Wing upgrade

[twain66]

Hi, I have recently purchased a sonerai 2L with type 'A' wing.
Does anybody have plans specific to upgrade To type 'B' wings.

[soneraifred]

For a copy of the A-wing modification drawings, contact me off line at [e-mail]

[edolejsi]

What is the difference between the two versions? I just purchased a Sonerai II L.
Thanks,
Ed

[soneraifred]

Ed:
There are four versions of the Sonerai II wing. They are all the same length and chord, and all use the same NACA 64A212 modified airfoil.
1. The "A" wing was the original design wing. It has nine wing ribs in each panel, with each of the ribs attached to the main spar with a pair of 1/8" stainless Cherry "N" pop rivets.
2. The modified "A" wing: In 1983, Monnett Experimental released a service bulletin requiring the modification of the original "A" wing if the owner wished to fly aerobatics in the airplane at 750 lbs gross weight. This modification consisted of the addition of 1-1/4"x1-1/4"x1/8" aluminum angles to the top set of spar caps, plus the addition of the 1"x1"x1/8" aluminum angles at the front and main rib attachments to the main spar for the first five ribs and mid way between these ribs. There is also a sheet aluminum reinforcement on each rib where the angles attach. This mod significantly increased the safety margin to failure when performing aerobatics.
3. The "B" wing followed the release of the "A" wing mod, and incorporated the mods, along with two extra ribs in the inboard half of the wing, resulting in 11 ribs in each panel. The primary reason for the the extra ribs was to make it easier to incorporate a wing walk for the low wing airplane.
4. The "S" wing was released when the "stretched" version of the airplane was introduced. The "S" wing and the "B" wing are essentially the same with one exception. On the "A" and "B" wings there are LH and RH wing ribs, meaning that in the right wing all of the rib flanges point to the left toward the fuselage, and in the left wing, all of the rib flanges point to the right toward the fuselage. In the "S" wing, all of the wing rib flanges point to the left, meaning that in the left wing the rib flanges point away from fuselage. This results in some slight structural differences in the left wing.

With all of this being said, the modified "A" wing, the "B" wing, and the "S" wing are structurally equivalent, and allow the gross weight to be increased from 950 lbs for the original "A" wing to 1150 lbs.

I hopes helps clarify things a bit. (For those of you with copies of the back issues, there is more information on page 3 of the April-May-June 1997 issue.)

[stepo]

Hello.
I am glad this thread has come up again . I have a Sonerai 1. part built . Spars and ribs made to the original 1972 plans(8 ribs) ribs not fitted yet, spars rivetted and signed off. i want to add the S mod while it is at this stage. . i have the S mod plans for the Sonerai 2.( not very clear)
I have studied the forum and forum seach for weeks but not found an answer.
My question is
How long are the 1-1/4 x 1- 1/4 x1/8 aluminun angles added to the top set of spar caps for a Sonerai 1
Do all the rivets have to be drilled out of the top spar caps
If 1-1/4x 1/8 flat cap strip spacers were used 15 inch and 18 inch, could the 1-1/4x1-1/4x1/8 aluminum angles not be about 53 inches ( full length ) and not need to spliced .
Hope this makes sense.
Best wishes.
Steve.

[soneraifred]

Steve:
1. On the "A" wing modification drawings, the two pieces of angle are shown on page 14. The inboard piece is 21" long, and the outboard piece is 18-1/8" long. So, if you wanted to use just one piece, it would be 39-1/8" long.
2. All of the original upper spar cap rivets where the angles mount need to be removed.
3. On the Sonerai I, if you wanted to use a one-piece angle, you'd need a 4-1/8" spacer, a 22-1/8" spacer, and a 34-1/8" spacer. All spacers would be the 1-1/4"x1/8" cap strip stock.

[stepo]

Dear Fred,

Thank you for your quick reply, your imformation is a great help.
Best wishes.
Steve.