A n important kick-off for the aviation weath- er business was the so- called “Hattara” (Cloudlet) proj- ect. The goal was the complete renewal of Helsinki-Vantaa Air- port's weather observing system on the initiative of the Finnish Meteorological Institute (FMI). The mission was to develop an “automated tool for the observa- tion, communication, control and registration of data”. FMI defined the requirements that the new system should meet, and Vaisala developed a solution based on the Company's knowl- edge of marine weather station technology. Because of its novelty, the new system was sturdy and pricey, and the negotiations were long and thorough. The system was delivered in October 1975. Hattara was one of the first auto- mated airport weather observing systems in the world, and thus a source of great pride for both Vaisala and the customer. The new system was proudly exhibit- ed at important international trade shows, such as the Ameri- can Meteorological Society's Annual Meeting. Today, the Helsinki-Vantaa Airport boasts its fourth generation Vaisala weather observing system, and the partnership between the two pioneers continues to be as strong as ever. Learning the tricks of the trade “After the Hattara project, two more important deals were won – from Medina and Taif airports in Saudi Arabia, both delivered in the late 1970s,” remembers Harry Alm, the now-retired Re- gional Manager of the area. Dur- ing the early stages of the airport weather observing systems busi- ness, competition was fierce and the market extremely heteroge- neous, as everybody was busy developing different kinds of da- ta logging systems and sensors to match. It was not until the breakthrough in microprocess- ing technology and the develop- ment of relevant applications for meteorological measurement that the market started to find shape and direction. One important lesson learned by Vaisala from the first steps in the field was that it was beneficial to become indepen- dent from other suppliers of me- teorological sensors. Thus, in the mid 1980s, the decision was tak- en to start the in-house develop- ment and manufacture of visibil- ity and cloud height sensors, the key sensors for aviation measurement at airports. Just as today, only the best was good enough – the best sensor perfor- mance and reliability within the industry. With the development of the ceilometer and Runway Visual Range (RVR) systems, Vaisala started to claim its posi- tion as the market leader in avia- tion weather. The Vaisala MIDAS Auto- mated Weather Observing Sys- tems (AWOS) series became the star Vaisala Aviation Weather so- lution. It has seen three phases before reaching its current config- uration as MIDAS IV: MIDAS 360, 400 and 600. Dubai Interna- tional Airport could be men- tioned as another significant ear- ly project, as it was the first major two runway system realized with MIDAS 400. This was in 1984. The collapse of the Soviet Regime in the early 1990s also generated a lot of business for Vaisala, as old airport systems, particularly in Eastern Central Europe, required renewal but were left without product sup- port. For example, MIDAS 600 12 167/2005 Vaisala Aviation Weather Celebrates its 30th Anniversary Marikka Metso Editor-in-Chief Vaisala Helsinki, Finland Vaisala Aviation Weather celebrates 30 years of business in 2005. Many things have changed since the early days; the operations of our customers have developed significantly with the increasing volume of air traffic around the world. Despite the changes, accurate and reliable weather observing and forecasting continue to be key factors in ensuring passenger safety and the efficient flow of air traffic.