New Guy, Looking at the Cozy-IV

[Evan West]

Hey all,

 

Im a propeller engineer living in the Dayton OH area. Working on my private pilots licence and will peruse IFR after. (Im the guy on the left in blue in my profile picture) Im looking to start scratch building a Cozy-IV. Some day the plan is to build a Velocity turbo XLRG but that will be ~$250k so that has to wait. What doesn't tho is scratch building the C-IV. I was originally looking at building a long EZ however I know id quickly grow out of it as my goal is to take myself, my 2 dogs, and occasionally a passenger or two, cross country fast. So ive pretty well settled on a C-IV. Once I finish renovating my house I plan to get myself some plans and start in on it. 

 

Being a propeller engineer I plan to get a constant speed prop put on the thing, curious if anyone else has a CS prop currently?

 

Lots of other newbie questions:

1) Why is the rear seat weight limit in the Cozy-IV 300lbs? Is this arbitrary like the "300lb front seat limit"? I have several pilot friends and we all weigh ~180lbs and id like to put two 180lb people in the back for short breakfast runs (ik its cozy back there lol) 

2) What is the max takeoff weight? I think ive seen 2050lbs quoted most often but the CG calculator sheet I found (from cozybuilders.org)  has 2175lbs as the max??

3) I see lots of talk about nose extensions on the Cozy....Why? 

4) Price estimate to build the airframe only? My best guess is 18k-20k?

Edited July 22, 2020 by Evan West

[Kent Ashton]

There are pushers with CS props but the props are expensive, heavier (?) and it is expensive to repair damage from stones or a tip-back. 

2 X 180# persons in the back probably means 4 persons total.  Ok for a short trip, I suppose.  The weight can be whatever to build and test for but on a hot day, even in Ohio, the takeoff gets long and climb is slower.  I generally fly with my wife, baggage and almost full fuel.  See the Wt&Bal below, you can plug those nums into your own spreadsheet.  That's about as heavy and I want to fly in the summer. (O-360 & fixed-pitch prop).  There are no flaps to help with takeoff speed and the airplane cannot fly until the canard reaches a speed to lift the nose.  These are not short-field airplanes.   To me they are two-persons + ample baggage airplanes.

Nose extensions: Not usually done.  you are probably reading Long-EZ comments.

15-20 years ago I would have said $20K to build the airframe.  These days I would guess $25-30K for the airframe but there are many discontinued projects that come up.  They will save you a bunch

 

 

Edited July 22, 2020 by Jon Matcho
Typo/correction

[Jon Matcho]

Welcome Evan!

3 hours ago, Evan West said:

3) I see lots of talk about nose extensions on the Cozy....Why? 

Whether this is for Long-EZs or Cozys, your question sums it up:  Why?

My take is that longer and pointy noses imply a faster airplane. Aerodynamically there's no advantage here.

3 hours ago, Evan West said:

Once I finish renovating my house I plan to get myself some plans and start in on it. 

Make sure you include time to renovate your shop/garage/shed/barn/dining room/etc.

3 hours ago, Evan West said:

Being a propeller engineer I plan to get a constant speed prop put on the thing, curious if anyone else has a CS prop currently?

I have seen some use MT props, but they're expensive as heck.

[Evan West]

1 hour ago, Kent Ashton said:

There are pushers with CS props but the props are expensive, heavier (?) and it is expensive to repair damage from stones or a tip-back. 

2 X 180# persons in the back probably means 4 persons total.  Ok for a short trip, I suppose.  The weight can be whatever to build and test for but on a hot day, even in Ohio, the takeoff gets long and climb is slower.  I generally fly with my wife, baggage and almost full fuel.  See the Wt&Bal below, you can plug those nums into your own spreadsheet.  That's about as heavy and I want to fly in the summer. (O-360 & fixed-pitch prop).  There are no flaps to help with takeoff speed and the airplane cannot fly until the canard reaches a speed to lift the nose.  These are not short-field airplanes.   To me they are two-persons + ample baggage airplanes.

Nose extensions: Not usually done.  you are probably reading Long-EZ comments.

15-20K years ago I would have said $20K to build the airframe.  These days I would guess $25-30K for the airframe but there are many discontinued projects that come up.  They will save you a bunch

 

 

Good info, yeah working for a major prop manufacture (Hartzell Propeller) I am well aware of the issues with pushers and CS props. I am looking into doing retractable gear mainly for extra clearance on rotation for the prop and to get the gear track outside of the prop disc to help save the prop some. Im just interested in the CS prop to both minimize takeoff roll and maximize cruise speed. Lucky for me my home airport and most destinations I want to go to regularly are ~5000ft or more paved runways. 

Attached is a screenshot from my weight and balance sheet. According to it the MTO is 2175lbs. If I take that as my MTO then I can fit 4 people and partial fuel for short runs to get food or visit friends in the next state over.....provided the back seat can do 360lbs. The back seat weight has a small effect on CG but it is stated that "structural limit is 300lbs".

