Airlines operating Boeing 787 Dreamliners with certain Rolls-Royce Trent 1000 engines are facing further disruption after the UK engine manufacturer called for additional inspections of a problematic part. The manufacturer said the increased inspections were driven by “our further understanding of the durability of the Trent 1000 Package C compressor”. The engine’s problems have already forced airlines to change schedules and lease other aircraft but moves to reduce Extended Range Twin Engine Operational Performance Standards (ETOPS)  for affected planes will have further consequences for long-haul routes. US regulators are expected to reduce the ETOPS, which defines how far an aircraft can fly from an airport suitable for an emergency landing,  from 330 minutes to 140 minutes There are 380 package C engines currently in-service with airlines. Rolls-Royce said the new regime does not impact Trent 1000 Package B engines or Trent 1000-TEN engines. It also noted that the cost of the problem was expected to rise higher than £370 bill it indicated in its annual results but said this would reduce discretionary spending to offset the increase. Not all Dreamliners are powered by Rolls-Royce engines and those using General Electric GEnx engines are also unaffected. The Qantas Dreamliners flying between London and Perth, for example, have GEnx engines. “Our focus is on supporting our customers and doing all we can to minimise any impact on their operations,’’ Rolls-Royce chief executive Warren East said in a statement. “We sincerely regret the disruption this will cause to our customers and our team of technical experts and service engineers is working around the clock to ensure we return them to full service as soon as possible. “We will be working closely with Boeing and affected airlines to minimise disruption wherever possible." Read: Rolls-Royce faces turbulence over engine issues. The engine manufacturer has increased its maintenance, repair and overhaul capacity by 300 percent over the past two years and has mobilized support teams to cope with Trent 1000 problems. It has also redesigned specific parts of the compressor, with the first parts currently in manufacturer and due to be incorporated in engines early next year after first being validated and certified. Air New Zealand is one of the airlines affected by the problem, with nine of the Package C engines, said it expected there would be some impact on its international schedule as a result of the additional checks. The airline said the directive by Rolls-Royce and European safety agency EASA reduced the check frequency from 2000 take-off and landing cycles to 300. “Trent 1000 Package C engines that have operated fewer than 300 cycles are unaffected by this directive,’’ it said.  “Air New Zealand also has Trent 1000 TEN model engines in its 787 fleet and these are unaffected. “Air New Zealand expects there will be some impact to its international schedule as a result of the checks and thanks customers in advance for their patience as it works through this challenge at what is a very busy time for travel.” Other airlines facing disruption include British Airways and Virgin Atlantic.