Report on serious incident near Klanten airfield, Norway on 26 May 2015 with Alexander Schleicher GmbH & Co Segelflugzeugbau ASK 21 Mi, LN-GMI

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The pilot was on a flight from Otrøvatnet to Klanten when he got a low engine oil warning. A check of the engine installation after landing revealed a crack in the exhaust system. This has led to heat damages and signs of fire.

The investigation has shown that it can be difficult to detect cracks in the exhaust system. To make it easier to identify this safety issue, operators must be given relevant information about the signs of an incipient crack. AIBN has issued a safety recommendation to the manufacturer about this.

Safety recommendation

Safety recommendation SL No. 2016/01T

Cracks in the exhaust silencer of Alexander Schleicher GmbH & Co Segelflugzeugbau ASK 21 Mi aircraft can cause heat damage and possible fire in the engine compartment. In the opinion of the Accident Investigation Board Norway, this has not been sufficiently covered and emphasised in the aircraft's flight manual, maintenance programme or other official information from the glider manufacturer.

The Accident Investigation Board Norway therefore recommends that Alexander Schleicher GmbH & Co Segelflugzeugbau makes public relevant information so that users of ASK 21 Mi can be advised on how to detect leaks in the exhaust silencer at an early stage.

Near Klanten airfield, Norway (ENKL)
Occurrence date
ICAO Location indicator
Øvrige motorglidere
Meteorological conditions
Type of occurrence
Serious incident
Type of operation
Private (club)
Category of operation
Light, aeroplane (< 5 700kg)
Aircraft category
Sailplane (incl. motorglider), Single-engine
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