Airworthiness certification Short

Airworthiness Certificationof Fighter Aircraft AIRWORTHINESS CERTIFICATION OF FIGHTER AIRCRAFT K Nagaraj Former Chief Executive (Airworthiness) Centre for Military Airworthiness and Certification (CEMILAC) Bengaluru, India Defence Research and Development Organisation Ministry of Defence, New Delhi – 110 011 2015 3:629. no part of this publication may be reproduced.017 © 2015. electronic. Series 623.DRDO MONOGRAPHS/SPECIAL PUBLICATIONS SERIES AIRWORTHINESS CERTIFICATION OF FIGHTER AIRCRAFT K Nagaraj Series Editors Editor-in-Chief Gopal Bhushan Assoc. mechanical. Title II. Defence Research & Development Organisation. DESIDOC. The views expressed in the book are those of the author only.7. Fighter aircraft 2. Editor Kavita Narwal Editorial Assistant Gunjan Bakshi Cataloguing-in-Publication Nagaraj. without the prior written permission of the Publisher. New Delhi – 110 011. Airworthiness I. Except as permitted under the Indian Copyright Act 1957. The Editors or the Publisher do not assume responsibility for the statements/opinions expressed by the author. Editor-in-Chief Dr GS Mukherjee Editor Anitha Saravanan Asst. Delhi – 110 054. Cover Design Anjan Kumar Das Printing SK Gupta Marketing Rajpal Singh Published by Director. K Airworthiness Certification of Fighter Aircraft DRDO Monographs/Special Publications Series 1. photocopying. Metcalfe House. distributed or transmitted. or otherwise. in any form or by any means.746. stored in a database or a retrieval system. . recording. ISBN 978-81-86514-84-9 All rights reserved. Contents Foreword xi Preface xiii Acknowledgements xv Terminology and Institutions xvii List of Acronyms xxi Introduction xxix CHAPTER 1: TECHNOLOGY DEVELOPMENT 1 CHAPTER 2: PROJECT INITIATION AND DEVELOPMENT 2.2 Project Definition 3 3 5 CHAPTER 3: CONCEPTS OF AIRWORTHINESS CERTIFICATION 3.2 Airworthiness Certification 9 9 9 CHAPTER 4: AB-INITIO DESIGN.1 Introduction 4.6 Transition from Development to Production 13 CHAPTER 5: FACETS OF AIRCRAFT DESIGN 23 CHAPTER 6: AERODYNAMICS 6.4 Review Systems 4.1 Introduction 3.2 Pressure 25 25 25 13 13 14 16 17 20 .1 Feasibility Study 2. AND PRODUCTION 4. DEVELOPMENT.3 Evaluation of Design 4.5 Methodology to Deal with Defects During Development 4.2 Pre-requisites 4.1 Air 6. 6 Wing Analysis 7.4 Airflow 6.3 Electro Magnetic Compatibility 8.3 Structural Design and Analysis 7.1 Overview of Aircraft Electrical System 8.7 Stability and Handling of Aircraft 25 27 28 43 48 CHAPTER 7: STRUCTURES 7.4 Static Strength Analysis 7.5 Fuselage Analysis 7.2 Wiring 8.6.2 Air Load Estimation and Wind Tunnel Tests 7.8 Vertical Tail Analysis 7.10 Excitation Procedures 7.11 Aerodynamic Effects 65 65 65 67 67 67 68 69 69 78 82 87 CHAPTER 8: ELECTRICAL SYSTEM 8.9 Validation of the Total Aircraft 7.4 Electrical Power System Requirements 8.3 Electro-Hydraulic Servo-Valves 10.6 Aerodynamic Forces in Flight Manoeuvres 6.1 Configuration Study 7.5 Load Characteristics 91 91 93 94 95 98 CHAPTER 9: HYDRAULIC SYSTEM 101 CHAPTER 10: FLIGHT CONTROL SYSTEM 10.1 Doppler Navigation System 11.1 Flight Control Actuation System 10.5 Aircraft Aerodynamics 6.7 Horizontal Tail Analysis 7.2 Very High Frequency Omni Range 121 122 126 vi .3 Density 6.2 System Design 10.5 Comparison of EHSV with DDV Servo Actuators 10.4 Direct Drive Valves 10.6 Built-in Test/Redundancy Management 107 113 113 114 114 114 119 CHAPTER 11: NAVIGATION SYSTEM 11. 4 Inertial Navigation Systems 11.2 Tests Required to Prove the Gun Installation 18.1 Software Development Process 20.1 Thrust Augmentation 179 180 vii .2 Radio Communication 12.5 Automatic Direction Finder 128 128 130 CHAPTER 12: COMMUNICATION SYSTEM 12.3 Cabin Distribution Subsystem 153 154 154 155 CHAPTER 17: BRAKE PARACHUTE SYSTEM 157 CHAPTER 18: WEAPON SYSTEM 18.3 Integrated Weapon System 159 160 162 167 CHAPTER 19: ESCAPE SYSTEM 19.11.3 Antennae 12.1 Bleed Subsystem 16.2 Software Development Activities 20.5 Reducing the Effects of Noise and Interference 131 131 131 133 135 136 CHAPTER 13: LANDING GEAR SYSTEM 139 CHAPTER 14: FUEL SYSTEM 145 CHAPTER 15: OXYGEN SYSTEM 15.1 Means of Escape 169 169 CHAPTER 20: SOFTWARE SYSTEM 20.1 Fixed Gun Installation 18.4 Sources of Noise 12.1 Very High Frequency/Ultra High Frequency Technology 12.4 Formal Methods 173 173 174 177 178 CHAPTER 21: PROPULSION SYSTEM 21.2 Air Conditioning Subsystem 16.3 Tactical Air Navigation System 11.1 On-board Oxygen Generation Systems 147 149 CHAPTER 16: ENVIRONMENTAL CONTROL SYSTEM 16.3 Process Improvement Models 20. 