Twirling Trouble
Pilots in the traffic pattern worry enough about looking for other airplanes that many ignore helicopters, even when tower controllers call out the traffic. The reasoning may be something like: They dont fly patterns that interfere with airplanes, so theyre not a collision threat, and theyre so much smaller than an airliner, how bad could a wake vortex really be?
The risk of collision is something only the pilot in the pattern can assess, but the threat of wake vortices from helicopters is actually much more ominous than most pilots realize.
Real-world research into the effect of helicopter rotor vortices on general aviation aircraft shows that some of the characteristics are the sa…