After applying pressure to the pitot line of D100 to obtain Air Speed of 130 Knots. The speed decreases of 5 knots every 10 to 15 seconds. A test done on the air speed WINTER with the same pitot line always gives a result with the good indication after 30 minutes. The test of the D100 is it normal? or do you think that there’s a leak internally of D100. The flight indicate of the D100 is less than 10 to 15 Knots from that of the GPS with no wind and the D100 displays a wind of 10-15 knots, and despite the correct calibration of the compass it disrupts after one hour of flight. Do you have an idea? Thank you for your answer.