2 Types of Drawings 23.2 Techniques of Simulation 261 261 262 CHAPTER 26: SAFETY ASSESSMENT OF AIRCRAFT SYSTEMS 26.1 Types of Simulators 25.2 Flight Worthiness Evaluations 26.1 Aerodynamics 276 27.1 Types of Specifications 22.12 Safety Interlocks 24.5 Hydraulic System 24.5 New Hazards 265 267 267 268 270 271 CHAPTER 27: GROUND TESTS 275 27.3 Master Record System for Drawings 187 187 190 191 CHAPTER 24: DESIGN EVALUATION FOR AIRWORTHINESS 24.7 Ergonomics 24.1 Hazard Risk Assessment 26.11 Armament/Stores Integration 24.3 Software Safety Assessment 26.6 Installation 24.1 Drawing Standard 23.4 Systems Clearance 24.3 Ground Firing Tests 283 viii .9 Life Support Systems 24.2 Aerodynamics 24.3 Electrical System 24.8 Aircraft Lighting 24.2 Armament Stores 280 27.10 Avionics Architecture and Avionics Subsystems 24.1 Introduction 24.4 Software Development: Safety Assessment 26.CHAPTER 22: STANDARDS AND SPECIFICATIONS 22.2 Implementation of Specifications/Standards 183 183 185 CHAPTER 23: DRAWINGS 23.13 Computer 193 193 195 205 210 221 242 248 249 249 252 254 255 257 CHAPTER 25: SIMULATION 25. 6 Avionics 28.1 Items Having Licence Agreement 34.5 Pilot–Vehicle Interface 28.2 Flight Tests 30.CHAPTER 28: DOCUMENTATION 28. DEFECTS.1 Introduction 29.2 Structures 28.1 General Requirements 28.4 Propulsion and Propulsion Systems 28.1 Flight Test Instrumentation 30.1 Aircraft Accidents 331 CHAPTER 34: INDIGENOUS DEVELOPMENT 34.1 Dos 35.2 Aircraft Level Aspects 32. and Lubricants 335 336 336 339 CHAPTER 35: LIST OF DOS AND DON’TS 35.2 Standard of Preparation of Aircraft 301 301 302 CHAPTER 30: FLIGHT TESTS 30.7 Electrical System 28. AND ACCIDENT INVESTIGATION 33.8 Computer and Software 28.2 Approval of Non-Critical Items 34.3 Flight Control System 28.2 Don’ts 343 343 345 ix 331 .3 Evaluation of Test Results and Acceptance 307 307 308 310 CHAPTER 31: RELEASE TO SERVICE 317 CHAPTER 32: CONTINUED AIRWORTHINESS 32.3 Weapon System Augmentation 32.4 Licence-Built Aircraft 319 320 323 324 328 CHAPTER 33: INCIDENTS. Oil.9 Armament Stores 289 289 290 291 293 294 295 296 297 298 CHAPTER 29: FLIGHT CLEARANCE CERTIFICATE 29.1 Modifications 32.3 Consumables: Approval of Fuel. 2 United Kingdom 36.1 United States of America 36.4 Russia 36.CHAPTER 36: CERTIFICATION IN FOREIGN COUNTRIES 36.5 Conclusions List of References Index x 347 348 348 349 350 350 353 363 .3 France 36. . . and user services. It is of particular significance during design and development. the deficiency may have to be carried forward till the aircraft is phased out of service. fresh entrants into the certification group. they can be extremely difficult. personnel engaged in the design. and all other factors will only help to achieve the capabilities built into the product by design. R&D scientists. This publication. in both military and civilian usage. if not impossible. to introduce and implement at later stages. Pandit Jawaharlal Nehru. the famous German designer. It is an extremely challenging and rewarding experience to be involved in an ab initio design and development project. airworthiness certification has not got the recognition that is the due of such a vital and important subject in the military sphere. who had the privilege of working for five years in the HF-24 design team of Dr Kurt Tank. development. production and service life cycle of an aircraft and airborne store. This monograph also attempts to bring out the fact that if corrective actions are required. Thus. therefore. and to process the activities of concurrent certification and accord flight clearance for the first flight and a block of initial flights. development and certification scenario. due to the constraints of time and cost. It also brings in the practical experience in aircraft system design of the author. certification groups. However. development of fighter aircraft with the objective of meeting the user’s requirement. deals in some depth with the design and design evaluation aspects. Airworthiness means different things to different people. The certification personnel will have to meet several challenges in the concurrent design. since a product can only be as good as it has been designed. This task is all the more exciting if the aircraft incorporates state-of-the-art technologies for which certification standards are scant and have to be evolved . who set up a design team at the invitation of the then Prime Minister.Preface This monograph is written for use by students pursuing the aeronautical engineering degree course. It is an essential prerequisite if the product has to be of utility to the user services for deployment in an operational scenario. This publication highlights the aspects of airworthiness certification that have to be assimilated into all facets of design. unlike in the civilian sector. The author was privileged to shoulder this awesome responsibility and accord such a flight clearance for the Light Combat Aircraft (LCA).as the work progresses. out of compulsion. What has been presented. The scope of activities and nuances involved are too vast and intensive to be consolidated in one publication. is of such a nature and depth that will enable the interested and the practitioner alike to grasp the overall approaches to aircraft design and airworthiness certification. Bengaluru K Nagaraj Former CE (Airworthiness) Centre for Military Airworthiness and Certification xiv . The material presented in this monograph is. The author will derive immense pleasure