The world's longest aircraft, nicknamed the "Flying Bum", appeared to land on its nose after breaking free from its mooring in a field on Wednesday afternoon.
The £25 million Airlander 10, which is part plane and part airship, nosedived into a field in Bedfordshire after the ropes tying the back of the aircraft to the ground came loose, witnesses said.
Engineers in high visibility jackets were then seen rushing out to secure the giant airship, which has just undergone a vast amount of improvements following a crash last summer.
"We were walking past the field and suddenly saw the back end of the airship lift off the ground," said Paul Britton, 44, from Kimbolton, Cambridgeshire.
"The airship has been outside for a couple of weeks and is fastened to the ground, but the back fastenings came undone and the aircraft did a nosedive.
"We suddenly saw lots men in high-vis jackets come running out to secure it. It seemed as though a large gust of wind had caused the ropes to come loose."
A Hybrid Air Vehicles spokesman however denied it was a mishap, saying: "The Airlander hadn't broken free, it was just part of its normal testing."
The airship has recently been refurbished after it nosedived into a field in Bedfordshire after its second test flight last August.
No one was injured in the accident, but the cockpit was destroyed and since then the 92-metre long aircraft has been undergoing extensive repairs at a hangar in Cardington.
The new-look airship was recently revealed and includes two huge inflatable "airbags" which are stowed during the flight and protect the cock pit on landing.
The massive inflatable "landing feet" are officially called an auxiliary landing system, according to Hybrid Air Vehicles.
They are one of a number of changes which have been made since the crash, which happened when the Airlander climbed to an excessive height because its mooring line became caught on power cables, an Air Accidents Investigation Branch report has now revealed.
The airbags, which also allow the aircraft to land safely at a greater range of landing angles, are more than three metres in length and contain 15m3 gas
The Air Accidents Investigation Branch found the crash was caused when Airlander couldn't be secured to its mooring mast at the end of its flight because a faulty winch meant the mooring line was hanging below the aircraft.
It meant the airship was much higher than ideal and began to descend nose first.
The company has now made both an automatic system to retract the mooring line and a new mobile mooring mast with greater power and manouverability.
It hopes the Airlander will take to the skies again at the end of the month.