Abstract: A trench containing a pipeline is backfilled by temporarily supporting the pipeline at grade in the trench on deflatable airbags spaced along the bottom of the trench. The trench is then backfilled below and around the pipe by pneumatically blowing a granular fill material into the trench first beneath the pipe and then progressively upwardly about its opposite sides to about its spring line so as simultaneously to backfill the trench and uniformly compact the fill material about the pipe without leaving any voids. The fill material is blown into the trench through a pair of opposed air ducts with upturned lower outlet ends extending into the trench on opposite sides of the pipe so that backfilling progresses upwardly on opposite sides of the pipe simultaneously. As backfilling operation progresses along the trench and approaches each support pad, the pad is deflated and removed so that the operation can proceed uninterruptedly.