Amiga500!!!!!!!!!!!!!!!!!!!!!!!!!!!
Future of Russian Air force right here:
http://russianplanes.net/images/to52000/051382.jpg
Ooooft.
Look at the increase in wing area/lifting body compared to the Flanker!
I never realised it was that pronounced – that thing will be a beast in sustained turn performance.
Amiga500If so, any reason why its shape is different from regular radomes?
You can fit more T/R modules in that way.
Tradeoff between directivity losses due to angle away from bore and the number of T/R modules.
Amiga500whilst military action is off the table by law
What exactly is that supposed to mean? :confused:
Law are only adhered to by the folks in charge when it suits them. 🙂
Amiga500It can be done, but if the Levcons are lowered more than ordinary during flight, wouldn’t it mean the elevators would have to counter-trim and in that way RCS spike of higher level due to the elevators trim?
The larger planar surfaces of both would still be pointed in very unlikely directions for a direct radar return.
They probably aren’t thinking of it – its most likely just me being daft. 🙂
Amiga500Wings and layout for Military Transports are sized for field performance not for efficient cruise and climb like civil.
thus I don;t think it would be profitable for mass market. may be niche, not mass. [/quote]
Hmmmm – kinda. There is no absolute right or wrong.
A high wing can work, and work well – for instance, both the ATRs and the Dash-8s have high wings; meanwhile where is the Saab 2000?
I would imagine Embraer will use the military rough field design margin in the undercarriage to take heavier civilian loads on paved-only surfaces in a stretched frame (as Hammer is indicating).
If they are good with aerodynamic design, and I have no reason to suspect otherwise, they’ll use leading and trailing edge devices to make short-field capability without sacrificing cruise performance. Then, simple mods to the LE/TE will allow an efficient cruiser for civilian cargo lift.
Besides, whats the market alternative? A 727/757 or A310?
btw, Embraer will anounce a A320/737 competitor sometimes this year.
That would be interesting.
5 aircraft in the 150-200 seat market? Well, there probably is enough demand to sustain at least 4 players in that arena.
Amiga500Edit: Nevermind it’s obvious here:
http://russianplanes.net/ID51168And the Levcon deflection is out of this world. Can’t wait to see a true flight demo someday…
Interesting. Very interesting.
When going from subsonic to supersonic flight, the aircraft centre of pressure typically moves aft. Therefore the elevators have to deflect downward to maintain trim; with a subsequent loss of nose up pitch authority when it comes to active maneuvering. The F-22 has such good supersonic maneuverability because it uses TVC to trim the aircraft and keeps the elevators roughly in their neutral position.
I wonder could the PAK-FA fly at high speed with the LERX partially down… you may reduce the movement in C.o.P, reduce the effective engine intake area, and perhaps mask the intake duct from nasty radar waves. 3 birds with 1 stone… maybe.
Amiga500Let’s not all forget one of the biggest sellers of the cabin: the enhanced passenger comfort that comes from increase in internal pressure and as such, higher humidity and lower perceived altitude.
Traditional cabin altitudes are 7,000-8,000 ft.
The 787s is gonna be around 6,000 ft.
The A380 is at 5,000 ft.
Legacy aircraft have single digit cabin humidity in cruise, the 787 has a cabin humidity of ~14% in cruise and the A380 about 15-25%.
The 787 will be more comfortable than previous aircraft, but its performance is not solely the result of a composites fuselage [unless you count GLARE as composites as well…].
Amiga500For what expert opinion is worth, however, I polled a number of aerodynamicists about whether AF447 would likely have responded to a nose-down command, and all of them, while saying that this was no more than a feeling or a hunch, thought that it would.
I’d agree – with the caveat that the engines must be used correctly. Given the under-wing engines are quite significantly below the aircrafts centre of mass, having the engines produce significant amounts of thrust may offset the (limited) elevator authority.
Hence why I included:
So try to go to fixed pitch rate on the nose (using gyroscopes as reference), enter into at least a 30 degree dive – in extreme situations use retarded throttles/thrust reversers as necessary to achieve this. Then the accelerometers coupled with the altimeter will tell you of your air speed. Once acceptable airspeed has been/will soon be achieved, commence pull-out.
The recommendation of advancing throttles in a potentially ‘deep-stalled’ (OK, not strictly the definition, but it’ll do for what I mean) situation is idiotic on an under-wing engined aircraft. I believe the authorities have previously re-visited and changed this.
A while back.
