chornedsnorkackOK – I think most B777 operators actually have 9 seats abreast in Coach. Sometimes it is 2-5-2, sometimes 3-3-3. Some operators have 10 abreast, too. I they have 8 abreast, 2-4-2, it would be Premium Economy.
chornedsnorkackWas it questions about things you didn;t know…or are you just testing us.
If its the latter, sorry for giving all the answers 😛
Questions about the things I did not know.
The definitions I thought I understood, so those are not new.
chornedsnorkacktotal MTOW of the plane: MTOW=Maximum Take Off Weight. Therefore the greatest weight that the aircraft, and more importantly the lift-generating devices can cope with.
Indeed. It is, of course, harder to measure than the OEW of a plane!
chornedsnorkackHow many jumpseats do the 3-crew 747-s have?
chornedsnorkackHow many hours can a 3 pilot crew fly?
Do Airbus 340-500 and Boeing 777-200LR fly with 4 pilots, or are their ranges longer? The Worldliner record flight of 22 h 42 min had 7 pilots, but this was a demonstration… will service flights need 5 or 6 pilots?
Do 747SP or 747-200 or -300 long flights need extra flight engineers as well?
chornedsnorkackIf anyone saw coverage on the A380, on the upper deck the windows were quite high compared to current aircraft so hopefully tall people such as Mark L and myself are not bending our necks in the future! I was surprised how tall the fokker 100 windows where too.
chornedsnorkackYeah, but if you look at the DC-8, the windows seem to be spaced out more than your typical narrowbody. None of the Boeing narrows seem to be like this.
Indeed. The DC-8 idea was to have big windows at every seat row – every 40 inches. Comfortable… but when you try to cram coach seats at less than 40 inches pitch, problems begin.
Boeing 707 had much smaller windows every 20 inches. So, you have small windows and if the pitch is not a multiple of 20 inches, they are in different positions – but at least every row has some. Except some windows are blocked.
At any rate, I’ll take an aisle seat on a flight longer than 2 hours any day. Don’t get me wrong, I like looking at the surroundings as much as the next guy, but once my bladder takes over, I like to be able to move around at my discretion and not have to climb over people. On shorter flights I take the window. I mainly like looking outside while taxying and takeoff and landing. I’m not a big fan of looking at glaciers, oceans, clouds, and checkerboard patterns for extended periods of time.
Which means the best plane for long flights is ERJ. 3 seats abreast, 2 of which are aisle seats. Only one non-aisle seat and one seat is both window and aisle seat…
chornedsnorkackOh, and as for weather – Helsinki in summer, like late August, has similar weather to Britain… monthly average temperature around 15 degrees (that´s averaged over day and night, fair and foul weather) and quite more rain than, say, in June.
chornedsnorkackTime of day
Does anyone know the time of day that A380 enters into service? SQ flies SIN-SYD 3 times a day – which of them would have the EIS flight?
chornedsnorkackI don’t know anything about window sizes but it drives me nuts when I can’t get a window seat. For me one of the pleasures of flying is not just the aircraft/airline/airport etc but being able to see where you are passing over.
Then sounds like narrowbodies are better. In a MD-11, there are 9 or 10 seats abreast, just 2 of which have a window. In a DC-8, there are just 6 seats abreast, and still 2 of them with a window…
chornedsnorkackI’m looking at possibly catching a connecting flight via Helsinki in August where I would have a 15 hour layover. Does anybody have any information on this airport, in terms of: 1) How far it is from downtown,
About 15 km or so.
2) Is there a train/bus that is easily accessible to the downtown area,
No train (and not expected nearby for several years), but buses go comfortably to city centre.
chornedsnorkackWhen an airline goes bankrupt there are two options.
1) Either the plane continues on its route, and ends at the final destination. Sometimes going back to base afterwards with the passengers booked for the home leg. But often the homeleg can not be done because local creditors seize the plane.
2) The plane goes back to the home base mid-flight.Which of the two happens depends on a multitude of factors. First and foremost obiously the ability to do so. When a plane does not have sufficient fuel to go back to base, then obviously the flight will continue.
Typically an airline would want to keep its assets on its home base. A plane makes a nice object for creditors to make a claim on. So a plane that gets stuck at a remote airport stands a good risk of local contractors (maintenance, fuelers, ATC, ground handling etc) putting a claim on the plane to force the swift payment of their services rendered.