and feel rewarded if a large number in the aeronautical community read the book and benefit from the contents. therefore. only a small part of the mammoth activity that goes under the generic title of Airworthiness and Certification. and to benefit from the experience of the author in this field for over three-anda-half decades. who have specialised and worked in the specific areas and on several projects. Agra. countless number of revisions and other miscellaneous types of work. DESIDOC and gratefully acknowledges with thanks the efforts of the officers and staff of DESIDOC and in particular Smt Anitha Saravanan. The author wishes to place on record his thanks to Dr Raghothama Rao for his painstaking and meticulous effort in proofreading of the document. Director. wholehearted support and generous help from Shri S Krishnasamy. data collection. Delhi. former Chief Executive. The author expresses sincere thanks to these gentlemen in this regard. Head. CEMILAC. DRDO. A publication of this magnitude and content requires a good deal of effort in typing. and Director. on aircraft structures. experience and expertise of several distinguished people. The author gratefully acknowledges with thanks the efforts of Shri Edwin Oliban. ADRDE. who has helped in preparing this document as per schedule and in an extremely presentable form.Acknowledgements A work of this scope and magnitude has to draw upon the knowledge. compilation. former Associate Director. CEMILAC. K Nagaraj . The author sincerely thanks Shri Gopal Bhushan. proofreading. Monographs. The project has been made a reality by DESIDOC. on aerodynamics and Late Shri VK Kalyanam. The author has been very fortunate in getting the cooperation. . Certificate of Design: The Certificate of Design is the document which certifies that the store complies with all the requirements laid down in the Technical Specification with exceptions quoted therein. systems/software/equipment/materials/components. Indian Navy. for all activities leading to certification of fighter/transport aircraft. and/or formulate Statement of Work (SOW). 7. Chief Resident Engineer/Regional Director: The heads of RCMAs are designated as Chief Resident Engineers or Regional Directors. Chief Resident Inspector: The Chief Resident Inspector is the resident representative of the Director General Aeronautical Quality Assurance to ensure quality assurance of the stores during design. 4. STIs. 6. respectively. continued airworthiness activities like defect/incident/accident investigation. CEMILAC/RCMAs: Centre for Military Airworthiness and Certification is responsible through its Regional Centres for Military Airworthiness. The design authority is the Design Department of the Development Agency or any Design Approved Agency or R&D establishment. 3. etc. FOL. requirement for an equipment or system for IAF.Terminology and Institutions 1. 2. Design Authority: Responsible for the detailed design and development of the aircraft. Indian Army. . Design Approved Agency: Design Approved Agency is an agency whose design/development department has been approved by the Chief Executive. UONs. and modifications. and approval of corrective actions through SIs. etc. helicopters. development. in qualitative terms. software. ASR/NSQR/GSQR/ISQR: The ASR/NSQR/GSQR/ISQR is a document which describes. 5. CEMILAC as competent to carry out design. aero engines. Critical Item Development Specification (CIDS) and software related documents. systems. Prime Item Development Specification (PIDS). airborne equipment. and Inter Services. engines. indigenous substitution of a particular class of stores/material/equipment. indigenously developed airborne stores. development and production phases. mid-life upgrades/life extension programmes of indigenous/license production/bought out aircraft. modification. software. The Provisional Clearance is issued because documentation is pending. aero engines. etc. from flight tests. Main Contractor: A development and/or production agency entrusted with the total responsibility for development and/or production of aircraft/aero engines/systems/software/equipment/components/material. 10. agencies created by the government from time to time for such purposes. 13. 9. Production/Limited Series Production: Production refers to bulk production at the production agency or Limited Series Production (LSP) carried out either at the development agency or at the production agency. systems. critical. R&D laboratories. government R&D organisation. and non-critical shall be described by the main contractor in consultation with RCMA. 11. DGAQA/RDAQA: Directorate General of Aeronautical Quality Assurance through Regional Directorate of Aeronautical Quality Assurance is the approving authority for quality assurance during manufacture and quality assurance for all the activities listed under CEMILAC. This also refers to the overhaul or repair of the aircraft or airborne stores. xviii . and pneumatic components. or because some of the long cycle life tests (such as fatigue test) are pending. materials. pending final approval by CEMILAC. A Provisional Clearance is issued to the effect that the store under development meets all the laid-down specifications and test requirements with the exceptions stated therein. There is no difference between a Provisional Clearance and a Type Approval in so far as the safety of the aircraft or airborne store is concerned. hydraulic. The design and development agency may be a public sector undertaking. 