PIA TS 135  4.3.5.3  Precondition for not less than 400 continuous hours with a 200 lbf (889.6 N) or greater load  applied to compress the pack in a manner similar to that most likely to be encountered in actual  use. Test drop within 1 hour after removing the load.  4.3.5.4  Alternate preconditioning. The preconditioning requirements for 4.3.5.1 and 4.3.5.3 may be  combined as follows: The complete test parachute assembly may be placed in a vacuum bag  and preconditioned at +180   F (82.2   C) for 18 hours at a constant vacuum of  not less than 25”  Hg (0.846 bar). Stabilize to ambient and drop.  (a)  Test weight = Maximum operating weight x 1.2  Test speed = Maximum pack opening speed x 1.2  (b)  Test weight = Maximum operating weight multiplied by the factor from Figure 1  Test speed = Maximum pack opening speed multiplied by the factor from Figure 1  4.3.6 STRUCTURAL OVERLOAD TESTS: No material(s) or device(s) that attenuates shock loads and is not an integral part of the  parachute assembly or component being certified may be used. Tests may be conducted for  either a complete parachute assembly or separate components. There shall be no evidence of  material, stitch, or functional failure that will affect airworthiness. For reusable items the same  items shall be used for all 4.3.6 tests. Peak opening force shall be measured on all 4.3.6 tests. The parachute must be functionally open within the number of seconds calculated for 4.3.8 tests. Parachute assemblies shall be tested in accordance with the following schedule:  -OR-  However, the test speed must not be less than 180 KEAS (333.4 km/h) for reserve and  emergency parachute assemblies and the test weight must not be less than 264 lb. (120 kg). For dual harness parachute assemblies the test weight must not be less than 600 lb. (272.7 kg)  and the test speed must not be less than 200 KEAS (370.4 km/h).  Three drops shall be made with weight and speed in accordance with 4.3.6. When using test  method (b), in 4.3.6 a 4$^{th}$ drop must be added using the same parachute under the same  conditions in the first three drops. Where non-positive locking hardware is used to attach the  canopy or riser(s) to the harness, a cross connector must be used and one of the above drops  shall be with only one attachment engaged to test the cross connector and hardware.  4.3.6.1  STRENGTH TEST, COMPLETE PARACHUTE ASSEMBLY: 4.3.6.2  STRENGTH TEST, ALTERNATE MEANS OF COMPLIANCE CANOPY (ONLY): Three drops shall be made with a gross weight and speed in accordance with 4.3.6. When using  test method (b), in 4.3.6 a 4$^{th}$ drop must be added using the same canopy under the same  conditions in the first three drops. A test vehicle (e.g., a bomb) may be used. The canopy and  any required additional components (i.e., deployment device, pilot chute, and risers) shall be  tested as a unit. The connector links (if used) shall be attached to the risers in the same manner  as the intended use and the riser(s) should be secured to the test vehicle in a manner  appropriate to the test objective. For example, if the parachute risers are to be tested on the  bomb drop, it should be arranged in a manner as to duplicate the loading found on the personnel  parachute harness. Where non-positive locking hardware is used to attach the canopy or  riser(s) to the harness, a cross connector must be used and one of the above drops shall be with  only one attachment engaged to test the cross connector and hardware.  DISTRIBUTION STATEMENT: All Rights Reserved. No Part of this publication may be reproduced without prior written permission from Parachute Industry Association. PIA Headquarters, Parachute Certification St andards Committee, 3833 West Oakton Street, Skokie, IL 60076 Phone: 847-674-9742 Fax: 847-674-9743 or  website www.pia.com for contact details.  Disclaimer: This document is published by the PIA to provide technical and engineering standards that can be used by reference by all those who may benefit from them. The use of this document is entirely voluntary, and its applicability and suitability for any particular use, including any patent or trademark infringement  arising there from, is the sole responsibility of the user. There may be errors, especially in numbers. PIA disclaims any responsibility for accuracy. The PIA reviews each technical publication periodically, at which time it may be reaffirmed, revised, or canceled. The PIA invites your written comments and suggestions.  Copyright © 2010 Parachute Industry Association.  PIA TS-135, Revision 1.4, Issued April 22, 2010, Page 8 of 18  A-33 Change 1 (December 2015)