mrifixplanes

Heathrow

Kind words indeed, thankyou. C and D checks are completed at the airline's engineering base at Cardiff for 777 and 747, these are referred to as 'Majors'. 767 Majors are carried out at the Heathrow base. Thanks, I was just looking through the Youtube Analytics page and discovered that Avsim was where quite a lot of the view count was coming from, thought I'd take a look to see what was being written about them here Yes, it's just the park brake holding the aircraft. There are chocks near to the wheels but not right up against them. The 777 has 12 mainwheels and each are fitted with multiple rotor carbon brakes, there are 6 pistons on each brake pack operating at 3000psi. I'd have to measure the diameter of the piston to calculate the force but they are at least an inch so that would give 14137lbs on each brake at least

Hi, As that is my video I'd thought I'd give you some insight into how/why/when although Cimber has already explained some of the reasons a test is carried out. At the Engineering base at Heathrow we do what are known as 'A' and 'B' checks, 'A' checks are carried out about every 3 months and 'B' checks are once a year. An 'A' check lasts about 24 hours and a 'B' check lasts about 48 hours with engineers, technicians, and mechanics working around the clock to complete the tasks involved in that check. The tasks include aircraft normal and back-up systems being function tested, serviced, and inspections are carried out and any defects are rectified. After every visit to the hangar, the aircraft is towed into the run pen for an engine run. The type of run varies depending on what work has been carried out and on what systems. A normal 'A' check would result in an idle run only. This is to ensure no leaks are present in the disturbed systems. If the fuel system is disturbed anywhere (even just replacing a fuel filter), a high power run such as this is carried out. The high RPM is required to get maximum pressure from the high pressure fuel pump. Other high power runs are carried out for various reasons. A vibration survey would be one example, using the engine's on board sensors to monitor vibration readings throughout the power range of the engine. The onboard maintenance computer can then calculate if and where any balance weights need to be added. The tests are carried out by a qualified engineer in accordance with the appropriate manual and the appropriate measurements monitored. He is in contact with an engineer or technician on the ground (as seen in the video) via a headset which is plugged into a panel on the nose landing gear. The ground man is there to give the all clear for engine start and run and can notify the flight deck of any abnormailities or safety concerns. Engine intake guards are normally used but on this test, with uncertainty regarding the grip available, the engineer didn't want to take the risk of the aircraft sliding into said guards. Other safety measures were put in place. The ground man is standing as far forward as the headset lead would allow, which is about double the intake safety distance and all other personel are well clear. Wouldn't mind answering any further questions if you have them. Cheers