Monday 7 May 2012

Fly safely

For anybody who is not familiar with a jet engine, a jet fan blade should be perfectly smooth and shouldn't have anything attached to it.  The balance of the engine is quite critical to its safety, and a detached blade can not be described as anything better than a bad thing!

Jet engine blades do become detached from time to time, and the casing of the engine is designed to contain the debris.  But when you are 10,000 metres above ground level I think most of us would prefer it if the people maintaining our aircraft try to prevent this sort of problem.

Are the same standards adopted world-wide?  Apparently not.  I gather that this report was going around 'the industry' a couple of years ago, but a friend recently sent me this scare story which might be worth remembering if you happen to be flying on a Chinese plane.

A pilot for a Chinese carrier requested permission and landed at Frankfurt, Germany, for an unscheduled refuelling stop. The reason became soon apparent to the ground crew: The Number 3 engine had been shutdown previously because of excessive vibration, and because it didn't look too good. It had apparently been no problem for the tough guys on the ground back in China: as they took some sturdy straps and wrapped them around two of the fan blades and the structures behind, thus stopping any unwanted wind-milling (engine spinning by itself due to airflow passing thru the blades during flight) and associated uncomfortable vibration caused by the sub optimal fan.

Chinese jet engine - safely strapped together!

Chinese jet engine - damaged blades

That's not to say that everything in China is subject to the same standard of Quality Assurance.  But even if the engine was not in use when it landed in Frankfurt you do have to wonder how it had been allowed to reach this state.

Given that China is officially an atheist country you can't even say that they were trusting in god!

1 comment:

Derby Sceptic said...

I think I remember this in the media. The engine was on a 747 which makes it even worse. Why? Because the 747 has the capability to carry a non functioning engine under the port wing thus leaving four working engines to fly the aircraft.

Having worked for a company repairing components from gas turbine engines I can confirm that they do come into the workshop in conditions like this and worse. Quite often at this stage they are complete scrap though.

Makes you think twice which airline you want to fly with!