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DownwardDog said:
One blade would be the theoretically most efficient if not the most practical.

More blades are used when the load on the rotor disk is too great for fewer blades. To generate a relatively greater lift the speed of the advancing tip would get very high compared to the speed of the retreating tip - the 'Advance Ratio'. If this ratio gets out of limits then the retreating blade will stall. Even if the retreating blade doesn't stall then the advancing blade will start to hit Mach Buffet in the transonic regime and then that blade would stall.

To get around this and reduce tip speed, more and smaller blades are used. Their are also logistical and size constraints where more, smaller blades would be preferred over fewer, larger.
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DownwardDog said:
One blade would be the theoretically most efficient if not the most practical.
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Yea, well sort of. I've read a good few arguments for it mostly around being further behind the previous blade for a given rpm, but well.
I find this south african bloke always does good summations of subjects on the lighter side of flying that are very accessible for the curious with little background (in case there are some non air-heads reading this)
I remember the control line speed models going through a phase in the 70s-80s with single blade props turning fecking silly rpm, weird looking things, One wing, one horizontal stabiliser and one prop blade

edit, I put it stoopidly, of course a blade is always the same distance behind the other one regardless of rpm, what I mean is further behind in time not space for a given rpm, but dont really know how to put it as I've just had a big piece of my special cake about an hour ago
 
pseudonarcissus said:
So what happened to drones in naval warfare if suddenly they’re a great threat in the Black Sea if you are Russian, or the Red Sea if you are anyone else? These things are older than us!
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In the medium-large segment t's more to do with the massive improvements in the systems on board than the vehicles themselves, development of guidance and sensor tech and its miniaturisation, which itself together with small brushless motor and battery advances has brought the smaller sized vehicles into usefullness also
 
From the Telegraph:

The crash occurred during landing after the plane experienced a malfunction, with early reports suggesting that a bird strike may have caused a landing gear failure.
 
Hollis said:
From the Telegraph:

The crash occurred during landing after the plane experienced a malfunction, with early reports suggesting that a bird strike may have caused a landing gear failure.
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The video on bbc website just before the crash suggests landing gear was not down
 
Hollis said:
From the Telegraph:

The crash occurred during landing after the plane experienced a malfunction, with early reports suggesting that a bird strike may have caused a landing gear failure.
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All the reports mention that, but if anyone can tell me how a bird strike can cause a landing gear malfunction on any passenger jet Im all ears.
They may well have had a bird strike then some chain of events led to them either forgetting due stress or something other than a birdstrike also occured that rendered the gear inoperative which itself would be pretty rare it would basically have to jam as even with no hydraulics or electrics they are designed to extend purely by gravity as a last resort.

Its hard to forget to lower them with a loud alarm going of but its been proven that in times of very high workload the first thing the brain switches off is auditory input
 
Very sad and tragic incident. Apart from the initial footage seen on TV, the footage below shows a very controlled and professional emergency touchdown under the circumstances.



Tragically the pilots seemed to have lost the necessary hydraulic functions to deploy not just the landing gear but the flaps and ailerons used to slow down a plane at touchdown. Coupled with a bloody concrete wall a mere 250-odd metres from the end of the runway, it seems to have combined into a a lethal clusterfuck.

RIP to all concerned. It is devastating to picture yourself in the mind of the pilots, having executed an incredibly smooth belly landing, seeing the plane wasn’t slowing down fast enough and seeing a solid barrier laying just off the end of the runway :(
 
T & P said:
Very sad and tragic incident. Apart from the initial footage seen on TV, the footage below shows a very controlled and professional emergency touchdown under the circumstances.



Tragically the pilots seemed to have lost the necessary hydraulic functions to deploy not just the landing gear but the flaps and ailerons used to slow down a plane at touchdown. Coupled with a bloody concrete wall a mere 250-odd metres from the end of the runway, it seems to have combined into a a lethal clusterfuck.

