Applies to All Model 415 Series and Models E and G Aircraft.
Compliance required as indicated.
As a result of several Ercoupe accidents, the following precautionary measures should be taken:
1. Before the next flight and at each 25-hour inspection:
(a) Inspect the aileron balance assembly (Erco P/N 415-16009) and ailerons for cracks in support
structure and skin, respectively. Repair or replace defective parts.
(b) Inspect the four No. 6-32 screws which attach the balance weight support to the aileron for
looseness and damage. Replace defective screws with AN 526-632 screws, taking care not to
overstress during tightening.
2. Before next flight and at each 100-hour inspection, thereafter, inspect the aileron hinges and aileron
control system for excessive looseness or wear in hinge pins or bearings. If, with one aileron
blocked in the neutral position, the total play of the other aileron, measured at the trailing edge,
exceeds 7/16-inch, all the joints and bearing should be checked and those which are loose should
be tightened or replaced.
3. If the aileron balance weights have been removed in accordance with Erco Service Bulletin No. 57,
item 1 above and AD 47-20-06 do not apply. However, any previous cracks in the aileron skin or
beam which occurred prior to removal of the aileron balance weights must be repaired or the parts
replaced. The free play referred to in item 2 above must be reduced to 5/16-inch.
4. Before the next flight, determine that the air speed instrument is distinctly marked in accordance
with the operating limitations.
(Engineering and Research Corp. Service Memorandum No. 56 covers this same subject.)
This supersedes AD 49-02-02; the new material is contained in item 3.