30 votes
Accepted

Are there any gliders that can fly over the Himalayas?

Do gliders (sailplanes) use ridge and wave lift in the Himalayas to go to extreme altitudes, possibly above Everest's peak? Yes, there are gliders touring Himalayan peaks over 8,000m, including ...
mins's user avatar
  • 73.2k
26 votes

Why are 3- or 4-seat gliders so rare?

Because much of the fun in being in a sailplane, is in actually flying the sailplane. It's not a means to get from point A to point B, it's a means to enjoy the magic of flight, much of which ...
quiet flyer's user avatar
  • 22.6k
22 votes

Is it feasible to circumnavigate the Earth in a sailplane?

No. Both night and oceans would be major obstacles. Night time can be survived by parking the glider in ridge lift but it requires a steady wind during the night. This is possible and has been ...
Peter Kämpf's user avatar
21 votes
Accepted

Why do sailplanes have such large tails?

Keep in mind that not all sailplanes are designed for extremely light weight. Decreasing the weight also decreases the minimum sink rate, but doesn't help the still-air glide ratio, and actually ...
quiet flyer's user avatar
  • 22.6k
20 votes
Accepted

Do thermals stop rising when clouds are formed?

No, the opposite is in fact true. When the water condenses, it releases latent thermal energy, causing the air to rise even faster. That is why some glider pilots (who are appropriately licensed) fly, ...
60levelchange's user avatar
18 votes
Accepted

What happens if only rudder is applied in a turn without ailerons? Do the two have to be applied together all the time?

To turn – any vehicle, not just an airplane – you need to generate corresponding centripetal force. When you only apply rudder, the plane will turn a bit, but because unlike boat it has no keel, it ...
Jan Hudec's user avatar
  • 56.3k
14 votes

Why are 3- or 4-seat gliders so rare?

As you suspected, the reasons boil down to performance and cost. CG management can be handled by using a 1-2-1 seating arrangement, with little drag penalty (if the cockpit shape is optimized for ...
Zeiss Ikon's user avatar
  • 17.1k
13 votes
Accepted

Is there an abnormal condition that could have caused this fatal accident involving a stall?

Possibly a Center of Gravity beyond the aft limit could do it, but with 2 adults on board I don't think that's likely unless the person up front was really small and the PIC failed to load ballast to ...
John K's user avatar
  • 131k
12 votes
Accepted

Is it feasible to circumnavigate the Earth in a sailplane?

To complement Peter's answer, let me mention that the farthest a glider has ever flown is 2256km (actual distance record is just beyond 3000km, but that was not in a straight line, but going back and ...
Martin Argerami's user avatar
12 votes

How to prevent dizziness when thermalling in the back seat?

Motion sickness is a somewhat complicated mechanism with a lot of variables, and ones propensity to get motion sickness may vary substantially even within the same day. Over time most people will get ...
Jpe61's user avatar
  • 28.7k
10 votes
Accepted

What is the difference between a glider and a sailplane?

The sailplane article is focused around sport and recreational planes. The aircraft article describes a wide variety of aircraft, not simply planes, like hang gliding and paragliding. Which makes ...
corsiKa's user avatar
  • 224
9 votes

What is the difference between a glider and a sailplane?

From the FAA Glider Flying Handbook, pages 1-3 and 1-4: The Federal Aviation Administration (FAA) defines a glider as a heavier-than-air aircraft that is supported in flight by the dynamic ...
StephenS's user avatar
  • 27.7k
9 votes

Why are 3- or 4-seat gliders so rare?

Another concern is ground handling. All ground operations for gliders tend to be pretty labor intensive. Gliders can't taxi under power. So, they are maneuvered using human muscle and tow vehicles. ...
Adam's user avatar
  • 2,167
7 votes

What happens if only rudder is applied in a turn without ailerons? Do the two have to be applied together all the time?

If you apply (say) right rudder without any aileron input, the immediate effect is that the aircraft will yaw: the nose will swing to the right. Note that this does not mean that the aircraft will ...
Tanner Swett's user avatar
  • 5,771
6 votes

What is the difference between a glider and a sailplane?