RIP to all concerned. It is devastating to picture yourself in the mind of the pilots, having executed an incredibly smooth belly landing, seeing the plane wasn’t slowing down fast enough and seeing a solid barrier laying just off the end of the runway :(
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I dont know who wrote that, but they don't even know what an aileron is and are probably trying to put in their own words stuff they read on an aviation site without much actual understanding of the subject
 
Yep, I carried silver for years, you needed 600 points, a round trip to New York in first netted 480, a business class return to Europe 80, so easy to get if you book in advance, (during the sales first to NY can be had for £1300 at times, business to Rome £180 and so on). Now for silver you need to spend £7500 a year, so that's not happening. Though for a lot of my punters £20k for gold is easy as fuck, a fully flex first class to LA is £18,303.00 + tax (tax doesn't count towards tier points).
 
I have until mid-March to get 140 more points to retain Bronze. I know it doesn’t have lounge access or fast track, but the usage of business class check in desks, the priority boarding, and ability to choose your seat for free seven days before the flight are actually brilliant perks and have made my flying experience so much more pleasant this year. So I guess I’ll be doing a couple of domestic business class trips to nab it for another year.

Elpenor Bahnhof Strasse . Regarding Avios miles, of which I have 32,000-odd, will the conversion rate remain broadly similar, or should I use them before April?
 
I dropped to Bronze earlier this year after years on Silver. Have got 300K household points and a companion voucher and want to use it to visit our eldest who will be in China next academic year. Only problem is (a) we won't know where she is until March (probably Shanghai) and (b) we have to fly in the two week October half term so that the youngest can come with us.

I very much doubt that it will work out - the only time I've successfully used a companion voucher it was over the summer school break where we had more flexibility (ended up flying out on a Tuesday and back on a Thursday or something to be able to nab the reward flights.
 
T & P said:
I have until mid-March to get 140 more points to retain Bronze. I know it doesn’t have lounge access or fast track, but the usage of business class check in desks, the priority boarding, and ability to choose your seat for free seven days before the flight are actually brilliant perks and have made my flying experience so much more pleasant this year. So I guess I’ll be doing a couple of domestic business class trips to nab it for another year.

Elpenor Bahnhof Strasse . Regarding Avios miles, of which I have 32,000-odd, will the conversion rate remain broadly similar, or should I use them before April?
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No idea on what your Avios are worth, AFAIK they are not changing, but 32k isn't that much, but again, really don't know, I sell flights for money, people amaze me by asking if I can book them flights for free with their Avios...

btw, I have a way of getting you whatever seats you like (except row one in first), but I need to book them, which is why I am always in row one...
 
Winot said:
I dropped to Bronze earlier this year after years on Silver. Have got 300K household points and a companion voucher and want to use it to visit our eldest who will be in China next academic year. Only problem is (a) we won't know where she is until March (probably Shanghai) and (b) we have to fly in the two week October half term so that the youngest can come with us.

I very much doubt that it will work out - the only time I've successfully used a companion voucher it was over the summer school break where we had more flexibility (ended up flying out on a Tuesday and back on a Thursday or something to be able to nab the reward flights.
Click to expand...

Dunno much about Avios reward flights except they never seem to be available to anywhere you want to go, especially if you have specific dates, and never during school holidays...
 
holy jesus fuck

news.yahoo.com

A flight attendant has died after the cabin of the plane he was working on filled with smoke

The Airbus A220, which was flying to Zurich, made an emergency diversion to Graz, southern Austria, after smoke started to fill the cabin and cockpit.
news.yahoo.com news.yahoo.com

A young Swiss International Air Lines flight attendant died a week after being exposed to smoke that filled the cabin and cockpit during a flight he was working.

The December 23 flight from Bucharest, Romania, to Zurich made an emergency diversion to Graz, in southern Austria, after engine problems spread smoke through the plane, the airline said in a press release.
 
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