The PMA – Parts Manufacturing Approval

Part of Device Technologies Inc's (DTi) mission is to help MRO's improve their efficiency and their profitability.  Part of that mission means seeking approvals where appropriate so our best-in-class protection products can meet the needs of industries that require their components to have the appropriate testing and permissions.

As a result, DTi has just applied for FAA Design Approval for a PMA -Parts Manufacturer Approval for Spring-Fast® Wire Protection.  When it gets approved, aerospace engineers and techs in MROs can take advantage of the best-in-class M22529 grommet technology and replace the old legacy MS21266 glued nylon grommets.

DTi worked with the Boston Aircraft Certification Office to complete the application and as part of that has identified the make and model of a wide range of Type Certified (TC) aircraft on which Spring-Fast M22529 grommets can be proposed as a suitable replacement -and preferred alternate- for the MS21266 series nylon grommets.

The design approval phase of a PMA certifies that a replacement component -in this case, Spring-Fast- complies with the airworthiness standards of eligible products. DTi had to show/prove this compliance through submitted tests and computations.

The submission cites the technical data needed to support the application and its approval.    Approval is expected quickly.

Significant End-User Benefits

For end users, Spring-Fast M22529 provides best-in-class cable and wire (EWIS) protection while also offering install savings of 49%, a significant reduction in the FO/FOD footprint of MS21266, plus the complete elimination of glues, solvents, and VOCs, such as MEK and trichloroethylene.

The certification of the Spring-Fast product line will offer the industry a way to ensure best-in-class wire protection at half the cost of nylon grommets (MS21266).  It is expected to make inroads into the after-market first and then work its way into new designs.

This PMA will apply to the two current on-market variants of Spring-Fast M22529/1 and M22529/2.


Comparison of the Old vs the New Grommets

The Old —-Nylon MS21266 grommet:

  • Slow, costly, labor-intensive, and multi-step process.
  • Multiple items for application and safety have to be gathered in the prep phase.
  • Edge abrasion & cleaning – is required for proper adhesion.
  • MS21266 has to be glued into place as it has no inherent retentive strength
  • Nylon's hardness & rigidity result in non-flexible conformance set onto panel edges/radii so fixturing is needed to hold it in place while the adhesive cures.
  • The excess adhesive has to be cleaned with a MEK solvent.
  • Dis-bonding happens often and leads to rework – affecting the cost of poor quality.
  • Temperature gradients & material differences in coefficients of expansion can cause nylon to detach from the application panel edge resulting in the risk of electrical system failure.

The New —-Spring-Fast M22529 grommet:

  • Save at least 49% on total install costs
  • Fast, easy finger pressure application – snaps into place without adhesive.
  • Opposing finger-like castles exert a compression force for retention without glue.
  • Passed 20/20/20 G static load tests – even when 4 castles are removed for clearance on a support clip.
  • Minimized FOD footprint- fewer shop consumables like gloves, cloths, adhesive, tape, solvent, and masks.
  • Easily reworked without loss of edge retention
  • NAVAIR Qualified.

Any OEM using nylon grommets with adhesive can achieve install savings of at least 49% by switching to Spring-Fast.

Spring-Fast is also greener as it needs no adhesives, solvents & VOCs increasing workplace safety with no PPE required. It also helps reduce consumables’ usage which saves money and also cuts FO/FOD risk.

Read more about Spring-Fast Mil Spec grommets here

Order Free samples here

Read a related article on product benefits on ThomasNet