Airship Italia was a semi-rigid airship used by Italian engineer Umberto Nobile in his second series of flights around the North Pole. It crashed in 1928, with one confirmed fatality from the crash, one fatality from exposure while awaiting rescue, and the disappearance of six crew members who were trapped in the still airborne envelope.
Nobile planned five flights for the expedition, each starting from and returning to Ny-Ålesund (Kings Bay) and exploring different areas of the Arctic.
After the necessary engine and structural repairs were completed, the first flight departed from Kings Bay on 11th May 1928. Italia was forced to turn back after only eight hours flight because of thick ice forming on the envelope, as well as fraying of the control cables due to the extreme conditions.
The second flight left at 13:20 on 15th May and lasted 60 hours. In contrast, this time the weather conditions were excellent and visibility perfect. Valuable meteorological, magnetic and geographic data were gathered in a 2,500 mile (4,000 km) flight to the hitherto uncharted Nicholas II Land and back. Malmgren gathered weather and ice observations, while Pontremoli and Běhounek made measurements of magnetic phenomena and radioactivity. The ship returned safely to base on the morning of 18 May.
The third flight started on 23 May 1928, and following a route along the Greenland coast, with the assistance of strong tailwinds, reached the North Pole 19 hours later at 00:24 on 24 May 1928. Nobile had prepared a winch, an inflatable raft, and survival packs (providentially as it turned out) with the intention of lowering some of the scientists onto the ice, but the wind made this impossible. Instead they circled the pole making observations and at 01:20 dropped the Italian and Milanese colours, as well as a wooden cross presented by the Pope and a religious medal from the citizens of Forlì onto the ice during a short ceremony. At 02:20 on 24 May, the Italia started back to base.
The same tail wind that had helped Italia to the Pole now impeded their progress. Nobile calculated the return journey would take 40 hours, and had discussed their options with Dr Malmgren in the hours before their arrival at the Pole. Nobile considered a trans-polar route to Mackenzie Bay in Canada. According to Nobile, Malmgren advised a return to Kings Bay, predicting lessening winds on their return trip. On the other hand, Malmgren predicted a head wind all the way if the Canadian route was attempted. No doubt the prospect of a forced landing in the Canadian wilderness was unpalatable to both men, as it would mean the end of the expedition.
Heading directly south on a heading for Kings Bay, after 24 hours of increasing head winds and thick mist the Italia was only halfway back to base. The airship struggled to gain ground and break through to the zone of calmer winds which expedition meteorologist Finn Malmgren predicted was just ahead. Ice formed on the propellers and shot off into the envelope, necessitating running repairs. Engine speed was increased but with little effect, except for a doubling of fuel consumption. Dr Běhounek, in charge of the compass, started reporting variations in course of up to 30 degrees, and the elevator man Cecioni had similar problems maintaining control. By 07:30 on 25 May, Nobile, who had been awake for over 48 hours, knew that the situation was critical and Giuseppe Biagi, the wireless operator, sent out the message: "If I don't answer, I have good reason". By dead reckoning, Nobile estimated his position as 250 miles (400 km) northeast from Moffen Island. This estimate was 350 miles (560 km) off.
At 9:25am on 25 May the first critical incident occurred, when the elevator control jammed in the downward position while the ship was travelling at less than 1000 feet (300 metres) altitude. All engines were stopped and the airship began to rise again after it had dropped to within 300 feet (90 metres) of the jagged ice pack. The airship was allowed to continue rising to 3000 feet (900 metres) and above the cloud layer into bright sunlight for 30 minutes. After two engines were restarted the ship descended to 1000 feet (300 metres) with no apparent ill effect, with the headwind appearing to decrease slightly allowing an airspeed of 30 mph. Malmgren took the helm with Zappi supervising him. Cecioni continued to operate the elevators.
At 10:25 the ship was noticed to be tail-heavy and falling at a rate of 2 feet per second (0.6 m/s). Nobile ordered full elevators and emergency power, but although the nose rose to an upward angle of 21 degrees, the descent continued. Nobile ordered foreman rigger Renato Alessandrini to the tail of the envelope to check the automatic gas valves. A short time later, seeing a crash was unavoidable, Nobile ordered full stop and the cutting of electrical power to prevent a fire on impact. The port engine engineer failed to notice the order and the ship began to bank. At the same time Nobile ordered Cecioni to dump the ballast chain, but was unable to carry out the order in time owing to the steep angle of the floor and the secure way the chain was lashed.
Seconds afterwards the airship's control cabin hit the jagged ice and smashed open. Suddenly relieved of the weight of the gondola, the envelope of the ship, with a gaping tear in the keel and part of one cabin wall still attached, began to rise again.
Nine survivors including Nobile's fox terrier and one fatality were left on the ice, and six more crew were trapped in the still drifting airship envelope. The envelope and the crew members aboard it have never been found. The position of the crash was close to 81°14′N 28°14′E, about 120 km (75 mi) northeast of Nordaustlandet, Svalbard. The drifting sea ice later took the survivors towards Foyn and Broch islands.