I’m absolutely amazed by how this aircraft is able to lift off without actually “taking off.” It seems to me that many light aircraft could benefit from this propulsion technique. So, I’m wondering, why isn’t it more prevalent?
I can see functional use on aircraft carriers. The entire deck could be filled (instead of a portion of it because of the runways) with various jets using that propulsion technology.
I can understand the speed issue. I know the Harriers aren’t very fast in comparison to jets which use conventional jet engines. But, is that the only deterent?
Numerous reasons:
[ul]
[li]Mechanical complexity. Harriers are very complex planes. Complex craft have a higher failure rate than simple craft.[/li][li]Delicacy. You average A-10 Thunderbolt II (aka Warthog), a simple, straightforward craft can take a shitload of damage. After a small fraction of that damage a Harrier would be smoking rubble.[/li][li]Flight complexity. Harriers are more trouble to fly than your average plane, even after special training.[/li][li]Cost. Harriers are very expensive. Few could afford one, even governments.[/li][li]Performance issues. You’re right, they aren’t as fast. I don’t think they’re as manuverable, either.[/li][/ul]
So don’t look for VTOL craft to dominate anytime soon.
I’ve heard lots of flip-over stories about Harriers. One good cross-wind, half the plane dips, then the formerly-downward thrust then flips the plane like a spatula flips a pancake.
Shooting planes off with the big rubber band (I know, it’s actually a steam-powered sled) is much safer.
1: Expensive to make
2: Difficult to engineer
3: VERY VERY loud
4: Slow (already mentioned)
5: Complex to service
6: Fuel hog / short range
6: To date non-Harrier applications of this re-directed thrust technology has a questionable reliability/safety record (see Osprey)
One day it may be the way to go for more general purpose applications but that day is not yet here.
The British and the Russians have carriers that are exclusively used by V/STOL aircraft – it’s a nice, cost-effective solution for navies on small budgets.
On the other hand, it’s probably cheaper to make sure your airfields are well-protected and easily repaired than it is to design, build and maintain a fleet of aircraft that don’t need to use them.
I can’t really see many civil applications – airports are conveniently designed as transport hubs – and militarily V/STOL aircraft don’t have the capacity or performance to match conventional designs for many missions.
It’s impractical for a passenger plane because the whole fuselage is filled by a single, huge-ass engine.
If you’re going to use VTOL commercially, it’d have to be like the V-22 Osprey. Anybody seen the latest issue of Popular Mechanics with the story about the 4-engine one?
Because if you want something that takes of verticaly , you already have helicopters. If you want something that can fly fast and well, you already have regular planes.
The VTOL are hybrids that do both things and none of them well.
Would you buy an umbrella that could be used for enemas? Would you see that as an advantage? I’d rather have dedicated things that work well rather than multiuse things that don’t do anything well.
(Hmmm… come to think about it, this umbrella idea might be worth patenting…)
Slightly off topic, but years ago when I had some family contacts into the Corps, I was told that when selecting Harrier pilots, the Marines looked for candidates with NO flight experience. It was said that conventional flight experience was a detriment to learning to fly the Harrier. Any flight instincts developed with “regular” airplanes handicapped Harrier pilots.
Harriers also have horrible accident rates. That initial takeoff and hover is a very dangerous phase of flight.
Incidentally, Harriers don’t normally take off by climbing straight up. It’s much safer and uses much less fuel to use a short runway and use the vectored thrust to help you into the air. Once the airplane is going fast enough for the flight controls to be aerodynamically effective it’s much more controllable.
Are you sure about that? I have no direct knowledge (maybe a Marine poster can help), but I don’t think they’re going to put you right into the Harrier. I’d assume that the pilot candidate would train in the Beech T-34C Turbo Mentor, then the Rockwell T-2C Buckeye (if those are still around) or the Boeing T-45 Goshawk. Once the pilot has demonstrated proficiency, I’d think he’d be put into another high-perfomance aircraft (perhaps an F/A-18) before they’d let him fly a Harrier. I think that the Marines only take the “best of the best” to fly Harriers.
Again, I don’t have direct knowledge; but I think that’s how it’s done.
One thing I did hear from a Harrier pilot: “If you move a control and something unexpected happens, put the control back where it was.”
Hovering really isn’t that hard. And it seems the bigger the helicopter, the easier it is to fly. (Or so I’ve been told.) But the helicopter in a hover is using much more power to hold that hover than it would be using in forward flight. The reason is that the rotors are creating a lot of turbulence. Once you get faster than about 15 knots, your rotors are operating in undisturbed air and they become more efficient. Helicopters make “running takeoff” when weight and/or density altitude makes a normal takeoff impossible. Running takeoffs can be done on helicopters equipped with skids as well as ones that have wheels. Run-on landings are made for the same reasons.
I think that’s right. I suspect (not completely sure) the only time they have been used in meaningful air to air combat was the Falklands when they were up against inferior craft for the most part. However, the pilots were able to use some pretty nice tricks. One, I recall mention of, was when a Harrier was being pursued by two Argentinean planes (not sure of the type), the pilot vectored the engine, the Argentineans flew past and he went after them. Two sidewinders later, two downed Argentineans. Not the sort of thing an Air Force can practice countering unless they have Harriers. Must have confused the hell out of the pilots.
I understand they are very manoeuvrable – thing is, although you can slow the speed dramatically if pursued, you aren’t also a sitting target as you’re also moving vertically and peel away if you wish.
Also, they have been widely modified for different roles. The US Marines version is very different from the ground attack which is different again from the Sea Harrier.
Since we’re discussing this… out of curiousity, in the (obviously special effects) scene from the movie “True Lies” when Arnold is manuvering under his daughter hanging from the crane and telling her to jump to the hovering Harrier, is the plane really this manuverable and steady hovering in real life or this a Hollywood conceit?
astro: Possibly, except for a little phenomenon called “sideslip”, which in layman’s terms, is something like this: Airplane hovers on column of vertical jet exhaust. Airplane tilts to the right a little. Jet exhaust thrust is no longer directly beneath airplane. Airplane literally slips sideways and down.
The Harrier used for the movie was solidly mounted atop a set of hydraulic rams. Johnny L.A.: That’s what I meant… “hard to hover” in the sense of “hard for those itty-bitty wings to produce enough lift to hold it up and steady when they aren’t moving foward”
Speaking of V/STOL…remember the modified C-130s developed to land in a sports stadium during the Iran hostage situation in the '80s? They had rockets pointing foward to slow 'em down on landing.
I was told by a friend in the military that it is very impressive to see a Harrier appear over the horizon and swivel about, hovering looking for a target.