Indeed… I have heard that the crew of one Braniff plane mutinied when the airline went bankrupt and diverted the plane to San Francisco… they continued to Honolulu as scheduled…
chornedsnorkackYes that would be the case, but……
…… in most cases when an airline files for bankruptcy everything will have been mortgaged already. I can not recall the last time an airline that owned planes went bankrupt. It is highly common for struggling carriers to sell their planes, and lease them back. Same goes for real estate (tripple mortgages), cars (rental/lease) and most other assets that would be worth something.
Do the buyers get to keep the planes?
Or are the recently sold-off assets regarded as fraud on creditors and seized to be sold again?
Also, when an airline goes bankrupt, what happens to planes in flight? And what becomes of luggage transported by the airline at time of bankruptcy, or unaccompanied minors in transit?
chornedsnorkackBoth Reynolds number and Mach number effect the degree to which laminar flow is possible, with Mach number probably being the more significant.
So with Global Flyer being jet powered and hence with its need to operate at altitude to get the best engine presure ratio, this probably suppressed its LD, but this is not the whole story. Several other factors apply;-
– The best L/D has an optimum speed which is generally quite low and above this the LD slowly decays. For example the S10 although it has a top speed of 270kph, its LD at this speed is about 20:1;- its best LD of 50:1 occurs at about 110 kph. I suspect Global Flyer again being jet powered achives its optimal propulsive efficiency at a speed higher than its best LD.
– Higher wing loading generally suppresses LD (and laminar flow?)
– Laminar flow breaks down with the slightest provocation (ice, dead flies etc). For a really long flight it may be necessary to select a wing section which is a little more bug/water drop tolerant, but again this is at the expense of really optimising the LD. (Competition Gliders often use “bug wipers” to clean the laminar flow portion of the aerofoil I.e. thin plastic strips drawn along the leading edges by fine wires whilst the glider is in flight )For the highest LD ever for a manned aircraft try the glider called “ETA”.
Ah yes. L/D 72 – and that is a powered aircraft no less.
It was mentioned that the “Open” class gliders are restricted to 850 kg total weight – and that this causes design compromises.
So, logically, propeller craft staying at low TAS and Mach should have better L/D than the Global Flyer… especially if they also use wing wipers…
chornedsnorkackIt’s actually an issue regarding Laminar flow (and improvement to materail allowing higher aspect ratio’s).
The Laminar flow sections that were first introduced in the early 40’s were a head and shoulders better than any wing section used up until then but where aimed at quite a wide speed range. However as you get faster the area of the wing subjected to laminar flow reduces quite rapidly. Above 0.7 Mach natural laminar flow is pretty much impossible to achieve. Remember when comparing really old aircrafts LD with modern aircraft the key difference is the cruising speed. However the observation that modern airliners have an LD not that much different to the early generation is quite valid. (first generation Comet, 707 had an LD of about 17-20:1 and the latest B7/A3something have LD’s of around 25-26:1……. Interestingly Vulcan has an LD of 23-24:1, stunningly good for it’s time I think!)
Why have Gliders improved so much more in the same time period well, the first really practical low speed optimised laminar flow wing sections were introduced by Prof Wartman in the late 60’s. As gliders only operate at relatively low speeds, the introduction of these sections resulted performance jumping from a max of about 38:1 (BS 1 – Eppler – glassfibre – c1965) to 60:1 (Nimbus 3 – Wortman – glassfibre c1975) in a very short space of time.
If the speed is low enough to allow extensive laminar flow (and the aspect ratio is high enough) then LD’s of 50+ are possible from a self lauching powered aircraft indeed this has already been done – Check out the Stemme S10
Is laminar flow dependent on Mach or Reynolds number?
Stemme S10 has a wingspan of 23 m, speed goes to 270 km/h, wing area 18,7 square metres, MTOW 850 kg, OEW 660 kg. So, wing loading in the region of 40 kg per square metre.
Global Flyer has a wingspan of 34 m or so, speed much faster (over 460 km/h), wing area 40 square metres, MTOW 10 tons, OEW 1600 kg. So, wing loading in the region of 250 kg per square metre on takeoff.
Helios has a wingspan of 75 metres, speed up to 270 km/h, wing area 186 square metres, MTOW 930 kg, OEW 600 kg. Wing loading in the region of 5 kg per square metre.
Did the Global Flyer have trouble maintaining laminar flow because of its higher speeds, larger size and therefore higher Reynolds numbers than Stemme S10?
And would a powered glider the size of Helios also have trouble with high Reynolds numbers causing loss of laminar flow?
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