14. equipment..Airworthiness Certification of Fighter Aircraft 8. some results which cannot be obtained from ground tests. Classification into major and minor equipment. Minor items are those which do not affect the safety and interchangeability aspects of the aircraft maintenance and operation. or because of the necessity to obtain. brake pads. Minor and Major Airborne Equipment: Airborne equipment is classified as minor and major. etc. Development Contracts: This is a contract placed on a development agency for development of an aeronautical store on the basis of service requirements. Proprietary items that are being imported and constitute only forming and machining operations may also be considered as minor equipment. or private sector firms. etc. shall be considered as major items. 12. electro-mechanical. Design and Development Agency: Undertakes design and development of aircraft. Electrical black boxes. Provisional Clearance: A Provisional Clearance could be issued by one of the RCMAs for a limited period. 20 Technical Specification: Technical Specification is a document laying down design and performance characteristics of the stores.. 19 Type Record: Type Record is a document giving a description of the store. development. and in-service phase. private sector. Type Approval: Type Approval is a certificate issued by the approving authority. and other aircraft stores. identified by the main contractor for the development and/or manufacture of a specific airborne store. The terms and conditions for approval are given in DGAQA. It deals with all aspects of technical clearance of the airborne stores during design. JSS 0254-01 April 1983. Subcontractor: Any agency. which acts on behalf of CEMILAC. information on dimensions. its functional performance characteristics. 17. The Type Approval is issued after the Design Authority/Main Contractor submits a full Type Record with all the relevant documents to the satisfaction of CEMILAC. Regional Centre for Military Airworthiness: Regional Centre for Military Airworthiness is a unit of CEMILAC. R&D institutions. including PSU. The technical specification shall contain full details of the equipment. and other information for the safe operation of the product. functional and performance tests. Quality Assurance Approved Firm: Quality Assurance Approved Firm is a firm whose quality assurance organisation has been approved by DGAQA as competent to carry out quality assurance during manufacture/overhaul/repair/ storage of aircraft/aero engines and its associated equipment. and the certificate of design. i. It includes all documents and specifications approved by CEMILAC. materials. production.Terminology and Institutions 15. standard of the main xix . In such places where there is no establishment of RCMA. It should also indicate instructions for continued airworthiness of the product. Ministry of Defence document ‘Approval of Firm’s Inspection Organisation/Department’ and also ‘Quality Control System Requirements for Industry’. accessories. and processes necessary to define the structural strength of the aeronautical product. 16. list of applicable drawings. summary of strength and other calculations along with reserve factors. environmental envelope of operation and storage of the store. 18.. weight data. The subcontractor is responsible to the main contractor. Chief Executive. results of all the tests including environmental.e. etc. CEMILAC to the effect that the store under reference meets all design specifications and test requirements laid down by CEMILAC. operating limitations. authority may be delegated to Visiting Technical Officers (VTOs) of CEMILAC. the environmental conditions. User Acceptance: Acceptance of the airborne store for service use and end use requirements will be the responsibility of the concerned services. 