Long Ez modifications

[zies8]

I have a set of Long Ez plans that are incomplete. Until my new set arrives that I just bought on ebay I will be in the dark unless I ask y'all my question.

There are many modifications that you guys are making to the canard planes. When these modifications are made what method are you using to come to your new design criteria? I mean what starting point are you using to develop a CG envelope for your new plane? I would like to start a long ez and I need to make modifications like the limo ez and long nose etc. Do the plans come with a set of FS #s that one could use for developing the CG envelope or would you need to start by weighing your airframes CG and go from there? I need to design my plane with my 270 lb frame in mind (no fat).

[Waiter]

I think we are talking about two different things (CG and W&B)

Unless you change the relationship between the canard and the wing, the plans CG envelop will remain the same, i.e. you need to operate the plane between these numbers: If you ARE changing the relationship, then you are way out of my league, and I would have thought that you should already know the answers to the questions your asking.

 

(OK HERE GOES THE BAD MEMORY THING AGAIN!, I'll post the correct numbers after I look at the book:irked: )

 

FS#98 to FS#103.5 (First flight - FS#98 to FS#102.5)

 

There are people with a lot more knowledge on this subject then I. So, the simple answer for folks like me is, as long as I don't mess with the "relationship" between the wing and canard, the plans CG envelope will apply.

 

I'm going to determine if my plane falls within the envelope by performing a W&B.

 

NOW, I think your questions is; "What impact will my modifications have on the Weight and Balance?

 

Every EZ is different, so its a little bit of guess and a lot of science.

 

I would start by building a W&B worksheet in an Excel spreadsheet. ( Remember I said in an earlier post that you need to be familiar with how the W&B is performed.) Start by using the original weights and FS# locations that are in the flight manual, and see how things look. Now modify the weight numbers for a heavy engine (50 - 75 lbs heavier than an O-235), a 30 lb prop with a 8 inch extension instead of a 4 inch extension. Change the battery from the plans location to about 18 inches forward. Change the pilot weight from 180 to 270.

 

As you modify the weights and FS#, you'll see how these new weights and FS#s effect the W&B. The goal would be to come up with a plane that puts your W&B in the center of the flight envelop (approx FS#101)

 

I have three thoughts on this:

 

1) If your planning on installing an O-360 (about 75 lbs heavier than an O-235), AND your about 100 lbs heavier than plans. These two are just about going to cancel each other out. I would guess that you may not need to move the battery forward to compensate for the heavy engine.

 

2) HOWEVER - If I were building this plane, I would build two battery compartments, one at the plans location, and one approximately 18 inches forward of the plans location. If you ever decide to sell this plane, (or later need to move the CG forward) then the battery can simply be moved to the forward compartment.

 

3) Placard this plane for pilot weight. I guarentee if the W&B is correct for your weight, it will be way aft of the CG limit if a 180 lb pilot jumps in. This will be fatal.

 

NOTE: Your spreadsheet may not call out specifically the weight and FS# of specific components i.e. engine, battery. In this case, you will need to do a good educated guess as to weight and FS#. Do a little research and your weight and FS# numbers should be fairly close.

 

EXAMPLE 1 - The center of gravity of the engine is approximately (MEMORY GUESS) at FS# 150, so if your installing an engine thats 75 lbs heavier than the plans, add 75lbs at FS#150

 

EXAMPLE 2 - The plans battery is about 20lbs at FS14. If you move the battery forward by 18 inches, and install a 28 lb battery, you would need to make two corrections to your W&B. Enter a (minus)20 at FS#14 (to remove the old battery) and add a 28 at FS#(minus)4 (The new battery weight and location) REMEMBER, ALL FS#s are based on the instrument panel being at FS#40.

 

 

You will find a sample W&B with FS#s and sample weights in the Pilot Operating Handbook. DO YOU HAVE ONE?????

 

Waiter

[zies8]

I do not have an operating manual. I will have shortly when I get my new set of plans.

You are right that I should have been refering to the W&B instead of the C/G for most of the equation.

