G loading for MkIV Flyer

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Posted · Report post

Hello All,

Because importing already built Avid Flyer to Finland I have to state load factors to Finnish CAA.

I haven't succeeded to find those from the documents delivered with the plane.

She has Speedwing ribs and Heavy Hauler span. What are load factors for Speedwing and Heavy Hauler?

+3.8?

-1,5?

Picture attached. Still old markings painted...

Regards,

Kekkuli

post-177-12835888396414_thumb.jpg

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Posted · Report post

According to Avid Aircraft Brochure:

AVID FLYER MK-IV HEAVY HAULER SPECIFICATIONS

Wing Span- 29 ft. 10.5 in.

Wing Area- 122.46 sq. ft.

Wing Chord- 42 in.

Wing Chord Including Flaperons- 51 in.

Aspect Ratio- 7.29

Wing Loading @ Gross- 9.39 lbs.

Length- 17 ft. 11 in.

Length with Wings Folded- 19 ft. 9.5 in.

Width with Wings Folded- 7 ft. 9.5 in.

Width of Horizontal Stabilizer- 93 in.

Height- 71 in.

Cabin Width- 39 in. (not including bubble doors)

Across Ears (upper carry thru tube)- 33.5 in.

Across Seat Truss- 35 in.

Across Bottom of Panel / Knees- 33 in.

Seat Truss to Firewall- 25 in.

Toe Room (Cross Tube to Floor at Firewall)- 11 in.

Across Panel- 29 in.

Empty Weight- 440-510 lbs.

Gross Weight- 1150 lbs. (+4.4 / -2.2 G's)

Useful Load- 540 lbs.

Fuel Capacity- 26 US gal. + Header

Fuel Consumption- 4 gal./hr

Cruise- 90-100 mph

Range @ 65%- 500 mi.

Endurance w/ reserve- +5 hrs.

AVID FLYER HEAVY HAULER PERFORMANCE

Stall Speed- 32mph solo, 36mph gross

Never Exceed Speed (VnE)- 135mph

Rate of Climb- 1700fpm solo, 1000fpm gross

Climb Angle - 45 solo, 28 gross

Best Rate of Climb Speed (VY)- 45mph solo, 50mph gross

Best Angle of Climb Speed (VX)- 40mph solo, 50mph gross

Takeoff Distance- 90ft solo, 140ft gross

T/O Over 50ft Obstacle- 200ft solo, 350ft gross

Landing Distance- 150ft solo, 200ft gross

Service Ceiling- 12,500+ ft

* Performance with liquid cooled 65hp Rotax 582 and Rotax 3.0:1 model "C" gear reduction drive at sea level and standard temp conditions.

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Posted · Report post

According to Avid Aircraft Brochure:

AVID FLYER MK-IV HEAVY HAULER SPECIFICATIONS

...

Thanks for the Heavy Hauler specs & perf.info.

Does th Speedwing have different load factors?

Anybody knowing Speedwing numbers?

Kekkuli

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Posted · Report post

Well...

Do you have the full length 144" long spars, or the short speed wing/aerobat spars with spliced-in wing extensions?

What is the spar material thickness, .083 or .065?

What is the rib spacing, 12" or 18" O.C.?

Do you have wing tanks that replaced certain internal drag support tubes?

Lots of factors come into play with 'custom' wings. For G loads, I would [think] that wing construction matters more than the rib profile and, personally, I would use that as my guide. BIG caveat though, I'm not an aeronautical engineer so take my comments with a grain of salt.

Unfortunately I don't believe Avid ever published G-loads for wing configurations other than their four 'official' wings, differences detailed HERE.

Maybe that helps some, good luck.

P.S. - Nice looking Avid! Be sure to support the tail when trailering with wings folded to prevent broken tail spring.

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Posted · Report post

I also believe that these were working loads with the 150% safety margin, I have seen testing that takes it much beyond the 4.4 G load. where as Zenith publishes ultimate load.

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Posted · Report post

Well...

Do you have the full length 144" long spars, or the short speed wing/aerobat spars with spliced-in wing extensions?

What is the spar material thickness, .083 or .065?

What is the rib spacing, 12" or 18" O.C.?

Do you have wing tanks that replaced certain internal drag support tubes?

Lots of factors come into play with 'custom' wings. For G loads, I would [think] that wing construction matters more than the rib profile and, personally, I would use that as my guide. BIG caveat though, I'm not an aeronautical engineer so take my comments with a grain of salt.

Unfortunately I don't believe Avid ever published G-loads for wing configurations other than their four 'official' wings, differences detailed HERE.

Maybe that helps some, good luck.

P.S. - Nice looking Avid! Be sure to support the tail when trailering with wings folded to prevent broken tail spring.

Thanks, I also like how she looks :-)

Not knowing what that spliced in wing extension looks like... Based what I read from the papers, I assume that it has been built using full lenght 144" spars.

Thickness of the spar walls is 2mm => 0.083".

Rib spacing is that 12".

So at least those seem to be built closer to Heavy Hauler specs.

Wing tanks on both sides. Total capasity 130 liters => 36 gal. Thank is 24" long in each side (replaces at least one rib),

but I don't know what the structure is inside the wing...

About the tail spring... That advice came a tad too late. I towed the thing around 1500 km => 940 miles to get it

here (Finland). The spring seems to be ok, but thanks for the hint. I hope that I don't have to tow it too much any more :-)

Kekkuli

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Posted (edited) · Report post

Help me understand the G-loading question. In looking for load ratings for the different wings used on the Mk IV, I think I have this right:

Gross Weight G-load Wing Span

Speedwing: 1050 +6/-3 23' 11.5"

Heavy Hauler: 1150 +4.4/-2.2 29' 10.5"

My question is, if the Speedwing is +6/-3 at 1050, how does that change with increased weight? My simple calculation is 6 X 1050 = 6300 pounds loading. 6300/4.4 = 1432. So why not set the max gross at 1432? Or set it at 1320, and have a G-load of 4.77? If someone can direct me to authoritative load ratings for the other wings, I would appreciate it. Thanks.

