The first helicopter landed safely after the collision but the second one crashed, killing all three people who were on board.
A Russian Su-25 fighter-bomber crashed into the Sea of Azov on Monday.
"They have recovered size and weight, really they are very well," Astrid Caceres, the director of the country's child welfare institute, told journalists.
The National Transportation Safety Board will investigate the crash, the FAA said.
Researchers at MIT have developed new algorithms that could help human pilots deal with extreme near-crash events.
Rescuers, supported by search dogs, had previously found discarded fruit the children ate to survive, as well as improvised shelters made with jungle vegetation.
To this day, nobody knows why the small jet lost contact minutes after takeoff and crashed down to earth, four and a half hours later.
The reason for lack of response from the pilots remains unclear to authorities.
The four children, aged 13, 9 and 4, as well as an 11-month-old baby, survived the impact and were rescued over two weeks after the crash.
Juliana Koepcke was 17 when she boarded a flight from Peru to Germany, when suddenly lightning struck the plane and it crashed as she fell 3 kilometers to the Amazon jungle.
JPOST Digital Library
