Introduction

MODIFICATION AND TECHNICAL NEWS SHEETS

GIPSY MAJOR SERIES 10

SPECIAL NOTE

Gipsy Major 10 Mk.1 engines embodying Mod.2385 will be identified as Gipsy Major 10Mk. 1-1A, 3A or 7A. Gipsy Major 1 series engines embodying Mod. 2385 will have the suffix 'Z' added to existing type. (To carry out Mod.2385. Mod 1049 must already have been embodied)

INTRODUCTION

PRESENTATION OF MODIFICATION NEWS SHEETS

This folder contains technical information on all approved modifications for this type of engine. Two indexes arc provided. In the first, the modifications are classified under the engine component headings to which they are applicable. The second index lists the modifications in numerical sequence.

Separate Modification News Sheets are issued, to give full descriptive details, for all modification in categories "A" "E" and "O" and certain modifications of a low category where interchangeability is affected, or, where special fitting instructions are necessary. These should be placed in the folder in numerical sequence of modification numbers with the higher number at the front.

PRESENTATION OF TECHINICAL NEWS SIIEETS

Periodically, under the heading of Technical News Sheets, recommendations are put forward to assist in the efficient operation of the engine.

The information in a Technical News Sheet may he introduced eventually into the Maintenance and Overhaul Handbook; in which case the relevant News Sheet is removed by the issue of an amendment instruction. There will, therefore, be gaps in the sequence of Technical News Sheet numbers, and from time to time a checking list is issued to assist operators to keep their files up to date.

AVAILABILITY OF SPARES

Due to frequent variations in the supply position of materials, it is not considered practicable to quote in Modification News Sheets availability dates, or prices for sets of modification parts.

This information, however, may be obtained on application to:

H+S Aviation Ltd.,Division One,Airport Service Road,Portsmouth, Hampshire. P03 5PJ

England

and, for our advance information, we would he grateful if operators would indicate the approximate mm1ber or modification sets which they may eventually order.

NOTE: Where the name "de Havilland", or "Bristol Siddeley", appears in this publication it should be read as "H+S Aviation Ltd.".

Feb 1987

MODIFICATION NEWS SHEET

July 31, 1964

GIPSY MAJOR SERIES 10 ENGINES

CATEIGORIES OF MODIFICATIONS

This News Sheet supersedes Modification News Sheet "Categories of Modifications" dated December 29th, 1958.

The Modifications have been separated into six categories which should be interpreted as follows:

SYMBOL	INTERPRETATION
'A'	Modifications which are considered by the Air Registration Board to be mandatory for the safety of the aircraft, the non-embodiment of 1-'hich, within a certain specified period, would invalidate the aircraft Certificate of Airworthiness. Such modifications must be embodied by the date quoted on the relevant Modification News Sheet.
'E'	High priority modifications, the non-embodiment of 1-'hich imposes operational limitations or seriously reduces maintenance efficiency. Such modifications should be embodied in new production, reconditioning and repair as soon as parts are available. Embodiment in engines already in service should be at the first convenient opportunity as soon as parts are available.
'O'	Modifications 1-'hich are highly desirable and strongly recommended by H+S Aviation Ltd. to be embodied not later than the next complete overhaul provided parts are available.
'M'	Modifications of a desirable nature introducing minor improvements in design, or modifications introducing salvage or repair schemes or changes to assist manufacture. Such modifications should be embodied at the discretion of the operator.
'R'	Modifications which are embodied in all engines, the modifications being raised merely to cover the official procedure involved introducing new equipment into the Engine Specification.
S.0.0.	Modifications introducing specific requirements.

All the above categories are recommended by H+S Aviation Ltd. in collaboration with the Air Registration Board.

When a modification has an 'M' category, it is permitted to use existing stocks of the pre-modification standard parts. Therefore, it may be some time before parts to the new standard become available, particularly if the existing parts are seldom renewed at overhaul.

IMPORTANT

IT IS REQUESTED THAT THE ATTENTION OF PERSONNEL RESPONSIBLE FOR PLACING ORDERS IS DRAWN TO THE FOLLOWING PROCEDURE:

When ordering a Modification Set, even if it consists of only one item, the order should quote the Modification Number, and number of sets required, for example:

Modification G.2150 3 sets.

When ordering individual items of the Modification Set, as replacement, or spares holding, the part number, description, and quantity required shou be quoted, for example,

SP 47C Washer, spring 2.

AS 2227-404 Rivet 8.