After a serious technical glitch grounded Angela Merkel's official jet the previous day, the German chancellor finally set off early Friday morning for the G20 summit in Argentina.

Boarding a different aircraft belonging to the German air force, the chancellor flew first from Cologne/Bonn airport to Madrid with only a small delegation accompanying her, a government spokesman said.

She landed at the airport in the Spanish capital, where around 9 am (0800 GMT) she continued her journey on a scheduled flight of the airline Iberia to Buenos Aires.

Her delegation includes Vice Chancellor and Finance Minister Olaf Scholz, government spokesman Steffen Seibert and foreign policy adviser Jan Hecker, a spokesman said.

The air force told dpa on Friday that the technical fault that grounded the chancellor's plane was not the result of sabotage.

"There is absolutely no indication of a criminal context," a spokesman from the Luftwaffe told dpa.

The Rheinische Post newspaper reported earlier that the case was being investigated as a potential crime, citing security sources. Government sources said it was normal in such instances for investigations to be carried out "in all directions."

Initial findings by the Luftwaffe point to a possible fault in an electronic distribution box, which controls both the radio system and the system for discharging kerosene.

The plane's satellite communication system is located in a different distribution box, the Luftwaffe said.

The "Konrad Adenauer," a four-engined Airbus A340-300 jet used by the government for official travel and diplomatic business, took off from Berlin on Thursday but turned back over the Netherlands when it completely lost communications with the ground one hour after taking off, prompting the pilots to immediately break off the flight and land in Cologne.

The pilot, described by Merkel as "the most experienced captain in the special flight mission [that flies the chancellor]," spoke of an unprecedented failure of the communication system.

Large parts of an electronics system that is essential for flight operations is believed to have failed, dpa has learned.

Merkel spoke to Defence Minister Ursula von der Leyen about the incident, the Rheinische Post reported.

It is believed that the chancellor was only brought to safety by the expertise of the captain: "It was a serious glitch," Merkel said afterwards in Bonn, where she was forced to spend the night in a hotel.

Merkel's husband, Joachim Sauer, who was on the original flight, had decided to return to Berlin and would not accompany his wife to Buenos Aires after all, government spokesman Seibert said.

The fleet of German government aircraft has experienced equipment problems before.
The "Konrad Adenauer" was grounded in Indonesia last month after rodents gnawed through the cables of the government plane during the annual meetings of the International Monetary Fund.