::Aero-Experiments::

**** Note spring 2014: I've started an new, alternate home/ page / site map for the Aeroexperiments website, linked to some newer content. Click here to advance to the new home page/ site map.****

SITE MAP (current and future) for Steve Seibel's Aeroexperiments website

Introductory notes: (click here to skip over these notes)

*You've come to the right place--the Aeroexperiments website is intended to be navigated primarily from this site map. The Aeroexperiments website covers a wide range of topics; please take the time to scroll all the way through this page!

*See "Log of additions and revisions to the Aeroexperiments website" for details on recent updates.

*A few articles appear more than once in the site map. Please don't rely on the numbering system in the outline for long-term reference, because the site map is re-arranged from time to time as the website grows.

*A note on printing: most of the articles on this website can be displayed in a more compact format if the url suffix is changed from ".shtml" to ".html", or if no suffix is present, if the suffix ".html" is added.

SITE MAP:

1) Intro (home page)

2) Brief bio information, and a list of the author's past articles for Hang Gliding magazine

3) Log of additions and revisions to the Aeroexperiments website

4) Links--aerodynamics, weather, and more (100+ links here) and reading list

5) Photo gallery--aerial experiments

6) Photo gallery--other aviation-related (hang gliding, RC aircraft, other aviation, etc) and photos from aircaft

7) Photo gallery--photos of birds taken while hang gliding

8) Photo gallery--general

9) Notes on the "Bright Spot", the earth's shadow, and other interesting optical phenomena

10) Practical articles

a) Notes on using the Canon A620, A630, A640, and A650 IS digital cameras for hang gliding and more

b) An expanded manual for the Brauniger IQ Comp GPS variometer

c) An idea for a new McCready pointer

d) Using a GPS in soaring flight

e) Notes on the Garmin GPSmap 76S

f) Notes on the Garmin Etrex Vista H

g) Notes on the Garmin Etrex Vista

h) Notes on the glide ratio functions of some Garmin GPS receivers with pressure sensors, including the GPSmap 76S/CS/CSx, GPSmap 60CS/CSx, and Etrex Vista/ Vista C/Cx

i) Map screen size comparison of some handheld Garmin GPS receivers with numerical data fields enabled: GPSmap 76S, GPSmap 76C series, GPSmap 60 series, and Etrex series

j) Build your own G-meter for hang gliders and airplanes (more to come, for now see here in "Gallery-experiments".)

k) Polarized vision for pilots and hawk watchers (also appears as 19b and 20b)

l) Notes for new hang glider pilots--On the cost of learning to hang glide

m) Notes for new hang glider pilots--Safety gear

n) Notes for new hang glider pilots--Before you order a new Wills Wing harness...

o) Notes for new hang glider pilots--Ridge soaring safety

p) Notes for new hang glider and trike pilots--On sideslips

q) Notes for new hang glider pilots--Judging the wind direction while on the ground

r) Notes for new airplane pilots--Finding a "true" visual reference point in an aircraft with side-by-side seating

s) Notes for new airplane pilots--Headlamp for night flying

t) A simple, time-based plotter for light aircraft navigation

u) Compass errors in flight

v) Using a compass as an emergency cloud-flying aid in hang gliders, paragliders, and "conventional" aircraft

w) Using a GPS as an emergency cloud-flying aid in hang gliders, paragliders, and "conventional" aircraft

x) Emergency tools and strategies for cloud flying without gyro instruments in "conventional" aircraft and hang gliders

y) Success stories and cautionary tales: successful and unsuccessful attempts at adding control surfaces to flex-wing hang gliders: spoilerons, rudders, ailerons, and more.

z) Polar curve calculator and speed-to-fly calculator

aa) Legal-ese: Definitions of night and cross-country, limitations on ultralights

bb) Diagrams, tables, and photos for practical articles

Note: the "RC special interest" section also contains some articles that will be of some practical interest to pilots of full-scale aircraft. Topics dealt with in this section include: drawbacks of differential elevon travel on flying-wing aircraft, drawbacks of differential aileron travel during negative-G flight, rudder usage during negative-G flight.

