19 Radio Detachment - Gander, Newfoundland

1943 - RDF Phenomena - National Archives of Canada

August 5th, 1943

SECRET

Air Officer Commanding,
No 1 Group Headquarters,
St John's, Newfoundland

RDF PHENOMENA

1. Date - August 3rd, 1943
Time first detected - 1930 GMT.
Azimuth (from Gander) - 040º to 060º Mag
Range (from Gander) - 45 to 70 miles
Location - Fogo Island.

APPEARANCE

HR Tube - Area of 4 to 7 miles in width appeared as if congested with 20 aircraft. At irregular intervals assumed the appearance of broad IFF, accompanied by a "Squittering" across the lower section of the tube. This squittering was similar to but more regular than the appearance created by normal interstation interference. There was no regularity to it, as it would appear 45 miles at one time, and 60 or 70 miles the next time. Some intervals were only 20 seconds, others over one minute.

PPI - Over the ranges mentioned above appeared as an abnormal and irregular broadening of the trace, which was not the normal color, but more of an orange yellow shade. Interval of signals corresponded to those on the HR tube.

ACTION TAKEN

Reported to filter officer on duty.
Controller and technical officer of #19 RD called to duty.
Filter decided to send aircraft to investigate.
Two Hurricanes airborne at 2032 and controlled by #19 RD - First plot at 20.43.30.
At approximately 2045 hours, when about five miles from nearest point of disturbance, aircraft reported entering severe thunderstorm and immediately given a "steer" for base.
Last plot at 21.06.30 when three miles from and within sight of base.
The disturbance in this particular area subsided within a few minutes after the return of the aircraft and normal operations were resumed.

2. INTERFERENCE

The echoes mentioned above were unusual inasmuch as not only did the electrical storm cause heavy static, but fairly sharp defined echoes were seen of the approximate duration of an IFF return. These echoes would show simultaneously at 50 and 70 mile range, decreasing in magnitude with an increase in range.

The echoes could not be confused with the common spurious echo from fog-banks or heavy low-flying cloud formations but were strong, sharply defined returns.

Observers with field glasses were able to note the synchronization of this interference with the electrical discharges of the storm.

The returns then became more compact and a solid echo was seen to the west of the station which had the appearance of 20 aircraft, this approached the station at an approximate rate of 55 mph, then moved to the north and gradually faded, bringing the interference to an end. Approximately one hour later, a short but extremely heavy rain and thunderstorm broke over Gander Station.

Paul F Peter, F/O
for (CE Hill) F/O,
OC #19 Detachment,
RCAF Station, Gander, Nfld