In the approach phase, engine 1 of [Cathay Pacific flight 780](https://en.wikipedia.org/wiki/Cathay_Pacific_Flight_780) got stuck at about 70% N1 and it forced the crew to do an overspeed landing (230knots).

Why didn't they shut it off by turning the fuel pumps off? Is there a backup mechanism if the fuel valve fails like in this scenario?
['https://aviation.stackexchange.com/questions/59303', 'https://aviation.stackexchange.com', 'https://aviation.stackexchange.com/users/36788/']
You can find the [full incident report here](https://www.webcitation.org/6Rk7TGDPW?url=http://www.cad.gov.hk/reports/2%20Final%20Report%20-%20CX%20780%202013%2007%20web%20access%20compliant.pdf) and this topic is touched upon briefly, but in short they had little to no time to entertain any other options but a full speed landing.

> 
> It was not until the aircraft [was] on the final descent for landing that
>  the Commander realised they could not reduce the thrust on the number
>  1 engine. The speed was not controllable and from that point, there
>  was no time for the crew to consider other strategy nor procedure to
>  cope with such emergency situation.
> 
> 
> 

and more in the conclusion section... 

> 
> **t.** At that stage, there was no time for the flight crew to consider other
>  strategy nor procedure to cope with such emergency situation. The
>  flight crew concentrated on flying the aircraft for a safe landing.
> 
> 
> 

First off, the engine was throwing errors throughout the flight and they were talking to the maintenance team at other points. Ultimately, the proper steps were taken and everything was done by the book. They were prepared for an engine-out landing. When you have a runaway engine malfunction (or throttle stuck at full) shutting down prior to landing *may* not be the right decision if the running engine provides no immediate safety risk. If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again.

Considering that most airports have a bit (or a lot) of extra runway, [EMAS systems](https://en.wikipedia.org/wiki/Engineered_materials_arrestor_system) and often land at the end of the runway, coming in overspeed and burning through your tires and brakes may be safer than cutting the engine and potentially falling short of the runway.
I could be wrong but reverse thrust from the running engine helped to stop the plane1 as it was approaching at a great speed way over the recommended landing speed, so shutting the running engine off right at approach would have made the plane to overshoot the runway, making the situation worse.

---

1: Source:

> 
> [...] The aircraft then rolled left seven degrees and
>  pitched down to -2.5 degrees at the second touchdown during which, the lower
>  cowling of No. 1 engine contacted the runway surface. Spoilers deployed
>  automatically. **Both engine thrust reversers were selected by the Commander.
>  Only No. 1 engine thrust reverser was deployed successfully and ECAM message
>  “ENG 2 REV FAULT” was annunciated.** Maximum manual braking was
>  applied. ... *[[Accident report](https://www.webcitation.org/6Rk7TGDPW?url=http://www.cad.gov.hk/reports/2%20Final%20Report%20-%20CX%20780%202013%2007%20web%20access%20compliant.pdf), page 26. Engine #1 was the one that was stuck at 74% N1.]*
> 
> 
>