Results 1 to 27 of 27

Thread: Wag Aero 2+2 gross weight.

  1. #1

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like

    Wag Aero 2+2 gross weight.

    Hi all, First post on here but have spent a lot of time reading over the years. I am considering scratch building the 2+2. But I am trying to figure out the difference in weight to the PA-14. I want to build it as light as possible and try to keep it as as cub like as I can and hopefully keep my fuel burn down. Can anyone explain the the gross increase on the 2+2 over the 14. Iím guessing it has to do with what wing is usedÖ.. I wonít be building the wood wing so Iíll have to choose from something else. Cheers
    Likes RVBottomly liked this post

  2. #2

    Join Date
    Jan 2007
    Posts
    2,513
    Post Thanks / Like
    Gross weight = max weight (people, fuel, gear). That is determined by several factors including wing, landing gear, fuselage, engine, prop, climb rate. I think you are talking empty weight = plane empty just needs fuel and pilot to fly. I think Javron has about the lightest wing for what you want. You will most likely get your best fuel burn running a 0360. Fuel burn/speed changes little if any with passengers and gear in my cub. I would build the plane to fit your mission. So what is your Mission?
    DENNY
    Likes BC12D-4-85 liked this post

  3. #3
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,252
    Post Thanks / Like
    J-kid, Iím building one and I had the same question. The PA 14 has a max gross of 1850 while the Wag 2+2 says 2200. I spent a lot of time trying to account for the difference but couldnít pin it down.

    Marty57 here is also building one and has a valuable website chronicling his build. He said somewhere he ask an aeronautical engineer to look at the wings and he ended up being comfortable with the Wag GW.

    Iím building a wood wing and I still might get an expertís opinion.


    Sent from my iPhone using SuperCub.Org

  4. #4

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Ok thanks yes thatís my question..
    Yes I looked at a lot of Martyís blog. And also another guy I was talking to has a gross weight around 2900 but it has Pawnee type wing. If I could build it to the same weights as the plans that would be perfect for me. How realistic do you think Wag Aeroís empty weight of a bit over 1000lbs is?? I would want a wing with flaps.

  5. #5

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Quote Originally Posted by DENNY View Post
    Gross weight = max weight (people, fuel, gear). That is determined by several factors including wing, landing gear, fuselage, engine, prop, climb rate. I think you are talking empty weight = plane empty just needs fuel and pilot to fly. I think Javron has about the lightest wing for what you want. You will most likely get your best fuel burn running a 0360. Fuel burn/speed changes little if any with passengers and gear in my cub. I would build the plane to fit your mission. So what is your Mission?
    DENNY
    No I am talking Gross weightÖ I will look into the Javron wingÖ I own a Rans s7s. I Want something that flys similar to the S7 with side by side seating and room for camping gear ect. I really donít want fuel burn over 7gph hopefully. I have looked at the bearhawk for years but I think itís just to big and thirsty for what I want.

  6. #6
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    3,100
    Post Thanks / Like
    How was the GW of the 2+2 determined?

    Gary

  7. #7

    Join Date
    Feb 2011
    Posts
    23
    Post Thanks / Like
    Thirsty is a function of the engine used, have you looked at the bearhawk companion,it looks like what you say you want?

  8. #8

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    I havenít looked at the companion closely noÖ.. last I looked no kits were completed.

  9. #9
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,252
    Post Thanks / Like
    Quote Originally Posted by BC12D-4-85 View Post
    How was the GW of the 2+2 determined?

    Gary
    That's the question. The original designer is long gone and I don't think WagAero has anyone who can say now. I don't know if static tests were ever done or if it was calculations, or what.

    I'm half way through my build and I wonder about it a lot, especially after looking at what Javron and others did to beef up wings after some actual tests.

    It is a lot of work, but I'm contemplating doing static tests on my own. I'd hate to break a wing, but on the other hand, I'd rather break a wing on the ground than in the air.
    Likes BC12D-4-85 liked this post

  10. #10
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,252
    Post Thanks / Like
    Quote Originally Posted by j-kid View Post
    No I am talking Gross weight… I will look into the Javron wing… I own a Rans s7s. I Want something that flys similar to the S7 with side by side seating and room for camping gear ect. I really don’t want fuel burn over 7gph hopefully. I have looked at the bearhawk for years but I think it’s just to big and thirsty for what I want.
    I think around 1000# empty is very optimistic. It is similar to a PA 12 and most of those seem to fall into the 1100-1200 range. Flaps add pounds, of course. Bigger engine than the original O-235 adds weight. Etc.

