Meet the strangest aircraft ever conceived, the Focke-Wulf Triebflügel
- In the closing months of WWII, the Germans were experimenting with some very fascinating aircraft designs, like the Focke-Wulf Triebflügel.
- Part helicopter and part conventional plane, this aircraft used ramjets to turn its unique rotor design.
- Thankfully for the Allies, it never saw the light of day.
In 1944, the indestructible and unbeatable reputation of the German Army was in tatters. Under pressure from the East and West, it was gradually being pushed back to the German homeland.
The Allies had developed mass bombing raids to smash German industry in an attempt to bring the German war machine to its knees. With the Luftwaffe seriously understaffed, though not outclassed, new means of helping protect the skies over Germany were becoming an urgent need.
Some of the earliest jets were already close to production, but some aircraft designers were thinking outside of the box. Let us introduce you to perhaps the strangest aircraft ever conceived, the Focke-Wulf Triebflügel.
What was the Focke-Wulf
What was the Focke-Wulf Triebflügel?
The Focke-Wulf Triebflügel, or simply Triebflügeljäge (literally meaning "thrust-wing hunter"), was a German concept aircraft designed in the last years of World War 2. Intended to defend against the escalating Allied bombing raids on central Germany of the time, this interesting aircraft was developed in the hope that it might turn the tide back in favor of the Germans.
A form of "tailsitter" interceptor aircraft, it was designed to have vertical takeoff and landing for local defense of significant factories or locations with no airfields or only small areas for takeoff. Since it was developed late in the war, no working prototypes were ever produced, tested, or flown.
When Allied forces arrived at the manufacturing facility, a small, wooden model of the Triebflügel had just begun wind tunnel testing.
Focke-Wulf Triebflügel's vital stats
No working prototypes or full-scale units were ever built, but from what can be gathered from existing schematics and documents, the Triebflügel would likely have had the following characteristics.
Role: Multi-role supremacy fighter and interceptor
Length (in air)/height(on ground): 30 ft (9.15 m)
Wingspan: 38 feet (11.5 m) (38 ft 0 in)
Gross weight: 5,200 pounds (2,500 kg)
Powerplant: A mixture of Pabst ramjets (2,000 lb/foot thrust) engines, Walter liquid fuel rockets, and standard German Walter 109-501 Rocket-Assisted-Take-Off (RATO) units (3,306 lb/foot thrust)
Maximum speed: 621 mph (1,000 kph)
Never exceed speed: 1,730 mph (2,700 kph)
Minimum control speed: 150 mph (230 kph)
Service ceiling: 50,000 ft (15,300 m)
Rate of climb: 9,800 ft/min (50 m/s)
Armament: 2 no. 30 mm MK-103 cannons with a 100-round capacity and 2 no. 20 mm MG-151 cannons with a 250-round capacity.
What did the Focke-Wulf Triebflügel look like?
The Focke-Wulf Triebflügel's design is probably one of the most unique in all aviation history. It had no fixed wings and used an innovative rotor/propeller "airblade" arrangement that was cited roughly halfway between the cockpit and tailplane. A rotary collar would allow the wings to rotate a full 360 degrees around the fuselage. Their pitch could be adjusted depending on the flight situation.
This system would provide all lift and propulsion if the aircraft were ever built. The rotors would have worked similarly to a helicopter's rotor when the plane was in its vertical position. However, they would act more like giant propellers when the aircraft was flying horizontally.
The three rotor blades were put on a ring that was supported by bearings so that they could move freely around the fuselage.
Each blade of the rotor would have had a ramjet at the end. Simple rockets would have been used to get the rotors up to speed, at which point the ramjets would have been able to operate, and the rockets would have run out of fuel.
The speed and lift produced could be altered by adjusting the pitch of the blades. Since the ramjets at the tips of the rotor blades were moving them, there would be no response torque to make the fuselage turn in the other direction. Fuel would have been carried in the fuselage tanks and pumped to the jets along the rotors and through the center support ring.
Four tailplanes made up the cruciform "empennage" at the rear of the fuselage. These tailplanes included moveable ailerons that could serve as rudders and elevators.
The pilot would have been able to control the flight's pitch, roll, and yaw, and the tailplane would have stopped the fuselage from turning in the same direction as the rotor because of friction from the rotor ring.
The main undercarriage was a single, sizable, sprung wheel at the end of the fuselage. Each tailplane would have had four small castor wheels attached to struts that could be extended to keep the plane stable on the ground and let it move. When in flight, streamlined clamshell doors concealed the main and outrigger wheels.
How did the plane take off and land?
During takeoff, the rotors would have been tilted to provide lift when taking off, much like a helicopter. Once the aircraft reached a designated altitude, the pilot would tilt the bdes again in order to achieve level flight. At this point, the rotor blades would switch from a helicopter-like mode to a more traditional aircraft propeller-like mode (albeit with ramjets).
This mode of flight is akin to the modern-day Bell Boeing V-22 "Osprey" tiltrotor aircraft (but with the roto fixed to the fuselage and ramjet powered).
It is believed that once the aircraft accelerated to its top speed, the ramjet-powered rotors would probably turn at a rate of around 220 rpm to maintain level flight. The pilot would also have needed to maintain a slightly upward trim to generate enough lift to keep the aircraft airborne.
For this reason, the aircraft's main armament, situated in the front of the fuselage, would have been slightly tilted down from the centerline to compensate.
As for its armament, this would have been a very formidable firepower for Allied bombers of the day. It would have included two 3 cm (1.18 in) MK 103s with 100 rounds of ammunition and two 2 cm (0.78 in) MG 151s with 250 rounds.
If the pilot could get within range, several bursts would have likely shredded the strategic bomber formations in very short order.
When landing, the aircraft's pilot would likely need to reduce the craft's speed and tilt its fuselage until it was at the correct tilt to enable a vertical landing. At the point that the landing gear touched the ground, the pilot would gradually power down the ram jets to allow the aircraft to settle on its landing struts and "land."
Since the pilot would have been facing forward with his back to the ground, this would have been a very challenging maneuver indeed. Even if the pilot had been able to reposition to see to the rear, the rotor would have obstructed their view.
And that is your lot for today.
The Focke-Wulf Triebflügel might well be able to claim the mantle of the strangest aircraft ever designed. The U.S. captured the plans for the aircraft at the end of the war, who experimented with the design for some time before dropping it. No other aircraft designers have attempted a similar concept since, and, it is unlikely that its kind will ever be seen again.
Thankfully for the Allies, its technical design was probably far too complex for its day, especially for the stage in the war when the Germans attempted to make it a reality. If they had been able to overcome the technical challenges and make the aircraft en masse, and earlier in the war, the war's outcome in Europe could have been very different.
However, considering how vulnerable the aircraft would have been during takeoff and landing, it is probably more likely that the Allies would adopt hit-and-run tactics to eliminate Triebflügel squadrons before they could even airborne.
Of course, since they never saw the light of day, we can never know.
Award-winning meteorologist Nick Stewart told Interesting Engineering Starlink RV "did not have a single hiccup" during a recent storm chase.