BGA AIRWORTHINESS AND MAINTENANCE PROCEDURES PART 3, LEAFLET 3-3 MODIFICATION PROCEDURE FOR GLIDERS, SAILPLANES AND SELF SUSTAINING SAILPLANES APPLICABLE TO ANNEX II AIRCRAFT ONLY INTRODUCTION 1. Modifications to BGA Annex II (including BGA non transitioned) gliders, sailplanes and self sustaining sailplanes fall into two main categories; minor and major, and then requiring approval and not requiring approval for minor modifications. 2. All major modifications to BGA aircraft require BGA Technical Committee or aircraft manufacturers approval. The definition of a major modification is one that requires a significant change to the flight manual, a major structural alteration, addition of a self sustainer engine, conversion from fixed to retracting undercarriage or where changes to the flight characteristic are proposed and such like modifications. 3. Minor modifications, depending on complexity either will or will not require approval. a) Modifications requiring approval; installation of tailwheels, wheel brake conversions, winglets, canopy operation, seating and harnesses, substitution of structural components or materials, disabled pilot conversions. b) Modifications not requiring approval: instrumentation and avionics fit, mountings for removable equipment such as GPS or cameras, non-structural substitution, cosmetic modifications. Modifications that fall into the ‘not requiring approval’ category bust be assessed to ensure they comply with section 10 of this leaflet. 4. Modifications to EASA aircraft require EASA approval in the form of a technical note or approved modification approved by the manufacturer a design company (DOA) or EASA APPLICATION 5 Application should be made preferably using BGA forms BGA 261 for a minor modification and BGA 282 for a major modification. Minor modifications may be applied for after completion, however, it advised that at least a verbal confirmation be obtained from the CTO prior to incorporation to ascertain acceptability. A major modification should be applied for and approved prior to incorporation on a BGA aircraft. 6 Aircraft manufacturer (design authority) approved modifications would not normally require BGA approval provided that they did not alter the type certificate or designation of the aircraft. 7 The application form should be completed with as much detail as possible to enable the investigating engineer to assess the modification and make an accurate assessment without the need for constant referrals back to the applicant. Include sketches, drawings, wiring diagrams, manufacturers literature or specifications as appropriate. AMP 3-3/Dec 09 BGA AMP Part 3, Leaflet 3-3, page 1 APPROVAL 8 The CTO will normally approve minor modifications and where deemed necessary involve the technical committee if expert assistance is needed. A signed copy of the application form is used to communicate approval. 9 Major modifications are investigated and approved by the Technical Committee. Approval is communicated either by letter or by returning a signed copy of the application form. 10 Depending on the nature of the modification, if acceptable to the BGA, full approval will be given or in certain cases a permit to test may be granted. Again, depending on the complexity t his could be a simple note or e-mail or may involve a Technical Committee test programme or requirements. MODIFICATIONS NOT REQUIRING APPROVAL – CRITERIA TO BE MET 11 To check that a proposed modification meets the criteria for ‘not requiring approval’ please follow the flow chart below. If in doubt please apply for the modification to be approved, at the very least someone independent will then have the opportunity to review the proposed modification and advise if approval is required or not. Proposed Modification (Mod) Major Mod Ref. para.2 Minor Mod Ref. par. 3 a Ref. par. 3 b Has the Mod been assessed for the following and is it satisfactory? • Crashworthiness for injury to occupants or restricted access or increased hazard for Emergency Services • Ease of entering and exiting aircraft in normal and emergency situations • Safety of pilot or passenger • Interference with other systems or controls • Visual obscurity within cockpit or externally • Ease of operation so as not to unduly distract pilot • No structural changes • No configuration changes • Ease of maintenance • No change in operation of any system that is specified in JAR22 • Electrical safety • Electrical capacity or load requirements If satisfactory to all If not satisfactory to all AMP 3-3/Dec 09 Modification Not requiring Approval BGA AMP Part 3, Leaflet 3-3, page 2 Modification Requires Approval