Thursday, October 27, 2011


This paper describes the development of what might be considered the first successful ultralight sailplane.The SWIFT is a high performance foot-launched glider, designed to combine some of the convenience of hang gliders with the soaring performance of sailplanes. It takes off and lands like a hang glider, yet maintains exceptional performance at high speeds, achieving a lift-to-drag ratio of about 25:1. Although it is a fullycantilevered rigid wing with aerodynamic controls and flaps, it is light enough to launch by running from a hillside and is easily transported on the top of a car. This paper describes the design, development, and flying of this unique aircraft. Introduction and Background
 Introduction and Background
Pioneers of heavier-than-air flight were inspired with the idea of being able to fly like birds – not for the purpose of efficient, high-speed transportation, but for the shear freedom that such a capability would permit. This was the motivation for, and is the appeal of,modern soaring aircraft such as paragliders, hang gliders, and sailplanes. Although the performance of sailplanes has increased dramatically over many decades  so that lift-to-drag ratios of 60:1 have been achieved and 1000 km flights are possible, certain aspects of high performance sailplanes seem counter to the vision espoused by Lilienthal and others [1]. Especially for a group of graduate students in the San Francisco Bay Area, the cost of sailplane flying, along with the long drive to an airport that supported such activities, meant that achieving the goal of bird-like flight was only somewhat more realizable than it was 100 years ago.

How To Make Traditional Boomerangs

Construction of traditional Australian boomerang (for right hand)
Instructions how to make traditional boomerang
1. Take plywood sheet of 12mm thickness. Draw boomerang contour pattern as shown in picture above. The 107 degree angle size is not critical, just optimum. It can be more or less than 107deg. Chord length near the center of boomerang = 80 mm, and 60 mm near tips. Make wing chord length few millimeters wider as is required, because it necessarily reduces during sanding process. Also make some access length at boomerang wings tips, as it possible, that you will have to cut them during tune procedure of the boomerang.
If you make angle >>107, consider that rotation plate becomes small and it can be difficult to keep the
boomerang spinning.
If you make angle of about 90 degrees, the boomerang flight trajectory circle radius is minimum. Angles
<90 deg and >90 degrees increase circle radius.
2. First what you have to do is to sand dihedrals of wings. You have to make decision were is top and
bottom. Put plywood boomerang on flat table and see if the tips are up or down. The traditional Australian boomerang has positive dihedral. The best choice is to find position in which the boomerang wings tips are up. (Do not care about that if your plywood is absolutely flat).
Remove some material from boomerang bottom at distance of about D=70...90 mm from both tips. It can
be asymmetrical, but condition A+B = 14 mm should be satisfied.

Tuesday, October 25, 2011

Preflight and Ground Operations

Figure 6-1. Wing stand used during glider assembly.
Operating a glider requires meticulous assembly and preflight. Proper assembly techniques, followed by a close inspection of the glider using checklists contained in the Glider Flight Manual/Pilot’s Operating Handbook (GFM/POH), are essential for flight safety. In order to ensure correct and safe procedures for assembly of a glider, students and pilots unfamiliar with glider assembly should seek instruction from a knowledgable glider flight instructor or certificated private or higher glider pilot. Safely launching a glider requires careful inspection, appropriate use of checklists, and quality teamwork. Launch procedures should be carried out systematically and consistently each time you fly.
While preparing to assemble a glider, consider the following elements: location, number of crewmembers, tools and parts necessary, and checklists that detail the appropriate assembly procedures. The GFM/POH should contain checklists for assembling and preflighting your glider. If not, develop your own and follow it every time you fly. Haphazard assembly and preflight procedures can lead to unsafe flying conditions. Before assembling a glider, find a location that shields the project from the elements and offers enough room for completion. Wind is an important factor to consider during an outdoor assembly. Each wing is an airfoil regardless of whether or not it is connected to the fuselage; even a gentle breeze is enough to produce lift on the wings, making them cumbersome or impossible to handle. If assembling the glider in a spot shielded from the wind, great care must still be taken when handling the wings.
When performing the assembly inside a hangar, ensure there is enough room to maneuver the glider’s components throughout the process. Also, consider the length of time you anticipate to complete the entire procedure, and choose an area that allows complete undisturbed assembly. Moving the glider during assembly may cause parts or tools to be misplaced.

The Clark Y Airfoil is Ideal for RC Model Aircraft

Complete instructions on how to plot out a Clark Y airfoil Outline of a Clark Y airfoil

Clark Y is the name of an airfoil that is widely used in aircraft design. With its predictable and gentle stall characteristics and flat bottom outline, the Clark Y airfoil is an ideal choice for sport RC model aircraft. I have used the Clark Y airfoil for all my model airplane designs, from the Electro Aviator to the Finch.