10.25) Experimental results and theory: dynamics of sideslip and slip-roll coupling in hang gliders -- this section will give a new and more concise treatment of these topics; see the other related sections of this website below for much more.

a)Exploring the relationship between pitch inputs and sideslip in hang gliders

b)"Positive" and "negative" effective dihedral -- exploring the roll torque created by sideslip in flex-wing hang gliders

c)How billow creates anhedral

Note: Sections 10.5 through 18 of the Aeroexperiments site map deal with aerodynamic theory and experimental result in great detail. Many of these areas are still under construction. Click here to skip over these theoretical and experimental areas of the site map and proceed to the "RC special interest", "Birds", and other remaining sections of the site map.

10.5) Aerophysics themes

a) Overview of some themes explored in the aerodynamic theory and experimental results sections of the Aeroexperiments website

11) Experimental results and theory-- at present the articles in this section are a mix of pure experimental results, experimental results plus interpretation, and theory. For issues related to hang glider yaw and roll dynamics, I think the articles in this section (nearly all new for 2007) give a better treatment than the older articles in subsequent sections of the website. However do also see the "Aerophysics Exploration Pages" for a presentation of some basic aerodynamic principles.

a) Fundamentals: yaw string and slip-skid ball

b) Experimental results: yaw experiments with a controllable rudder and wingtip-mounted drogue chutes on flex-wing hang gliders

c) Experimental results and interpretation: yaw experiments with a controllable rudder and wingtip-mounted drogue chutes on flex-wing hang gliders -- same as above, but with more interpretation of results

d) Experimental results and interpretation: using yaw inputs for roll control while ground-handling flex-wing hang gliders

e) Interesting experiments: Zagi RC glider with variable anhedral/dihedral geometry, and rudder

f) Flight characteristics of the variable-geometry Zagi, configured with dihedral and no fin

g) Flight characteristics of the variable-geometry Zagi, configured with anhedral and no fin

h) Flight characteristics of the variable-geometry Zagi, configured with dihedral and a fixed fin

i) Flight characteristics of the variable-geometry Zagi, configured with anhedral and a fixed fin

j) Some thoughts on sail billow, anhedral, and VG setting in flex-wing hang gliders

k) Yaw-roll oscillations in flex-wing hang gliders

l) Looking for the "slipping" turn while hang gliding--overview

m) Some notes on sideslip in an Icaro Laminar R-12 hang glider

n) Looking for a connection between pitch inputs and sideslips in sailplanes and airplanes--overview

o) Effect of pitch inputs on yaw coordination in a Schleicher Ka-6 sailplane

p) Notes on sideslip in steady turns in flex-wing hang gliders

q) Notes from other experimenters-- spoilerons on flex-wing hang gliders

r) Uncoordinated roll inputs in a Schleicher Ka-6 sailplane

s) Using the rudder as a roll control in 3-axis aircraft

t) How dihedral creates roll stability, controlling roll with yaw inputs in aircraft with dihedral, and some thoughts on "pendulum stability" in paragliders and hang gliders

u) Brief notes on the competing effects of sweep and anhedral

v) Do flex wing-wing hang gliders have effective dihedral or effective anhedral?

w) Does adverse yaw strongly decrease the turn rate in flex-wing hang gliders?

x) On "flat turns"

y) Details: yaw oscillations during roll inputs in flex-wing hang gliders

12) The Aerophysics Exploration Pages -- (under construction!) This feature was newly introduced in 2006. The goal is to offer a integrated, modular tutorial that is easy to navigate and makes many of the theoretical ideas explored elsewhere on the Aeroexperiments website accessable to pilots without a strong background in aerodynamic theory. Eventually this feature will incorporate many diagrams, photos, and external web links.

a) 2 paths

b) An "unconventional" approach?

c) Your thoughts are welcome...

d) What is a turn?

e) Definition of the relative wind

f) 2 kinds of yaw

g) Oblique and side views of aircraft with dihedral

h) A definition of dihedral

i) Oblique and side views of aircraft with anhedral

j) A definition of anhedral

k) The rudder as a roll control: aircraft with dihedral

l) The rudder as a roll control: aircraft with anhedral

m) Definition of a "positive coupling between yaw (slip) and roll"

n) Definition of a "negative coupling between yaw (slip) and roll"

