{
  "$type": "site.standard.document",
  "description": "A method of operating a multi-engine system of an helicopter includes the multi-engine system having a first turboshaft engine having a first shaft, a second turboshaft engine having a second shaft, a gearbox having a clutch system (152), and a range of rotation speeds defined as a placarded zone…",
  "path": "/patents/1399481",
  "publishedAt": "2026-05-13T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B64C27/12",
    "PRATT & WHITNEY CANADA [CA]"
  ],
  "textContent": "A method of operating a multi-engine system of an helicopter includes the multi-engine system having a first turboshaft engine having a first shaft, a second turboshaft engine having a second shaft, a gearbox having a clutch system (152), and a range of rotation speeds defined as a placarded zone. The method includes: rotating the first and second shafts at a first idle rotation speed (NLLI) below the placarded zone when clutched to a load; increasing a rotation speed of the first shaft from the first idle rotation speed (NLLI) to a flight rotation speed (NLF) above the placarded zone; unclutching the second shaft from the load during the increasing; and increasing a rotation speed of the second shaft to a second idle rotation speed (NLHI) when the second shaft is unclutched from the load, the second idle rotation speed (NLHI) above the placarded zone and below the flight rotation speed (NLF).",
  "title": "SYSTEM AND METHOD OF OPERATING MULTI-ENGINE SYSTEM"
}