MD-11F noise testing

Lufthansa now flying much quieter: One hundred Airbus A320s have already been equipped by experts from Lufthansa Technik with noise-reducing vortex generators. On test flights in Magdeburg-Cochstedt Lufthansa Cargo measured how efficiently special engine-mounted silencers can reduce noise.

The Lufthansa Group and German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, DLR) project is part of the research group “Quieter Transport” (“Leiser Verkehr”), has thus reached an important milestone. Since November 2014, Lufthansa has equipped its short and medium-haul aircraft of the types Airbus A319, A320 und A321 with the noise-reducing components on the underside of the wings. It is the first airline in the world to do so. In total, 157 aircraft in the short and medium-haul fleet are being equipped with a vortex generator. Newly built Airbus aircraft have already been delivered to Lufthansa with the sound-reducing technology since the beginning of 2014. More than 200 Lufthansa jets will fly much more quietly in future. Equipping or converting the A320 fleet is one of the most extensive voluntary measures for active sound reduction undertaken by Lufthansa to date.

These days, also with Lufthansa Cargo, everything is about how to make the MD-11 much quieter.

On two days in July ‘Charlie Charlie’, ‘Fox Charlie’ and ‘Charlie Mike’ circled over the airport of Magdeburg-Cochstedt for hours. This was neither for the pilots’ pleasure nor neighbours’ annoyance, but for a project conducted by Dr Gerd Saueressig, Manager Environmental Concepts and head of the Modal project, which is to examine the efficiency of modified silencers mounted in the inlet of engines. On the ground Michael Pott-Pollenske of the German Aerospace Centre (DLR) measured noise levels, while Captain Marcus Schwarz, Technical Pilot MD-11F, and his colleagues steered the freighters as precisely as possible over the microphones in a carefully coordinated choreography. During each flyover an array of microphones on the ground recorded the sound of the aircraft flying at different altitudes. Take-off flyovers and measurements from the ground at different fan speeds completed the test series.

After assessing the outcome of these data, it should be clear whether a modification of silencers can help to further reduce noise.