Their average age is 43, and some members said they considered themselves too old for front-line duty.

All surviving Z-10s were removed from front-line duty in summer 1942.

After 1915, she was withdrawn from front-line duty again and returned to service as a training ship based in Flensburg.

After April 1916, she was withdrawn from front-line duties to be used for training.

The course given to observers was intended to cover all areas necessary to qualify the observer for front-line duty.

He said the plans could free more than two thousand officers for front-line duties in England and Wales.

When the military situation deteriorated, she declared her intention of joining front-line duty.

The assignment may not have been front-line duty, but a measure of its risk is to ask yourself whether you'd do it.

However, they continued in front-line duties through the early part of World War I.

He rose to first lieutenant on December 14, 1864, but did not return to front-line duty until March 1865.