This is a classic example of fallback to INS. Most of the track data is coming from GPS. For some reason the GPS signal is lost momentarily causing a fall back to INS. The INS is offset by about 1km to the NordeastNortheast, which appears as a jump. Next position report is from the GPS again, in line with the original track. This happens several times.
In the transmitted data these spikes will be flagged as data of low integrity. This allows for filtering them out.