SchorschThe numbers provided are misleading. Relevant is neither the total number of killed people nor the number of crashes, but the number of hull loss events or fatal accidents per 1 million departments.
Overall, the safety is good in Western Europe, North America and major international airlines. The current level of crashes does not lead to any conclusions which areas must be addressed. Number of overruns and runway incursions are still a bit worrying.
SchorschI’m fairly sure the KC-30B can also refuel another KC-30B
It is indeed the first inflight-refuellable Airbus.
SchorschFor what it’s worth, he wasn’t the only person to think the days of manned aircraft were over.
The USAF never produced a follow-on to the 1956 F-106 interceptor. But they did buy BOMARC SAMs.
Canada cancelled the CF-105 arrow in favor of BOMARCs.
The feeling was “why build interceptors when the enemy will attack with ICBMs?”
Even the Air Defense Command itself was abolished in the late 60s…it was downgraded to part of TAC.The US never replaced the B-47 medium bomber fleet (except for a half-hearted attempt with B-58…2100 B-47s vs. 100 Hustlers).
And it took until 1981 for a B-52 “replacement” …the B-1B…to be approved.Everyone liked missiles…”cheap & cheerful”.
Look at the number of closed SAC and interceptor bases closed by the late
60s. A lot of money was saved.
That has nothing to do with manned or unmanned. In case of the F-106 the job was done by Phantoms or later F-15s & F-16s with similar or better performance. The F-106 stayed in service until mid 80s.
The B-47 was a nuclear striker and it was a medium bomber because that was the upper limit of the jet technology. It was replaced by the real strategic bomber and there was no mission for a medium bomber, at least none people thought of.
“Unmanned” systems are nearly everything from land mines to ICBMs. If the assumption of the White Paper was that basic strategic defense can be achieved with those unmanned ICBMs it was actually right. Money spent on Mach 3 bombers was money wasted while money spent on ICBMs was money spent well.
Schorsch… in which case a place to lie down and rest, a place to go to the toilet, and a place to get hot food are much more important than max range.
Which – together with the home cinema (HD ready) set – the Suchoi 34 all carries in its fuselage. All important international newspapers are on board. American movies only on international deployments.
SchorschNot true, the EMB-145XR has a MTOW of 53,131 lbs.
Buddy,
53131 pounds are equal to 53131 times 454 grams or .454 kilograms, so in the end effectively 24121.5 kg, or 24.12 metric tons.
SchorschWhat about Embraer 145?
Less than 25t MTOW. The CRJ-1000 is close to 35t. E-Series goes up to 52t.
Indeed. NO business jet except Mcdonnell 119/220 has underwing engines. Even the biggest Gulfstreams and Bombardiers have tail engines.
I would think that for the top end business jets a underwing config would make sense, too, but design heritage overruled it. For a business jet manufacturer the investment into a totally different configuration doesn’t pay off given the overall small numbers he produces. And even if it sounds strange: fuel costs due to 5 or 10% more weight are no big concern for business jets.
SchorschThe higher drag from ETs aside and less range from that, no reserves left the rough calculation gives for the Su-34:
114000 kg internal for 4000 km or 2,85 kg of fuel per km, that is (~0,78 specific fuel weight)
14615 litre internal for 4000 km or 3,35 litre of fuel per km
Even a fictious 3000 litre ET with zero drag and weight itself gives 2340 kg of fuel.
What gives a theoretical + of ~820 km or 4820 km with a 3000 l ET added.
In reality that gives ~4500 km, when the ET is dropped, when empty.
All that is ferry range without any weaponsload under optimum conditions.
To reach a ferry range of 5500 km the Su-34 is in need of three ETs of 3000 litre each or 7020 kg of extra fuel. Add to that the weight of the ETs and the external load of that is ~8100 kg. What is the MTOW of the Su-34?!
Which shows that external fuel tanks are a dubious gain if the aircraft is clean and flies ferry (optimum altitude), and has large internal fuel volume. Current fighters easily achieve a lift over drag in excess of 10 at optimum conditions and the engine’s SFC is quite low, too. If used, the external tank is potentially dropped after take-off and climb when the extra fuel can be used to increase burner time and reduce time to altitude.
SchorschFor these smaller and lower a/c the rear mounted engines offer the optimum solution as wing weight is less critical…as the scale increases the relief offered by mounting the engines along the wing become the driver, provided they are located equally and correctly….so the real 747 has it right.. the twin podded version seen on the ‘Dunsfold’ mod for the James Bond film are most definitely wrong…
The interesting fact is that aft mounted engines were the choice for
– DC-9 (kept until latest model)
– Tu-334
– Fokker 70&100
– B727
– BAC 1-11
While similar capacity aircraft of later designs have underwing configuration:
– Dornier 728/928
– Embraer E-Series
– Bombadier C-Series
– Mitsubishi MRJ
– Sukhoi Gayjet
The only exception is the ARJ-21, which cannot really be called an independent design.