    7gph is likely optimistic too if you are running a big enough engine to make it worthwhile.

    Also, you might want to look closer at the side-by-side aspect of the 2+2. I widened mine a bit, but it is still going to be snug for "modern-sized" people.

  11. #11
    Wag2+2's Avatar
    Join Date
    Nov 2011
    Location
    West Michigan
    Posts
    185
    Post Thanks / Like
    I did not build the one I have but it’s gross is 2500. The wing is a Riblett 66” from D&E. Good performance at gross. Empty weight about 1300 with an O-360. 9-10 gallons per hour leaned. Seems to be a pretty good combination.
    Likes RVBottomly liked this post

  12. #12

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Yes 1000lbs sounds very optimistic to me. Ok I had seen were some quoted 6-7gph for supper cubes with O360 so I thought a PA-14 would be similar. I am aware of the narrow cabinÖ. I think it would be ok for us. I need to look more at my engine optionsÖ..
    Thanks JeffP thanked for this post

  13. #13
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    11,476
    Post Thanks / Like
    Quote Originally Posted by j-kid View Post
    Yes 1000lbs sounds very optimistic to me. Ok I had seen were some quoted 6-7gph for supper cubes with O360 so I thought a PA-14 would be similar. I am aware of the narrow cabin…. I think it would be ok for us. I need to look more at my engine options…..
    You are dreaming if you expect to regularly get 6-7 gph with the plane loaded. The consumption is related to the amount of power being used. Unless you build in drag reduction details your plane will be flying very slow at that consumption rate.
    N1PA

  14. #14

    Join Date
    May 2017
    Posts
    1,167
    Post Thanks / Like
    Keep in mind that specific fuel consumption (LSA of fuel per hp per hour) goes up as you reduce power. If you are running an engine at low power settings, the fuel efficiency goes down.

    From a practical standpoint, an O-320 will burn close to 8 gallons an hour and an O-360 will be more in the 9-10 gph range. To expect better than that, you are fooling yourself. My O-235 burns about 6.5 per hour, I donít see any way you can run an O-360 at 7 efficiently.


    Sent from my iPhone using Tapatalk

  15. #15

    Join Date
    Jan 2007
    Posts
    2,513
    Post Thanks / Like
    Several factors are involved with fuel burn in fix pitch aircraft like ours. The prop you have and speed you want to cruse at is very important I have a 160 hp 0320 fly with two 180 hp cubs similar to mine in wing and mods. They are both faster and burn less fuel with the same load. I did a long fly around with a 150 hp 0320 also set up like mine and I had a better fuel burn. I went out this weekend and just played around at 6 gal/hr because I was not in a hurry to go anywhere. Came back from Kotz once with a 185 I pushed up to 2650 RPM and he pulled everything back still got to fuel stop 1/2 hour before me and we had about the same fuel burn. Things to ask yourself, how fast do I want to fly? How short of strips do I want to use? What do I want for a climb rate? We need some 0360 fish spotters to add on what kind of fuel burn they are getting. People have a very hard time getting a cub in at 1000 lbs I would say a side by side is going to be hard below 1200. But not to worry they all fly fine. DENNY
    Likes Crash, Jr. liked this post

  16. #16
    Marty57's Avatar
    Join Date
    Jan 2005
    Location
    Nipomo, Ca
    Posts
    1,472
    Post Thanks / Like
    Quote Originally Posted by RVBottomly View Post
    J-kid, Iím building one and I had the same question. The PA 14 has a max gross of 1850 while the Wag 2+2 says 2200. I spent a lot of time trying to account for the difference but couldnít pin it down.

    Marty57 here is also building one and has a valuable website chronicling his build. He said somewhere he ask an aeronautical engineer to look at the wings and he ended up being comfortable with the Wag GW.

    Iím building a wood wing and I still might get an expertís opinion.


