Soviet Union's Giant Ekranoplane (Ground Effect Vehicle)

hey airport kit, what is the difference between a traditional seaplane, Howard Hugh's Spruce Goose, and the WIGs??

Hey Rokeby, you say Sailplanes are often incorrectly called Gliders, but doesn't the FAA just classify everything by weight (i.g. small, large, large+, heavy) so aren't sailplanes just called ultralights?? Or do you need an engine to be classified an ultralight?? And for that matter are hot air balloons registered (November yada yada) because they cannot technically be controlled by ATC?? I know balloons technically stick to uncontrolled VFR airspace, NOTAMs are issued and pilots are expected to keep visual seperation. Obviously in VFR airspace pilots aren't permitted to fly into clouds but balloons don't really get to choose where they drift to.

 

I'm not the Kid, but the Spruce Goose had enough power to get out of the water, so almost for sure had enough power to fly, even though it was never taken above ground effect heights.

 

The Hughes H-4 Hercules *is* a traditional seaplane; it's just a very big one. Seaplanes can takeoff and land on water, but they fly up in the air away from the water.

WIG vehicles must fly close to a surface to produce ground effect. In essence, they skim a few feet over the water or ground.

A pilot's license, or airman's certificate, comes with categories and ratings. For example, the common private pilot's license is usually for heavier than air, single engine.

A common balloon pilot's license would be lighter than air, hot air balloon with airborne heater. The categories and ratings set the specifics. There are also captive gas balloons and airships.

For sailplanes you need the glider category. Sailplanes are a type of glider, but not all gliders are sailplanes. The distinction comes from the lift to drag characteristics. Gliders do just what the name implies, but sailplanes can often "sail" on uplifting currents of air. It isn't a sharp distinction, but ranges from brick-like gliders to sailplanes like those pictured above.

Tom

 

Just to make things interesting, the Spruce Goose never flew out of WIG (not saying it couldn't have), Erkoplane's had rated service ceilings of 3,000M to 8,000M depending on the model.

I wonder what an Erkoplane would have been like to fly at altitude?

 

+1 on what Tom said in post #23.

Everything you could want to know about soaring: Soaring Society of America

 

I figured someone would point out the details.

The Erkoplanes could fly as aircraft if needed, but were designed to exploit WIG.

The H-4 was designed as a conventional aircraft, but wasn't finished on time. Hughes flew it once just to prove that it could fly. He lifted it off of the water, skimmed along for a short distance, and brought it down to finish its one and only flight.

All aircraft can fly as WIG and gain additional lift, but that doesn't mean it makes sense to do it, except during takeoff and landing.

Tom

 

I don;t think it would take much of a turn to put an Erkoplane into a high speed stall. I wonder what the odds of that pig recovering from a high speed stall in a turn are?

 

probably nill, I don't think the Russians are very straightforward with the public about deaths occurring during the training and development of aircraft and spacecraft. I don't think its cause they're scared of lawsuits, its probably just good old fashioned pride.

thanks everybody for setting me straight on the diff b/t gliders and sailplanes, is there any way to easily visually spot one from the other?? I've never known a distinction and therefor always assumed any glider could stay up all day just riding uplifts under fair weather cumulus clouds.

So am I to assume that a glider has to be towed up by a regular plane, whereas a sail plane can be flown either by hitching a tow on a plane or being launched off the top of a fast moving vehicle. If this is the case, and given that qbee says gliders can't ride uplifts, why would anyone purchase a glider instead of a sail plane??

 

It's news to me that sailplanes and gliders are not synonomous. A popular tpe of hybrid craft that puts an engine on a high performance sailplane airframe is called a "motor-glider". Sailplane is more elegant sounding than glider and connotes capability beyond mere gliding, but as words they're interchangeable, with one exception: during WWII cheap, disposable cargo gliders were developed to get troops and equipment to battle quickly, and they were in no respect "sailplanes" designed to to be fully capable aircraft; they were more properly characterized as parachutes with wings, to get their cargo down out of the sky as fast as possible without damaging the load. They were gliders - and barely that.

As to riding thermals to gain altitude, ALL airborne craft, including helicopters and even those WWII troop gliders, will ASCEND if traversing an air mass that's rising faster than their rate of descent down through it. I've used thermals and waves to get my Cessna more comfortably above ridge lines in the mountains. A high performance sailplane (or glider) with a high glide ratio will of course find air rising faster than its descent rate more frequently and easily than more bricklike craft, and enjoy higher rates of ascent, but even a discarded bubblegum wrapper will climb if picked up by air going up faster than gravity can pull it down.

