MIL-HDBK-274 Electrical Grounding For Aircraft SafetyThis handbook has been prepared to provide U.S. Navy and Marine Corps aircraft maintenance and operations personnel with the background and technical details of the different types of aircraft grounds and how they are applied. In addition, this handbook provides background information for aircraft grounding, static electricity theory and how it affects aircraft, and techniques used for measurement of grounding points. This handbook is intended for use by all U.S. Navy and Marine Corps aircraft maintenance and operations personnel for the purposes of ensuring that aircraft are properly and safely grounded. This handbook is for guidance only and cannot be cited as a requirement.

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MIL-HDBK-274A

6.2.1 Details of grounding issue. After shutdown from flight, aviation ordnance personnel began the procedure for loading Mk 82 practice bombs on outboard racks. After successful completion of jettison release checks, the jettison release cartridge was being installed on the

port outboard station. As the jettison cartridge was being inserted into the breech, the cartridge actuated. Personnel injuries were superficial and there was no damage to the aircraft. Immediately after the incident, ordnance personnel checked both cockpit switches to determine switch positions and stated both were in the OFF/SAFE position. It was noted that the aircraft was not grounded. While inconclusive, a potential cause of this incident could be the failure of ordnance personnel to properly ground the aircraft prior to executing loading procedures.

6.3 Responsible technical activity. The NAVAIR E3 Division provided the technical information contained in this handbook. Contact the preparing activity currently listed in ASSIST for this document for contact information on the E3 Division.

6.4 Changes from previous issue. Marginal notations are not used in this revision to identify changes with respect to the previous issue due to the extent of the changes.

6.5 Subject term (key word) listing.

Cable Clamp Ordnance Power Plug

Reel Shipboard Shore-based Static

Tie-down chains

Custodian: Preparing activity: Navy - AS Navy - AS

Project EMCS-2011-004

NOTE: The activities listing above were interested in this document as of the date of the document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST online database at https://assist.daps.dla.mil.