He waited until he knew by the tread that the sentry had turned and was going back over his post.

Then it was that Dick stole upon him from behind.

Another leap, a grip around the man's throat, and sentry number two was on his back, where Reade gave him the grace blow.
Without a word the chums picked up this sentry, carrying him around to the rear.

Then Dick sought the small rear door of the hangar.
It opened softly, and they entered, closing it behind them.
All was darkness in here until Reade, producing his pocket electric torch, threw a beam of light over the scene.
While Dick stood still, now holding the automatic pistol, Tom took a rapid look over each of the two air machines.
"This nearer one looks like the newer, better one," Reade declared.
"I'll look over the machinery to make sure that the engine is all right and that I understand the engine and the controls.
Her machine-gun is ready for business and we may need it." Dick stood patiently by, wondering how soon the guard was due to be relieved.

If that happened soon, and the knocked-out sentries were discovered, the chance for escape looked like three less than nothing! "All right," whispered Tom at last.