As a matter of historic interest, take a look at the largest troop glider ever built, the German Messerschmitt Me-321 "Gigant", towed by three Me-110 fighters:

 

As I said before, sailplanes are gliders, but not all gliders are sailplanes. The troop glider shown in the video is not a sailplane; it's more of a rock with wings.

Glider:


Sailplane:


There isn't a fixed threshold at which point a glider becomes a sailplane. Some gliders are more sailplane-like than others. The two photos show the ends of the spectrum, and as stated before, all sailplanes are gliders, so the use of the label "sailplane" is somewhat arbitrary and subjective. Mostly the distinction is applied to a glider than can easily ride thermals and up-currents.

Tom

 

A sailplane is to a glider as a Prius is to any other hybrid.

The term "glider" is still used, even with some frequency, by those
in the soaring community as a form of self deprecation. But when used
by outsiders it is considered to be derisive, or a sign of ignorance.

There are similarities to driving a Prius to achieve max MPG and
staying aloft in a sailplane. In a Prius, all forward motion (kinetic
energy) ultimately comes from gas (chemical energy) used wisely in
response the external conditions. In a sailplane, all forward motion is a
trade off of altitude (potential energy) for motion. Just as a Prius can
refill the gas tank, a sailplane can be "refueled" by finding lift from
thermals, ridge lift, atmospheric waves, etc. To be successful at either,
you must be extremely observant of and responsive to external
conditions, and have multiple strategies to be used as the changing
conditions require... with special emphasis on the altimeter and
distance to closest safe landing site.

"Flying low and slow and plumb out of ideas," is a soaring metaphor for
impending disaster... or someone who isn't too bright.

Flying full size sailplanes can be expensive. Fortunately you can
vicariously experience the thrill and quiet beauty of the sport by flying
RC sailplanes. It is a relatively inexpensive way to get into the air. You
can start with plane/radio combos that are ready to fly and have 5-6 ft.
wingspans with simple rudder and elevator controls. At the upper end
there are 14+ ft. wingspan scale models that have everything the big
boys do: rudder, elevator, aileron, flaps, spoilers, droppable water
ballast, wheel brake, and even self-launch capability with a retractible
gas engine or electric motor. Join an AMA sanctioned club (free
insurance) or find an experienced trustworthy pilot to help you get past
the early jitters/difficulties/crashes.

The sky, how quickly you learn, and your wallet are the only the limits.

 

thank you Rokeby, people say driving a pure electric car (leaf, tesla) can result in 'range anxiety', but it sounds like flying a glider would result in 'altitude anxiety' and 'Where the F can I set this down' anxiety.

Nobody has answered my questions fully yet:

A glider with a lower glide ratio (therefor not what some would call a sailplane) cannot take advantage of thermals as well as a sailplane, and therefor has to be towed up to altitude by an airplane, is this assessment correct??

A glider with a higher glide ratio (Sailplane) can take advantage of thermals and therefor doesn't have to be towed up by an airplane, it can take off a fast traveling vehicle's roof, is this assessment correct??

Obviously if you fly a glider/sailplane even remotely near class A airspace you'll pass out, but are there any classes of airspace that a glider is officially (per FAR) not allowed in?? how about unofficially?? By unofficial I mean is it considered rude to enter class B or C airspace because you'll screw up ATCs pattern??

And lastly, if the pilot is properly rated and the glider is properly equipped (I've never seen a Pitot tube on a glider), can you fly IFR or must they always fly in VFR conditions?? (Why one would fly a glider in poor visibility or foul weather is beyond me but I am just curious)

 

All enclosed gliders/sailplanes are towed to a few thousand feet AGL by powered aircraft as the most practical means of getting more than a few minutes of flight. Hang gliders are launched off ridges and ledges because they're little more than wings strapped to a human body and the pilot would be killed and the hang glider destroyed if subjected to the velocity and stress of launch by a powered aircraft. ALL unpowered craft can and are flown into rising air masses to gain altitude after releasing the tow or jumping off the cliff.

