N79969, and AirNewZealand,
There have been several incidents that have happened with SQ which were definately avoidable, and ones which really make you question the thinking of some of the crew, and the operating procedures.
The biggest and most obvious is SQ006. Taking a wrong turn in an airport the crew were probably semi-familiar with, especially when the weather and visibility was bad. They should have taken extra care to make sure they were there they thought they were. Lack of airport lighting compounded the problem as well. The crew blatantly ignored the PVD, which accurately tells crews if they are lined up or not. I seem to remember the FO expressing doubt as to their location, but they both did nothing about it, and continued anyway. We all know what happened next.
There was an A340 that lost all hydraulics because one of the crew accidentally switched off the wrong buttons. I don't fly A340s, and am not sure what buttons they were going for (fuel pumps?) but whoever pushed the buttons neither checked himself before pressing all 4 buttons, and never waited for confirmation from the other crew member before going ahead with it.
Then there's the A310 incident over the Bay of Bengal. I can't remember the details but due to crew actions, or inactions, they lost control of the aircraft which then went into a spiral dive along with other exciting manouvres. Fortunately they regained control.
A more minor incident, but they had an A310 over run the runway somewhere. KL was it? Or Penang? Somewhere like that. This shows a resistance to go-around and come in again on a more stable approach rather than just 'go for it and hope for the best'!.
There have been other big CRM issues that I have heard about, and just from what I see, in day to day operations, things which lack airmanship, like highspeed taxying in a crowded apron area, or stopping the aircraft halfway round a tight turn, which puts a lot of stress on the gear and tyres.
You can go to and do a search and you will find lots of pilots complaining about SQ. Bear in mind though that there are a lot of bitter people on that website and their comments do reflect that, but the incidents that are referred to did happen and you can have a good read there.
Having said all that, I have no problems with their service which is very good, as well as all their IFEs and PTVs etc.I also have no doubt that they have some very good pilots, but I don't want to be a passenger on one of the flights where a couple of inadequate pilots are at the controls.