science

RFB X-113

RFB X-113 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand RFB X-113 rather than just read about it. In short: The RFB X-113 Aerofoil Boat was an experimental ground-effect vehicle intended to work over water. It was one of three such aircraft designed by Alexander Lippisch in the 1960s and early 1970s.

Key takeaways

RFB X-113 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect RFB X-113 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of RFB X-113 from memory before moving on to harder problems.

Reference excerpt

The RFB X-113 Aerofoil Boat was an experimental ground-effect vehicle intended to work over water. It was one of three such aircraft designed by Alexander Lippisch in the 1960s and early 1970s. The X-113 first flew in 1970; only one was built.

Design and development Lippisch's development of his Aerofoil Boat, a ground-effect vehicle for use over water, began whilst he was working in the aviation division of the Collins Radio Company in Cedar Rapids, Iowa, US. The first test of concept was the Collins X-112, flown in the mid-1960s. In 1967 development was continued in collaboration with Rhein-Flugzeugbau (RFB) in Germany, funded by the German government. This resulted in the X-113. The X-113 was an inverse delta aircraft; that is, it had a wing which was triangular in plan but with a straight, unswept leading edge. Combined with strong anhedral, this layout produces stable flight in ground effect. Specifically, it is claimed that it is stable in pitch and also that it can fly in ground effect at altitudes up to about 50% of its span, allowing it to operate over rough water. This contrasts with the lower aspect ratio square wing of the Ekranoplans which leaves ground effect at only 10% of span, limiting them to the calmer waters of lakes and rivers. The Aerofoil Boat was built using glassfibre sandwiches with foam or tube cores. Its wing was set high on the fuselage, with swept fins at the tips inclined at about 60°, carrying short ailerons. The tips also carried long, wide planing floats which projected a long way forward of the leading edge to support the fuselage stably above the surface when on water. Forward of the wings the fuselage was flat sided and quite shallow, so the pilot was semi-recumbent under a long canopy. Aft, a long dorsal fin extends to a T tail with rudder and horizontal stabiliser. The Aerofoil Boat was powered by a Nelson flat four engine derated to 30 kW (40 hp), driving a two blade, wooden, tractor propeller. The engine was mounted uncowled over the fuselage near mid-chord on a pylon constructed from three pairs of narrow angle V-struts. The first flight was made in October 1970 on Lake Constance and the initial tests to explore the performance of the Aerofoil Boat were also done there. These were deemed satisfactory and later flights over the North Sea showed that it could be operated over rough water. It also demonstrated its ability to fly out of ground effect, reaching at least 457 m (1,500 ft). Flight tests continued at least until 1974 and possibly later. The X-113 was displayed in public at the Paris Salon in May 1973.

Specifications (X-113 Am) Data from Jane's All the World's Aircraft 1974/5.General characteristics Crew: One Length: 8.43 m (27 ft 8 in) Wingspan: 5.89 m (19 ft 4 in) Height: 2.07 m (6 ft 9 in) Empty weight: 255 kg (562 lb) Gross weight: 345 kg (761 lb) Powerplant: 1 × Nelson H63-CP flat four, 30 kW (40 hp) derated from 36 kW (48 hp) Propellers: 2-bladed, 1.17 m (3 ft 10 in) diameter wooden, tractor Performance

Cruise speed: 80 km/h (50 mph, 43 kn) Service ceiling: 460 m (1,500 ft) out of ground effect, at least Take-off speed: 40 km/h (25 mph) Efficient cruise height: 175 mm (7 in) Ground effect limit: 3 m (118 in) approximately, 50% of span

Video "The aerofoil Boat", Lippisch research Corporation (https://www.youtube.com/watch?v=gnflnBF7jWk)

References

Patent US3190582, 1965

Illustrations

Worked examples

Example 1 — a first encounter with RFB X-113

Start with the simplest possible case. Write down what RFB X-113 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to RFB X-113 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about RFB X-113 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of RFB X-113

In research: RFB X-113 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses RFB X-113 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: RFB X-113 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1970s German experimental aircraft, Aircraft first flown in 1970, Ground-effect vehicles, so understanding it makes those chapters shorter.
In everyday life: Look for RFB X-113 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study RFB X-113 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what RFB X-113 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain RFB X-113 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is RFB X-113 in simple terms?

The RFB X-113 Aerofoil Boat was an experimental ground-effect vehicle intended to work over water. It was one of three such aircraft designed by Alexander Lippisch in the 1960s and early 1970s.

Why does RFB X-113 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study RFB X-113?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on RFB X-113.