 

Edited July 22, 2020 by Evan West

[Evan West]

7 minutes ago, Jon Matcho said:

Welcome Evan!

Whether this is for Long-EZs or Cozys, your question sums it up:  Why?

My take is that longer and pointy noses imply a faster airplane. Aerodynamically there's no advantage here.

Make sure you include time to renovate your shop/garage/shed/barn/dining room/etc.

I have seen some use MT props, but they're expensive as heck.

Haha yeah I will start in on the garage reno as "phase 1" of the plane build. 

Also I happen to be bias due to my employment and will be putting a Hartzell CS prop on it  ......provided it passes vibration surveys. 

[Jon Matcho]

4 hours ago, Evan West said:

Being a propeller engineer I plan to get a constant speed prop put on the thing, curious if anyone else has a CS prop currently?

Now you got me looking into CS options for my Quickie TriQ-200. It had an MT prop on it. After a nose gear failure splintered the 2 blades, I decided to move to a fixed pitch considering the $8,000 approx. to repair. 

https://www.kitplanes.com/constant-speed-props/

1 hour ago, Evan West said:

Also I happen to be bias due to my employment and will be putting a Hartzell CS prop on it

I don't think Hartzell offers anything in the sub 120 HP range (for my Quickie)?

[Evan West]

16 minutes ago, Jon Matcho said:

Now you got me looking into CS options for my Quickie TriQ-200. It had an MT prop on it. After a nose gear failure splintered the 2 blades, I decided to move to a fixed pitch considering the $8,000 approx. to repair. 

https://www.kitplanes.com/constant-speed-props/

I don't think Hartzell offers anything in the sub 120 HP range (for my Quickie)?

Did MT/a repair shop quote you $8000 to fix the prop? The first question is if your engine has provisions for a hydro-mechanical CS prop. 

[macleodm3]

7 hours ago, Evan West said:

Lots of other newbie questions:

1) Why is the rear seat weight limit in the Cozy-IV 300lbs? Is this arbitrary like the "300lb front seat limit"? I have several pilot friends and we all weigh ~180lbs and id like to put two 180lb people in the back for short breakfast runs (ik its cozy back there lol) 

2) What is the max takeoff weight? I think ive seen 2050lbs quoted most often but the CG calculator sheet I found (from cozybuilders.org)  has 2175lbs as the max??

3) I see lots of talk about nose extensions on the Cozy....Why? 

4) Price estimate to build the airframe only? My best guess is 18k-20k?

1.)  Rear seats are built similar to the front... perhaps 300 is what fits.  I am 5’8”, 180 and am comfortable back there for an hour.

2.). 1000 lbs more than you build it.

3.). Weight and balance to offset heavy rear ends (540 Lycomings and CS props).

4.). You can save a few thousand $ by scrounging projects and secondhand parts.  If you build with all new materials (esp new engine, CS prop, dual glass panel,...) you will have $100k in it to finish.

[Evan West]

10 minutes ago, macleodm3 said:

1.)  Rear seats are built similar to the front... perhaps 300 is what fits.  I am 5’8”, 180 and am comfortable back there for an hour.

2.). 1000 lbs more than you build it.

3.). Weight and balance to offset heavy rear ends (540 Lycomings and CS props).

4.). You can save a few thousand $ by scrounging projects and secondhand parts.  If you build with all new materials (esp new engine, CS prop, dual glass panel,...) you will have $100k in it to finish.

Any advice on finding half done projects/2md hand parts. The for sale here dosen't seem overly active. I'm not so concerned about end cost but the airframe cost is roughly what I will spend over the next 2-4 years to get started on it. I can save for engine, avionics and prop. 

Edited July 22, 2020 by Evan West

[macleodm3]

5 minutes ago, Evan West said:

Any advice on finding half done projects/2md hand parts.

Charles has his project for sale at cozy.caf.org

[macleodm3]

Joseph Heagerty has a project for sale too... 

“After messing around near 25 years, I’m willing to admit I will not complete. The project has always been in the Southern California area. There’s lots of parts, stock, & support materials. The project is just enough on its gear to make it easier to move around the hangar. It does have the Wilhelmson electric nosegrear retract with the pitot speed sensor extend feature and the Featherlight main gear bow.

If interested in purchasing this project to get a little head start, please contact me off list at joeheag-at-gmail.com.”

 

Join the Cozy builders email list... several projects a year sow up there.

 

 

Edited July 22, 2020 by macleodm3

[Jon Matcho]

2 hours ago, Evan West said:

Did MT/a repair shop quote you $8000 to fix the prop? The first question is if your engine has provisions for a hydro-mechanical CS prop.

I just checked: The quote was from MT USA and was for $6,150 with the 2 prop blades accounting for $4,300 of it. I figured I could buy 2 excellent fixed pitch props for that price. The unit was electrical, so "no" on the hydraulic question (the engine is a Continental O-200).

