GOVERNMENT OF INDIA             CIVIL AVIATION REQUIREMENTS
CIVIL AVIATION DEPARTMENT       SECTION 2 - AIRWORTHINESS
                                SERIES 'I' PART III
                                ISSUE I,DATED 24TH APRIL '1992

File No. 11-690/92-AI(2)        EFFECTIVE : FORTHWITH

Subject : MAINTENANCE_OF_TEST_EQUIPMENT.

1.   INTRODUCTION

     Rule  57 requires that every aircraft shall be  fitted  with 
     approved instrument and equipment including radio  apparatus 
     as may be specified further modern aircraft are fitted  with 
     many instruments, equipments whose function is vital to  the 
     aircraft   operation.    These   equipment   indicate    the 
     performance  of the various aspects of airframe, engine  and 
     system  performance.   Any  inaccuracy  introduced  in   the 
     indication system will result in incorrect operation of  the 
     aircraft,   engine  and  its  system.   It  is,   therefore, 
     necessary  that  such  instruments,  equipments  and   other 
     accessories  are  checked  at regular  intervals  for  their 
     correct  functioning and indication.  For this  purpose  the 
     instrument, equipment, accessories require overhaul and test 
     with  the help of test equipments which are expected  to  be 
     accurate and error free during use.

     The   test  equipment/benches  are  generally  set   up   in 
     accordance     with     the     equipment     manufacturers' 
     recommendations.   Operators who are approved to  carry  out 
     overhaul,  test  and certification of  equipment  must  have 
     proper  test  equipment, the manuals, and also  ensure  that 
     such  test  equipment  are  kept  properly  maintained   and 
     calibrated at regular intervals.

2.   Maintenance of Test Equipment

     The  test equipment and its serviceability and  accuracy  is 
     vital as the primary functioning of instrument and equipment 
     depends  on the serviceability and the accuracy of the  test 
     equipment.    The   test  equipment  therefore   should   be 
     maintained  in accordance with the recommendations  of   the 
     manufacturers  given in the manuals.  A  proper  maintenance 
     schedules  should  be  framed  so  that  the  equipment   is 
     subjected  to  proper inspection and  servicing  at  regular 
     intervals.   The  interval of maintenance  schedule  may  be 
     based on the frequency of the use.  The test equipment which 
     are not frequently used may require different check than the 
     ones which are frequently used.  Accordingly the maintenance 
     schedules may be based on either the calender period or  the 
     hours  of operation depending on the amount of work  of  the 
     operator.    Such schedules will have to be prepared by  the 
     shop  incharge, approved by the Quality Control  Manager  of 
     the company.  Copy of the same will have to be kept  amended 
     and updated.

3.   Calibration of the Test Equipment

     Apart  from  maintenance  the  test  equipment  have  to  be 
     calibrated  with  reference  to  the  master  gauges/primary 
     standards.   Such primary standards are generally  available 
     with  the national laboratories or the approved test  houses 
     established  by  the various scientific departments  of  the 
     State Government /  Government of India.  The operators need 
     not  have  a primary standard whose cost is  very  high  and 
     which may not be required during day-to-day use.   Secondary 
     master  gauges  could  be developed with  reference  to  the 
     primary standards and used in the day-to-day work.  A proper 
     record should be maintained of the calibration done and also 
     the  next calibration due.  A list of all primary  standards 
     and secondary standards be kept in the shop.

4.   Certification  of  Maintenance  Schedules  and   Calibration 
     Equipment

     The maintenance schedules of the test equipment as and  when 
     performed  will have to be certified by persons approved  by 
     the local airworthiness authorities in consultation with the 
     QCM.  Such persons will have to show their familiarity  with 
     the  test equipment, literature and also must provide  proof 
     that  they are familiar with the job they are   required  to 
     perform.    These  persons  should  also   be   specifically 
     authorised   to  carry  out  calibration  check  and   issue 
     certificate to this effect.

     The  Quality Control Manual/Inspection Manual will  indicate 
     the various instruments/equipment calibration period so that 
     all  the instruments and the gauges are checked  at  regular 
     intervals  by  the  persons  duly  approved  as  stated   in 
     preceding para using the test equipment.

5.   Validation of Software of Computers used as Test Equipment

     It  will be the operators responsibility to get  appropriate 
     certificate from equipment manufacturer that software  which 
     has  been  supplied with the  computer or  separately  which 
     will  give   results  identical  to  the  values  given   in 
     specifications of equipment being tested.  Procedure  should 
     also   exist  to  carry  out  the  validation  of   software 
     periodically and proper record has to be maintained of  such 
     validation checks.   BITE or  SELF test accuracy should also 
     be  clearly  indicated.   The  procedure  be  documented  in 
     operation manual.

6.   Standard Room

     Standard  Room is established wherein master  standards  and 
     secondary standards are kept.  Only a few dedicated  persons 
     are  utilised  to carry out calibration and  test  of  other 
     gauges.   The Standard Room has to be kept  clean/dust  free 
     and  proper record of all the test equipment and the  gauges 
     available  with  history  of  their  test  and  certificates 
     obtained  for  the test should be available.   Such  Standard 
     Room will also provide service to other small operators  who 
     cannot  afford to have such facilities established  for  few 
     instruments and equipment.

7.   Non-compliance   of  these  requirements  will   result   in 
     withdrawal   of  the  approval  of  the  operator  for   the 
     maintenance,  overhaul,  repair of  the  aircraft,  aircraft 
     engine  and  systems and the approval so withdrawn  will  be 
     only  restored after it has been certified by  the  Regional 
     Airworthiness   Office   that  test  equipment   have   been 
     maintained  and calibrated in accordance with  the  approved 
     programme.

                                           Sd/-
                                    (S. L. Srivastava)
                        Deputy Director General of Civil Aviation