21. xx .Airworthiness Certification of Fighter Aircraft store. interface and integration requirements. the specifications/standards followed in the design and manufacture. besides performance and functional requirements. started under the leadership of Prof Kurt Tank. the CREs were brought under the functional and administrative control of DRDO. to look after the Military Aircraft Airworthiness Certification aspects. In 1968. The Directorate of Technical Development and Production (Air) [DTD&P (Air)] was subsequently formed by the Ministry of Defence. All design clearance activities were undertaken by HAL. However. under the leadership of Dr S Neelakantan. The CRIs remained under DTD&P (Air). the active participation of CRE (Aircraft) was considered essential and ensured with the concept of involvement in all activities of design and development. Defence Production.Introduction The aeronautical industry took shape in India in 1940. in-depth interactions/involvement of CREs for the design clearance activities were lacking. through the Director of Aeronautics. It was consolidated through takeover by the Government of India in 1942. After the crash of HF 24 aircraft with reheat version of modified engine. and brought out the requirements for re-type tests similar to UK procedures. it was certified by DGCA. leading to clearance of the aircraft for development flights on a flight-by-flight basis as a mandatory requirement. under the overall guidance of Dr S Neelakantan. CRE (Engines) was formed to look after the clearance activities of the engines. The impetus for indigenous design and development was given by the HT 2 basic trainer project. in view of the increased aeronautical activities taken up in the country. for overhauling USAF aircraft. reached its peak. During this period. reporting to SA to RM. The first branch office of DTD&P (Air) was started in 1958 at Bengaluru within the premises of HAL. reporting to the Secretary. These requirements were subsequently extended to other . structured similar to airworthiness groups in the UK. The design and inspection related functions were separated in 1960. with the establishment of Hindustan Aeronautics Limited (HAL) as a private enterprise by late Walchand Hirachand on land generously sanctioned by Shri Krishnarajendra Wodeyar. the Marut (HF 24) design activities. Government of India. including overseeing of company inspection. since there was no Military Certification Agency in existence at that time. the then king of Mysore. and entrusted to Chief Resident Engineer (CRE) and Chief Resident Inspector (CRI) respectively. Although this all-metal aircraft was primarily meant for use by the Indian Air Force. Hyderabad. These aircraft were certified for release to service for operational deployment by the CRE (Aircraft). This document has since been reviewed. and interactions with HAL/Air Force/Navy/Army/DRDO laboratories/private companies are looked after by the respective RCMAs in their allocated areas of disciplines. quality assurance personnel. HPT 32. IN. Civil Aviation (DGCA). Koraput. Defence Research. CEMILAC.Airworthiness Certification of Fighter Aircraft projects like HJT 16. Bring up to the attention of CEMILAC. Defence Research. and at Armament Research & Development Establishment (ARDE). at Defence Research & Development Laboratory (DRDL). under Directorate of Aeronautics. certification. the officers of CREs were started at the HAL divisions at Foundry & Forge. Defence Research as its Chairman and members drawn from IAF. users. reporting to the Secretary. An advisory council was formulated with Secretary. Hyderabad and Lucknow. Kanpur. and Directorate General Aeronautical Quality Assurance (DGAQA) to periodically review and provide guidelines for the effective functioning of CEMILAC. Air/Naval/Army Headquarters/ Ministry of Defence. and private companies. with the head of CEMILAC designated as Chief Executive. amended. RTO. Subsequently. but started functioning in 1971. etc. cases where there is difference of opinion between xxx . Chandigarh. at Base Repair Depot (BRD). The CE. These offices were called Resident Technical Office (RTO). The RTOs were named as Regional Centres for Military Airworthiness (RCMAs) with their heads designated as Regional Directors (RDs). Ajeet. with CRE as the head. Director General. Aviation. academic institutions. The same was issued by the Ministry of Defence as a mandatory requirement to be followed by the certification authorities. RESPONSIBILITIES OF CRES/RDS During Prototype Development Phase • • Be responsible for ensuring that the firm is cognisant with. The day-to-day activities on safety. CEMILAC reports to the Secretary. DRDO. correctly interprets and applies the technical requirements. All CREs were brought under the technical and administrative control of the Chief Executive (CE). industry. Ministry of Defence. and re-issued by the Ministry of Defence as DDPMAS – 2002. The Centre for Military Airworthiness and Certification (CEMILAC) was formed at Bengaluru in 1995. Pune. DRDO felt the necessity to have a dedicated setup to look after the airworthiness functions. Army. The experience of CREs in certifying a wide variety of aircraft and equipment were consolidated into a procedure document called Design Development and Production of Military Airborne Stores (DDPMAS –1975). PSU. Nasik was established in 1968. Korwa Helicopter. Examine modification proposals put up by the contractor in respect of projects under his control. technically accept the modification proposals. CEMILAC periodically on evaluation of design features. safety interchangeability. Additional tests should be