On Monday and Tuesday, May 17-18, NLR operated three further test flights to assess the volcanic ash cloud disrupting air traffic in Europe.

The purpose of the flights was to verify the forecasts of the Dutch weather service KNMI regarding the position, altitude and concentration of volcanic ash in the atmosphere. Verification was based on observation and measurement. The flights were operated at the start of daylight operations, departing from Amsterdam Airport Schiphol around 06:00 local time.

All three flights achieved their purpose. The observations were incorporated into the KNMI forecast on volcanic ash concentrations in Dutch airspace, which was used in decision-making on the adjustment of air traffic capacity in Dutch airspace at the beginning of the week. NLR is fully prepared to operate further measurement flights for as long as the volcano on Iceland remains active.

Picture: Observation of volcanic ash, May 17th. The dark strip above the horizon indicates a higher concentration of ash in the atmosphere.