Is it possible to land a jet on water with modified pontoon landing gear?
We’ve seen airplanes done successfully, why did they stop there?
Airplane are slower than jet planes. IIRC a jet lands at >100 mph, which is close to top speed for the prop planes.
So my official answer is a jet can’t go slow enough.
And there is probably something about a jet carring the extra weight of the pontoons which, even if they were carried, would rip off due to the above mentioned speed issue.
-Sandwriter
Actually, there have been attempts at building these. The problem has been that with many of the designs the engines have sucked water and put themselves out.
It’s been tried: Jet Seaplane & Jet Flying Boat Page. I don’t know if all of those made it into reality, but I remember the Seadart and the Martin Seamaster.
Uh, no.
I thought Cesna’s and Piper’s had top speeds of 80mph or there abouts.
**100mph is nowhere close to the top speed of a prop aircraft. The airplane I fly in training does about 140mph. You can build a prop plane in your garage that does 340mph. Rare Bear, a racing aircraft, does 528mph. 100mph doesn’t even come close to the top speed of a prop aircraft.
**Would a Harrier be slow enough? There is no rule that says you can’t make a slow jet aircraft.
Most seaplanes are small and designed to fly low and slow. It’s better suited for what people use a seaplane for, recreation and getting into inaccessible areas. To power this airplane, you want an engine that performs better at low altitudes, slower speeds, and is sized for small aircraft. You also want something cheap, and resistant to foreign object damage. Something that burns a fuel you can get at just about any marina. This would be a piston engine. Chances are, if you have a piston engine, it’s gonna have a propeller.
Jet engines are very expensive to purchase and maintain, and are better suited for high altitude and high speed flight. There are very few made for the size of a typical seaplane. Their charactaristics just aren’t made for the type of flying a seaplane does. You COULD do it, but why would you when something 1/10th the cost would do it just as well, if not better?
Someone posted a good link above, it shows some of the specialized jet seaplanes that have been built over the years. None of them are very popular today, if they ever were in the first place.
Some (very few) may, but the vast majority are a lot faster.
The Russian Beriev company has been making flying boats for decades and is currently trying to market a twin-jet flying boat. (See http://www.beriev.com). The aircraft designer needs to be somewhat more careful about putting the engines out of possible water spray, but this is an issue for prop engines as well.
Smaller airplanes, such as floatplanes, just aren’t economically worth putting a jet on, especially given the top speed limitations imposed by standard float designs. Weight and landing speed can easilly be kept to the same range as a prop plane.
Joey G, you are killing me. Sure there are SOME prop planes that go super fast, but you make such a big point out of saying how fast they can go and then you spend three sentences talking about how slow seaplanes are.
A Harrier can’t land on water either.
As I was typing that a jet can’t go slow enough the Harrier did pop into my mind, yeah, a Harrier can take off and land vertically like a helicopter, hey a Helicopter makes a great water to water transportation vehicle and it can fly faster than a sea plane, but not faster than the fastest prop plane. But the OP was about airplanes and not helicopters.
So if you want a more expensive and faster ride than a SLOW sea plane, try a Helicopter.
**You stated (incorrectly) that prop planes had a top speed close to 100mph, so I corrected you, citing several examples.
**Once again, you stated (incorrectly) that a jet can’t go slow enough, so I corrected you. Again. A jet airplane can go very slow, the Harrier is an example. So why don’t they make an amphibious Harrier? Read the rest of my first post and see.
So why even bring them up? I stand by my first post, if you feel any of my points were in error, correct them. He asked a question and I gave him an answer, not a series of guesses.
The guy posted 5 Q, I was rushing through trying to answer them all.
I don’t want to get in a flame war with you, but if you want it, start it in the Pit and I’ll find it.
The Convair XF2Y Sea Dart was an experimental prototype of a jet fighter. It had a giant retractable skis for landing on water, and was supersonic. They built four of them and flew them off water plenty of times.
A friend of mine works as a patent lawyer and frequently tells tales about the crackpots that come to see him; one such tale involved a man who reasoned that commercial airliners should land in the middle of the ocean on water skis, because ‘there is nowhere left to build runways’
- he had completely neglected to consider what would happen when the forward velocity of the plane reduced to such a point that the water skis would not keep it above water and as soon as this was mentioned, he stood up and walked out without saying a word.
As for “pontoon” -equipped aircraft, the DHC-6 Twin Otter prop plane has maximum cruising speed of 180mph, and right here in SJ harbor there are a couple operating from pontoons. It’s a 20-seater short-range AC.
Anyway as mentioned before, for any transport plane of that size or smaller, operating mostly short hops at low altitude, the most economically efficient solution is to have it prop-driven (in the dash-6 it’s turbine engines driving the props, it uses jet fuel but not as much as a straight jet would).
The quick, affordable way to get a seaworthy plane in that category is to add pontoons to an existing model. But if you want domething with larger capacity or “hotter” performance that will be optimized to operate primarily from water (or just that will be optimal for water operations), the industry’s answer most often is to design it from the start with a “flying boat” hull. (which can be made “amphibian” by adding a retractable landing gear).
What Cessna has a “top speed” of 80 mph?
I fly Cessna 150s on a regular basis - they cruise at 90-100 mph. Once landed one at 110 mph (still remember what my instructor said: “That was amazingly well done. Now don’t EVER do that again…”)
Don’t know about Piper Cubs - they might have top speeds under 100 mph - but anything post-1950 design is faster than that.
But I see no reason to jump on SandWriter since the only time most people see the small Cessnas and Pipers is on take off and landing, at which point they are moving at well under 100 mph (if you’re doing it correctly)
As for small, slow jets - a guy in Ohio built one that conformed to FAR Part 103 rules - that’s an ultralight - and brought it to Oshkosh to show off some years ago. Had the gumption to put it on a scale (weight limits) and have its speed measured to prove he’d done it within the regs. Totally jet-propelled, top speed in level flight under 63 mph. BUT - he built it to prove it could be done. It has no useful purpose (as usually define) whatsoever. So you CAN built small, slow jets but it’s sort of silly. For that sort of application props are much more efficient both cost and fuel-wise.
There was a time in aviation when floatplanes were the fastest thing aloft - and then retractable landing gear was invented.
In theory, you should be able to outfit a jet with pontoons and land it on water, but above a certain size the practical realities of weight and engineering start to interfere with the end goal of not sinking like a rock when the plane stops moving.
I found THIS site about the Sopworth Camel. So even propeller driven planes built in 1915 could top the 100 MPH mark.
Say whaaa?
Float = Drag. Lots and lots of parasitic drag. I can’t think of a design that was faster with pontoons than with wheels/skids.
The pre-war Schneider trophy planes (floatplanes) were extremely fast but I’m not sure they were faster than their peers in the Bendix cup like the Gee Bee. The supermarine planes were a stepping stone to WWII aircraft like the Spitfire and P-51.
Broomstick is right. There was a time when the fastest airplanes were seaplanes, and there used to be major seaplane races that were hugely popular.
In fact, one of the most successful seaplane racers was the Supermarine S6B went 407MPH in 1931! That plane was the basis for the famed Supermarine Spitfire.
In comparison, the fastest land planes of the time were the GeeBee racers, which could do about 295mph. In 1935, the Hughes H1 was doing 350.