German Chancellor Angela Merkel missed the opening of the G20 summit in Argentina after her plane was forced to land shortly after leaving Berlin.
The plane carrying Mrs Merkel's team turned back while flying over the Netherlands late on Thursday, because of a communications failure.
The Airbus made a safe but unscheduled landing in Cologne.
Mrs Merkel flew to Madrid on Friday then boarded a scheduled Iberia airlines flight to Buenos Aires.
Among her fellow passengers on board the Iberia flight was Agustín Agüero, who tweeted a picture of the chancellor on board.
'Multiple system malfunction'
On Thursday evening the captain of Mrs Merkel's plane told those on board that he had decided to turn back after the "malfunction of several electronic systems".
The plane's communications system went down and the crew had to use a satellite phone to contact air traffic controllers, Germany's Spiegel website reported.
The problem is thought to have been with an electronic distribution box, which controls both the radio and discharge of aviation fuel. At no time was there any risk to the lives of passengers, a spokeswoman for Mrs Merkel stressed.
The German air force denied suggestions that the plane's electronics could have been sabotaged. "There's is absolutely no indication of a criminal background," a spokesman said.
'Overheated braking system'
An added problem for the plane was that Cologne airport's longer runway was unavailable, Spiegel added. As the A340 had to slow down quickly and it was still fully laden with fuel, its braking system overheated and the fire brigade met the plane on the tarmac.
The German delegation was kept on the plane for some time before officials decided to travel by bus to a hotel in Bonn.
The chancellor and a smaller delegation including the finance minister travelled to Madrid on an air force plane on Friday morning before leaving for Argentina on an Iberia plane, a spokesman said.
Mrs Merkel's husband was among those on the initial flight who remained in Germany.
Although there is a standby government plane for long-haul flights, no crew was available to fly it, German media report.
Organising an alternative route proved a headache for the German government, as Mrs Merkel's entourage had to include several security officials.
Merkel misses key talks
The chancellor missed the "family photo" at the start of the G20 summit and officials were trying to reschedule planned bilateral meetings with national leaders.
German TV's satirical Heute Show tweeted an image showing three other G20 leaders arriving alongside an airport baggage hall, with the caption: "Merkel decided on an alternative arrival."
The chancellor had been due to have talks on Friday with President Donald Trump and China's Xi Jinping but was due to arrive in Buenos Aires only by early evening.
Amid the continuing crisis over Russia's seizure of 24 Ukrainian sailors, a spokeswoman in Berlin said the chancellor's meeting with Russia's Vladimir Putin on Saturday would go ahead as planned. President Trump has cancelled a meeting with the Russian leader.
The Airbus A340-300 hit by technical failure is named Konrad Adenauer after West Germany's first post-war chancellor.
For finance minister Olaf Scholz, the plane's technical problems are nothing new.
In October he was on a trip to Indonesia when the plane was grounded because rodents had gnawed through electrical cables during an annual meeting of the International Monetary Fund (IMF).
Last month, President Frank-Walter Steinmeier arrived late for a trip to South Africa because one of the plane's engines would not start.