    Sent from my iPhone using SuperCub.Org
    A few points about the 2+2; I'm covering mine BTW so hope to be done soon. I had to modify my wood spar to clear the lift strut; I think I had to sand a curve about 3/16" deep over a 3" area of the front spar; the modification scared me. I consulted a friend; aero engineer; who ran the numbers for me. The mod reduced the strength of the spar to something like +/-10G's at 200 knots vs the original of +/-12 g's at 250 knots. Bottom line, the wing is overbuilt. I know that isn't the only factor in GW but the wing is definitely strong. Regarding fuselage size, I chose not to widen my fuselage because modifications to one dimension seems to have a cascading effect on way to many other unforeseen issues down the line. I handled the narrow fuselage by having my seats on sliding tracks. Unless I'm getting instruction from someone with the same short stance as me, sliding one seat back keeps the shoulders from touching, making it fit a lot better. Yes, it is narrow but how often will I really fly with someone else up front? I also added flaps to my wing, and I added the standard bow wing tip so that made changes to my wing; again everything is wood. The weight of my wing (uncovered, no cables, tank, or tank bay cover) was 64 lbs. That includes the modification I made to remove the cross brace in the fuel tank bay and put a 1/8" plywood shear plate under that tank bay; again after getting calculations done to support the change. All in all, my 2+2 wing is a lot different from the plans but it still seems to be very light and strong. I feel pretty good about the 2200lb gross weight in the plans but likely won't operate at that weight since I'm using a O290D2 so my HP is a bit limited. I attached my modified drawings for my wing.

    Marty57

    Click image for larger version. 

Name:	Wing layout for SC.jpg 
Views:	35 
Size:	440.0 KB 
ID:	58009
    Attached Files Attached Files
    Last edited by Marty57; 10-20-2021 at 12:48 AM.
    N367PS
    Psalm 36:7 "High and low among men find refuge in the shadow of His wing"
    www.marty2plus2.com
    Likes RVBottomly liked this post

  17. #17

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Ok thanks for all the info.. I have only ever had a rotax so it takes a bit to get my head around the different engines. I realize there is no free lunch and I donít mind putting a bit of fuel in if Iím loaded up and going somewhere. But I still hope to be able to fly around locally without feeling like Iím speeding all my money on fuel.

  18. #18

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Quote Originally Posted by Marty57 View Post
    A few points about the 2+2; I'm covering mine BTW so hope to be done soon. I had to modify my wood spar to clear the lift strut; I think I had to sand a curve about 3/16" deep over a 3" area of the front spar; the modification scared me. I consulted a friend; aero engineer; who ran the numbers for me. The mod reduced the strength of the spar to something like +/-10G's at 200 knots vs the original of +/-12 g's at 250 knots. Bottom line, the wing is overbuilt. I know that isn't the only factor in GW but the wing is definitely strong. Regarding fuselage size, I chose not to widen my fuselage because modifications to one dimension seems to have a cascading effect on way to many other unforeseen issues down the line. I handled the narrow fuselage by having my seats on sliding tracks. Unless I'm getting instruction from someone with the same short stance as me, sliding one seat back keeps the shoulders from touching, making it fit a lot better. Yes, it is narrow but how often will I really fly with someone else up front? I also added flaps to my wing, and I added the standard bow wing tip so that made changes to my wing; again everything is wood. The weight of my wing (uncovered, no cables, tank, or tank bay cover) was 64 lbs. That includes the modification I made to remove the cross brace in the fuel tank bay and put a 1/8" plywood shear plate under that tank bay; again after getting calculations done to support the change. All in all, my 2+2 wing is a lot different from the plans but it still seems to be very light and strong. I feel pretty good about the 2200lb gross weight in the plans but likely won't operate at that weight since I'm using a O290D2 so my HP is a bit limited. I attached my modified drawings for my wing.

    Marty57

    Click image for larger version. 

Name:	Wing layout for SC.jpg 
Views:	35 
Size:	440.0 KB 
ID:	58009
    Thanks Marty thatís great info. Iíll look at it more closely on the weekend. Hopefully the wag aero plans will turn up soon. What sort of cruise speed do you expect to get? I plan to fly a lot with my wife but she is not very big, I am 6ft but Iím not very wide, from my measurements I think we will fit okÖ. And itís part of the reason I like itÖ. I donít want something big.

