science

URMV-3 IS-3

URMV-3 IS-3 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 URMV-3 IS-3 rather than just read about it. In short: The IS-3 was the basis of a family of high performance gliders designed by Iosif Șilimon and built in Romania in the 1950s at the URMV-3 (Rom: Uzinele de Reparatii Material Volant-3 - Glider repair and manufacture factory) factory at Brașov. Design and development The IS-3 was designed as a high performance sailplane for record-breaking and international competition flying.

Key takeaways

URMV-3 IS-3 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect URMV-3 IS-3 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of URMV-3 IS-3 from memory before moving on to harder problems.

Reference excerpt

The IS-3 was the basis of a family of high performance gliders designed by Iosif Șilimon and built in Romania in the 1950s at the URMV-3 (Rom: Uzinele de Reparatii Material Volant-3 - Glider repair and manufacture factory) factory at Brașov.

Design and development The IS-3 was designed as a high performance sailplane for record-breaking and international competition flying. The development of the IS-3 was in four distinct phases with differences in wing position and construction as well as fuselage design. The original glider, first flown on 19 August 1953, was built primarily of wood with a pod and boom style fuselage and high-set wings. The streamlined pod contained the enclosed cockpit with a flush-fitting canopy and supported the wings and the Duralumin sheet tubular tailboom, which supported the conventional tail surfaces at its extremity. The tapered wings were built with plywood-covered torsion box leading edges with fabric covering aft of the main spar, incorporating spoilers for approach control and differential ailerons to reduce adverse yaw. With the exception of the IS-3c and IS-3d the IS-3 family followed the pod and boom arrangement with variations in wing position, span, wing construction and undercarriage arrangement. All versions had a single mainwheel with nose and tail skids, varying in skid sizes and mainwheel position. The IS-3c and IS-3d were drastically different in having a conventional wooden fuselage and further minor variations in wing construction and roll controls.

Operational history Data from: Romanian Aeronautical Constructions 1905-1974

IS-3 The IS-3 set several national records, at a 1954 international gliding contest at Leszno in Poland and at other times: Speed - 74.5 km/h (46.3 mph; 40.2 kn) over a 300 km (186.4 mi; 162.0 nmi) straight line with reference point, piloted by Mircea Finescu at Lesno. Distance - 305 km (189.5 mi; 164.7 nmi) straight line with reference point, piloted by Mircea Finescu at Leszno. Speed - 72.3 km/h (44.9 mph; 39.0 kn) over a 100 km (62.1 mi; 54.0 nmi) triangular circuit, piloted by Mircea Finescu at Leszno. Speed - 72.3 km/h (44.9 mph; 39.0 kn) over a 100 km (62.1 mi; 54.0 nmi) with reference point, piloted by Ovidiu Popa. Distance (women) - 325.6 km (202.3 mi; 175.8 nmi) straight line between Iași and Cuza Vodă, Călărași, piloted by Aurelia Roșianu-Gheorghiu. IS-3d The IS-3d set several national records: Speed - 48.42 km/h (30.1 mph; 26.1 kn) over a 200 km (124.3 mi; 108.0 nmi) triangular circuit, piloted by Ovidiu Popa. Speed - 83.82 km/h (52.1 mph; 45.3 kn) over a 100 km (62.1 mi; 54.0 nmi) with reference point, piloted by Gheorghe Gilcă. Speed (women) - 48.425 km/h (30.1 mph; 26.1 kn) over a 100 km (62.1 mi; 54.0 nmi) triangular circuit, piloted by Aurelia Roșianu-Gheorghiu.

Variants Data from: Romanian Aeronautical Constructions 1905-1974

IS-3 Original prototype with high-set 16 m (52.5 ft) span wings on a pod and boom fuselage, with two part differential ailerons and non-speed-limiting airbrakes/spoilers. IS-3a A revised IS-3 with wings lowered to the mid position and tailboom also lowered. The IS-3a wings were similar to the plywood D-box and fabric-covered aft section of the IS-3 but incorporated flaps with two part differential ailerons and non-speed-limiting airbrakes/spoilers. IS-3b The IS-3b was essentially identical to the IS-3a with the exception of having no flaps and having plywood skinned wings throughout. IS-3c The IS-3c was markedly different from its predecessors in having high-set 17 m (55.8 ft) span wings, skinned throughout with plywood, with three-section differential ailerons and introducing speed-limiting airbrakes. The new long span wing was supported by a conventional fuselage, incorporating the streamlined enclosed cockpit and a conventional tail unit. IS-3d Essentially similar to the IS-3c, but with a 15.3 m (50.2 ft) wing, single-section ailerons, streamlined wingtip fairings, and speed-limiting airbrakes. IS-3e Reverting to the pod and boom layout the IS-3e had high-set 17 m (55.8 ft) span wings, with a plywood D-box and fabric-covered aft section, two section ailerons and speed limiting airbrakes. IS-3f A variant with a 15.3 m (50.2 ft) wing completely skinned with plywood, otherwise similar to the IS-3e.

Specifications (IS-3) Data from The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde Volume IIGeneral characteristics Crew: 1 Length: 6.46 m (21 ft 2 in) (IS-3) 6.66 m (21 ft 10 in) (IS-3a / IS-3b) 7.26 m (23 ft 10 in) (IS-3c / IS-3d) 7.0 m (23 ft 0 in) (IS-3e / IS-3f) Wingspan: 16 m (52 ft 6 in) (IS-3 / IS-3a / IS-3b) 17 m (55 ft 9 in) (IS-3c / IS-3e) 15.03 m (49 ft 4 in) (IS-3d / IS-3f) Height: 1.43 m (4 ft 8 in) (IS-3 ) 1.6 m (5 ft 3 in) (IS-3a / IS-3b / IS-3c / IS-3d / IS-3e / IS-3f) Wing area: 16.0 m2 (172 sq ft) Aspect ratio: 16 (IS-3 / IS-3a / IS-3b / IS-3e) 18 (IS-3c) 15.3 (IS-3d / IS-3f) Airfoil: Root:NACA 23015, Mid NACA 23012, Tip NACA 23012 Empty weight: 215 kg (474 lb) (IS-3) 245 kg (540 lb) (IS-3a / IS-3b) 270 kg (595 lb) (IS-3c / IS-3e) 230 kg (507 lb) (IS-3d / IS-3f) Gross weight: 305 kg (672 lb) (IS-3) 335 kg (739 lb) (IS-3a / IS-3b) 360 kg (794 lb) (IS-3c / IS-3e) 320 kg (705 lb) (IS-3d / IS-3f) Performance

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with URMV-3 IS-3

Start with the simplest possible case. Write down what URMV-3 IS-3 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 URMV-3 IS-3 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 URMV-3 IS-3 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 URMV-3 IS-3

In research: URMV-3 IS-3 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 URMV-3 IS-3 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: URMV-3 IS-3 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1950s Romanian sailplanes, Glider aircraft, so understanding it makes those chapters shorter.
In everyday life: Look for URMV-3 IS-3 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “URMV-3 IS-3” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study URMV-3 IS-3 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what URMV-3 IS-3 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 URMV-3 IS-3 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is URMV-3 IS-3 in simple terms?

Why does URMV-3 IS-3 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 URMV-3 IS-3?

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 URMV-3 IS-3.