VH-OJU the veteran 19 year old B747 operating QF26 HND-SYD apparently had a contained engine failure and diverted to CNS on the early Mother’s Day Sunday 12 May. It is reported the engine failure occurred 2 hours before landing. Initially the aircraft descended (not dived) from FL320 to FL240 dropping 8000 feet.
An aircraft will not normally be able to maintain altitude after the loss of an engine, unless they're already flying lower than optimum (which does happen a fair bit on busy routes). After shutting down an engine, if you're lucky enough to be below the 3 engined altitude, there's not really anything that needs to be done immediately. But, if you're above that altitude, the the autopilot will maintain the current altitude, the power will be rolled up to MCT....and the speed will start to decay. The rate of decay will depend upon just how far from the 3 engine altitude you are, but it can be quite rapid.
So, you need to descend. There are two ways to do this. You can disconnect the auto throttle, and manually push the power to MCT. Then select your target altitude and FLCH (flight level change). The aircraft will descend at the selected airspeed, but because it cannot reduce the power, the descent will be very slow. This isn't likely to be something ATC like, so it's generally better to just carry out a normal descent, and to get it over with.
If indeed this was true then the failure occurred north of the PNG landmass.
In itself not an issue. 3 engine altitude will be well above any terrain, unless you're in the Himalayas.
Operating on 3 engines after shutting down one. The normal routing takes the flight near CNS anyway so it was easy to go to CNS. Reports were of the pilot taking 2 hours to
find an Australian airport to land the aircraft
Unless it's been moved, I'm sure that it took about two seconds to load it as the destination. Found. Assuming it was a reasonably clean shutdown, they wouldn't have to land at Cairns. Fuel burn is higher, but the aircraft would probably have sufficient to get to Brisbane. Nevertheless, it's a good idea to land at the nearest reasonable airport, without any pressure to do so.
I wonder what this means for the retirement of OJU. Presumably the engine will need to be replaced - with a new one?. Do refurbished engines as an entire unit exist in this industry?
I'd expect to see another 747 drop into Cairns at some stage with a 5th pod. Engines are stored as more or less complete units. How many Rollers remain, I have no idea.