Edited by Dwight B Van Zanen

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Posted · Report post

Help me understand the G-loading question. In looking for load ratings for the different wings used on the Mk IV, I think I have this right:

Gross Weight G-load Wing Span

Speedwing: 1050 +6/-3 23' 11.5"

Heavy Hauler: 1150 +4.4/-2.2 29' 10.5"

My question is, if the Speedwing is +6/-3 at 1050, how does that change with increased weight? My simple calculation is 6 X 1050 = 6300 pounds loading. 6300/4.4 = 1432. So why not set the max gross at 1432? Or set it at 1320, and have a G-load of 4.77? If someone can direct me to authoritative load ratings for the other wings, I would appreciate it. Thanks.

Huh? :dunno: Your getting way to serious about these little airplanes. I are pilot :BC:

Here ya go

cessna185skywagon_360.jpg

Horsepower: 300 Gross Weight: 3300 lbs

Top Speed: 153 kts Empty Weight: 1560 lbs

A 185 should clear up any gross weight concerns you might have.

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Posted (edited) · Report post

Huh? :dunno: Your getting way to serious about these little airplanes. I are pilot :BC:

Here ya go

A 185 should clear up any gross weight concerns you might have.

Yes. Very serious. I would still like to see information on the G-laod for the other wings, and some information on issues with increased loading. I have seen a Mk IV STOL with a max gross listed as 1320, but the flight testing seems to have all been done at 1070. If the engineering results in a +6/-3 for the Speedwing, then it seems like added weight is not an issue for the wing structure. Ihe issue would be performance, stall speed, climb rate, ceiling... If that is right, it seems like a change of gross weight to something a little higher ought to be approved if you do some flight testing (as a major alteration) at the higher weight to determine the performance is all acceptable. Again, am I missing something here? Why would this work/not work?

Another post on this issue said simply, you have no weight limit on an EXP. The implication is that the statement in the operating limitations requires the flight test information to be recorded in the log book, but that is not a weight limit. The W/B done when you submit your program letter signed by the DAR is just the first W/B and you are free to make a new one anytime. The data plate on the tail has a spot for gross weight, but builders are told to leave it blank by EAA. You are free to load as much as you want, and "experiment". That just did not seem right to me. Another post, on another forum, said a weight change proposal is handled just like any other major alteration, with some flight testing in a test area.

Has anyone proposed a weight increase after phase 2 testing? And what was the process you were required to follow? And was it approved? Thanks.

Edited by Dwight B Van Zanen

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Posted · Report post

It is an experiment, your experiment. If you want to up the weight you carry in the plane do it! Unless it is a factory built LSA then there is NO Gross weight other than that "reccomended" by the factory. They have no idea if your going to do a shitty build job or not so there is some "fudge" factor in there. At the end of the day, these planes are NOT CERTIFIED to ANY standards that would really apply to factory built planes.

You can go down to the hardware store and cobble together a EMT conduit and cover it with a tarp and still be legal to fly the thing. NOTHING is said that you have to use certified materials, certified techniques, or a certified mechanic.. you build them in the garage or the living room, some guy comes out and looks it over and gives it his best JUDGEMENT that it wont fall apart while you are beating the air into submission, and away you go to do your flight testing.

OK, so here is where it gets good.. Do you HONESTLY think that everyone does flight testing like we are getting ready to lauch a new fighter aircraft... Um, NO. Guys take off, and if all goes well the first flight and the plane does not beat the ambulance to the scene of the crash, they will go up and do some stalls. Some will record numbers, but most just kinda try and remember the numbers when they land. There is no hard fast regimented flight testing program for a low slow flyer. If I was building a thunder mustang or some high zuite go fast turbine powered retractable rocket, I may be a bit more inclined to go A HELL OF ALOT SLOWER on the flight testing, and test out one system at a time till I am sure everything plays well with each other.

Guys doing weight testing while in phase one.... I got a pay check that says 90 + % of the guys that build the plane and do their own flgiht testing dont just bump it up in 25 or 50 # load increases until they hit gross. I would even venture to say that most dont really put the weight on a scale to assure that they are DEAD on the weights. They take off the first flight solo with half, maybe full tanks, if all goes well, they burn the hell out of the sky and may put some weight in there just for shit and grins while doing phase one... maybe not! I cant tell you how many times I have heard "damn, when I got my phase I done and actually got to fly a passenger, I cant beleive how much the performance decreased". That pretty much tells me that they NEVER. loaded that plane up to gross in phase I.

Take it for what it is worth, but I can tell you that the FAA paperwork does not have a gross weight listed so you can put what ever you feel like in it and fly as long as it is in the published CG range. There have been soo damn many "gross weights" on the Avid and KF line that I dont think anyone can honestly tell you what the older model planes are really good for. If its not blowing 90 out and is smooth air, I will load mine down. If I know it is gonna be bumpy, I pull the power back a bit and dont load quite so heavy.. Easy enough for me.

:BC:

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Posted · Report post

Good, honest explanation of the 'system' we work with!

Thank you!

Dave

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Posted · Report post

Very interesting. Thanks. That will make it easier to do what I think I want to do. I was not worried about the structure of the speedwing, just the process to keep it "legal". If no process is needed, beyond what I think I need to determine it will fly safely, that works for me.

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