The plane turned back while it was over the Netherlands, Germany's dpa news agency says.
The plane had suffered a complete breakdown of the on-board communication system, a problem described as extremely rare, which forced the pilot to communicate via a satellite phone instead.
He stressed, however, that there was no danger to the people on board. Threat to the passengers on Board the plane "Konrad Adenauer" was not, she assured.
The German Luftwaffe, or air force, is suffering a crisis of aircraft maintainance which spreads from the government duty jets they maintain for Dr Merkel and other senior members of the government including the German president, to combat aircraft.
Ebola kills 198 in Democratic Republic of Congo
The outbreak is the tenth in DRC since Ebola was first detected there in 1976. "We will not rest until this outbreak is finished". The combination of rebel violence and pre-election unrest is creating a "perfect storm" for an even worse epidemic, he said.
New Jersey Man Charged With Killing Brother, Family In Colts Neck
The prosecutor's office has not discussed a possible motive in the crime. "His family fully support his defense of this charge". Hours later, the blaze at the home of his brother Keith was reported about 10 miles (16 kilometers) away in Colts Neck.
Former police officer charged with the murder of St Lucian
She said most officers are good, but in this case, "We're talking about bad cops that go out there and do things against the law". The indictment came three months after Guyger fatally shot Botham Jean , 26, on September 6, after she returned home from work.
"The part concerned was an electronic distribution box, which we have changed", Henrich, adding that the Air Force was sending another plane to Argentina on Friday for Merkel's return journey from the G20.
The German leader plans to fly to Madrid early Friday and from there take a commercial flight to Argentina, accompanied by Finance Minister Olaf Scholz and a small delegation, according to an official.
In June, problems with the hydraulics system on the same plane forced President Frank-Walter Steinmeier to take an alternative aircraft to Minsk.
"It was a serious malfunction", Merkel told reporters hours later, after the delegation was brought to a hotel in Bonn.
Its G36 assault rifle had trouble firing straight at high temperatures and is being phased out.