called where necessary. Local Concession Committee. Define periodically the design standards for production/overhaul of aircraft. During Production Phase • • • • • Be the Chairman for Local Type Test Committee. Shall attend the debriefing meeting when necessary. The CRE/RD is also responsible to ensure compliance of design and test requirements required for technical clearance of the stores by CEMILAC. examine and approve changes to ground and flight test schedules. structural. and act as the Chairman of the Local Modification Committee constituted for the various projects. call for the tests required.Introduction • • • • • • the contractor and the concerned CRE/RD regarding compliance of a particular requirement. ground and flight tests carried out. xxxi . Evaluate design features of all military projects at the contractor's works and verify conformity to design requirements. when strength. Witness ground tests where necessary and verify adequacy of loading and test conditions. urgent operating notices (UONs). or otherwise concessions. One set of these shall be forwarded periodically to CEMILAC. special technical intructions (STIs). and Lifing Committee. Arrange to collect Type Records. Approve the Development and Qualification Test Schedules and specify the test and analysis requirements for clearance of airborne systems and stores. Examine the acceptability. In the discharge of this responsibility. mechanical and system tests. Examine and approve all draft servicing instructions (SIs). proving trials and flight tests. Where these are inadequate. one shall take all necessary actions to ensure acceptance of the modification by the user services prior to his formal technical clearance and prescription in the standard of preparation. referred to by CRI. urgent servicing notices (USNs). including test reports on wind tunnel. and Lifing Policies that are required to be issued for the maintenance of airworthiness standard of the aircraft manufactured at the contractor's works. one shall advise the contractor for revision of testing to appropriate loading and test conditions. bench test. service bulletins (SBs). Submit technical appreciation reports to Headquarters. examine cases of concessions put up by the contractor for non-compliance of modifications. Analyse flight results and examine adequacy. are affected. etc. It has branch offices located at the various divisions of HAL in a manner similar to RCMAs. xxxii . Be responsible to approve specifications/drawings of the material/components and lay down test requirements for approving the same in respect of items proposed by the contractor to indigenise or substitute. DGAQA is responsible for the quality assurance and acceptance of aircraft/aeroengines/helicopters and aeronautical stores manufactured/overhauled/repaired at various divisions of HAL. material or components from other countries. Maintain day-to-day contact with service headquarters in respect of aircraft in service use. Be satisfied himself on the adequacy of production. ground and flight test schedules. Repair Schemes. STIs. All defect investigations carried out during development phase shall have member from RCMA. The responsibilities of DGAQA and ADGQAs are summarised below: • Exercise control over the quality control organisation of a firm and report to headquarters of any fall in the standard of the firm's quality assurance organisation/staff. and approve the ground and flight test schedules and their amendments. The head of DGAQA is the Director General and its headquarter is located in New Delhi. stores manufactured by ordnance factories and in private sector. besides other responsibilities. the branch offices are termed ADGQAs.Airworthiness Certification of Fighter Aircraft • • • • • • SIs.. organisation and interactional ambit of CEMILAC. and overhaul of aircraft manufactured by the contractor. on matters arising from technical and operating experience of such aircraft. UONs. Examine tests carried out on components indigenously developed at the contractor's works and forward. USNs. Directorate General of Aeronautical Quality Assurance The Directorate General of Aeronautical Quality Assurance (DGAQA) is under the Department of Defence Production and Supplies in the Ministry of Defence. and take action as considered necessary to ensure maintenance of airworthiness. recommendation for type approval. during manufacture. Participate and ensure adequacy of investigation of defects and incidents carried out by the contractor on design aspects. to CEMILAC. STRUCTURE OF CEMILAC The flow chart indicates the structure. etc. DRDO. Whenever there are deviations of a major nature affecting safety. PSU.. strength. the firm's quality assurance responsibility should be permitted. through physical examination. If there is a need to deviate. DGAQA DRDO Labs Public Sectors Support to BRDS Avionics Group • RCMA (L) • RCMA (HYD) • RCMA (KW) • RCMA (AA) Airworthiness • IAF Assurance to User • IN • Army Aviation Services ADA Ensure. it