GOVERNMENT OF INDIA             CIVIL AVIATION REQUIREMENTS
CIVIL AVIATION DEPARTMENT       SECTION 2 - AIRWORTHINESS
                                SERIES 'X' PART V
                                ISSUE II, DATED 15TH APRIL '1977

File No. 9/497/76-AI(2)         EFFECTIVE  : FORTHWITH 
                                                                                       
Subject : Concessions.

1.   BACKGROUND :

     An operator or overhauling/repair organisation is  sometimes 
     faced    with   a   problem   of    procuring    replacement 
     parts/materials,   meeting  specifications   stipulated   in 
     approved  type  design  documents  or  of  effecting   major  
     repairs/major modifications in the manner as approved by the 
     manufacturers,     in    respect    of     aircraft/aircraft 
     component/item   of  equipment.   Under  such  circumstances 
     marginal   deviations  from  approved   specifications   not 
     affecting  the  safety of aircraft may be approved by  DGCA.  
     This may be covered by the grant of a "concession".

2.   DEFINITIONS :

     (a)  "Concession"  is defined as permission by the  DGCA  to 
          use   a   limited  quantity   of   material/parts   not 
          manufactured    exactly   in   accordance   with    the 
          manufacturer's  approved  design specifications  or  to 
          effect  major  modification/repair  not  completely  in 
          conformity  with  that approved by  manufacturers,  but  
          are acceptable to DGCA, keeping the safety of  aircraft 
          in view.

     (b)  "Major  Modifications"  are those  alterations  to  the 
          primary   structure/parts/equipment/systems  that   are 
          likely  to jeopardise the safety of aircraft and  those 
          on  board if not carried out at all or if  carried  out 
          improperly  and affect its weight, centre  of  gravity, 
          structural  integrity  or  cause change  in  design  or 
          material or  flight characteristics.  

     (c)  "Major Repair" is a repair, which if not or  improperly 
          (using  unapproved  procedures/methods)   accomplished, 
          would   adversely  affect    the  aircraft   structural 
          strength,   performance,  flight  characteristics   and 
          consequently its safety as well as the safety of  those 
          on board.

3.   SCOPE :   

     (i)  Aircraft operators or overhauling/repair  organizations 
          finding  difficulty in procuring  approved  replacement 
          material/parts,  may  approach  Regional  Airworthiness  
          Office   with   a  request   furnishing   details   (in 
          triplicate)  as listed in the appendix to this part  of 
          the  CAR  for using substitute  material/parts  in  the 
          assembly  of aircraft, aircraft  components,  equipment 
          and  systems,  provided such substitutes  are  procured 
          from  sources acceptable to DGCA and are able  to  meet 
          type specification requirements.

     (ii) Requests for grant of "Concessions" relating to use  of 
          material/parts in, or effecting minor modifications  or 
          carrying  out minor repairs to aircraft secondary  (not 
          primary) structure, aircraft systems other than primary 
          systems  like  flight  control  system,  landing   gear 
          system,   pressurization system,  navigational  system,  

          Auto   flight,   Electrical   Power   Generation    and 
          Distribution,  Fire  Extinguishing,  Hydraulic   Power, 
          engine   control   system,   fuel   system,   emergency 
          evacuation  system   etc., will be disposed of  by  the 
          Regional Airworthiness Offices.  However, such approved 
          firms,  whose scope of approval  specifically  includes 
          such  delegation may use substitute  material/parts  in 
          aircraft  systems  other than those mentioned  in  this 
          para,  under the authority of Quality  Control  Manager 
          provided  proper  records are maintained  and  Regional 
          Airworthiness  Offices are informed of  such   actions, 
          soon after accomplishment of work.

     (iii)Requests for grant of "Concessions" relating to use  of 
          material/parts  or  effecting  major  modification   or 
          carrying   out  major  repairs  to   aircraft   primary 
          structure or to aircraft systems mentioned in para (ii) 
          above   must   be  referred  to  DGCA,   via   Regional 
          Airworthiness Offices for prior approval.

4.   Repairs, major or minor, carried out strictly in  conformity 
     with  the standard aeronautical practice, spelt out in  well 
     recognised documents, like Federal Aviation Administration - 
     'Aircraft  Inspection and Repair - AC 43.13 Manual'  of  USA 
     and 'Civil Aircraft Inspection Procedures' of Civil Aviation 
     Authority of UK need not have prior approval of DGCA.

5.   The   approval  will be indicated on the  format  (appendix) 
     itself,  one  copy  of  which  will  be   returned  to   the 
     applicant.    Such  approved  formats  shall  be   carefully  
     preserved by the applicant for future reference for as  long 
     a period as the log books are kept.

6.   Whenever such materials/parts (covered under Concession) are 
     used, the related documents like log books, procedure sheets 
     etc., must make a mention of the same.


                                             Sd/-
                                        (V. N. Kapur) 
                                  Director of Airworthiness
                           for Director General of Civil Aviation



                                                  A P P E N D I X


                 C O N C E S S I O N     F O R M



Station                           Applicant's reference/Drg.

                                  Concession No.

                                  Date of Application :

Application made by 

A concession is hereby requested 
to (quote job and/or process).

Reason  for requesting Concession.

Aircraft registration or Serial No. 
of Engine accessories to which 
concession applies.

Quantity of Parts to be covered
by this Concession :

Part No. of the item(s) involved
and details of similar concession 
granted earlier (if any).

List  relevant  deviations  from
type specifications, such as material
composition/gauge/strength, dimensions, 
process, operating limitations etc.

Person responsible  for certification
of Job :

Drawings attached                         No.         

                                          Signature of applicant.
                                        
                                          Designation:

The above Concession is/not  granted to 

Subject to

Concession No. allotted

Date                                       Signature

Station                                    Designation :
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