75-17-36 BALLOON WORKS, HOT AIR BALLOONS: Amendment 39-2326. Applies to Models Firefly 6, 6B, and 7 with burner S/N 510 through 562.
Before next flight, accomplish the following or an equivalent approved by the Chief, Engineering and Manufacturing Branch, Southern Region.
To avoid separation due to a possible brass nipple failure, install safety wire extending from each of the three corners of the bottom plate to the lower portion of the upper Rego valve body. Assure wires are uniformly tightened.
Within the next five hours of time in service from the effective date of this AD, accomplish the following:
1. Disconnect main burner tubes from manifold.
2. Drill out nine rivets holding pan to the bottom plate.
3. Unhook three burner support springs.
4. Remove upper burner assembly from lower burner assembly.
5. Unscrew nuts to remove pilot light tubes.
6. Clamp square section of Rego valve in vise.
7. Unscrew and remove burner manifold.
8. Inspect nipple. If nipple is steel, reassemble the burner,* if nipple is brass, proceed through the following steps.
9. Unscrew nipple with pipe wrench.
10. Replace brass nipple with steel nipple, Balloon Works P/N A4032B.
11. Reassemble in the reverse order.
Safety wire is not required after steel nipple is installed.
*Use teflon tape or pipe dope type sealant on nipple threads.
This amendment is effective August 13, 1975, and was effective on receipt for all recipients of the air mail letter dated July 24, 1975 which contained this amendment.