o) "Conventional" use of the rudder

p) Definition of a "coordinated" turn

q) Definition of a "slipping" turn

r) Definition of a "skidding" turn

s) Roll torque created by dihedral during slips and skids

t) Roll torque created by anhedral during slips and skids

u) Oblique and side views of "W"-shaped wings

v) Oblique and side views of "M"-shaped wings

w) The flexible hang-glider wing: how billow contributes to anhedral

x) Looking at anhedral in flex-wing hang gliders: VG off versus VG on

y) Sweep creates a dihedral-like effect

z) The dihedral-like effect of sweep depends strongly upon angle-of-attack

aa) The roll torque created by dihedral or anhedral is not strongly dependent on the angle-of-attack of the wing as a whole

ab) Competing effects of sweep and anhedral

ac) Interesting experiments: Zagi RC glider with variable anhedral/dihedral geometry, and rudder

ad) Interesting experiments: adding a controllable rudder and other yaw devices to 4 flex-wing hang gliders

ae) Interpreting in-flight observations: roll torque created by the combined effects of anhedral and sweep in flex-wing hang gliders, VG off versus VG on, high airspeed versus low airspeed

af) A more "complete" consideration of adverse yaw in flex-wing hang gliders, with notes on fixed vertical fins: does adverse yaw create a helpful roll torque or an unfavorable roll torque?

ag) In-flight observations supporting the idea that a flex-wing hang glider has more anhedral with the VG off than with the VG on, with notes on yaw-roll oscillations, tow dynamics, and spiral instability

ba) The main cause of adverse yaw during rolling motions: the "twist" in the relative wind

bb) Roll and yaw torques due to the difference in the airspeed of the left and right wingtips

bc) Curvature in the relative wind about the yaw axis

bd) A constant-banked climbing or descending turn involves a continual rolling motion

ca) Misconceptions: The "simple" view of how dihedral contributes to roll stability

cb) Misconceptions: the "sideways gravity" and "missing lift" explanations of how dihedral contributes to roll stability

cc) A holistic view of how dihedral contributes to roll stability and anhedral contributes to roll instability

cd) Seeking pilot input on the effect of a vertical fin on flex-wing hang gliders

ce) Spiral instability in flex-wing hang gliders: VG on versus VG off

cf) The "parasol" or "pendulum" effect: location of the wing above or below the aircraft CG: influence on yaw (slip) roll coupling and spiral stability or instability, with notes on flex-wing hang gliders and paragliders

da) More detailed definitions of "slips" and "skids"

db) Aerodynamic sideforce during slips and skids

dc) Sideslips and forward slips

dd) "Kicking out the crab"

de) The aerodynamic sideforce generated by a slip depends on the shape of the aircraft

ya) Pool of images for the Aerophysics Exploration Pages

(z through zz: Selected links from remainder of Aeroexperiments website.)

13) Experimental tools (see also the Photo gallery--aerial experiments for brief notes on some other experimental tools that are not yet covered here.)

a) Clamp to hold a light airplane's control yoke in a fixed position in the pitch axis

14) See for yourself--simple in-flight demonstrations that you can do to the explore the physics of flight

a) In a "conventional" airplane:

1) Noting the control yoke position at the stall angle-of-attack

2) Flying without using the control yoke or control stick -- creating a pitch "phugoid" oscillation

3) Flying without using the control yoke or control stick -- exploring relationships between yaw and roll, and between roll and pitch

4) Flying with a fixed elevator position� -- creating a pitch "phugoid" oscillation

5) Flying with a fixed elevator position -- exploring relationships between roll and pitch

6) Flying without using the rudder -- looking at adverse yaw

7) Exploring yaw oscillations

8) Direction of tail's lift

9) "Feeling" the wind direction in flight?

b) In a hang glider (coming soon)

15) Advancing our knowledge--experimenters wanted for in-flight investigations in flex-wing and rigid-wing hang gliders. Your participation in any of these areas would be most welcome.

a) Seeking pilot input on the effect of a vertical fin on flex-wing hang gliders (this article is embedded within the "Aerophysics Experiments Pages" section)

b) Vectored-thrust experiments in flex-wing and rigid-wing hang gliders

c) Exploring roll stability in rigid-wing hang gliders

d) Exploring sideslip in the Moyes CSX hang glider

16) Aerial experiments: notes from in-flight experiments in hang gliders and other aircraft. Note summer 2007: this section will eventually become redundant with sections 10.5 through 12, but at present some of the articles below contain information that is not presented elsewhere on the aeroexperiments website.

