Geht einen Meter vom Schirm weg.
|die effektivste Aufteilung|
|Hersteller von Tagesleuchtfarbe|
|Hersteller von Folien|
|Statistiken warum man die Farbe draufschmieren sollte|
|Report of the Collision Avoidance Subcommittee|
by Herbert Pirker
According to the German BFU (www.bfu-web.de) about 15% of all FATALITIES in glider accidents, averaged over the last 10 years, were caused by MID AIR COLLISONS. But in 1998 an alarming peak of 45% (!) with 8 collisions was registered . Bill Scull (<firstname.lastname@example.org> , OSTIV-meeting 1999) reported also about increasing mid airs in the UK.
One mid air happened at the pre-worlds in Bayreuth. Therefore, the proposal was made at the last meeting that ANTI COLLISION COLOUR MARKINGS and/or STROBE LIGHTS be mandatory for all gliders flying at competitions.
The delegates were not sure about the effect and applicability of such measures and asked for more background information.
Many pilots sent their opinion, experience, knowledge, papers etc. to the igc-info-list (email@example.com), to the internet discussion group (www.dejanews.com) or directly to me (firstname.lastname@example.org). The German LBA (Helmut Fendt, www.lba.de)was so kind to send papers which explained why the LBA (German Regulatory Authority, equivalent to the US FAA) does not require colour markings or strobe lights on gliders. Andreas Deutsch and others sent a lot of papers, reports and publications on the subject. I would like to thank all for their great help and I feel sorry that I am not able to mention them all by name.
Cause of mid airs:
Mid airs happen mainly because pilots are not able to see each other:
Overall, objects are not seen under a certain minimum size (threshold of acuity). Therefore, the outline of an object is seen first, then the main colour and finally any colour markings. So, anti collision markings have little or no effect, if gliders are on a collision course. This does not necessarily mean that anti collision colour markings are not well seen on other occasions where gliders are NOT on a collision course, where they have significant changes of angle with respect to the viewer.
(For further details, please see papers collected by Andreas Deutsch, for instance:
3) See also lecture held at the OSTIV meeting in Bayreuth (7.8.99) by W.G. Scull [email@example.com].)
Pilots discussed also the importance of contrast, reflectivity and the camouflage-effect.
The best overall colour for the conspicuity would be: 1) black, at least for military jets 2) yellow 3) lime green or pink day glos 4) white, (TiO2 would enhance the reflectivity). Bad conspicuity: gliders painted totally in red.
Problems of colour markings
Common opinion about anti collision colour markings:
We note a diversity on opinions about the effect of anti collision colour markings. Some pilots are enthusiastic about them, although there is no evidence of their effectiveness and on a constant bearing (collision) course the shape is always seen before any colour. However, in France, especially in the alpine regions, pilots are required to use red stripes on the wings. In Austria, the Gliding Commission decided colour markings to be mandatory for competitions. On the other hand, many pilots, the German LBA and other organisations have come to the conclusion, mainly because of investigations and detailed research work that colour markings have little or no effect at all in preventing mid air collisions. Many pilots stick on colour strips where this is mandatory and then take them off again when they return to places where such a rule does not apply.
Strobe Lights, Anti-Collision Lighting
The effectiveness of strobe lights is mainly a question of power consumption.
Tests by Richard Johnson (see Sailplane & Gliding, April/May 1990, page 79) showed that at 12 Volts and 1 Ampere and a flash frequency of 2 sec, was noticeable at a range of 480ft in bright sunlight and of 700ft in bright overcast. However, to recognise colliding gliders in time, a range of 2-3km would be necessary which might need a current of 10 Amperes. One solution could be brighter flashes at less frequency, and this is worth further research. In darker conditions such as dark overcast or twilight, strobe lights with a power consumption of 12V/300mA (strobe light from Streifeneder for instance) might work quite well, especially when the glider is viewed against dark cloud or ground.
Because of the foregoing reasons, the German LBA and other authorities do not insist on anti collision colour markings or strobe lights for gliders.
Proposals by CASP:
At Bayreuth members of IGC, OSTIV (SDP and SP) formed the "Collision Avoidance Sub-Panel" (CASP). According to this Panel it is important to consider improved ground training of the pilots before they use highly sophisticated electronic devices in the cockpit. Manufacturers should deliver instruments which are easy to operate (at best in a self-explaining manner, low numbers of operating steps), have a special mode for training purposes on ground and supply the pilots with good manuals and training software for home PCs. See 1st meeting of CASP [Michael.Rehmet@t-online.de] .
Radio aids for collision warning
Transponders. Nigel L. Rotherham [firstname.lastname@example.org] is developing a low cost (appr. 200 Dollars) 'anti collision' system based on low power transponders using a free radio frequency band.
3-D Position Reporting. According to Walter Dittel from Filser (FE_Seischab@gmx.net) the developement of the so called:
Automatic Dependent Surveillance -Broadcast (ADS-B)
This is a new aviation surveillance concept whereby aircraft transmit their positions (usually derived from a GNSS receiver on-board the aircraft) over a radio data link. Position information is transmitted
and received by every aircraft in the vicinity so that all users have knowledge of their own location and the locations of all other surrounding aircraft. The position information may be displayed in the cockpits of suitably equipped aircraft to give new situation awareness capabilities. Also, ground vehicles and fixed ground stations can also be equipped to transmit and receive position data, allowing surveillance of all types of traffic and
a two-way data link capability. ADS-B is an enabling technologies that can help to deliver the free flight concept to airspace users.
Disadvantages. Radio methods would involve extra expense, would have to be fitted to both aircraft involved, and would be subject to "false alarms" if they had the necessary sensitivity to warn of collisions in time for pilots to take action. Also, when thermalling it would be difficult to avoid constant alarms. The problem could be solved by using simple displays in combination with the warning by a computer voice if gliders are on collision course.
5) Electronic devices like moving maps, variometer systems etc. should be easy to operate, in a more or less self explaining manner, without having to study voluminous operating manuals.
Annex: Diagram of the visual acuity of the human eye (Courtesy of Jane's Simulation Systems)