SchorschInteresting is that today the aft mounted engines were rather common in the 60ies, while nobody does it today (except for the copy-paste design ARJ-21).
The reason is as far as I know primarily a weight issue. The only advantage of aft mounted engines is lower landing gear and less yawing moment in case of engine failure. A reason why it made sense for the B727 to switch off an engine when in cruise. Obviously the “clean” wing was more famous in the 60ies. The wing mounted engine increases the pain for the designer of the wing, not only structurally but also aerodynamically.
I think, because most small jets find 2 engines enough and big jets put their engines elsewhere.
ALL the disadvantages you mention about tail mounted engines are equally applicabl to 3 and 2 tailmounted engines. 2 engines in the tail continues to be the standard layout for regional and private jets, for very good reasons. 3 engines in tail continues to be the configuration of Dassault Falcon 7X. And yes, you can have high-bypass turbofans in the rear, like the 2 engine MD-80 and B-717, and 3 engine Yak-42 and Dassault Falcons. However, BAC 3-11 was not built…
The critical size seems to be somewhere close to the current Bombadier CRJ series. B717, ARJ21 and CRJ900 have rear-engine configuration rather due to heritage.
The business jets need lower landing gear. Additionally, they gain from the wing being positioned farer back (wing box does not interfere with cabin). But business jets are not really representative for jet design of all weights. Pain increases with weight.
SchorschThe D2 nozzle do help to lower that two.
You mean for trans- and supersonic trim?
SchorschWhen we take Sweden and Israel as fitting examples (both are even smaller and have (especially in case of ISrael) a weaker economy), we see what actually was developed in-country and what not. Both countries purchased:
– engines (the heart of a fighter!)
– weaponry (or parts of it)
– FBW consultation
SchorschI think with the Delft University still teaching aerospace some capability is in place. However, having some idea is one thing, doing something on industrial scale is a another. The things The Netherlands did in the late 80s are history now, most people have vanished into other industries. A lot went to Germany, France or the US (I once had a Dutch professor in lecture in the USA).
A fighter is not just some fly-by-wire. It is a lot of disciplines combined with the ability of management and – sometimes underestimated – the ability to set requirements right. Even if we skip the engine and key offensive/defensive avionics, we still have many fields that are not in any way covered.
In general I wouldn’t rate the capabilities lower than in Spain, Italy, Germany, not to talk of France, Sweden or the UK. The Netherlands could have preserved some capabilities if they had joined the Eurofighter, but they elected not to do so. The workshare (both production-wise and design-wise) they get on the JSF will be pathetic.
SchorschI don’t get it. Purely theoretically, if this was the real reason and US really managed to turn Iraq into a capitalist democracy, how in the world would that solve the problem with Islamic terrorism? Where is any slightest connection between Iraq and Palestinian, Saudi or Lebanese terrorist organizations?
The Israel-issue is still high on Islamistic agenda, but I doubt it is the main driver. Today’s terrorism is a mixture of reasons and motivations. The Al Qaida and Bin Laden thing is more a Saudi Arab thing and has indeed a connection to the US presence in the Gulf region, which was not needed for Israel’s security in the 1990s but rather to contain Saddam Hussein.
More terrorists are sourced from Afghanistan and Persia noqadays, countries that traditionally have not so much pain with Israel, although the opposition against Israel seems to be common standard in the whole Islamic world.
Anyways, the reasons for terrorism are plenty. The question in the end is what really drives a particular person to end his life as terrorist. I guess that numerous push and pull factors are in place.
Iraq war was only indirectly connected to terrorist threat. That the elimination of Saddam Hussein removed a direct terror threat is surely wrong. Similar thing with Iran: Iran may support certain groups, but I think it is no general supporter of terrorism, at least not when it isn’t forced to. The current problem with Iran is more a geo-strategical thing.
SchorschThey has, because of the overweight problems of the F-35B, which is adressed by thrust-rise at first.
For the F-22 the overweight problem does not matter for all to see.
Thanks to FBW development the thrust-drag-ratio is still the same, when the range did suffer from use of higher settings.
Considering that the USAF once stated that the F-22 is a “40000lb-class” aircraft that would show that thrust weight ratio isn’t that exceptional. Of course, at speed and altitude the drag thrust ratio is extraordinary (due to low drag at first).
SchorschRussia has exactly the same problem.;)
Actually it is even more severe there.
But I don’t regard Russia as threat to Western Europe or the USA. In the near future Russia will be rather tend towards the West as it is too weak to remain strategically isolated (which it actually is). The many former USSR countries are large in area but neglectible in real world power, often Russia rather must stabilize these nations.
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