Paulo Jorge Frade <<paulo.frade>>
writes:

Recently one pilot taking off in perfect conditions (wind aligned
with the cart 15Km/h), inadvertently did not drop the left handle of the Dolly,
causing a lookout, fortunately without major consequences (although it was a
hard landing).

The main cause was the way he was holding the handle of the dolly. The pilot was
holding the handle with two fingers but in addition, the handle was being held
by the palm of the hand (shown in red) which caused to hold it long enough to
lower the left wing.

So, I suggest holding the handle underneath the bar (shown in green), so that
when you open your fingers, you loosen both handles simultaneously.

Personally I hold on with a lot more than two fingers on both
hands, but the hose is below my base tube.