After the war ended in 1948 with total Axis victory, Oberstgruppenführer Wilhelm Strasse, nicknamed 'Totenkopf', along with five other researchers, started uncovering documents from a recently discovered Da'at Yichud vault in Cape Town, South Africa.
What they found there was even more material for other superweapons. One of them, however, caught their attention. It seemed like it was some sort of machinery that could fly in almost all directions and took off upwards.
Deciphering the documents took more than five years until, finally, in 1953, work fully commenced on a new project which they called 'Whisper'.

Projekt 53.601 'Whisper' was a revolutionary VTOL aircraft that could take off upwards and fly in all directions, unlike the average airplane. It was propelled by a tandem of four propellers (two that took the aircraft upwards and two smaller ones that worked as counterbalance).

While, at first, the concept seemed easy to achieve, it wasn't at all. Many attempts were made at trying to make all four propellers work. The biggest problem was keeping the aircraft stable and, above all, making the propulsion system work.

The very first prototype, sometimes called 'Whisper I', was the most advanced aircraft of its time. It was a helicopter that had four propellers mounted on two moving arms that could extend when preparing for takeoff. Two of the propellers made the aircraft go upwards (thus providing the main power) and two smaller ones mounted right beneath the bigger ones acted as counterbalance (so as to counter the effect of the main propellers that tended to pitch the aircraft backwards). Two jet engines were mounted on top of the helicopter which could offer forwards propulsion.

First trialed in 1955, the Whisper I was accepted into military service in 1956. Wilhelm, personally, wasn't content with it, however. The helicopter was cumbersome and loud. Besides, it could only carry six MG-52G (G for Gatling- their configuration). It was also unreliable and hard to manoeuvre. The second phase of the project, Whisper II, promised to remove all these drawbacks and to improve upon the anti-radar system and the firepower.

Beware: this is my first 'true' helicopter. As such, treat it with great care. Why? Just as I mentioned above, it's VERY hard to maneuver. Do not pitch/roll too hard otherwise you will more than surely crash. Read the takeoff procedure carefully.

Takeoff:
Pitch down as hard as you can.
AG1 to activate the main propellers and extend the arms.
AG8 (activated by default) provides gyroscopic stability.
Slowly throttle to about 8-11% power. More than this will result in a total roll-over.
After you've gained some altitude, slowly move the Trim controller to about 25% (at most 50%).

During flight:
It is advised to not pull the levers too hard. As I said, the heli is incredibly delicate. To turn, you must roll a bit and then gently pitch. To gain/lose altitude, use the Throttle controller. Be careful not to overpitch (again).