Max pilot weight?

[mcjon77]

Does anyone have an idea what the maximum pilot weight is for a long-ez, and still remain in CG. For this example, lets assume it has an O-320.

 

Jon

[Firefly-YCTTSFM]

I'll hit the softball, so others can do the hard part:

 

"It'll vary from plane to plane based on empty CG, ballast, fuel, and other payload."

 

My opinion: posts here imply that O-320 EZ's tend to be near the aft-end of the CG limit and often require ballast in the nose. Based on numbers from my terribly out of date manual, I would think the limiting factor to the heavy pilot would be the gross weight (or the fuselage width), not the CG. Lighter pilots on the other hand might need a lot of ballast.

 

Caveat: the weight & CG limits for first flight are much tighter. I can see where a heavy pilot in a lop-sided airplane can run into trouble trying to make first flight.

 

But do the math and see what you get.

[Waiter]

Pilot weight has the most impact on CG. Most EZs are built with one particular Pilot in mind, and often, ballast is added/subtracted to adjust the weight for that particular Pilot.

 

As Firefly mentioned, LongEZs tend to run aft CG.

 

I would be very concerned if the scenerio were reversed, i.e. A Pilot who weighs 275 lbs in an EZ with mid to aft CG, just sold his EZ to a Pilot who weighs 170 lbs.

 

If the CG was at 103.0 with the 275 lb Pilot, the CG would shift aft to 108.0 when the 170lb Pilot got in.

 

The Bottom Line - As for Pilot Weight, I would say, if you can fit in it, (and the CG is OK) then you are good to go.

 

Waiter

[Kent Ashton]

A Cozy III is essentially a side-by-side LEZ. I flew my C-III with around 400 pounds in the front seats and once with around 450. Less than 400 was not too bad but it still makes the takeoffs longer and crashes less survivable due to higher glide speeds. The forward CG limit is more of a guide than an absolute number.

[saybeengineering]

I have a Long EZ with 0-320. Pilot weight, in this plane, is from a minimum of 180 lbs. to a maximum of 250 lbs to be within the CG range. I also ditto with the above comments with respect to empty weight, fuel and other characteristics....I am currently 235#, usually fly solo and it flies great.....

 

Cheers,

[michaelj]

Mostly agree with the preceeding comments. My 0320 Longez cg range allows for 400# in the front seat with 20 gallons of fuel. Realistically, you can't get a pilot in the front seat that weighs much more than 250 anyway. I weigh 170 and have to run some ballast in the nose. My son weighs 240 and barely fits in the airplane. His shoulder width is what is limiting his ability to fit, not the weight. There are some pretty good weight and balance spreadsheets available for free. Try entering "longez weight and balance" in your brouser.

[Waiter]

There are some pretty good weight and balance spreadsheets available for free.

www.iflyez.com

 

Look on the left side under "HOW TOs", click on "WEIGHT and BALANCE"

 

Waiter

[mcjon77]

I've heard the shoulder width issue mentioned before. Just how wide is the long-ez at the shoulders?

[Edge 513]

Funny story relating to this original posts question. I have been attempting to resist, but...

I title this, "If the Cockpit fits, wear it".

 

A lot has been said about the single seat Fighter-like cockpit of the LongEze. "It fits like a glove". "You wear this plane, you dont just sit in it". "The semi-reclining cockpit snuggs around you like a Formula Race car."

Welllllllll...

 

First though.

Was it Burt or Nat that made some remark about if you were too fat to fit in the front seat easily...go build yourself another airplane. I dont remember which, what or who exactly...

That did however, give me cause to pause when I heard it. I weighed 245 at the time.'Course I was building a Cozy. Hmmm.

 

Second. The story.

I was watching a guy crawl out of his L.E after a flight to a fly-in once and, I remarked to him as he was attempting to shed the front cockpit as if he were a snake and it was a second skin. I mean THIS GUY was Houdini. He was a LARGE Houdini. A veritable XXXL sized Houdini. How in hades did he get IN there in the first place??? Well maybe only a doubleXL...I dunno.

So I said, "Sure doesnt fit like it used too"..attempting to be lighthearted.

"Ooopfhh, ahhhhhHHH, OH sh%#*T, ahhhhUghhh",and out he popped..like a cork out of a bottle up onto the strake. He grinned and said, "Man am I glad to get that clipboard outta my ass". I said "Whaaa?". Him, " Yea I gotta lose some weight. I slid down into the seat and my little clipboard with my checklists slipped offmy armrest and sideways onto my seat. I first thought no big deal, but in moving around to try and get it out, and I couldnt, I been riding with that clip thing stuck in my crack for the last 3 hours and that AINT FUN".

So the moral of that is what you make of it. But if you cant maneuver your hoover in the seat well enough to retrieve your clipboard, it's time for some kinda change in the diet department. Or build a bigger plane, according to Nat or Burt or Harry Houdini.

[Wayne Hicks]

Maybe you oughta give the guy some slack.

