The He 274 also featured a pressurized compartment for a crew of four, this employing double walls of heavy-gauge alloy, hollow sandwich-type glazing and inflatable rubber seals, a pressure equivalent to that at 2,500 m (8,200 ft) being maintained at high altitude.
The significance of this design is that had this aircraft entered production and been used in operations over England it would have been impossible for Allied fighters to intercept over the target, owing to its extreme high altitude performance.