Does anyone know if the canard of the cozy is moved forward? Seems that I read somewhere that it is or the limo is. I'll check the article that Mr. Kridel sent me. If that is the case why should'nt the Long Ez work with the same canard forward position. Ass-u-me ing the the cozy is different. I ......"GUESS"....... the C/G is the same on the Cozy in relation to the main wing.

[Waiter]

Send me an e-mail:

 

waiter (AT) iflyez (DOT) com

 

and I'll hook you up with some W&B stuff

 

As for the Cozy, I don't know. I don't recall anything unusual about the W&B calculations, so either they are very close to or exactly the same as a LongEZ.

 

I've performed several First Flights on Cozy's, and I always review the W&B with the builder and/or the person that performed the W&B. (to make sure they know what they're doing)

 

Take a look at the stuff I send you, If your not comfortable with it, or just can't seem to catch on, This would be a good opportunity to sit down with a someone who has gone through it, or even spend an hour with a CFI doing W&B stuff.

 

Waiter

[Waiter]

CORRECTIONS:

 

Per the LongEZ POH:

 

Normal limits = FS97 to FS103 (Originally FS104, but Rutan moved it forward to FS103)

 

First Flight = FS99 to FS101.5

 

APPROX Engine CG = FS140 (use the engine Oil FS number)

 

Original Battery = FS19

 

Waiter

[Drew Swenson]

The Cozy went through an extensive flight test program to determine the forward and aft limits of the CG envelope. Test pilot wore a parachute and they used a lead weight that could be adjusted in flight to put the aircraft through the extreme CG locations. The flight test revealed that the Cozy needed the lower winglets and several inches were cut off of the canard in increments until they got the envelope where they wanted it.

[longez360]

My CG worked out perfectly. When I first flew the aeroplane I was 286lbs (crikey!!), I'm now 235lbs...

 

I used the O-360, the Wilhelmson nose gear and a tiny 17AH Odyssey battery moved 9" forward in front of NG31. Plan that simple (or with a 320), and find out where you finish up... It's an easy calc in the building process, but not meant to be an exact science. With the Wright nosegear, I didn't need the nose extension for the 360. It does look a damned sight better than the stnadard nose however IMO...

 

I have flown the aeorplane right through the CG envelope and right out to 1975lbs. On the day I did that test (30/12/06), I took off from Leigh Creek airport in South Australia, OAT was 101degF, field elevation was about 860ft. . DA was HIGH! It was the test of tests for my aeroplane.. I climbed out at 1200 ft/min and flew home to Mangalore averaging 201KTAS at 9500ft AMSL, although I pulled it back to 160KTAS with moderate turbulence. The Long EZ is a super SUPER aeroplane! I can't shut up about it. :-)

[Waiter]

I posted my CG spreadsheet on my web site.

 

Take a look at:

 

http://www.iflyez.com/LongEZ_Weight_and_Balance.shtml

 

I hope this helps:)

 

Waiter

[zies8]

I recieved my Long Ez owners manual in the mail and it sheds a lot of light on the process of preparing the airplane for flight. I think that the mocifications that I have in mind will be doable. They are;

1. Considering using the wings and canard from the Cozy. setting up the Long EZ for the specs on the Cozy (namely F/S of Canard and F/S of wing) I am thinking will get me the 1000# gross that I am looking for.

 

Any thoughts???......................Mike

 

 

P.S. Thanks for the Excell spreadsheet Waiter!!!!!!!!!!

[zies8]

I am considering using some of the design criteria for the Cozy on a Long Ez (wing and wing F/S to Canard F/S and canard design). Can anyone let me know what the weigth and balance sheet looks like on a Cozy?

 

First flight envelope.

F/S numbers

 

etc. etc.

 

The Cozy looks like a nice airplane but to get the economy of build and the utility that I am looking for I am going in this direction.

 

Thank you .....................Mike

[zies8]

I am considering using some of the design criteria for the Cozy on a Long Ez (wing and wing F/S to Canard F/S). Does the Cozy Mk IV have larger wings / canard or F/S #s than a Long Ez?

Can anyone let me know what the weight and balance sheet looks like on a Cozy?

 

First flight envelope on the Cozy IV?

F/S numbers on the Cozy IV?

 

etc. etc. on the Cozy IV?

