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Questions tagged [glider]

Use for gliders; combine with specific tags, e.g. [sailplane], if required.

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3 votes
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A question on stalling and flat spin - in gliders

Very short version: Do gliders do stalls, and flat spins, as aerobatic tricks (as do say aerobatic biplanes). -- As I understand it, with an aerobatic plane, a pilot can and does, for "fun" ...
Fattie's user avatar
  • 1,932
10 votes
1 answer
5k views

What's the minimum survivable mid-air collision altitude in a glider?

This weekend I had my first gliding experience in an ASK21. My first surprise was being given a parachute. The briefing was simple, if we have a mid air collision, unbuckle the belt harness, remove ...
Cloud's user avatar
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2 votes
2 answers
324 views

Pitch of a glider with altitude

I'm designing a high-altitude glider. Just to clarify a few points before my question: The glider will weigh close to 200 grams. It will be using the A18 airfoil. The glider is dropped from 80,000 ...
Charles Nicholson's user avatar
0 votes
3 answers
154 views

Conundrum about designing a glider relating to coefficient of lift

I'm designing a high-altitude glider. Just to clarify a few points before my question: The glider will weigh close to 200 grams. It will be using the A18 airfoil. The glider is dropped from 80,000 ...
Charles Nicholson's user avatar
0 votes
2 answers
127 views

How to maximize L/D ratio by design in a high altitude glider? [closed]

EDIT: Some initial confusion with TAS and IAS confused me, I now understand this better, thanks for everyone who helped. I'm designing a high-altitude glider, and I'm wondering how the angle of attack ...
Charles Nicholson's user avatar
2 votes
2 answers
293 views

Why do gliders need more rudder when flying straight?

I came across a Captain Joe video in which he had said that gliders require much more rudder in straight and level flight, as opposed to powered aircraft. Can someone explain the reasoning and physics ...
Boeing787's user avatar
  • 6,464
-1 votes
1 answer
102 views

How does a glider in steady descent glide with negative AoA? [closed]

EDIT: I now understand relative wind is parallel to the travel of the glider. Ignorance was the basis of my earlier confusion. I looked at some toy and commercial gliders and all of their wings were ...
Charles Nicholson's user avatar
0 votes
1 answer
46 views

What should be decalage angle for high lift to drag ratio biplane glider?

Assuming hypothetical biplane variant of a modern conventional glider, wingspan of 8m, 1m separation between the wings, no stagger, no struts, what should be the decalage between the wings assuming ...
user avatar
5 votes
1 answer
521 views

Glider Flying Handbook page 5-6 error on effects of weight to stall speed?

I've been reading the FAA's Glider Flying Handbook, 2013 (FAA-H-8083-13A). Page 5-6 in chapter 5 states the following, but it doesn't seem right to me. The heavy glider has a higher stall speed and a ...
JaredC's user avatar
  • 207
1 vote
1 answer
91 views

IAS vs ground speed when calculating speed to fly in wind

It's common for discussions around a glider's Polar Curve to describe how to use the Polar Curve to identify the best speed (Indicated Airspeed, IAS) to fly in a given wind condition (let's assume a ...
JaredC's user avatar
  • 207
4 votes
2 answers
391 views

Does Best L/D sink rate increase as altitude increases?

As a glider pilot, we learn that Best L/D airspeed does not change with altitude. That is, the Indicated Airspeed (IAS) to fly in order to achieve Best L/D is the same no matter the altitude or air ...
JaredC's user avatar
  • 207
9 votes
2 answers
4k views

Are glider pilots who are 14 or 15 years old more dangerous than those who are 16 when soloing?

With a student pilot certificate and an endorsement, it is legal to solo a glider at 14 years of age. When I was 14, I would have probably thought I was old enough to solo a glider, but looking back (...
Someone's user avatar
  • 7,097
3 votes
3 answers
799 views

Minimum Sink Rate in Sailplane

How do gliders ascend (either with an engine or thermal) at best rate of climb if it is very close to stall? Or they move up by sacrificing that best Rate of Climb. In image the best CL^3/CD is ...
andy's user avatar
  • 135
1 vote
1 answer
119 views

How long can a foreign registry glider stay in the US before having to change the register to N or having to leave the country?

This is a qualification on a previous question, specifically for gliders. Here is the link to the answer to the more generic question. Juan Jimenez thanks for the answer there. As other sources ...
Edoardo Jacucci's user avatar
2 votes
0 answers
60 views

Program to make glider polars

I was using flow5 to make some speed polars for a glider with real dimensions, however I read about PGEN (polar generation software) that could simulate the thermal effect, but apparently it is an ...
andy's user avatar
  • 135
0 votes
0 answers
105 views

Incidence angle in Sailplane

I am determining the shape of the fuselage of a sailplane and I found something that gives me a little conflict, and that is that in most sailplanes it has an inclined tip, I read that this helps ...
andy's user avatar
  • 135
4 votes
1 answer
233 views

Can new thermals be generated above a cloud layer?

