Jacob's ladder noun a sturdy rope ladder dropped from a hovering helicopter for descent to and ascent from the ground US
Early the next morning engineers and medical personnel reached the unit, descending through the jungle canopy on “Jacob’s ladders” dropped from the rear of the hovering CH-47 Chinook helicopter. — Shely L. Stanton, TheRiseandFallofanAmericanArmy, p. 94, 1985