{
  "$type": "site.standard.document",
  "description": "In an aircraft comprising a set of lean-burn gas turbine engines each operating in pilot-plus-mains mode with a given initial fuel flow Wo, a method of controlling the optical depth of contrails produced by a first group of the engines comprises the steps of (i) reducing fuel flow to each engine in…",
  "path": "/patents/1408337",
  "publishedAt": "2023-11-01T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F02C9/00",
    "ROLLS ROYCE PLC [GB]"
  ],
  "textContent": "In an aircraft comprising a set of lean-burn gas turbine engines each operating in pilot-plus-mains mode with a given initial fuel flow Wo, a method of controlling the optical depth of contrails produced by a first group of the engines comprises the steps of (i) reducing fuel flow to each engine in the first group to change the operation of each engine in the first group from pilot-plus-mains mode to pilot-only mode, and (ii) adjusting fuel flow to one or more engines in a second group of the engines such that the total fuel flow to engines of the second group is increased, all engines of the second group remaining in pilot-plus-mains mode, and wherein the set of lean-burn engines consists of the first and second groups. Depending on atmospheric conditions, the average optical depth of contrails produced by the engines may be enhanced or reduced compared to the case where all engines operate in pilot-plus-mains mode with a fuel flow W.",
  "title": "METHOD OF CONTROLLING AIRCRAFT VAPOUR TRAILS AND PROPULSION SYSTEM PROVIDING FOR CONTROL OF AIRCRAFT VAPOUR TRAILS"
}