Poor visibility caused one F-7 jet to fly into a telecommunications tower near Magway air force base more than 500 kilometres northwest of Yangon, an air force official told AFP.
"He had no time to eject," said the official, who did not want to be named.
A 10-year-old girl, who was studying at home, was hit by a piece of the plane after it struck the tower, lawmaker Kyaw Swan Yee from nearby Min Buu town said.
"She died after arriving at hospital," he said.
In the other incident -- which occurred just 10 miles (16 kilometres) away -- the pilot managed to eject from his plane but was killed when he hit the ground according to the official.
The pilots were named as Captain Hein Thu Aung and Captain Phyo Maung Maung, both in their thirties.
Magway's chief minister and a delegation of lawmakers paid their respects to the girl's family, Kyaw Swan Yee said.
The crashes are the latest aviation catastrophes to blight the country's air force.
In April an F-7 pilot died after his jet crashed due to a technical failure.
In June last year a Chinese-built Shaanxi Y8 carrying military personnel and their families plunged into the Andaman sea after taking off, killing 122 people, 15 of whom were children.
The F-7 is a Cold War-era fighter jet -- a Chinese made variant of the Soviet Union's MiG-21.