 

The Cozy looks like a nice airplane but to get the economy of build and the utility that I am looking for I am going in this direction.

 

Thank you .....................Mike

[CP Tomes]

iirc from reading through threads, the Cozy uses the same wings (airfoil and planform but have spars?) , canard, and geometry as a Long. I do not know about Long-EZ, but there was an update to the canard incidence jig for the Cozy, and the canard is shorter than the original Cozy plans, so it may be shorter than a Long-Ez canard.

 

I'm in pre-build reading through the plans stage of my Cozy. I have no experience with Long-Ez.

[zies8]

CP; Thanks for the response!! If the Cozy uses the same wing and canard rigging how does the Cozy attain its Useful load which is higher than the Long?

[CP Tomes]

CP; Thanks for the response!! If the Cozy uses the same wing and canard rigging how does the Cozy attain its Useful load which is higher than the Long?

Might also be conservative numbers for the Long-Ez?

 

(waiting for Marc to check in on this forum and correct me...)

[mak790]

CP; Thanks for the response!! If the Cozy uses the same wing and canard rigging how does the Cozy attain its Useful load which is higher than the Long?

check this

http://canardaviationwiki.dmt.net/wiki/index.php/Shareware_complete_plans_for_the_Aerocanard_and_Aerocanard_SB

[raiki]

I am pretty sure the Cozy III used the same wings and canard as the Long, however the Mk IV had an increased wing span to accomodate the extra weight.

 

Long has 26.1ft span and 82ft2 area. Cozy IV has 28.1ft span and 88.3ft2 area.

 

Long has 11.8ft canard span with 12.8ft2 area. Cozy HAD 12.6ft canard span and 14.7ft2 area, however I think these are the old measurements before Nat reduced the canard span to allow a more rearward CG. To lazy to look in my plans at the new maximum canard span. I think 6" was trimmed off (3" off both tips).

[zies8]

In considering use of the Cozy wing design on a Long Ez. I am looking for someone who can come to a conclusion as to how the Cozy structure is carrying the increased useful load. I now know that the E racer has a befed up wing and that the Cozy has a larger wing. Is the Cozy IV wing also beefed up to get the additional useful load over a long?

 

Maybe that I need to post this in a Cozy forum........

 

 

........................Mike

[raiki]

Along with the larger wing, the Cozy IV has extra plys in the bottom and top spar cap, compared to the LongEZ. The Spar Web looks to be the same.

 

These extra plys, approx. 40% more, will definately give the Mk IV a stronger wing. This, combined with the larger span, allow the higher gross.

[zies8]

I knew there had to be something about the Cozy that gives it some kind of logical reason to have a higher useful load.

 

 

Thanks Raki...............Mike:cool:

[raiki]

In the early days, when LonzEZ plans were hard to come by, I thought about buying the Cozy plans, but making it narrow for 2 seats. I think that would be the easier way for your idea. Forget about a longEZ, and make a skinny Cozy.

[zies8]

Raki; You are making sense. I am looking at Cozy plans on ebay as we speak.

 

 

..............Mike in Utah

[tonyslongez]

I have a question. Is the landing gear the same? I think a useful load variable is what the landing gear can handle. I may be wrong. I had an engineer buddy of mine tell me that the Long Ez useful load was governed almost entirely by the landing gears abililty to absorb the higher load, the spar and wings are very capable of handling higher loads, but it's the landing gear that is the determining factor. You can fly a house aorund with the right landing gear on the bottom

[zies8]

Tony: After consulting with the group here that line of logic that I am going to follow is to switch from Long Ezplans to Cozy plans.

This reply to your lasst post would then become a question........Are the Cozy landing gear legs beefed up to take on the 1000 lb useful load of the Cozy? We should be able to assume so.

 

......................Mike

[tonyslongez]

Mike

 

My apologies. I thought I was reading retrofiting cozy wings and canard to the Long Ez. I'll shut up now!

 

Tony

[RGlos]

I'm not exactly sure of this but based on others construction photos, the main gear is wider on the Cozy IV due to the wider fuse.

 

That being said is the wingspan longer because of the extra fuse width or are the wings the same and just sticks out further from the centerline?