 

If he built the plane, I bet he wasn't that weight when he started building it. I was 185 when I started building my Cozy eleven years ago. I weigh alot more than that today. It's a fact of life for those of us not genetically pre-dispositioned for thinness or who travel too much to eat and exercise regularly.

 

Did he have a smile on his face? 'nuff said.

[Edge 513]

The guy was chuckling.. It was a not a bad thing. No slack needed. We joked together about me stopping my then current fast food eating habits. "As you eat more fast food, you move less and less fast to get it".

I offered the story and BURT/Nats axiom as a tongue in cheek observation.

...sheeesh Wayne! You think I was pointing my finger at the guy and...?...

 

Oh well.

[Wayne Hicks]

No need to sheeesh Wayne me. The story is funny. I'm just putting it out there so folks know that few folks rationally decide to build a plane they won't fit in comfortably.

[Edge 513]

No need to sheeesh Wayne me. The story is funny. I'm just putting it out there so folks know that few folks rationally decide to build a plane they won't fit in comfortably.

Well said.

Nobody plans on getting fat. It just happens one bite at a time. Ask me how I know.

I did change my eating habits and reduced almost 55 pounds and now with this medication I have been taking, I have gained 30 back. Age is a pain in the neck. Cant wait to get off this med.

I'll sheeeesh myself...

Cheers,

[Orinoco]

I, on the other hand have the opposite problem. I'm as fat as I've ever been at 136 pounds (5'6" tall) this morning. Has anyone ever put a O-320, 160 hp in a Cozy? My wife and I together weigh about 265. How about a water ballast system using a bladder which could be stored easily when not needed?

 

Laying up the shear web on the canard today.

 

Mike

[argoldman]

I, on the other hand have the opposite problem. I'm as fat as I've ever been at 136 pounds (5'6" tall) this morning. Has anyone ever put a O-320, 160 hp in a Cozy? My wife and I together weigh about 265. How about a water ballast system using a bladder which could be stored easily when not needed?

 

Laying up the shear web on the canard today.

 

Mike

 

Not only can it be stored but you can fill it enroute if you deplane a passenger.

 

(also may come in handy for CG shifting on long flights)[forward shift of liquid weight for those of you not awake yet]

[Marc Zeitlin]

...Has anyone ever put a O-320, 160 hp in a Cozy?

Yes, there are a few flying - Kevin Funk's MKIV, for one that's been flying for a long time.

 

How about a water ballast system using a bladder which could be stored easily when not needed?

Bad idea - water is nowhere near dense enough. Takes up WAY too much space for the amount of weight needed. Steel is 7.8 times as dense, and lead about 13. You'll never find enough space to use water. Or at least you won't want to.

[argoldman]

C'mon Marc,

 

You have heard of Heavy Water haven't you???

[Cozy1200]

You have heard of Heavy Water haven't you???

Isn't that stuff radioactive or something like that?

[mfryer]

Not only can it be stored but you can fill it enroute if you deplane a passenger.

 

(also may come in handy for CG shifting on long flights)[forward shift of liquid weight for those of you not awake yet]

And also what would happen if your system leaked?

[argoldman]

And also what would happen if your system leaked?

similar to the moist feeling, in the seat of your pants, one might get after a near miss:irked:

 

 

Of course you could ask the same question about the fuel tanks.

 

It behooves us, when designing an unproven mechanism, to do so that it doesn't fail in normal or abnormal service. (don't use grocery bags for containing the H2o perhaps a thicker polyethylene type material with securely closing top (kinda like portable fuel tanks) is in order. You could even make the nose cone a self-contained balast tank with filling and draining fixtures built in.

 

I believe that he Concord used fuel shifting from aft to forward tanks to change the CG of the aircraft as the CL changed when going supersonic.

 

I think that Marc's weight limiting comment was more to the point, if great (relative term) nose weight is needed.

 

The amount of weight needed can be roughly predicted, preliminarily, by doing a W&B calculation.

 

If you need more weight than water can provide in the limited space, what about using sand rather than water. This material is readily available at most places. Measurement of weight is quite easy with a small spring scale. The design obstacle that one has to work with this, of course is how to remove it, if necessary, (water can be relieved with a valve), however the sandy solution is not undoable.

 

 

the real design challenge, here, is to design a mechanism, as far forward as possible (to reduce weight necessary) which uses a locally available material, which can be removed and disposed of so you don't have to carry it somewhere else in the plane when CG concerns make it necessary to remove it.

 

If you always fly with the same pilot and G/BIS (girl/boy in side) permanent nose ballast (or none depending on what's in front) is great. (assuming that the back seat load doesn't mail you out of the envelope.

 

If the weight and distribution is variable, especially in the same trip, then this type of addressment might be in order

[Waiter]

If your considering using water for ballest, keep in mind that when water freezes, it expands and can rupture tanks, plumbing, etc.

