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Lachmann, G

Publications and source records attributed to Lachmann, G.

Practical Tests with the "auto Control Slot." Part II : Discussion

For some time the D.V.L. has been investigating the question of applicability of Handley Page slotted wings to German airplanes. Comparitive gliding tests were made with open and closed slots on an Albatros L 75 airplane equipped with the Handley Page "auto control slots." This investigation served to determine the effect of the auto control slot on the properties and performances of airplanes at large angles of attack. The most important problems were whether the angle of glide at small angles of attack can be increased by the adoption of the auto control slot and, in particular, as to whether the flight characteristics at large angles of attack are improved thereby and equilibrium in gliding flight is guaranteed even at larger than ordinary angles of attack.

Lachmann, G

Practical Tests with the "auto Control Slot." Part I : Lecture

For some time the D.V.L. has been investigating the question of applicability of Handley Page slotted wings to German airplanes. Comparitive gliding tests were made with open and closed slots on an Albatros L 75 airplane equipped with the Handley Page "auto control slots." This investigation served to determine the effect of the auto control slot on the properties and performances of airplanes at large angles of attack. The most important problems were whether the angle of glide at small angles of attack can be increased by the adoption of the auto control slot and, in particular, as to whether the flight characteristics at large angles of attack are improved thereby and equilibrium in gliding flight is guaranteed even at larger than ordinary angles of attack.

Lachmann, G

The span as a fundamental factor in airplane design

Previous theoretical investigations of steady curvilinear flight did not afford a suitable criterion of "maneuverability," which is very important for judging combat, sport and stunt-flying airplanes. The idea of rolling ability, i.e., of the speed of rotation of the airplane about its X axis in rectilinear flight at constant speed and for a constant, suddenly produced deflection of the ailerons, is introduced and tested under simplified assumptions for the air-force distribution over the span. This leads to the following conclusions: the effect of the moment of inertia about the X axis is negligibly small, since the speed of rotation very quickly reaches a uniform value.

MANEUVERABILITY

Stall-proof Airplanes

My lecture has to do with the following questions. Is the danger of stalling necessarily inherent in the airplane in its present form and structure, or can it be diminished or eliminated by suitable means? Do we possess such means or devices and how must they operate? In this connection I will devote special attention to the exhibition of stall-proof airplanes by Fokker under the auspices of the English Air Ministry, which took place in Croyden last April.

AIRFLOW - WINGS, SLOTTED

Development of light and small airplanes

The author has endeavored to select only the most important lines of development and has limited the description of individual airplanes to a few typical examples. Comparisons are presented between German and foreign accomplishments.

Lachmann, G

Results of recent experiments with slotted wings

This report gives the results of a recent series of experiments performed on a wing designed for a cantilever monoplane. Both wings were trapezial in their ground plan, with their tips rounded elliptically. These wing sections combine all known devices for increasing the lift, namely, the slot, the increased camber and angle of attack by means of an aileron running the whole length of the span. The last advance included in the wing section was an increase in wing area by means of an auxiliary wing adjusted by a sort of rectangular joint.

BOUNDARY LAYER THICKNESS

Results of experiments with slotted wings

This report recounts some of the successful experiments conducted in England and Germany on slotted wings and ailerons. Wind tunnel test results are given and examples of aircraft constructed with these new wing components are described.

WINGS, SLOTTED