The paternal grandparents of an infant girl born in the restroom of a jetliner and abandoned there by her mother were awarded temporary custody of the child Friday.

John and Frances LoCasto of New York City were granted custody during a juvenile court hearing and were expected to fly back East with the baby during the weekend, said attorney Gerry Hilliard of the San Mateo County Social Services Department.The newborn Alyssa was found stuffed under a sink in the DC-10's lavatory after it had landed in San Francisco. The mother gave birth just before the plane took off from Newark, N.J., and hid the baby for undetermined reasons. She later pleaded not guilty to a felony charge of child endangerment and is free on $50,000 bail.