Thermals rise from the ground due to uneven heating from the sun, then stop rising once they start condensing into clouds. My question is can new thermals be formed at the top of this cloud layer? I ...
rhobot's user avatar
  • 43
3 votes
3 answers
289 views

Design glider without aileron

What difficulties would it take to build a glider without ailerons? I read that "if you can control the turns with the rudder maybe you don't need ailerons." Well, apart from the fact that ...
andy's user avatar
  • 135
0 votes
0 answers
52 views

Use twist to improve stall characteristics in ideal distribution of lift coefficient

Is practical use twist (geometric or multiple airfoils to improve stall characteristics) when it has lift coefficient distribution ideal or near due to wing plataform? I am analyzing a "Schuemann&...
andy's user avatar
  • 135
2 votes
3 answers
162 views

Cruise-climb in glider with electric motor?

I have been looking for the definition of cruise-climb for gliders that use an electric motor, but so far I have only been able to find a definition based on liquid fuel. I'm asking because that ...
andy's user avatar
  • 135
0 votes
1 answer
254 views

Trailing edge tapered and leading edge straight

It is true that a wing with a straight leading edge and a tapered trailing edge has good stall characteristics?. That is, we can assure that when it enters stall, it will first be at the root and then ...
andy's user avatar
  • 135
3 votes
1 answer
169 views

Effect of wing flexible in stall

How true is it that the deflection (due to large aspect ratio, flexible wing ) of a wing has a certain effect on the stall characteristics? I read about this in the case of large wingspan gliders. ...
andy's user avatar
  • 135
11 votes
3 answers
3k views

With existing tech and knowledge of meteorology, can aircraft be designed to reliably improve their range or loiter using updrafts to gain altitude?

Just what the question says. I want to know if aircrafts' range, loiter time, or other measures of merit can be dramatically and reliably increased using our current understanding of meteorology and ...
Sorghum's user avatar
  • 113
11 votes
1 answer
3k views

Why don’t gliders use swallow tails?

I’ve always wondered this. Why do gliders use a T-style tail, as opposed to a V-tail ie a swallow tail design? I think it would represent a significant reduction in weight over a conventional ...
Romeo_4808N's user avatar
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0 votes
0 answers
43 views

Maximise Range Vs Pitching Down while flying a Glider in a Downward Air Mass

While flying a glider, if I encounter a downward moving air mass (i.e. sink) while on final, should I fly to maximise range (best lift to drag ratio) or should I pitch downward in order to exit the ...
JF0001's user avatar
  • 101
0 votes
0 answers
103 views

SPL to PPL(A) conversion

I'm currently flying with gliders as a hobby whilst getting my SPL for it. (Belgium - EASA) I know there is SPL TMG and PPL(A) TMG. (don't know the difference) Once I get to PPL(A) TMG, I want to get ...
meiko's user avatar
  • 1
1 vote
1 answer
144 views

What FAA legal interpretation clarifies that glider sight-seeing operations do not need a drug testing program?

I came across this once, and despite searching with Bing and Google cannot find it again. As memory serves, the FAA counsel wrote a letter finding that glider sight-seeing operations do not need ...
Kenn Sebesta's user avatar
  • 5,152
4 votes
1 answer
192 views

Irrational acrophobia-like anxiety caused by wave soaring

This will probably sound utterly bonkers to many and I feel very awkward coming out with this publicly - I'm a gliding instructor with 650 hours flying experience, and I'm scared of heights. It's ...
Toby Wilson's user avatar
4 votes
4 answers
965 views

Why the heavier the aircraft is, the higher the airspeed must be to obtain the same glide ratio?

I know weight does not affect glide ratio. But why does higher weight need higher gliding speed?
Hitomhi's user avatar
  • 349
1 vote
1 answer
214 views

How does elevator control effectiveness change with altitude/ air density?

Suppose an unpowered, rigid, mechanical, lightweight aircraft (e.g. sport glider) is descending at a steady glide in a constant trim (hands off) configuration in a standard atmosphere. The pilot ...
Oleg Pryadko's user avatar
13 votes
3 answers
2k views

Does glide ratio improve with increase in scale?

Will the same glider have higher glide ratio if its bigger in proportion or smaller in proportion?
Francis L.'s user avatar
  • 2,514
2 votes
1 answer
247 views

How does this total energy compensation pitot tube work?

This is a pitot tube I saw on a glider: The far right end plugs into a receiver. The far left end has the RAM port at the tip, the static ports just behind it, drilled in laterally, and a venturi ...
Kenn Sebesta's user avatar
  • 5,152
13 votes
2 answers
2k views

What is the FAA definition of a "flight"?