It's not a question of rudeness but legality. Class A and B airspace cannot be entered without explicit clearance from ATC. Class A airspace cannot be entered without filing IFR. Filing IFR does not require bad weather, it only means your flight will be supervised by ATC at all times. Gliders/sailplanes fly into Class A all the time to achieve altitude milestones and set altitude records. They must maintain two-way communication with ATC, of course, so carry a battery for the radio and flight endurance may be limited to the duty cycle of the battery. Oxygen is also carried aboard for flights into Class A - and is recommended above 12,000 feet.

Class C & D airspace only requires establishment of two-way communication with ATC; no clearance is required. With a radio, a glider/sailplane can fly anywhere. (Class A, B & C airspace require altitude encoding (Mode C) transponders too).

Gliders/sailplanes are often flown into regions of strong thermal or wave activity that would be seriously uncomfortable for powered aircraft, and with sufficient gyro instrumentation could be flown in clouds, if on an IFR flight plan.

They have to have pitot tubes or their airspeed indicators won't work. They may be located under the wing, or on the leading edge of the vertical fin.

Now, all the above I've set down from memory, without consulting my FARs or the AIM, so I may be out of date - the best place to get these answered definitively is Google & Wikipedia.

 

Adding to Airportkid's comments, sailplanes are also launched by winch. A long tow cable is spooled out from a powerful winch and attached to the sailplane. The cable is reeled in, lifting the sailplane like a child running with a kite. At the highest point of the arc the cable is dropped from the sailplane.

Winch launching produces less altitude, but is cheaper. It is often used in areas where a lot of altitude isn't needed. Most of the gliding around here is done in this fashion, since it is mostly slope soaring. We don't get great thermals, but we do have big sand dunes on the edge of the lake. The sailplanes ride the upcurrents just over the top of these dunes.

Winch Launching Libelle Sailplane at Long Mynd - YouTube

Tom

 

Some gliders don't need a high glide ratio.
See this skier speedflying. Whoa.

Speedflying in Wengen 2010 - YouTube

 

And then theres' the Wingsuit:

 

yeah and don't forget Jay Leno's jet powered flying squirrel wing suit which allows him to get the first acura nsx

thanks a lot airportkid but you said oxygen is recommended above 12000'. If I recall my training I thought oxygen was required by FAR for the pilot above 12000' and required for all passengers above 12500' (I can't recall if this is AGL or MSL)

But I still want to know what aircraft is launched off the roof of a car?? I assume they can't get much altitude unless it is a day with good uplifting thermals.

 

I am not aware of any widely used mechanism/method for launching a
sailplane directly from the roof of a vehicle. Such a launch would
essentially be a catapult launch, and I can't see getting significant
altitude.

However, it the 'plane were launched directly into strong lift, like from
wind blowing against a high, steep cliff, you wouldn't need a whole lot
of altitude -- just a whole lot of balls. But the same result could be
achieved with other methods that I know have been used in this very
special situation; either a winch or a great whacking bungee cord.

Trying to catch a thermal at low altitudes, lets say less than 500 ft AGL,
would be risky buiness. The thermal would be relatively small diameter
and require a very steep bank angle to stay in it. Increased bank
results in decreased vertical lift component. So you have to sacrifice
some altitude to increase speed and lift. If you don't get it right you're
flying low and slow, and better have a damn good idea that can be
implemented RIGHT NOW. It can be done, I concede it probably has
been done as a desperate attempt from having to land where damage/
personal injury is likely, but a old aviation adage goes:

"There are bold airmen and there are old airmen, but there are no old
and bold airmen."

That said, there is some literature on launching a sailplane by towing it
behind a vehicle. From a brief review of the following link, minimum
requirements are at least 5,000 feet of "runway," and 1,500 feet of tow
cable.

Vehilce Ground Launch


A vehicle and a sail plane, all that's needed is the field and a rope.

Hope this helps.

 

Just for fun:

Another Russian behemoth that didn't quite make it, the K-7 bomber (1933):




Read more: K7 Russian Bomber cir 1933

 

This would be great in a hollywood blockbuster as the airplane of an evil mastermind, such as Red Skull in last year's Captain America movie.

Airportkid, thanks for letting me know that gliders have a pitot tube, I'm just so used to seeing airplanes with their pitot tubes on or near the nose I just assumed that was the only place to put a pitot tube for accurate airspeed indication.

as for wikipedia or google, the internet is full of garbage information, I prefer to get aviation information directly from aviators, there was a time when ATCs could fly right in the cockpit of commercial flights (I think it was called the FAN program, with the F standing for familiarization), but 9/11 put the kibosh on that.