should only be done in consultation with CRI. and introduce such checks and procedures as considered necessary from time to time. interchangeability or other operational aspects. Introduce stages of physical quality assurance that are comprehensive and cover quality assurance. DGCA. Academic Insts. These are to be reviewed periodically for ensuring better supervision over the firm's quality assurance organisation. Ensure that all deviations from the stipulated requirements are properly authorised and recorded. Army Aviation. IN. that the firm's quality assurance staff have carried out comprehensive quality assurance at all stages. these xxxiii . Whenever the CRIs' stages of quality assurance have been communicated to the firm. from raw materials stage to the final delivery of the product.Introduction Structure of CEMILAC Secretary Defence Research CEMILAC Advisory Council Analytical Inputs • HAL • Academic Institutions • Aero Labs • AR & DB Centre for Military Airworthiness and Certification (CEMILAC) Joint Civil Military Certification National Labs Private Sectors • • • Consultancy IFAA : CAA PE UK Propulsion Group • RCMA (E) • RCMA (KPT) • RCMA (M) • RCMA (C) • RCMA (GTRE) • RCMA (F&F) Aircraft Group • RCMA (A/C) • RCMA (N) • RCMA (KD) • RCMA (H) • Chairman : SA TO RM Co-Chairman : CAS Nominee Members : INF. from the incoming raw material and stores to the finished product and final assembly stage. Approach to confine clearing the aircraft for development flight tests. the system does not always take care of individual personalities. and Production • Trial Evaluation • Prototype Development and Production • Licence Programmes xxxiv . details of new design projects or manufacturing methods or processes that may affect the established inspection procedure. The concepts of milestones in the project are addressed. overhaul. testing. The headquarters of CEMILAC and DGAQA would then have to step in and smooth out the issues. Deviations affecting operational aspects shall be referred to Air/Naval/Army Headquarters/RD for decision. Specific certification activities for various facets of aircraft design. for according clearance for development flight tests. ensures a systemic interaction mechanism at all stages. LCC. development. production and life cycle management of the aircraft will be discussed covering the following aspects. etc. Interface between CEMILAC and DGAQA The involvement of RCMA and CRI in various day-to-day activities during development. Assist DGAQA Headquarters in indigenous substitution activity. production. associate with all phases of development and testing of stores. testing. However. snag rectification. based upon extensive wind tunnel simulation and ground test evaluation is elaborated. systems. ABOUT THIS MONOGRAPH This monograph discusses the aspects concerning the methodology adopted for airworthiness certification in India for military aircraft. The methodology adopted by the certification authority in evaluating the design from airworthiness and safety viewpoints throughout the design and development phase. During the prototype development of stores and trial installation. hardware and software.Airworthiness Certification of Fighter Aircraft • • • • shall be referred to CRE/RD for decision. Report to Headquarters.. • Project Initiation and Development • Overview of Airworthiness Certification • Technology Development • Ab-initio Design. which could cause stand-offs and sometimes confrontation on perceived overlapping of authority. Release aircraft for test flights by issuing Form 1090. The certification process through concurrent design evaluation and clearance to the next agreed stage are elaborated. Development. and raise critical observations thereon. is presented. and indigenisation tasks like LTCC. LC. reliability analysis. risk analysis. at the end of this process. failure tolerance criteria. xxxv . Pros and cons of delegation of airworthiness function to the contracting firm through approved designers and airworthiness groups within the firm will also be discussed. The document is structured in such a fashion. A brief explanation of the terminology used and institutions named in the document is given in pages xvii to xx and the evolution of Airworthiness Certification is covered in Introduction from pages xxix to xxxv.. Chapters six through twenty five provide information in greater detail to be of utilitarian interest to a practitioner of the discipline of airworthiness certification. that chapters one through five will provide information that is extent sufficient in scope and depth to be of interest to the individuals desirous of understanding the basic concepts of airworthiness certification.Introduction • • • • • • • • • • • • Introduction to Aircraft Design Design Evaluation Methodologies for Certification Bought out Aircraft Continued Airworthiness Various types of Modifications Mid-life Upgrades Weapon Systems Life Evaluation of Aircraft and Airborne Stores Licence Manufactured