* Posts by Jonathan Batchelor

3 publicly visible posts • joined 20 Apr 2007

Computer system suspected in Heathrow 777 crash

Jonathan Batchelor

@ Anonymous Coward re: Autothrottle

Thanks! :)

Although it is true to say that firewalling the throttles wouldn't give an immediate increase in thrust for a jet, so the increase in thrust on a normal approach to maintain final approach speed once you've dropped everything and slowed it down would also aid in the event of a go-around. Which I think is what I was trying to get at! :)

Jonathan Batchelor

Not "lost power"

The report says the engines failed to respond to a request for increased power from the autothrottle and then from the crew physically moving the throttle levers. It's not thought that the engines "lost power" as you put it in the article.

On approach they would have been at a low RPM (not necessarily at idle) and power is usually increased closer to the ground in preparation for a go-around if necessary (jet engines don't spool up to full power immediately). It's this increase request that didn't work, not a loss of power.

Here is the initial report from the AAIB: http://www.aaib.dft.gov.uk/latest_news/accident__heathrow_17_january_2008___initial_report.cfm

Pirate radio: the pros and the cons

Jonathan Batchelor

Causing havoc

They can cause havoc with aeronautical communications due to the fact that the transmitters aren't very good at broadcasting on the one frequency. It's a major headache when one sets up and bleeds onto Heathrow frequencies for example. The FM broadcast doesn't get picked up properly on the AM radios, but it sure interferes and makes normal communications almost impossible. Ofcom work with the Aviation authorities and concentrate on rapidly shutting down the transmitters rather than catching the culprits, but unfortunately this means they're free to set up again and again.