biology

Northrop XP-79

Northrop XP-79 is a biology 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 Northrop XP-79 rather than just read about it. In short: The Northrop XP-79, USAAF project number MX-365, was a rocket and jet-powered flying wing fighter aircraft, designed by Northrop. The pilot operated the aircraft in a prone position, permitting much greater g-forces to be resisted by the pilot in pitch.

Key takeaways

Northrop XP-79 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Northrop XP-79 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Northrop XP-79 from memory before moving on to harder problems.

Reference excerpt

The Northrop XP-79, USAAF project number MX-365, was a rocket and jet-powered flying wing fighter aircraft, designed by Northrop. The pilot operated the aircraft in a prone position, permitting much greater g-forces to be resisted by the pilot in pitch. The XP-79 also used a welded magnesium monocoque structure instead of riveted aluminum.

Design and development

In 1942, Jack Northrop conceived the XP-79 as a high-speed rocket-powered flying-wing fighter aircraft. In January 1943, a contract for two prototypes under the XP-79 designation was issued by the United States Army Air Forces (USAAF). It was planned to use a 2,000 lbf (8,900 N) thrust XCALR-2000A-1 "rotojet" rocket motor from Aerojet that used mono-ethylaniline fuel and red fuming nitric acid (RFNA) oxidizer. However, the rocket motor, which used canted rockets to drive turbo-pumps was unsatisfactory and the aircraft was fitted with two Westinghouse 19B turbojets and re-designated XP-79B. The XP-79 was built using a welded magnesium alloy monocoque structure with a leading edge thickness of 0.75 in (19 mm) which thinned out to 0.125 in (3.2 mm) at the trailing edge. The pilot controlled the XP-79 through a tiller bar and intakes mounted at the wingtips supplied air for the unusual bellows-boosted split elevons which opened differentially to provide lateral (yaw) control, by increasing drag on one side of the aircraft, in addition to providing roll and pitch. The aircraft was also fitted with airbrakes outboard of them, also for yaw control. No rudders were used, and the vertical surfaces were simple fixed fins with no flight controls.

MX-324 and MX-334 Northrop was given a contract to build three glider demonstrators to test the design. Given the Northrop designation NS-12, the three gliders were also given project numbers from the USAAF. Confusingly, two project numbers were used, one MX-324 when discussing secret aspects of the powered gliders, and another, MX-334, relating to the aircraft when being built and flown as pure gliders. The MX-334 was a flying wing glider with no tail surfaces, similar in layout and construction to the Northrop N-9M. Completed in late Spring 1943, MX-334 No.1 was tested in NACA Langley's wind tunnel, after which a large wire-braced fin was added for directional stability at high speeds. The first flight attempts were carried out by the no.2 aircraft towed behind a Cadillac car for low level take-off and landing tests, with no success. After modifications the first launch was carried out on 4 September 1943, towed behind a large truck. For more comprehensive testing, a Lockheed P-38 Lightning was used to tow the aircraft on 2 October 1943. In early 1944 the no.2 aircraft was modified to take the 2,009 lbf (8,940 N) Aerojet XCAL-200 rocket motor, and reverted to the secret MX-324 designation. Testing with the rocket motor commenced on 22 June 1944, with the first aerotow launch for a powered flight on 5 July 1944, making it the first US-built rocket-powered aircraft to fly. Flight testing was concluded by 1 August 1944 and the two remaining aircraft were disposed of. MX-334 no.3 was written off on its second flight, on 10 November 1943, after Harry Crosby lost control in the prop-wash of the P-38 tug.

Testing Following delays due to burst tires and brake problems during taxiing trials at Muroc dry lake, the XP-79B made its first flight on 12 September 1945. 15 minutes into the flight, control was lost for unknown reasons while performing a slow roll. The nose dropped, and the roll continued with the aircraft impacting the ground in a vertical spin. Test pilot Harry Crosby had attempted to bail out but was struck by the aircraft and died. Shortly thereafter, the project was canceled along with work on the second prototype.

Variants Data from: Northrop Flying Wings: a history of Jack Northrop's visionary aircraft

NS-12 Northrop company designation for the MX-324 program. NS-14 Northrop designation for the XP-79 program. MX-324 The "secret" designation for the powered version of the MX-334 glider. Only used for the no.2 glider, when powered by a single 200 lbf (890 N) Aerojet XCAL-200 liquid-fueled rocket engine. MX-334 The designation used to describe the pure glider version (including the no.2 aircraft before it was fitted with the rocket engine). MX-365 The USAAC project number for the XP-79 program. XP-79 The initial design for a rocket powered fighter, to have been powered by 2 x 2,000 lbf (8.9 kN) Aerojet XCAL-2000 liquid-fueled rocket engine. XP-79B Three aircraft were ordered but only one was completed, crashing on its first flight on 12 September 1945.

Specifications (XP-79B) Data from Northrop Flying Wings : a history of Jack Northrop's visionary aircraftGeneral characteristics Crew: 1 Length: 13.98 ft (4.26 m) Wingspan: 37.99 ft (11.58 m) Height: 7.58 ft (2.31 m) Wing area: 278 sq ft (25.8 m2) Aspect ratio: 5.19 Airfoil: NACA 66,2-018 Empty weight: 5,842 lb (2,650 kg) Gross weight: 8,669 lb (3,932 kg) Fuel capacity: 300 US gal (250 imp gal; 1,100 L) Powerplant: 2 × Westinghouse 19B axial flow turbojet, 1,150 lbf (5.1 kN) thrust each Performance

Maximum speed: 547 mph (880 km/h, 475 kn) Cruise speed: 480 mph (770 km/h, 420 kn) Range: 993 mi (1,598 km, 863 nmi) Endurance: 2.45 hours Service ceiling: 40,000 ft (12,000 m) Rate of climb: 4,000 ft/min (20 m/s) Wing loading: 31 lb/sq ft (150 kg/m2) Thrust/weight: 0.27 Armament

Guns: 4 x 0.5 in (12.70 mm) machine-guns

Illustrations

Worked examples

Example 1 — a first encounter with Northrop XP-79

Start with the simplest possible case. Write down what Northrop XP-79 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 Northrop XP-79 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 Northrop XP-79 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 Northrop XP-79

In research: Northrop XP-79 appears in biology 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 Northrop XP-79 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: Northrop XP-79 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1940s United States fighter aircraft, Aircraft first flown in 1945, Aircraft flown once, so understanding it makes those chapters shorter.
In everyday life: Look for Northrop XP-79 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.

Affiliate

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

How to study Northrop XP-79 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Northrop XP-79 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 Northrop XP-79 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Northrop XP-79 in simple terms?

Why does Northrop XP-79 matter?

Because it connects several biology 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 Northrop XP-79?

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 Northrop XP-79.