Aircraft and Airborne Stores Aircraft Accidents. etc. are discussed to demonstrate how. The tools adopted for design evaluation like failure analysis. Incidents and Defect Investigation Indigenous Development COTS and its Certification Implications Design implications of not following the concurrent clearance approach are discussed through a brief overview of the design aspect. the user gets an assurance that aircraft is safe to operate within the stipulated limits and the build standard of the certified aircraft provides the extent of performance level desired in the requirements spelt out by the service headquarters in appropriate Air Staff Requirements (ASR)/Naval Staff Requirements (NSR)/General Staff Quality Requirements (GSQR). . This demonstration enables the government to take a decision on project sanction. Thus. with impact on the time and cost schedules. cost overruns. In such a technology demonstrator programme of critical importance to decision-making. This resulted in performances shortfalls. time and cost to correct them can be significant. technology demonstrator programmes are an extremely important route for decision-making. and that he has the expertise and capability to undertake the programme. This will be necessary since such aircraft will also have to be flown by the service . the experience of USAF in the F111 and C5A programmes of the 1960s. the effort.CHAPTER 1 Technology Development Technology development can be a precursor to enable the government to commit to a particular programme. Hence. The most recent example is the demonstration of the control configured vehicle (CCV). These had followed the ‘total system’ acquisition concept of the then Defence Secretary Robert McNamara. and performance. Due to the very nature of a programme conceptualised to be a platform involving cutting edge technologies. A contractor provides evidence that the technology being proposed is viable. so as to bring out potential problems and take corrective actions. relying instead on analyses and simulation as the basis for decision-making. by a thorough assessment of safety aspects. CEMILAC/RCMAs will not have the advantage of availability of the technical specifications and standards to evaluate the design for safety. glass cockpit and composite technologies. and to provide statements of compliance. using actual hardware and software. the technology demonstrator phase should thoroughly evaluate the technologies and operational concepts. If unexpected technical or operational problems are uncovered after this point. the role of CEMILAC/RCMA will at best be limited to ensuring that safety-of-flight is ensured. It is worthwhile to note in this context. and schedule delays. which did not require technology demonstrators and hardware test demonstration. the safety criteria cannot be of a level lower than that with a conventional system. (2) National Aeronautics and Space Administration (NASA) and (3) Socity of Automotive Engineers (SAE) reports as well as proceedings of NFTE. The question arises as to how safety assessment can be done without a sound knowledge of the technologies involved. ensuring that adequate margins are provided for excursions. The next step is to make use of the interactive sessions with the various contracting firms in the form of technical meetings. It will be helpful if a detailed questionnaire is prepared and answers obtained. who in fact had drafted the specification. in respect of analytical as well as experimental work done in various organisations. and extensive literature survey with particular reference to (1) National Technical Information Services (NTIS).Airworthiness Certification of Fighter Aircraft pilots. NFTP. Whatever the technology level being dealt with. The safety considerations should be based on input/output criteria and definition of the number of failures a system should tolerate. will serve as the baseline knowledge. Keeping the above points in view. These cover the current technologies. and that in fact high temperature operation is more critical than low temperature operation for this class of aircraft. to assess the limits within which it is safe to operate and to determine the boundary conditions for operation. USA. The discussion with the scientist at Wright Laboratories. The only approach is a painstaking one–by means of a sound knowledge of the basic aspects of aircraft design. which would be particularly helpful to the younger entrants into the certification discipline. and IEEE seminars. CEMILAC/RCMAs should provide a statement on the performance achieved to enable decision-making by the government. brought out that fluid temperature gets hot due to the high frequency of operation of flight control actuators on statically unstable aircraft. 2 . An example is the case regarding the queries on low temperature operation of the flight control actuator. A systematic compilation of a good database. the design aspects have been provided a good coverage in chapters – 5 through 21.