Why cant airplanes/aeroplanes take off, stand in air and land like a defence jet? If design is the reason, why cant airplanes be designed similarly and thereby avoiding such a lengthy runway?
one reason is balance. only the best of the best can fly harrier jets without crashing. and those are smaller jets. can you imagine a jet thats ten times that size!
another reason is fuel consumption. while hovering or taking off vertically, they go through fuel faster than any other point in their flight.
still another reason is cooling them. harriers can only hover vertically for one and a half minutes. thats because thats all the water they can carry to cool off the engines. if they try to hover longer, they will damage the engines, crash, and probably burn.
i think that as technology progresses, that will eventually be the way that most planes will be built, but its still a long way off before its practical enough for commercial development.
Im gonna guess your from Europe and are talkin about the harrier jet. That plane has nossels that can point to the ground and let it take off straight up. Other planes use lift from the shape of the wings, mind you so does the harrier once it is in flight.
References :
Because it’s very inefficient. The power required to lift a heavy passenger plane (or non-fighter jet) vertically is astronomical… it’s quite simply not worth it. Even helicopters are very inefficient, and they trade speed, range, carrying capacity, size and economy for the ability to land vertically.
References :
one reason is balance. only the best of the best can fly harrier jets without crashing. and those are smaller jets. can you imagine a jet thats ten times that size!
another reason is fuel consumption. while hovering or taking off vertically, they go through fuel faster than any other point in their flight.
still another reason is cooling them. harriers can only hover vertically for one and a half minutes. thats because thats all the water they can carry to cool off the engines. if they try to hover longer, they will damage the engines, crash, and probably burn.
i think that as technology progresses, that will eventually be the way that most planes will be built, but its still a long way off before its practical enough for commercial development.
References :
because jet fighters dont all have VTOL (vertical take off and landing), only a few like the JSF do. and keep in mind that a passenger jet is MUCH bigger than a fighter jet.
besides, it would be too costly, and seeing as how a lot of airlines are losing money, i dont think they would be willing to invest in something like that anytime soon.
References :
wikipedia and google
The special engines and nozzles that Harriers and other jumpjets (VTOL – vertical takeoff and landing aircraft) use make the plane heavier and slower. To take off straight up or hovering uses an awful lot of power (and gas) compared to rolling down a runway and taking off like a normal plane. It also cuts down on the fuel and weapons that plane can carry compared to a normal takeoff.
It is also more difficult to take off vertically and a small problem is more likely to cause a crash then in a normal takeoff. Pilots need lots of special training before they can fly a plane like a Harrier.
Because of the negative effect on performance the extra engine parts and nozzles cause, a helicopter can do most jobs almost as well as a VTOL aircraft.
There are also aircraft that can’t really fly like a Harrier. Cargo planes, heavy bombers, commercial airliners, etc. They are too heavy to take off vertically and are going to need runways regardless of their takeoff method. If the runways are already there, most of the time the military is going to use much higher performance ‘traditional’ aircraft. There is ongoing research into VTOL since a modern airforce can be crippled by knocking out a few vital runways.
References :
http://en.wikipedia.org/wiki/VTOL
There is only one (two in trainers) person in the Harrier and the F-35B VSTOL Lightning II. Passenger jets just don’t have the power.
References :
That’s why they have helicopters, you know, the aircraft with the rotary wings..
References :
I’m a pilot…
good answers so far. i think it’s about economics. look at how much fuel a VTOL civilian aircraft would burn while trying to stay economically competitive with other carriers. the military doesn’t mainly focus on economics (how much fuel is burned to get the job done), their criteria is different. you could make a brick fly with enough thrust, but not economically efficient.
References :
The Harrier, and probably JSF cannot vertical off with a full stores load on. That’s one reason our "Through-Deck Cruisers" (We don’t have Aircraft carriers despite what the papers say) have the famous Ski-jump. They cannot hover with a full payload. Water is injected into the Eflux to give it more thrust at hover as it is. The nearest thing to an airliner that can do this is that tilting wing with rather large props on it
.
The only time an airliner will be able to do this is when they work out how to do anti-gravity.
References :
its not operationally cost effective with the current technology
References :
Because that is how Civilians Aircrafts are designed. If we do make them take off like many Mil. Crafts these days, it would cost 50X more than we pay now to buy them. So Cessna 172 would cost around $5,000,000. Even Donald Trump would not be able to buy it. I thought it was much of a comment sense.
References :
So…you’re like stupid right…do I need to spell this out in jello?
References :
There are only two current jet fighters that can do it. The Harrier and Lockheed-Martins new F-35B. the Harrier was the last program Sir Sydney Camm a design genius worked on. But it is a real killer! of its own pilots. They have to certify on both helicopters and regular aircraft. The F-35b is new and a much more stable and easier to control design. As for why airliners need runways. The closest answer I can give you is why can’t you dead lift 5,000 lbs straight up? Think about it.
References :
There are only a couple of military jet aircraft that can take off vertically or nearly so. The amount of power required for any airplane to take off straight up or hover is enormous, and it really isn’t practical. These aircraft are very complex, hard to maintain, costly, prone to mechanical failures, and have poor performance in other ways. So it is just not practical to make more than a few special-mission aircraft with V/STOL capability.
The overwhelming majority of "defense jets;" that is, fighter aircraft, are conventional aerodynamic implementations, and they use very long runways.
So it just isn’t practical. For more information, try an internet search on "vertical flight" and one on "basic aerodynamics."
Besides, contractors who build runways need to feed their families, too.
References :
retired airline pilot
Other than rotary wing aircraft, ie. helicopters, three western airplanes have that ability; the Harrier Jump Jet, the Osprey v-22 and a variant of the F-35 but at high design/manufacturing and operating cost.
Efficiency is the operative word.
Any fixed wing aircraft can take off and land at zero lateral speed if they have a take-off/landing speed equal to the head wind. Indeed a fixed wing airplane can fly backwards over the ground against a strong enough head wind.
References :
I see that aerodynamics to you is just another magic word. In studying the aerodynamics of the weight to thrust ratio, as well as the consumption of fuel/ weight transported, they have found (dah!) the fixed wing aircraft to be most efficient. Stay in school, try to be smarter than the average post.
References :
A VSTOL aircraft is very expensive to operate. It’s all about profits with the airlines.
References :
You would have to have lift engine the size of the engines on the 777 just to lift a 737 off the ground…
References :
Not only Cost as many have said, but Structure and Weight.
Where would you locate the Engines?
Modern Airliners and Small jets mount the Engines in pods called Nacelles on the wings or the aft end of the plane. This provides the maximum amount of cargo/passenger room in the fuselage and the best trade off for the structure vs weight problem that faces all Aircraft.
You need a Stronger Aircraft for VTOL so you need more structure, so it weighs more, so you need bigger engines, so you need more structure to support them, so it weights more so you need bigger engines ETC ETC…….
Aircraft Manufacture and Design is attempting to build the Strongest possible Airframe, while making it as light as you can. Given the Current Tech, a VTOL Airliner or Cargo Aircraft won’t work. The range would be so low that it would not be economically viable. And while the Military can afford to Operate some EXTREMELY uneconomical aircraft the Civilian Operators cannot.
BTW All of you forgot to mention the OTHER VTOL Jet in the World. The Yakolev-38 NATO Codename Forger. The USSR version of the Jump Jet.
References :
Former USAF Maintence. Current Aircraft Builder. Plane Nut.