【请问奶奶（美国公民）如何接孙子（美国公民，在中国）回美国】

以下是美联航的 unaccompanied minor service规定。五岁以上，直飞航班可用。

Our unaccompanied minor service is required for children who are 5-14 years old and traveling without a parent, legal guardian or someone who is at least 18 years old. These young travelers also need to follow certain requirements for their safety:

Unaccompanied minors can only travel on nonstop United or United Express® flights. They can’t use our unaccompanied minor service on codeshare flights and other flights operated by our partner airlines.
United does not offer unaccompanied minor service connecting to or from other airlines' flights.
Children younger than 5 can’t travel as unaccompanied minors, even if they’re flying with an older unaccompanied child.
-baidu 1point3acresYoung adults ages 15-17 can travel alone on any United- or United Express®-operated flight, or they can choose to opt in to our unaccompanied minor service.
It costs $150 each way for every two children traveling using the unaccompanied minor service.

在国内带孩子的人送孩子上飞机就行了吧 倒也没有那么多弯弯绕绕 值机的时候肯定能有特殊照顾说明的