There does not appear to be any formal definition I can find, but if one observes the aircraft that are typically described as a 'glider' or a 'sailplane'... Sailplane is generally used to describe ...
tj1000's user avatar
  • 8,777
6 votes

Do the rules used in modern soaring competitions forbid gyroscopic flight instruments, or forbid the use of AHRS-driven attitude displays, etc?

As I'm not a competition sailplane pilot, I can't answer all your questions. The Soaring Society of America (SSA) sets rules for soaring competition. The newest version of the rules (2021) state: 6....
Jeff's user avatar
  • 61
6 votes

How much altitude can a glider gain only from losing speed?

You can calculate a theoretical maximum (which will be well above the actual practical height gain) by considering the conversion of kinetic to potential energy. You can also make estimates based on ...
DJClayworth's user avatar
  • 4,053
6 votes
Accepted

Why are 3- or 4-seat gliders so rare?

There are technical limitations. When I fly a two-seater, my thermalling technique is different from flying 15m single seaters. With the single seater it is no problem to center the thermal while ...
Peter Kämpf's user avatar
6 votes
Accepted

What is the nature of the glider's vario lag?

The vario is essentially a high-sensitivity vertical speed indicator, operating on the same principle: the air flow rate in or out through the orifice is measured as a pressure difference between the ...
niels nielsen's user avatar
6 votes

Making sailplane go faster

Use this calculator to work it out. If your glider reaches it's L/D max at 70 kt indicated, pretty typical, and you tow it to 50000 ft, its max L/D will still be 70 kt indicated, but the TAS will be ...
John K's user avatar
  • 131k
5 votes

Would all these three things have the exact same effect on the flight duration of a glider?

Scenarios 2 and 3 would be almost exactly the same. Scenario 1 would be very different. However, the glider would be able to stay up for almost exactly the same amount of time in all three scenarios. ...
Tanner Swett's user avatar
  • 5,771
5 votes

Do thermals stop rising when clouds are formed?

No. You might notice flat bases on some of those clouds. That flat base is the point at which the temperature and dew point spread reaches zero. When the Temp/DP spread hits zero, visible moisture ...
acpilot's user avatar
  • 6,016
5 votes

Why don't [most] sailplanes use whole-airplane / ballistic parachutes?

Opposing viewpoint: BRS are already used in gliders The AC-4C and Phoenix both have models with a fuselage mounted BRS. I'm sure others do as well, I'm simply not familiar with them. I wear a ...
Kenn Sebesta's user avatar
  • 5,132
5 votes
Accepted

Why don't [most] sailplanes use whole-airplane / ballistic parachutes?

why aren't sailplanes equipped with ballistic parachutes? Because of their longevity. Most were built or designed before full-airplane parachutes were a thing. When Ballistic Recovery Systems started,...
Peter Kämpf's user avatar
5 votes

How to prevent dizziness when thermalling in the back seat?

As @Jpe61 says there's a lot of variables and variability with motion sickness and what works for one person may not work for another. That being said from my own experience and speaking to others who ...
GdD's user avatar
  • 54k
5 votes

Are there any recreational gliders with a yoke?

Are there any glider designs, historic or modern, which do not have a central stick but instead use a yoke, sidestick, ...? The Schreder HP-18 sailplane, offered as a kit to homebuilders, was ...
quiet flyer's user avatar
  • 22.6k
5 votes

Minimum Sink Rate in Sailplane

Usually, the designers make sure that the margin between the minimum sink speed and stall speed is larger. Take a look at a real example: the flight polar of the ASK21, one of the most common glider ...
Gypaets's user avatar
  • 4,375
4 votes
Accepted

Can a kite take advantage of crosswinds to gain speed?

Why do you need a kite? A glider is much better suited to the task. Again, nature has invented this long ago. Albatrosses use a technique called dynamic soaring to cover wide distances over water, ...
Peter Kämpf's user avatar
4 votes

How to prevent dizziness when thermalling in the back seat?

I would say it mostly requires desensitization from exposure. In other words, stick it out until you get used to it, and find ways to get similar exposure on the ground to speed up the process. The ...
John K's user avatar
  • 131k

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