On 29 December 1940, two Irish Gladiators were scrambled from Baldonnel to intercept a German Ju 88 flying over Dublin on a photographic reconnaissance mission, but were unable to make contact.[95] Although unable to intercept any intruding aircraft, the Irish Gladiators shot down several British barrage balloons that had broken from their moorings.[96] For a short time in 1940, an order was given to Irish fighter pilots to use their aircraft to block the runways of airfields. They were then to use rifles and shoot at any invaders.[97] Irish Gladiators also overflew the site of the sinking of the liner SS Athenia in 1939 and offered the help of the Irish military. The flight was fired upon by Royal Navy ships in attendance, consequently, the Irish Gladiators withdrew.[citation needed]