Note: the articles entitled "Questions of interest part 1...", "Questions of interest part 2...", and "Questions of interest part 3...", listed below, should give a good overview of the motivation for some of these experiments

a) Articles describing in-flight experiments to look at the relationship between pitch inputs and sideslips in hang gliders and other aircraft

1) Questions of interest part 1: Relationship between pitch inputs and sideslips in hang gliders and other aircraft (see below for more on these topics)

2) Notes for new hang glider and trike pilots--on sideslips (also appears as 10o)

3) Looking for the "slipping" turn while hang gliding--overview

4) Looking for a connection between pitch inputs and sideslips in sailplanes and airplanes--overview

b) Notes on experiments to look at the aerodynamic sideforce created by the sideways airflow as a hang glider sideslips (focusing here on experiments that didn't involve the rudder or wingtip drag devices)

1) Questions of interest part 2: Aerodynamic sideforce created by the sideways airflow as a hang glider sideslips

c) Experiments with rudders and wingtip-deployed drag devices on flex-wing hang gliders, primarily intended to explore the roll torque created by the sideways airflow component as a hang glider sideslips, and also intended to explore the aerodynamic sideforce created by the sideways airflow as a hang glider sideslips

1) Questions of interest part 2: Aerodynamic sideforce created by the sideways airflow as a hang glider sideslips

2) Questions of interest part 3: Roll torque created by the sideways airflow component as a hang glider sideslips

3) (from AEP pages) "Interesting experiments: adding a controllable rudder and other yaw devices to 4 flex-wing hang gliders"

4) (from AEP pages) "Interpreting in-flight observations: roll torque created by the combined effects of anhedral and sweep in flex-wing hang gliders, VG off versus VG on, high airspeed versus low airspeed"

5) (from AEP pages) "A more 'complete' consideration of adverse yaw in flex-wing hang gliders, with notes on fixed vertical fins: does adverse yaw create a helpful roll torque or an unfavorable roll torque?"

6) See also text in Gallery-experiments, and see also "Part 3:more detailed notes on experimental tools and strategies" in the Spring 2003 "Experiments" article, and see also the comments here in the Aeroexperiments "Links" page.

d) Articles describing the Zagi RC glider with variable anhedral/dihedral geometry, intended primarily to explore the roll torque created by the sideways component in the relative wind during sideslips

1) (from AEP pages) "Interesting experiments: Zagi RC glider with variable anhedral/dihedral geometry

2) See also text in Gallery-experiments

e) Exploring the direction of the aerodynamic sideforce created by deflecting a rudder on an Arianne Swift

f) Notes on the yaw orientation of a hang glider in a steady, constant-bank turn (more to come, for now see this paragraph in "Analyzing the "long-tailed slip" effect, with notes on how 'airflow curvature' affects a swept- or delta-winged aircraft".)

g) Maximizing the descent rate in a hang glider: reversing turns ("sideslips?") vs. sustained, steeply-banked spiral dive (more to come, for now see here in "Critiques and notes: the myth of the slipping turn in hang gliding and "conventional" aviation.)

h) Notes on yaw rotational inertia in hang gliders and "conventional" aircraft--see this paragraph in article 17b5 ("Causes of adverse yaw in hang gliders and "conventional" aircraft--with notes on slips, skids, yaw strings, slip-skid balls, rudder usage, yaw rotational inertia, "airflow curvature", aerodynamic "damping" in the roll axis, and flex-wing billow shift"), and see this paragraph in "Two kinds of yaw" from the AEP tutorial pages.

i) Spoilerons on flex-wing hang gliders (reports from other experimenters)

j) Notes from vectored-thrust experiments in rigid-wing hang gliders

k) Aft-edge-of-allowable-C.G.-envelope experiments in a light airplane--direction of tail's lift

17) T heoretical articles

Note: many new articles on the theory of flight, especially in relation to the physics of turns and slips and yaw-roll dynamics, may now be found in the "Aerophysics Exploration Pages" section of this website. Also, see the "Aerial Experiments" section (especially the "Questions of interest" series) and the "Critiques" section for some more articles that address practical and theoretical aspects of the physics of turns.

a) Series on physics of turns in wind (and other facets of life in a moving fluid...):

a1) Brain teasers for those who believe that downwind turns are "different"--i.e. that an aircraft can "feel" the wind direction in flight

a2) Downwind turns ARE "different"!