See later on in this article for complete instructions on how to plot out a Clark Y airfoil from tabulated ordinates. Drawing up your own airfoil shape is very easy to do. You can use the tabulated ordinate method to draw a Clark Y airfoil by hand, or use TurboCAD for the drafting task. You can then use TurboCAD to draw additional versions of the finished Clark Y wing rib shape for any length wing rib your model aircraft design requires.
Table 1: Ordinates to draw a Clark Y airfoil. All figures are a percentage of rib chord (top line), with percentage of chord upper and lower airfoil points on next two lines

Chickadee Fuselade Plan Side View,

Tips On Trimming and Flying a Catapult Glider

Now that there are two new indoor catapult glider classes, and there is still an outdoor catapult class, you guys can't use the excuse that your arm isn't any good anymore! Now all you need to do is pick up your old broken Wakefield, or Bostonian motors, and make a little loop for your catapult (1/4" dowel works nicely) and tie it on, pick up your glider, pull back, and let go! No more running twenty-five yards, lunging and throwing your arm out of its socket all day long, then complaining you're not getting any height. No, now all you need to do is add another loop of 1/4" tan II and let fly!

Keep in mind, many of these tips will also apply directly to a hand launch glider, in fact that's where many of them came from. So if there are any other brave souls that have caught the age old, highly contagious, HLG disease, keep your ears open.

principles Of Flight

Lesson Plan: Paper Glider Measurement
Grade Level:  5-6
Subject Area: Math
Time Required: 
  1.  Preparation: 1 hour
  2. Activity: 2-3 hours
National Standards Correlation: Math (grade 3-5)
Measurement Standard:
Apply appropriate techniques, tools, and formulas to determine measurements.
  1. • Data Analysis and Probability Standard: Understand and apply basic concepts of probability.
  2. • Data Analysis and Probability Standard: Select and use appropriate statistic methods to analyze data.
  3. • Representation Standard: Use representation to model and interpret physical, social, and mathematical phenomena. Math (grades 6-8)
  4. • Measurement Standard: Apply appropriate techniques, tools, and formulas to determine measurements.
  5. • Data Analysis and Probability Standard: Understand and apply basic concepts of probability.
  6. • Data Analysis and Probability Standard: Select and use appropriate statistic methods to analyze data.
  7. • Representation Standard: Create and use representations to organize, record, and communicate mathematical ideas.


DIRECTIONS: Divide class into flight squadrons (3 to 4 students per squadron). Have each student construct a 757 glider and write their name on the wing. Present glider challenges to squadrons. Explain to students the object of each event and how it is scored. Extra points can be obtained by completing a glider extension activity. Students should be encouraged to conduct some experimentation (i.e., add weight; reshape wing or tail) on their gliders in order to maximize the performance for the different objectives of each challenge. Rotate squadrons through the challenges keeping score on a squadron’s scoresheet. Debrief afterwards to discuss glider designs, experimentations, and outcomes.
Spot Landing Set-up: Tape off a large circle, 7 meters in diameter. Create a bull’s-eye ring with 3 circles, equally spaced from each other, inside the circle (5, 3, and 1 meter). Label circles (A, B, C, D) with A being the center ring. Give a point value to each circle with A being the largest point value and D being the smallest point value. Indicate the launching zone with another piece of masking tape 4 meters from the edge of outer circle. (You may wish to try a glider unmodified to see how far it can go and use the distance as a baseline for making adjustments.)
Playing rules: Object is to make modifications to the glider to improve its performance with the goal of launching the glider towards the circle and touching down inside circle A (the bull’s-eye).
Scoring: Points are determined by the spot the glider first “touches down” in the target area, not where it finally comes to rest. After each squadron member has landed their glider and determined the point score, the squadron’s combined points are entered on the score sheet.

757 Glider Kit

A Boeing 757-200 (B-757) was acquired in 1994 by the National Aeronautics and Space Administration (NASA) for aeronautical research. Given the call sign NASA 557, this aircraft is used for conducting research on increasing aircraft safety, operating efficiency, and compatibility with future air traffic management systems, benefiting the U.S. aviation industry and commercial airline customers. Part of the Transport Research Facilities (TRF) project, this twinengine commercial aircraft was modified extensively to create a “flying laboratory.” Most of the seats were removed to make room for a large test area capable of carrying over 5100 kg (10,700 lb) of experiment equipment. It is outfitted with electronics for extremely precise instrumentation and data gathering capabilities, and a flexible interior configuration allows future upgrades to be incorporated. The B-757 is continuing the work begun by NASA’s Boeing 737-100, which has been in service for over 20 years. The B-757 retains the experimental approach of the B-737, but offers newer technology and improved capability.

“Airborne Trailblazer” by Lane Wallace is an excellent history of NASA’s B-737 research aircraft. <see:> One of the basic working philosophies of the TRF project is the concept of “simulation to flight.” The main objective is to develop technical or operational concepts (e.g., electronic cockpit displays, flight management systems, airborne windshear detection sensors) and take them from ground-based simulation testing to flight testing in an easy and straightforward manner. The TRF project includes the B-757 aircraft as well as several ground-based simulators and a Research Systems Integration Laboratory (RSIL). Increasing the effectiveness of conducting experiments from simulation to flight will better meet the needs for bringing advances in safety, operations, and capacity into the ever-changing national airspace system. The NASA 557 will be maintained and flown by NASA’s Langley Research Center (LARC) in Hampton, VA. Listed below are some experiments that have used the NASA 557.