[Evan West]

3 hours ago, macleodm3 said:

Joseph Heagerty has a project for sale too... 

“After messing around near 25 years, I’m willing to admit I will not complete. The project has always been in the Southern California area. There’s lots of parts, stock, & support materials. The project is just enough on its gear to make it easier to move around the hangar. It does have the Wilhelmson electric nosegrear retract with the pitot speed sensor extend feature and the Featherlight main gear bow.

If interested in purchasing this project to get a little head start, please contact me off list at joeheag-at-gmail.com.”

 

Join the Cozy builders email list... several projects a year sow up there.

 

 

Sent him an email!

Edited July 23, 2020 by Evan West

[Evan West]

2 hours ago, Jon Matcho said:

I just checked: The quote was from MT USA and was for $6,150 with the 2 prop blades accounting for $4,300 of it. I figured I could buy 2 excellent fixed pitch props for that price. The unit was electrical, so "no" on the hydraulic question (the engine is a Continental O-200).

Unfortunately we only do hydromecanical CS props 😕

[Marc Zeitlin]

13 hours ago, Evan West said:

Being a propeller engineer I plan to get a constant speed prop put on the thing, curious if anyone else has a CS prop currently?

There are a few COZY's, Berkuts and other canards flying with CS props. I'd guess less than 1% of the total. Those that have them generally say that they help with takeoff/climb, particularly with O-540 powered aircraft, but either hurt or do nothing on the top end.

I always recommend NOT using CS props, due to the cost, weight, maintenance issues, etc. unless you have a VERY particular set of circumstances that requires it. Which fewer than 1% of folks do.

13 hours ago, Evan West said:

1) Why is the rear seat weight limit in the Cozy-IV 300lbs? Is this arbitrary like the "300lb front seat limit"? I have several pilot friends and we all weigh ~180lbs and id like to put two 180lb people in the back for short breakfast runs (ik its cozy back there lol) 

Nat invented weight limits to protect people from being stupid(er than they already are). There is no 400 lb. front seat weight limit, or 300 lb. rear seat weight limit that's determined by structural limitations. If the people can fit (and THAT'S the limiting factor almost all the time) AND you're within the MGW and CG limits, you're good to go.

13 hours ago, Evan West said:

2) What is the max takeoff weight? I think ive seen 2050lbs quoted most often but the CG calculator sheet I found (from cozybuilders.org)  has 2175lbs as the max??

MGW for any E-AB aircraft is whatever the manufacturer (you) say it is. In Phase I, you're required to test to whatever limit you set. If you set your limit higher than the designer specified, you better understand what limitations that puts on takeoff performance, "G" loading, and landing vertical velocities (amongst many other things).

13 hours ago, Evan West said:

3) I see lots of talk about nose extensions on the Cozy....Why? 

On Long-EZ's, people extend the nose a bit to fit a battery for CG reasons when they install an O-320 instead of an O-235. They extend the nose a lot when they don't have a clue what they're doing and think that they're making the airplane look better. In a COZY MKIV, there's exactly zero reason to extend the nose, although a few folks have done it (again, for aesthetics).

13 hours ago, Evan West said:

4) Price estimate to build the airframe only? My best guess is 18k-20k?

Eh. Closer to $30K, at this point, if not more, given shipping costs. Maybe if you're a great scrounge and buy in bulk you could do it for under $30K. Plan on $30K - $40K by the time you get through with it, and if you do better, congratulate yourself.

[Evan West]

7 hours ago, Marc Zeitlin said:

There are a few COZY's, Berkuts and other canards flying with CS props. I'd guess less than 1% of the total. Those that have them generally say that they help with takeoff/climb, particularly with O-540 powered aircraft, but either hurt or do nothing on the top end.

I always recommend NOT using CS props, due to the cost, weight, maintenance issues, etc. unless you have a VERY particular set of circumstances that requires it. Which fewer than 1% of folks do.

 

No particular set of circumstances that requires it other then wanting to and having the ability to. As far as loosing top speed goes that will be relative to the prop you had before. If you have a fixed pitch cruise prop then you could see a few knot loss with a CS prop (this still may not be the case as many of our installations on various aircraft gain 2-4kts ) but if you have a fixed pitch prop pitched for climb/takeoff then you should see a gain in your top end with a CS prop. 

For the most part I totally agree that for most people it is not needed.....as a propeller engineer I just want to do it  

Edited July 23, 2020 by Evan West

[Evan West]

8 hours ago, Marc Zeitlin said:

Nat invented weight limits to protect people from being stupid(er than they already are). There is no 400 lb. front seat weight limit, or 300 lb. rear seat weight limit that's determined by structural limitations. If the people can fit (and THAT'S the limiting factor almost all the time) AND you're within the MGW and CG limits, you're good to go.

Good to know, Like I mentioned I just wanna cram two of my 180 pound friends back there once in a while for short hops. Weight and balance says its fine (if i dont fill the tanks) and within limits. Just got tripped up on the "300 lbs rear seat limit"