A potential long-term fix to this, considering the fact that pilots are very limited in stick time these days – is that they should all possess degree level education on the aerodynamics, dynamics and system interactions of aircraft… and that it should be included in the type rating.
After all – if they are only flicking an autopilot switch most of the time when actually ‘working’ – it is not unreasonable to expect them to undergo a little bit more pain (i.e. education) to get to that stage.
Amiga500Please, please also plan for rapid disengagement (isolation) of multiple interacting systems when they get possibly doubtful error messages.
Are you being serious? :confused:
Do you really think such things are not planned for?
Typically well under 1% of code on aircraft deals with the intended full functionality of a system. The rest deals with the system when something isn’t functioning fully.
Amiga500It is.
The majority of pilots these days are not fit for purpose and are little more than glorified secretaries pushing a few buttons on a computer.
I’m sure this will invoke a hostile reception from some on here – but its generally agreed that the biggest problem in the industry is pilots that no longer know how to fly.
Amiga500Awww. Now we have to think of another witty replacement for “Engines Turn Or Passengers Swim”… 😀
Amiga500Have we forgotten about the stand-by Artificial Horizon, or the newer ISIS? 😉
The glass dash should automatically put it front and centre on the big screens of both pilots when alternate law is entered. Especially if it is due to inconsistent primary sensor readings.
Amiga500Laugh if you like but I’ve been back to a very primitive drawing board, and my early days of being a trainee CPL.
The BEA will report of the causes but what I am trying to achieve is ways to provide a simple lightweight, inexpensive manual replacement to failure of essential parameter displays.
I have possibly succeeded with a fail safe in cockpit horizon indicator.
When I was training to fly there was a centre brace in the middle of the windscreen (a fixed reference point/marker on the airframe directly visible in front of me at all times) on some of the trainers. I used to hang my car keys (dad’s car keys I should say to be honest) on a piece of nylon thread and let it dangle to approximately eye level from anything above on the roof of the cockpit to my right (when flying solo I was in the RH seat). Obviously it would be to my left if I had been on instructor led hours followed immediately by solo as then I may have stayed in the LH seat.
This gave me a wonderful but very useful in cockpit visual 3D horizon indicator (In theory all three X, Y and Z axes).
Yip – your 100% correct [I’m being serious here].
Put a pair of furry dice, or whatever hanging in the cockpit. In an emergency like this, check that the furry dice correlates with the gyroscopic indicators/accelerometers (perhaps the OEMs should even make it an integral function).
No correlation = aircraft in trouble.
So try to go to fixed pitch rate on the nose (using gyroscopes as reference), enter into at least a 30 degree dive – in extreme situations use retarded throttles/thrust reversers as necessary to achieve this. Then the accelerometers coupled with the altimeter will tell you of your air speed. Once acceptable airspeed has been/will soon be achieved, commence pull-out.
The recommendation of advancing throttles in a potentially ‘deep-stalled’ (OK, not strictly the definition, but it’ll do for what I mean) situation is idiotic on an under-wing engined aircraft. I believe the authorities have previously re-visited and changed this.
Amiga500Amiga, I would enjoy hearing the specifics of the two areas you mention.
Airbus don’t route electrical cabling through their fuel tanks. A pretty critical difference when it came to the centre fuel tanks exploding. Yet the FAA/EASA fuel tank flammability exposure rule applies/applied to both Airbus and Boeing (as well as Bombardier, Embraer etc).
The Airbus cargo bays don’t circulate air to the aircraft bilge; leakage is reduced markedly, meaning cargo fire suppression is somewhat easier.
I’ve always thought that Airbus tepid support of Extended Twin Engine Operations was due to wanting to protect their investment in the 340 and 380, and also due to some of their prime customers not exactly embracing it either. Lufthansa comes to mind.
I agree on A340 – but not on A380; it was started well after the 777 and to a lesser degree the A330 showed the potential of ETOPS aircraft. Don’t forget that Airbus’ future projects bunch would have been looking at A350* in the ~2000-2005 timeframe (if not earlier).
*which looking back, and considering NEO, was probably the right approach – they should have ignored the airlines – they are like little children wanting the newest toy rather than the most suitable solution.
Amiga500Boeing supported the new regs, Airbus was not obstructive, but their level of support was certainly tepid.
That might be due to different design philosophies between the two.
I can name two areas, connected but separate at the same time, which Boeing’s design philosophy differs markedly from Airbus, with corresponding sensitivities to regulations… or maybe a better way of putting it would be ‘with correspondingly different regulatory needs’. That may sound like BS, but given the design differences, does make sense.
I would imagine there are many more I don’t know of.
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