AD 48-34-02

48-34-02 Applies to All Aircraft Engaged In Sulphur Dusting. Replaces Airworthiness Maintenance Bulletin No. 63.

Compliance at time of original certification or if previously certificated and Airworthiness Maintenance Bulletin No. 63 has not been complied with compliance required by October 1, 1948.

To decrease the hazards from fire during dusting operations involving the use of sulphur dust the following fire preventive measures, formerly in Airworthiness Maintenance Bulletin No. 63 must be complied with:

(1) The engine exhaust system must be so arranged that it will not discharge exhaust gases under or along the bottom of the airplane.

(2) The fuselage aft of and in the vicinity of the hopper must be completely bonded. All fittings and struts adjacent to the hopper should be bonded to each other and the hopper to the fuselage.

(3) The agitator should be provided with sealed bearings or the bearings should be readily accessible for lubrication.

(4) The hopper gate should be of nonferrous material, well fitted to irs guide channels to prevent friction and accumulation of dust in the channels and should be bonded to the hopper.

(5) The lower surface of the fuselage, in the immediate vicinity and 3 feet aft of the spreader discharge opening must be covered with thin-gage metal, plywood or equivalent fire resistant material. Where fabric on the bottom of the fuselage is not eliminated in this installation, the protective covering, to be installed on the outside of the fabric, must be secured in such a manner that will prevent accumulation of dust between the protective covering and the fabric. This may be accomplished by using sealants such as acetate doped fabric tape or other adhesives to bond the protective covering to the fabric.

Aircraft which do not comply with these measures shall be restricted, against the use of sulphur for dusting, on the operation limitations.