  19. #19

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    I know you guys are not into rotaxís but would I run into big weight and balance issues with something like a Rotax 915? Probably about 215lbs including the propÖ.

  20. #20
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,252
    Post Thanks / Like
    Quote Originally Posted by j-kid View Post
    I know you guys are not into rotax’s but would I run into big weight and balance issues with something like a Rotax 915? Probably about 215lbs including the prop….
    Run the W&B numbers, move it forward if necessary.

    Quite a few have Rotax engines here. The main reason I don't look at them is the price. That, and horsepower is a little low for this application.

  21. #21

    Join Date
    May 2017
    Posts
    1,167
    Post Thanks / Like

    Wag Aero 2+2 gross weight.

    Quote Originally Posted by j-kid View Post
    I know you guys are not into rotaxís but would I run into big weight and balance issues with something like a Rotax 915? Probably about 215lbs including the propÖ.
    An O-320 dry is around 250, and am M74DM prop is another 32 lbs. 8 qts of oil another 16 lbs. figure another couple lbs for baffles, oil cooler, and 16 lbs for the exhaust.

    Add all that up, then figure the weight of the 915 ready to go with all fluids, exhaust, baffles, radiator and prop. That will give you an idea where you stand.

    Not a real fan of Rotax engines, but if you are out west and need to operate from high density altitudes, you canít beat something with a turbocharger.


    Sent from my iPhone using Tapatalk

  22. #22
    Marty57's Avatar
    Join Date
    Jan 2005
    Location
    Nipomo, Ca
    Posts
    1,472
    Post Thanks / Like
    Quote Originally Posted by j-kid View Post
    Thanks Marty that’s great info. I’ll look at it more closely on the weekend. Hopefully the wag aero plans will turn up soon. What sort of cruise speed do you expect to get? I plan to fly a lot with my wife but she is not very big, I am 6ft but I’m not very wide, from my measurements I think we will fit ok…. And it’s part of the reason I like it…. I don’t want something big.
    I suspect the cruise will be like a 12, maybe 110. It's a bit faster than an 18 due to the different AOA of the wing attach points. The 18 gives you shorter take off but slower cruse, 12 and 14 a bit longer takeoff but higher cruse; it's all about tradeoffs.

    Marty57
    N367PS
    Psalm 36:7 "High and low among men find refuge in the shadow of His wing"
    www.marty2plus2.com

  23. #23

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Quote Originally Posted by RVBottomly View Post
    Run the W&B numbers, move it forward if necessary.

    Quite a few have Rotax engines here. The main reason I don't look at them is the price. That, and horsepower is a little low for this application.
    Good to know there is some rotax ones out thereÖ I havenít been able to find much info on Rotax powered Cubs.

  24. #24

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Itís given me a heap to mull overÖ I need to sit down and run some numbers. I suspect that a 915 with a constant speed airmaster prop, having the turbo would preform similar to a 160hp lycoming, both operating at 3000ft on a warm day. Most of my operation is at around 2500 DA. 50% of the time with about 220lbs load 30% around 400lbs and 20% at 500lbs
    Air strips are dirt around 2000ft with rising terrain to about 500ft agl
    Thanks again

  25. #25
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,252
    Post Thanks / Like
    Quote Originally Posted by j-kid View Post
    Good to know there is some rotax ones out there… I haven’t been able to find much info on Rotax powered Cubs.
    I suppose I should have been clearer. I don't know of any actual Cubs with Rotax engines. But some here have Rans or Kitfox airplanes with Rotax. Now I remember you said you have a Rans S7.

    Long ago I was thinking a Wagabond project would love a Rotax.

  26. #26

    Join Date
    Oct 2021
    Posts
    11
    Post Thanks / Like
    Put it another way if I end up with 1250lbs empty weight + 480load = 1730lbs, I would want a climb rate not less than 700ftm at 3500 DA to feel safe.

  27. #27
    brown bear's Avatar
    Join Date
    Feb 2004
    Location
    emporia ks
    Posts
    600
    Post Thanks / Like
    dont kid yourself it still takes fuel to make horsepower
    https://bydanjohnson.com/flying-the-...ring-to-912is/

Similar Threads

  1. Gross weight STC
    By MarcR in forum Modifications
    Replies: 34
    Last Post: 12-10-2004, 12:17 PM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •