After take-off the pilot noticed that the airspeed indicator was fluctuating between 40 and 60 knots irrespective of the aircraft's actual speed. He elected to land again but, with his attention directed towards the faulty airspeed indicator, he forgot to lower the landing gear prior to touchdown. Although no fault was subsequently found with the airspeed indicating system, it was probable that a partial blockage of the pitot tube had occurred. The pilot was relatively inexperienced on the aircraft type and had not previously flown this particular aircraft .
