Originally Posted by
Celtoid
As an ex RAAFie myself .... a pilot is quite capable of burning the hot end out of a jet engine, over-boosting the old Caribou or over-speeding a prop in a C130J .... over-torqueing, stalling, breaking lifting surfaces off the aircraft ...
A whole myriad of things can go wrong and can be induced.
And if you knew anything about modern multi-engine jet aircraft you'd know that degradation or loss of one engine will allow you to run the other to exceed it's "safe" limits.
So Pat's comment about tuning may not be technically correct ... but ... no need for the Dis!
You've waded into a pool of so many variables with no way of measuring ...
The old L13 Lycoming engine in the H model Huey (1300SHP) was (once all the peripherals were taken off) quite a bit larger than the GE T700 that the Australian Blackhawk is running. As in, the turning and burning parts in the newer T700 are smaller but produce a lot more power ... in normal flight mode. They also have the ability in several levels of contingency to exceed 2000SHP. A Rolls Royce version of the same engine running in a civil Westland variant of the Blackhawk exceeded 3000 SHP.... same size engine.
So the RR engine was not designed for boy racers, nor was it down or over-tuned .... it was just designed.... possibly like the JLR Engines ;).
So did you get the other part? ... contingency power ..... I think it's common on all platforms! That was Pat's point I think.
What's the physical size difference of a Super or Classic Hornet's engine Vs the F111? I think they produce far more power for their size Vs the older engine, don't they? ... all from the same conservative US engine industry...
Panavia Tornados were capable of running on far more AB time than any American equivalent at the time. Doesn't actually make the engine any better (unless you are flying the thing and wanting to be somewhere else... for whatever reason) but it's just a case of engineering.
Is it possible ... has it crossed your mind, that the Yanks design under their limits to stop failures versus longevity. They design phenomenal stuff but their maintenance regimes and people are sub-standard (that sounds nasty ... but If you've worked in the ADF and have ever seen how the US AF, Marines or Army maintain their aircraft, you'd know exactly what I mean)....so they have to compensate. As an Ex-RAAF'ie you would know that to be true.
Mean Time Between Failure is stated but often not quantified or qualified in a true measurable sense .... and if you dug into the root cause of that analysis it's a Pandora's Box of politics, etc. When have you ever seen anything designed using the LSAR data? It's a BS methodology, yet the industry hangs on to it. It is useful as a CM tool but all the things about engineering being based on reliability engineering data, functional maintenance, etc, is generally BS. Geeks design and the Logis figure out (or not) how to support.
So getting back on track, is there actually anything to suggest a 3.0 TTD in a D4 is stressed? Never read that! :)
