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Passenger to Cargo Conversion

Due to the current pandemic situation the aviation industry requirements have changed significantly. In order to resolve this situation, aircraft operators are changing passenger aircraft configuration to a Cargo configuration, on a temporary basis and permanent basis as per their requirement’s. In this case Spires have implemented Design solutions for operators as per their business plan, to cater both customer & regulator in an effort  to convert their current passenger aircraft into a cargo aircraft or Combi.



Currently spires is carrying out a major Cargo conversion (STC) approved under through its FAA DER, and hence expanding its scope  from  Minor change’s  On-seat cargo to full cargo conversion STCs. Our experienced Design, Stress and Certification  team is capable of delivering  the requested change instructions as per our clients spec. Conformity inspections are carried out through our delegated Engineers to  inspect the aircraft  and extract the required data for the design change .

Spires experienced stress engineers monitor strength and installation orientation of it all the cargo tie down members to provide required strength to withstand the cargo in emergency landing conditions as shown below.

  1. Upward, 3.0g
    ii. Forward, 9.0g
    iii. Sideward, 3.0g
    iv. Downward, 6.0g
    v. Rearward, 1.5g

During all side forces up to factors defined in FAR 25.561 emergency condition, the cargo will be restrained using tiedowns attached to seat track. Therefore, the load path shall be as follows,

Cargo loading system is identical through each cargo section, although the size and weight of each section may differ. Thus, there are no other load paths that could interfere the system.

Cargo Net – Strength capability of the Cargo Net is much lower than the other load baring members of the system. Therefore, in order to simplify  and be conservative in the analysis, the strength contribution of the cargo net is neglected. The primary function of the Cargo Net is to support, along with the tie downs, to retain the shape / form of the cargo section.

Finally, the analysis performed here considers the maximum loading and maximum volume for each converted cargo aircraft to cater both operator and regulator. Furthermore, for our design we beforehand structurally substantiate tie down orientations of the cargo to make our design secure before carrying out the P2F Conversion physically on the aircraft.

Since our priority is customer satisfaction , this is coupled with satisfying the  regulatory requirements, through the respective authorities (EASA/ FAA/ UK CAA) expect from Spires Aviation & Spires Engineering.Other than the above we also have the capability to support the following:

  1. Aircraft Seat Covers repairs/changes
  2. Aircraft Carpets changes/repairs
  3. Aircraft Flammability Testing
  4. Aircraft Seat Cover changes
  5. Placard Design and modification
  6. Repair of Cowling delamination
  7. Internal Structures repair
  8. Business jets cabin interior Modification
  9. Registration /De-registration of aircrafts
  10. Aircraft External/Internal markings
  11. Aircraft Thrust Reverser
  12. Cargo Conversion 747 combi
  13. CS23, CS25, CS27 & CS29 support
  14. FAA STC

For any  Repair/Change  solution, please contact Spires Aviation on 01279 909422/ or email

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