 

Waiter`

[argoldman]

If your considering using water for ballest, keep in mind that when water freezes, it expands and can rupture tanks, plumbing, etc.

 

Waiter`

Good thought,

 

I forgot to mention to carry a small bottle of anti-freeze if you leave empty and want to drop off a front seat passenger. (you could also carry some salt to dissolve in the water that you add.) If you take off with a load of water ballast, anti-freeze it. (if conditions and your max altitude warrants) the sand idea sounds better all of the time.

[TMann]

Good thought,

 

I forgot to mention to carry a small bottle of anti-freeze if you leave empty and want to drop off a front seat passenger. (you could also carry some salt to dissolve in the water that you add.) If you take off with a load of water ballast, anti-freeze it. (if conditions and your max altitude warrants) the sand idea sounds better all of the time.

Sand or shotbags. Pretty easy to move around.

In my plane, if I drop off the front seat passenger .......... well, lets just say that would not make the backseat passenger happy.

[Marc Zeitlin]

... If you take off with a load of water ballast, anti-freeze it. (if conditions and your max altitude warrants) the sand idea sounds better all of the time.

So let me get this straight. Assuming that you need somewhere in the neighborhood of 50 lb. of ballast in the nose of your COZY when flying solo (that's what small/medium size folks seem to need for W&B reasons), you can either carry:

 

1) just under one cubic foot of water (try to find a place for THAT much volume in the nose)

 

2) 10% less than (1) of heavy water (yes, I know it was a joke)

 

3) 1/2 cubic foot of sand (and I'm sure there'll be a sandbox somewhere on the airport for you to grab some from, not to mention the fact that you'll never know exactly how much it weighs, since the density varies with type, moisture content, etc.)

 

4) ~1/8 cubic foot of steel

 

5) ~1/11 cubic foot of lead

 

The steel and lead will fit in the plane. The water and sand will not. Yes, you need to carry the steel and lead around with you when you might not need it, just like your toolkit, O2, jumper cables, extra tires/inner tubes, full fuel tanks, or any of the other things that are necessary for safe flight preparation.

 

There's a reason that no one uses water or sand for ballast in planes. It's not like they're brand new materials that no-one's ever heard of before, or hasn't thought of before.

[argoldman]

So let me get this straight. Assuming that you need somewhere in the neighborhood of 50 lb. of ballast in the nose of your COZY when flying solo (that's what small/medium size folks seem to need for W&B reasons), you can either carry:

 

1) just under one cubic foot of water (try to find a place for THAT much volume in the nose)

 

2) 10% less than (1) of heavy water (yes, I know it was a joke)

 

3) 1/2 cubic foot of sand (and I'm sure there'll be a sandbox somewhere on the airport for you to grab some from, not to mention the fact that you'll never know exactly how much it weighs, since the density varies with type, moisture content, etc.)

 

4) ~1/8 cubic foot of steel

 

5) ~1/11 cubic foot of lead

 

The steel and lead will fit in the plane. The water and sand will not. Yes, you need to carry the steel and lead around with you when you might not need it, just like your toolkit, O2, jumper cables, extra tires/inner tubes, full fuel tanks, or any of the other things that are necessary for safe flight preparation.

 

There's a reason that no one uses water or sand for ballast in planes. It's not like they're brand new materials that no-one's ever heard of before, or hasn't thought of before.

 

Easy for you, light of weight (but by no stretch of the imagination a light-weight), to say, Marc.

 

I will probably have to add helium to my nose to get into proper CG. (but then I will probably talk in a very high pitch for a while)

 

Is it my imagination but don't some sail planes use water for ballast???

 

1 ft cubed for water might be hard to find, however 1/2 foot, if that is all that is needed seems to be about the size of the volume forward of the forward bulkhead FS0. Or the volume can be increased (and the total weight of ballast decreased) by elongating the nose (for those lighter ones --- jealousy speaking here).

 

Sand, dirt or mud is usually available either on, or close by most airports, if needed. The airborne aquarium can be, of course used, with fillers, to safely carry lead or steel shot, ingots or anvils, concrete, or anything of the correct weight, that will fit through its opening.

 

As a matter of fact in rereading the above statement, why not use mud:rolleyes: you get the best of both worlds. (as inelegant as the thought is)

 

Yes, you are absolutely right about the variation in the density of different sand. That's what the spring scale is for.

 

If using steel or lead, both great, some method should be incorporated in the baggage area for securing the ingots, or whatever, when not secured in the nose. 50 Lbs of lead and 50 lbs of feathers weigh the same, but I would rather be hit by the feathers;) In a multi-g "arrival" ie 4 G, those metal things (at 50#) will have an equivalent weight of 200#.

will the standard baggage tie-down (are there any) withstand that kind of force??

 

Thanks again for your talk and your brutal self evaluation (no less expected from you) at the banquet. It was so right on, as shown by some of the posts that have been flying hither and Yon. I hope that we all learned from it. Keep plugging away.