Qustion regarding aircraft engines.

Gas turbines don't need electricity to keep them running once they are started. The combustion is continuous as long as there is a supply of fuel. Fuel is fed via engine driven pumps and electrically operated boost pumps in the wing. So, there would have to be total aircraft electrical failure which is highly unlikely. The reliability rate of jet emngines is almost 100%. The likelyhood of an engine failure due to electrical problems is far less then something catastrophic like a burst disc or fire (usually due to poor maintainence). I wouldn't worry about all the engines failing on a modern jet and if it should happen, they glide very well but very fast and stopping them when you arrive on terra firma is the problem.For instance, the 707 has a glide ratio of 18-1, Eighteen feet forward for every foot down but at something just under 200 MPH. An Air Canada 767 made a safe landing after it experienced " air in the fuel lines".....like running out of fuel.
Switches

 

Also to add to what SWITCHES has said, todays AC are very over powered and can maintain flight on just one operating engine as well. But in the event one of the engines has a "flame out" they have ways of restarting the engine in flight.

 

That ability is caled ETOPS ....Extended Twin Operations, pioneered by Boeing and its 777. An airline guy had another name for it, hoever. Engines Turn Or People Swim.
Switches

 

While the 777 was the first airplane to be ETOPS certified out of the box, ETOPS has been around for quite a bit longer. All twin engine airplanes that fly more than 60 minutes from land, ie over the ocean, are require to be ETOPS certified. The 767 has been doing it since the early to mid 80's.

 

Thanks for the inputs, Greg. I was only aware of what we were doing on the 777 to get initial certification for ETOPS. I worked on the 767 for 10 years and wasn't aware of them being operated as ETOPS specific.Both are darn good airplanes.
Switches

 

If we loose complete electrical power on the Airbus 330, we can still keep flying and land safely with no major drama's. By the way we have three generators, so you have to loose all three before you're in trouble.

We also have whats called a RAT that will supply electrical power till landing. The engines don't need electrical power to keep running, however the avionics do, thats where the RAT comes in. If it fails for any reason you are having a really bad day. The battery's will look after you for 30 mins.

We can also keep flying that thing if we loose all PFD's,ND's and EWD's in layman's terms the computer screens. Believe it or not we can land the Airbus without the side stick working, tricky but can be done.

Loosing electrics is the most un-likely situation you'll ever see, flying in severe weather will cause the most problems. If your flight is delayed due weather, thats a good thing for all concerned.


Flying is very safe, as long as you don't eat the food.


Regards

Jam.

 

Post of the year IMO

and from a guy with 3 posts even!