a3) Mathematics of circles in wind

a4) Notes on "dynamic soaring"

a5) The never-ending myth of the "dangerous downwind turn"

b) Series on the basic physics of turns, slips, skids, aerodynamic coupling between slip (yaw) and roll, adverse yaw, and more

b1) What makes an aircraft turn?

b2) You can't "feel" gravity!

b3) Complete analysis of forces: fully balanced turn, turn with inadequate lift or G-load, slipping turn, non-turning slip, and skidding turn

b4) Series on the aerodynamic coupling between yaw and roll in aircraft with sweep, dihedral, or anhedral--Note August 2006 this section is now retired and may be found in the "links to older content" section. The material has been given a fresh treatment which may be found in the "Aerophysics Exploration Pages" section.

b5) Causes of adverse yaw in hang gliders and "conventional" aircraft--with notes on slips, skids, yaw strings, slip-skid balls, rudder usage, yaw rotational inertia, "airflow curvature", aerodynamic "damping" in the roll axis, and flex-wing billow shift -- other topics addressed in this long article include notes on the aerodynamic sideforces created by the sideways airflow component in a slip or a skid, unusual cases where the yaw string and the slip-skid ball give different indications, balance of yaw torques and balance of roll torques in a sustained, constant-banked turn in hang gliders and in "conventional" aircraft, the myth of the efficient, flat, "skidding" turn, and more. Much of this material is now covered in a more accessible manner in the "Aerophysics Exploration Pages" section.

b6) Interesting special case: yaw string is centered, slip-skid ball is not, because the rudder is generating a significant aerodynamic sideforce

b7) A constant-banked turn involves a rolling motion

b8) Tail moment-arm, airflow curvature, and spiral stability

z) Diagrams, tables, and photos for theory articles -- includes photos that illustrate how sail billow contributes to the "net geometric anhedral" of a hang glider or trike, so more anhedral is actually present when the VG is off

18) Critique articles

a) The myth of the slipping turn in hang gliding

b) The myth of the skidding turn in hang gliding--see this section in article 17b5 ("Causes of adverse yaw in hang gliders and "conventional" aircraft--with notes on yaw strings, slip-skid balls, rudder usage, yaw rotational inertia, "airflow curvature", aerodynamic "damping" in the roll axis, and flex-wing billow shift")

c) Misconceptions about slips and skids in "conventional" aviation

d) Other myths from the world of general aviation

e) Notes on Harvey S. Plourde's "The Compleat Taildragger Pilot" in relation to the the physics of "kicking out the crab"

f) Notes on William K. Kershner's "The Flight Instructors Manual" in relation to the physics of rudder usage during single-engine operations in twin-engine aircraft

z) Diagrams, tables, and photos for critique articles

19) RC special interest: for pilots and builders of RC sailplanes and airplanes. Most of the content here is also applicable to full-scale aircraft; includes a special focus on control usage and control geometry in inverted or negative-G flight.

a) High-visibility color schemes for RC model aircraft

b) Polarized vision for pilots and hawk watchers (also appears as 10i and 20b)

c) Semi-scale Me-163 Komet slope glider with rocket boost

d) Why differential aileron travel increases adverse yaw during negative-G flight

e) Drawbacks of differential elevon travel on flying-wing aircraft

f) Rudder usage during negative-G flight: 2 scenarios

See also "Series on the physics of turns in wind (and other facets of life in a moving fluid...)", including notes on the physics of turns in wind and notes on dynamic soaring, listed under section 17 ("Theoretical articles") of this site map.

See also the entire "Aerophysics Exploration Pages" section

z) Photos for RC-related articles

20) Birds

a) Flight principles for hawk watchers

b) Polarized vision for pilots and hawk watchers (also appears as 10i and 19b)

c) White-Tailed Kites at Finley National Wildlife Refuge

See also the related article on this website entitled "Notes on dynamic soaring", including notes on flight strategies of albatrosses and other birds, listed here in the site map.

See also these raptor-related links on the "Links" page of this website: Bird cam: Golden eagle on the wing, Angelo d'Arrigo, Parahawking

21) Links to older content from this website

22) From the poetry and literature of flight

a) The sun dropped into low gold on the horizon... (Bach)

23) Acknowledgements and origins of ideas

24) The back pages: content unrelated to aeroexperiments themes

25) Contact info

**** Note spring 2014: I've started an new, alternate home/ page / site map for the Aeroexperiments website, linked to some newer content. Click here to advance to the new home page/ site map.****