I out of line on this?

Nope. Not in the least.

Originally posted by clifford

Is there any reason we can not use a standard pop rivet tool for these??

Standard rivet gun works fine - just takes a lot of force and hurts your palms.

Originally posted by codensr

Has anyone heard or had experance with elevator control with heavy load in the front seats. Some say the elevators are to small for heavier front seat loads,two large people.

I have flown my aircraft at full forward CG, at max gross and at minimum weight. Forward CG takes more runway for liftoff and more speed on landing, but it's not really a big deal. The elevators were "too small", whatever that means, and who are "Some"?

Originally posted by LargePrime

So how would one get the CSA back issues?

 

Is there any concensus on what a good shape would look like?

a) See:

 

http://www.canard.com/~csa/

 

and contact Terry Schubert. He's the editor and brains behind the newsletter.

 

b) Not really, but there are some things NOT to do, mostly having to do with sharp corners and angles. I wouldn't say it's been "solved", but there's been a lot of effort to figure out the kinds of things that work and those that don't. Whatever Klaus Savier does, copy it :-).

Originally posted by LargePrime

I have been looking at a lot of lower cowlings and it seems like the curve sharply to the prop. Perhaps too sharply? I cant see airflow sticking to the cowling. Did I miss something?

You are correct that there are issues with the airflow over the cowling, both top and bottom. The CSA newsletter is a wonderful reference, as there have been MANY articles written over the years with people doing oil flow studies of different cowl shapes with air attachement pictures. Invaluable information - get the back issues. There is no one "answer", but there are clues as to what to avoid and what to attempt.

 

Originally posted by dust

Also because of the prop in the vicinity, i doubt that you are getting laminar airflow, regardless of the shape, there is probably a "little" turbulence in the area, causing laminar flow separation.

I think that what you are trying to say is that the air is separated from the fuselage in the cowl area (the CSA oil flow studies show this clearly in places), but I can guarantee you that there is NO laminar airflow anywhere near the cowling.

 

By the time that the airflow has reached 3 - 4 feet back from the nose of the aircraft, it has long since transitioned from laminar to turbulent flow (this is dependent upon Reynolds #, which is a function of flow distance, viscosity, and speed). This is a GOOD thing, as it ensures that there is energy in the boundary layer that will keep it attached to the fuselage - if the BL remained laminar to this distance, it's extremely unlikely that it would remain attached, and the drag would go up considerably.

 

The reason that some people need turbulators in front of the NACA scoop to get adequate cooling air is because the boundary layer is 1/2" to 1" thick there, and more energy needs to be injected into it to keep it attached. By the time the air gets back to the cowl, the boundary layer is even thicker, even as a turbulent boundary layer, and it's all that we can do to keep it close to attached.

Originally posted by Nick Ugolini

No a real surprise. I saw the engine running on the velocity... must have been 3 years ago.

Nope. Four and a half. It was OSH, 1998 - that was the year I was there with Bose, and I remember seeing them taxiing a Velocity with no wings attached around on one of the taxiways as a demo. That was three years after seeing them run one on a test stand at OSH in 1995.

Originally posted by George Sychrovsky

I wrote a page on finishing a composite airplane, Some people facing the task might find it helpful.

 

http://curedcomposites.netfirms.com/finish.html

There are many ways of finishing composite aircraft. The only part of this that I would take exception to is the last section where you recommend using polyester glazing putty. These putties will shrink, and can cause imperfections later on in the painted surface. They also do not have as good adhesion as do the epoxies. There's no reason (especially if you use the "Smooth Prime" primer) to need or use these glazing putties.

Originally posted by clifford

My primary reason for turbo would be for full H.P. at high altitudes. So you see no reason an aftermarket automotive turbo would not work on a lycoming if the engine compression was set up for one??

I see no reason that turbo-normalization couldn't be made to work (in theory) on a lycoming. You will need a wastegate that never allows the boost pressure to be higher than sea level pressure.

 

The short answer is it should work.