Official abbreviation: H.T.F.
Instituted March 11th 1953 by King Frederik IX.
The oak leaf device was instituted 8. November 2005 by Queen Margrethe II.
Awarded to personnel in the Danish Airforce for 25 years of service, after their 20th birthday.
After 40 years of service, a Gold Oak-leaf will be added to the ribbon.
Design: Worn in a red ribbon with a wide white centre stripe. The obverse shows the monogram of King Frederik IX.
Other information: Personnel eligible for the Fortjenstmedalje, will get this instead of the 40 years Long Service Medal.
Official decree (Danish)