1958 03 15 Aviation No 247

Magazine Overview

This issue of the magazine features a prominent article titled "St-AUBAN: DIX RECORDS 'INVOLONTAIRES' - UN TRAVAIL SCIENTIFIQUE REMARQUABLE" (St-AUBAN: TEN 'INVOLUNTARY' RECORDS - A REMARKABLE SCIENTIFIC WORK), authored by Philippe Cousin and Lucien Espinasse. The cover also includes a photograph of a glider tow above the Durance valley.

The Saint-Auban Research Expedition

The article details a significant scientific endeavor conducted at the Saint-Auban gliding center in January, focusing on aerological research. The authors express their initial surprise at the quality and dedication of the individuals involved, expecting a more typical, perhaps even snobbish, sporting community. Instead, they found a group of serious scientists and pilots driven by a precise research goal.

The expedition brought together a team of about ten meteorologists with their equipment, radar specialists, and ground personnel, alongside skilled glider pilots. This multidisciplinary approach was central to the mission's success.

The "Wave" Phenomenon: A Mountain Under a Microscope

The core subject of study was the atmospheric "wave." This phenomenon occurs when a horizontal wind, typically a Mistral, encounters a mountain range like the Lure mountain. The mountain acts as a ramp, launching the wind upwards in a series of "steps" or waves that can extend into the stratosphere. These waves can generate vertical ascending and descending speeds of up to 12 meters per second, with some cases recording accelerations of 4g. This atmospheric wave has an effect on all aircraft, including jets.

The research laboratory was the Lure mountain, a 1,600-meter high barrier that serves as a natural ramp for the wind. The study area was the valley of the Durance, near Saint-Auban.

Observation Instruments

Six primary types of observation instruments were employed:

1. Balanced Balloons: These balloons, calibrated to specific altitudes, followed the atmospheric waves like a fisherman's float, revealing the undulating air currents.
2. Radar: Used to track the trajectory of the balanced balloons, allowing for the mapping of the horizontal cross-section of the wave.
3. Radio-sondes: Carried by balloons, these provided vertical cross-sections of the atmosphere from the ground up to 19,000 meters.
4. Light Aircraft (Storch and Stampe): Equipped with measuring instruments, these aircraft performed fine, local analyses of the phenomena.
5. Jet Aircraft: Deployed from the Orange airbase, these prospected the upper atmosphere.
6. Gliders: Considered the most valuable instrument for this research, gliders were equipped with measuring devices. They flew directly into the heart of the wave phenomenon, using its currents. They provided a perspective between that of a sounding balloon and an aircraft.

The Research Team and Methodology

The research was organized and sponsored by M. Agesilas (Director of SFASA), M. Viaut (Director of Météo), and Colonel Gentil (Director of the National Scientific Service). The primary responsibility lay with Norbert Gerbier, a meteorologist engineer, supported by Max Gasnier (Chief of the Saint-Auban center), Jules Landi (Head of the study section), meteorology technicians, and first-class glider pilots.

The methodology was described as simple and logical, focusing on observing, reporting, and formulating/testing hypotheses. Many of the pilots were self-taught, having studied relevant literature, with some, like Barbera, even delving into mathematics. Their discussions and analyses were presented as valuable lessons, linked to meteorological laws.

Static Observations and Data Collection

Beyond describing the phenomenon, the research aimed to identify its causes and the conditions favorable for its triggering. A meteorological radio-sounding station was set up for a month in the snows of Malfougasse. Three meteorology technicians worked meticulously for ten hours a day, collecting data on pressure, temperature, and humidity via balloons. This data was crucial for statistical analysis and revealed details like calm layers, wind at altitude, wind rotations, and jet streams.

Practical Application and Pilot Experience

The article includes personal accounts of glider flights. One pilot describes the experience of being fitted into a glider, the complex procedures, and the reliance on the pilot's skill. The sensation of flying within the wave is likened to being a "chick in its fifteenth day of incubation" within the cockpit, with numerous connections to the outside world. The stability and control of the glider, even in challenging conditions, are highlighted, attributing it to an instinctive, precise manual interplay.

The "Involuntary" Records

The research led to the discovery of "involuntary" records, suggesting that the gliders, by utilizing the atmospheric waves, achieved performances that were not solely due to pilot skill but also to the natural forces of the atmosphere. The article mentions specific measurements from January 25th, detailing wavelengths and vertical speeds of different waves, emphasizing the precision of these findings.

"Briefing Météo" and Daily Operations

The daily routine included "Briefing Météo" sessions where Gerbier, after his flights, would discuss conditions and hypotheses. Even on days with poor flying conditions, the team had access to photos and films from better days, taken by Landi and Snrech.

Jules Landi, described as a researcher with a practical approach, is highlighted for his ability to analyze phenomena from action to theory. His photos and films visually demonstrated the hidden mechanisms of atmospheric waves, showing cloud formations, the laminar propagation of waves, and their continuous formation and dissipation.

Daniel Snrech, an engineer who chose research over a more lucrative career, was responsible for processing data from aircraft and gliders, including pressure, humidity, temperature, wing stress, and pilot observations. His dedication is illustrated by his preparation for a flight in challenging cold conditions.

The Experience of Wave Flight

The article vividly describes the experience of wave flight, including the sensation of being inside the glider, the communication with the ground, and the visual spectacle of the landscape from altitude. The pilots' skill in navigating and utilizing the waves is emphasized, with Landi's ability to land a glider precisely inside a hangar at night being a testament to this.

The author concludes by stating that after experiencing wave flight, the question "What is the use of gliding?" becomes irrelevant.

Recurring Themes and Editorial Stance

The recurring themes in this issue revolve around the scientific exploration of atmospheric phenomena, particularly the study of atmospheric waves using advanced aviation technology like gliders and radar. There's a strong emphasis on the dedication, precision, and collaborative spirit of the researchers and pilots involved. The editorial stance appears to be one of admiration for scientific inquiry and the human capacity to understand and harness natural forces, presented through detailed reporting and personal anecdotes.