Helicopters as Towing Machines
The photos released last week of a Bell 412 towing a giant banner over the United Arab Emirates as part of a record-setting flight caught my attention. While helicopters do an admirable job of hauling sling loads from their bellies, they aren’t the ideal platforms for all types of towing.
I know this, in part, because my dad is enshrined in the U.S. Army’s record books as the first helicopter pilot ever to tow a glider. The idea back in the 1960s was to fill pilotless gliders with supplies and tow them with Hueys deep into the jungles of Vietnam, where they would be released by the pilot and crash land for the benefit of U.S. troops on the ground.
From the stories my dad has told me, those early attempts at towing gliders with rotorcraft weren’t pretty, and it wasn’t long before the idea was scrapped.
Last week's feat over the UAE coast set a world record for flying the largest banner ever, a giant UAE national flag in celebration of the country's National Day. Bell can rightfully be proud of the accomplishment, made possible by the 412’s outstanding power and payload carrying capability.
Still, towing a banner with a helicopter is quite different than towing a glider. It can be done, as my dad and other helicopter pilots have proved, but it’s not the preferred method, due mainly to the effects of wake turbulence from helicopter’s spinning rotor blades and the fact that if the helicopter slows down, the glider ends up dangling from the end of the tow line like a normal sling load.
To see what I mean, check out this intriguing and, at times, somewhat comical (and maybe a little scary) video from YouTube showing a glider unhappily married with a helicopter over Hungary: