Rear Spar Carry-Through Tube AD Repair Scheme #3

[CF-KYE]

Does anyone have the details for Method of Repair #3 for AD 49-11-2 concerning beefing up the rear spar fuselage carry-through tube? A friend of mine just bought an 85hp 7AC that's been modified, but not according to scheme #1 or #2 as described in Charlie Lasher's books.

It appears to have a fairly heavy (.096-ish) wall tube running full length and with only one bolt installed horizontally through the middle of the fuselage tube. The new tube insert appears to be very neatly welded inside the original at the butt ends but not the way described in method #1 where the top and bottom of the original tube are cut and then welded.

After removing the wing fairings I couldn't feel the welded seam along either the top or bottom of the original tube, nor are the bolts installed through the tube (method #2). After removing a wing we found the tube installed but not in a manner described in scheme #1 or #2. I understand there is a third method but I've never seen a description of what that is. My 7CCM left the factory with mod #1 installed.

Any help very much appreciated.

Dan Jones
warbirds@shaw.ca

[Mikek]

Does anyone have the details for Method of Repair #3 for AD 49-11-2 concerning beefing up the rear spar fuselage carry-through tube? A friend of mine just bought an 85hp 7AC that's been modified, but not according to scheme #1 or #2 as described in Charlie Lasher's books.

It appears to have a fairly heavy (.096-ish) wall tube running full length and with only one bolt installed horizontally through the middle of the fuselage tube. The new tube insert appears to be very neatly welded inside the original at the butt ends but not the way described in method #1 where the top and bottom of the original tube are cut and then welded.

After removing the wing fairings I couldn't feel the welded seam along either the top or bottom of the original tube, nor are the bolts installed through the tube (method #2). After removing a wing we found the tube installed but not in a manner described in scheme #1 or #2. I understand there is a third method but I've never seen a description of what that is. My 7CCM left the factory with mod #1 installed.

Any help very much appreciated.

Dan Jones
warbirds@shaw.ca

Is This want you are looking for see #3 for the FAA AD site

Mike k

49-11-02 AERONCA: Applies to Serial Numbers S7AC and 7AC-1 to 7AC-7170, Inclusive; 7BCM-1 to 7BCM-339, Inclusive; 11CC-1 to -150, Inclusive; and All S11AC, 11AC and 11BC Serial Numbers.

Compliance required at next periodic inspection but not later than May 1, 1949.

To prevent failure of the rear fuselage-wing attachment fitting, reinforcement is to be accomplished by either of the following methods:

1. Cut on both sides of the rear spar fuselage carry through tube, at each end, a vertical slot 1/4 inch long. Insert a 5/8 inch by 0.083 (or heavier wall) 4130 steel, square or round tube having a minimum length of 2 1/2 inches and weld both sides of slot top and bottom of tube. Drill and ream bolt hole 0.250 plus or minus .001.

2. Insert in each rear spar fuselage wing attachment fitting, on both sides of airplane, a 5/8 inch by 0.083 (or heavier wall) 4130 steel tube having a minimum length of 4 5/8 inches. The insert tube should have a 0.250 plus or minus .001 hole drilled 9/16 inch from outer end of tube, and reamed prior to installation. Bolt insert tube in fitting, then drill two vertical 0.250 plus or minus .001 holes through the fuselage carry through tube and the insert tube at 3 and 4 inches, respectively, from end of fitting. Four AN 4-11A bolts and AN 365/428 nuts or equivalent are required to bolt in the two insert tubes.

3. Insert through the entire length of the rear spar fuselage carry through tube a 5/8 inch by 0.083 (or heavier wall) 4130 round or square tube. The insert tube should have a hole drilled and reamed 0.250 plus or minus .001, 9/16 inch from each end of the tube to line up with the original bolt holes. The insert tube should be secured to the fuselage carry through tube by means of one AN 4-11A bolt and AN 365-428 nut or equivalent through both tubes anywhere between the longerons (drill and ream 0.250, plus or minus .001) or by welding both ends of the tubes together.

Airplanes having the 5/8 inch by .065 reinforcement tube installed prior to the issuance of this revision need not change to the .083 wall tube. (Aeronca Service Helps and Hints No. 43 covers this same subject.)

This supersedes AD's 47-50-01 and 49-02-03.

might try to look up the superseded Ad's list above along with the service helps & hints No. 43

[CF-KYE]

Thanks very much Mike - that was exactly what I was looking for!

Dan