For the purposes of aeronautical experience for glider ratings, the FAA requires a certain number of "flights". However, I cannot find a definition of "flight" in the federal ...
Kenn Sebesta's user avatar
  • 5,152
2 votes
0 answers
95 views

Size of speed brakes for glider

I have a concept glider and I am trying to calculate the required speed brake area. The clean glide ratio is currently 30, and with speedbrakes, I am aiming at reducing it to something around 7. I ...
Vincent Cerowski's user avatar
2 votes
3 answers
655 views

Airplane speed retention question? [closed]

Imagine the scenario when a plane is flying, then it turns off its engine and nose dives. After gaining a lot of speed, if the pilot pulls the stick back and the plane now points upwards again, will ...
user avatar
12 votes
2 answers
582 views

What is a tailwheel aircraft?

I just had a lesson in a SGS 2-33A and my CFI logged it as tailwheel time "because it has a tailwheel". I laughed and said I'm not sure that's how it works. The center of gravity is in ...
Zaz's user avatar
  • 1,569
0 votes
2 answers
173 views

How would IAS change with altitude for an unpowered parafoil?

Suppose an unpowered parafoil (e.g. a ram air parachute or paraglider) is descending (gliding) in a standard atmosphere. Suppose a pitot tube is positioned to always point into the relative wind (e.g. ...
Oleg Pryadko's user avatar
4 votes
3 answers
328 views

Currency requirement for a Private Pilot adding a glider rating?

I have a Private Pilot certificate {ASEL, instrument) that I got years ago, and I haven't flown airplanes in over ten years. I'm trying to get back into flying now, but not in airplanes; I want to get ...
mergeconflict's user avatar
0 votes
1 answer
164 views

landing glider with chronic right drift or float

I just completed 30 glider flights with my instructor. Over the 2 weeks of training everything improved except for this tendency for the glider to move, drift or float to the right and always ...
david's user avatar
  • 1
5 votes
1 answer
338 views

How were military gliders positioned to their departure point?

Modern sailplanes are usually positioned to their departure field using a trailer. How did military gliders get to their departure field?
Anonymous Physicist's user avatar
1 vote
4 answers
340 views

Is it normal to fly or glide only one mile per hour above stall speed?

At one point, Through Gates of Splendor describes Nate Saint gliding in his Piper PA-14 Family Cruiser at 45 mph; the plane's stall speed is 44 mph. Earlier in the book, he flew at 45 mph. Is it ...
Someone's user avatar
  • 7,097
6 votes
3 answers
816 views

Are there any recreational gliders with a yoke?

All gliders / sailplanes seem to use a single central stick to manipulate the primary control surfaces. In other airplane types, we also find yokes and sidesticks. Are there any glider designs, ...
Sanchises's user avatar
  • 13.4k
2 votes
3 answers
261 views

To what extent is it viable to launch manned gliders vertically using unmanned drones rather than tow planes?

An electric, vertical takeoff drone lifts a manned glider 5 km in the air. The glider is then released from the drone, and glides 50 km to carry its passengers across a lake. The drone meanwhile ...
Joseph's user avatar
  • 29
4 votes
1 answer
954 views

Can weight reduce a plane's glide ratio?

The FAA says glide ratio doesn't change, regardless of weight, here on page 5-7. Glide ratio is not affected by weight because, while a heavier glider sinks faster, it does so at a greater airspeed. ...
user66219's user avatar
1 vote
1 answer
546 views

How to determine the size and placement distance of vertical and horizontal stabilisers given the size of my wing? (it's a foamular250 glider)

If the wing has a Chord of 150 mm and a span of 800 mm, what about the distance to the tail? anf the size of horizontal and vertical stabilizer?
Liev Acal's user avatar
1 vote
1 answer
256 views

Calculating best glide speed

I recently started flying a SGS 2-33 glider. The POH lists the stall speed as 31 mph for solo flight. Min sink speed is 38 mph and optimal glide speed is 45 mph. Being an old glider with imperfections,...
105's user avatar
  • 11
25 votes
1 answer
3k views

What is the lift to drag ratio of a human being?

If a person falls at terminal velocity, and tries to steer himself with his limbs, what is the maximum lift to drag ratio he can achieve, and what position would that be in?
Abdullah is not an Amalekite's user avatar
0 votes
2 answers
307 views

Is it possible to have a foot powered hang-glider?

My goal is to build a pedal-powered hang-glider capable of traveling at least 80 kilometers per hour. Is such a unit possible in principle, or do we need orders of magnitude more power?
Entaldalpe's user avatar
3 votes
2 answers
566 views

How is a "turning polar" constructed?

To start with something familiar: here's a flight polar. As we learned, the best glide speed is found by starting at the 0,0 point, and drawing a line tangent to the sink rate line. The intersection ...
Xpector's user avatar
  • 175
4 votes
1 answer
394 views

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

I learned that glider's vario reading lags behind the vertical speed of the airmass. For example, when flying a steady circle and having a thermal not quite centered yet, the vario is reading a ...
Xpector's user avatar
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