Fenland_Flyer wrote:
Can some of you very learned people explain to me please why when I was at school (a very long time ago!) I was taught that 0° C is the melting point of ice and for water to freeze it needed to be less than that?
Back to the thread!
0° is the temperature at which water can exist in both liquid and frozen form. If you heat a quantity of ice, temperature will rise to 0°C. At that point the ice will start melting and the temperature will remain at 0°C until all the ice has melted and then the temperature will start rising again. Starting with water and cooling the opposite will happen.
(Of course this is an idealized description as in practise you can’t heat or cool a volume of ice or water uniformly, but in principle it is what will happen.)
Flyer59 wrote:
yesterday I learned that water freezes at 0° C
Can some of you very learned people explain to me please why when I was at school (a very long time ago!) I was taught that 0° C is the melting point of ice and for water to freeze it needed to be less than that?
Back to the thread!
My first flight – as a very awkward teenager – was on an early 737 with a thin stream of liquid trailing out of the wing. I decided it was probably rainwater, even though it kept on for the whole flight.
On arriving at Birmingham we circled a bit. Mum, who was in the plane-spotters gallery, overheard the pilot talking about problems with the landing gear.
Were the problems related? For example was the liquid hydraulic fluid? I don’t know. However these days I would have piped up and told someone.
Sorry to drag up an old thread but I feel I may be able to contribute with 2700+ A320 series flights under my belt (unfortunately not in the pointy end, however).
Quite often for some reason one engine will vibrate more than the other, and it shows on the ENG page on ECAM in cruise, but it’s not normally as strong as you describe.
An alternative could be rudder flutter. Occasionally the rudder will vibrate on some aircraft to a point that the metal canisters in the rear galley will rattle noticeably and water in a cup will ripple (similar to that scene in Jurassic Park). It is of course worse the further back you go but still noticeable around the middle.
@Josh, I believe the airplane I was referring to was a MD80 (which made up a big part of the SAS fleet back then), so rear-mounted engines. I particularly remember this synchronisation mechanism because it was the first time I heard of such a thing and I got a demonstration of the effect.
Aviator – I can speak for pretty much all Boeing/Airbus products. I would surmise the CRJ and other rear-engined regional jets may well have engine sync due to their configuration. All the bizjets I know much about do.
I think Snoopy turns water into ice regardless of the temperature.
I thought 0 degrees C was the melting point of ice, water freezes below that temperature (doesn’t it?)
Did you tell the crew about it?
Josh wrote:
No engine sync on large airliners.
Not too sure about that. I do have a memory abut having discussed engine synchronisation with the captain of a flight on which I flew jumpseat, and still remember the button labeled OFF/N1/N2.
