Originally Posted by dada
Is it unusual for a/c to shut one engine down taxying in after landing? also, what's the point ?
Most of the time it's a cost saving measure. At some airports - regarding 4 engine aircraft - it can be a FOD prevention practice to protect the outboard engines. However, it's not a procedure that I've encountered at any of airports that I've operated to, which include most major international airports around the world.
That said, starting or stopping engines away from the parking stand or airport gate is something that I personally consider to be a bad idea.
Here's why. In an effort to save some fuel, if I opt to start an engine during the taxi phase, and that engine should catch fire during the start, I am now that much further away from the ground staff who can put that fire out should it become un-controllable.
Furthermore, if I had to evacuate the aircraft due to an un-controllable fire, I would have hundreds of people sliding out and running around – in close proximity – to many other running aircraft. The potential for injury, or worse, would be immeasurable.
Near the airport gate, I have more available ground staff to assist, thus greatly reducing the risk of post evacuation injury.
Furthermore, the most common times that you find folks starting engine during taxi, would be when significant delays are encountered for take-off.
If theses delays were due to weather - and the above fire took place - the Airport Fire Brigade would have that much more difficulty finding you at the now congested, and weather effected airport (Haze, Fog, Mist, Rain, etc).
The same goes for shutting engines down during taxi after arrival.
Originally Posted by ETOPS
Just give it at least a minute after clearing the runway - thermal stress breaks engines...
True. And that break can cause a fire. Engine fires are more likely to happen during start-up or shutdown, so - in my personal opinion - this is something that should be done when closest to fire fighting equipment and personal.
If fuel is going an issue, and delays are expect, plan for it and fuel the A/C accordingly.
Originally Posted by barit1
Not a bad idea to check brakes after shutting one or two down to make sure you haven't lost brake hydraulics.
A UAL 747 capt found this out the hard way 30 years ago...
Is another example of the many reasons not to shut them down whilst taxiing.
Finally, the important issue here is, to ensure that an un-compromising level of Safety, comes before Economics.
Cheers, and fly safe.