Device Technologies (DTi) has announced that Sikorsky Aircraft Corp. (SAC) has executed an Engineering Change (EC) to use DTi’s Spring-Fast M22529/2 grommet edging in place of the legacy MS21266 nylon grommets for select applications on the Blackhawk UH-60M.
SAC turned to DTi for a solution because DTi’s Spring-Fast provides best-in-class EWIS anti-chafe, arcing and sparking protection at half the cost of legacy systems due to its fast finger pressure install with no glue, no clean up and no curing.
Sikorsky made the change after careful evaluation because critical machined fittings that are used to secure the Active Vibration System were being subjected to vibration of between 10 and 25 Hz. This was causing repeated, non-conforming, discrepancy reports as the legacy glued nylon grommets were dis-bonding and pulling away from the edges and surfaces to which they were applied.
Further compounding the problem were tight radii and reverse curves that made up the periphery of the machine fitting. Without protective edge grommets wiring was susceptible to chafing which created the discrepancy reports and over time it could lead to potentially catastrophic sparking and arcing.
“The Blackhawk is another success for DTi. We have supplied our Mil Spec quality grommets for numerous tactical aircraft like the V280 Velour, CH-47 Chinook, C-17 Globemaster, T38 trainer and many others,” said Nick Petri, Managing Director of DTi. “It takes time for OEM systems and thinking to change, but we know we have a better alternative than legacy systems, and our job is to show OEM’s the performance and cost benefits.”
The problem with the old MS21266 legacy grommet is that it lacked the flexibility and static friction needed to hold to varying radii. Despite the adhesive and heat being applied to soften and make the nylon more malleable during application, it retained its tendency to dis-bond. This created discrepancies as well as a high cost-of-poor-quality as installation work had to be rigorously checked and often reworked.
In contrast, the M22529/2 has superior retentive capabilities; its thin CRES substrate allows technicians to hand pre-form the grommet to rough interfaces and shapes and then easily snap them into place with just finger pressure. The M22529/2 has been static load tested to 20G on all three axes without adhesives.
“We are proud of this Blackhawk EC but this has implications far wider than aerospace as Spring-Fast grommet edging achieves a rare feat –it provides best in class performance for half the cost,”said Petri. “Any OEM in any industry who uses the old nylon grommet edging with glue can take advantage of this best in class performance for half of the installed cost.”
Device Technologies Inc.