Junkers J 1 facts for kids
Quick facts for kids Junkers J 1 |
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| The Junkers J.1 Blechesel | |
| Role | experimental/Pioneer aircraft |
| Manufacturer | Junkers & Co |
| First flight | 12 December 1915 |
| Retired | 1916 |
| Status | Retired |
| Primary user | Luftstreitkräfte |
| Produced | 1915 |
| Number built | 1 |
The Junkers J 1 was a special experimental airplane. It was nicknamed the Blechesel, which means "Tin Donkey" or "Sheet Metal Donkey." This plane was built by a company called Junkers during the early part of World War I.
What made the J 1 so amazing was that it was the first all-metal aircraft in the world. Back then, most airplanes were made from wood frames covered with fabric. The J 1 was a huge step forward because it used metal for almost its entire structure and outer skin.
The J 1 was designed by a brilliant engineer named Hugo Junkers. It was an experimental plane, so it didn't get a special military name from the German Army's aviation department. It was only known by its factory number, J 1. This plane is different from the later, armored Junkers J.I (Junkers J 4), which was also made of metal.
The J 1 took its first short flight on December 12, 1915. A pilot named Theodor Mallinckrodt flew it. It only went up about 3 meters (10 feet) at first. Later flights went higher and performed better. By early 1916, Junkers got a contract to keep developing his metal aircraft ideas. The Junkers J 2 fighter plane came after the J 1. The J 1 probably didn't fly again after January 1916.
In 1926, the J 1 was put on display at the Deutsches Museum in Munich, Germany. Sadly, it was destroyed in December 1944 during a bombing raid in World War II.
Contents
How the Junkers J 1 Was Developed
The Idea Behind the J 1
Hugo Junkers was a German engineer and a pioneer in aviation. Before working with planes, he was known for inventing things like a calorimeter and building internal combustion engines. Around 1897, he learned about airplanes from a colleague, Hans Reissner.
In 1907, Reissner asked Junkers to help design an early monoplane (a plane with one main wing). This first project in 1909 wasn't very successful. However, it made Junkers want to work more on airplane design. Five years later, Reissner and Junkers built an all-metal plane called the Ente (Duck). It first flew in 1912.
Junkers' company built parts of the Ente, like the wings and engine radiator. Working on the Ente made Junkers think a lot about how to build airplane bodies. He wanted to get rid of the outside wires and braces that most planes used. In 1910, he patented an idea for a thick, strong wing that didn't need outside support. This is now called a flying wing.
In 1910, Junkers received money to build a wind tunnel at his research center. This led to studies on how air moves around planes. These studies helped design the Junkers J 1 five years later. In 1911, Junkers left his teaching job to focus on his engine company.
It wasn't until 1915 that Junkers could fully work on designing and building planes. He opened a research institute called the Forschungsanstalt Professor Junkers. This institute was in charge of designing all-metal monoplanes that didn't need outside bracing.
When World War I started in August 1914, Junkers decided to work on projects that could help the military. Most airplane designers at the time were not trying new things. But Hugo Junkers was different. He and his team, including engineers Otto Reuter and Otto Mader, worked on the J 1. They built it as a private project to show off new technology.
Building the Concept and Getting a Contract
Junkers and his research team started working on planes that would have less air resistance by removing outside braces. His work on the Ente convinced him that metal was the best material for the main structure.
A metal alloy called duralumin had been invented earlier. It seemed perfect for planes, but it was hard to work with in thin sheets. So, early Junkers metal planes used heavier electrical steel sheets. This is similar to the metal used in transformers.
On June 8, 1915, Junkers began getting the tools needed to build the J 1. The J 1 was built as a research plane. It was meant to lead to future all-metal fighter planes. On December 12, 1915, the J 1 made a short flight in Dessau. Then, it was sent to a military testing ground in Döberitz for more tests. Its first real flight there was on January 18, 1916.
Design of the Junkers J 1
The Junkers J 1 was an experimental plane with its wing in the middle of the body. It had many modern features. Its wing was a cantilever design, meaning it was strong enough without outside supports. The entire plane was made of metal.
The J 1 looked very smooth and well-designed. Its outer skin was made of steel panels. These panels were reinforced in strong areas with extra sheets of corrugated steel underneath. This was the first time an all-metal "stressed-skin" design was used. This means the outer skin helped carry the plane's weight.
The rudder, which helps steer the plane, was an "all-flying" design. This means it moved completely without a fixed fin. The tail and wing structures were also made of shaped steel sheets. The angle of the horizontal stabilizer (part of the tail) could be changed on the ground.
The main structure of the J 1 was built around its central body and the inner part of the wing. These inner wing parts were where the main wings attached. The J 1's wings were unique because they didn't have traditional spars (main beams). Instead, they used layers of short, strong sections. Other parts like the nose and tail were also attached to the center section.
Unlike other planes of its time, the J 1's wing didn't have any outside braces or wires. The only outside supports were for the horizontal stabilizer and the landing gear. Inside, the plane used welded steel strips, I-beams, and steel tubes for its main structure.
The innovative cantilever wings were also covered in steel panels. The wing was very thick near the body. It also changed shape and tapered (got narrower) from the body to the wing tip. These wing shape changes became a signature of later Junkers designs. The J 1 also used steel panels with ripples (corrugations) hidden under the smooth outer skin. These ripples helped make the wing stronger.
The J-1 was powered by a Mercedes D.II engine. This engine had six cylinders and was cooled by liquid. It was placed inside a simple, two-part cover called a cowling. The plane had an advanced engine radiator for its time. The radiator was placed underneath the front part of the body. Its opening was just behind where the front landing gear attached.
Operational History
Flight Testing the J 1
Before the Junkers J 1 could fly, the German Army's aviation department, IdFlieg, required tests. They performed static load tests on the J 1's structure using sandbags. They also tested how much thrust the engine and propeller could produce.
These tests finished on December 3, 1915. Junkers' factory didn't have its own test field yet. So, the J 1 was moved to the Fliegerersatzabteilung 1 (FEA 1) airfield in Döberitz, near Berlin, for its flight tests.
On December 12, 1915, pilot Theodor Mallinckrodt was assigned to test the J 1. He managed to make it "hop" into the air, reaching almost 3 meters (10 feet) high. During this short hop, a gust of wind hit the right wing as the plane came down. This caused the left wing tip to scrape the ground. The left side of the J 1's body also bent inward.
Testing was stopped for repairs during the holidays. After repairs, more static load tests were done to check the fixes.
On January 18, 1916, the J 1 made its second flight at Döberitz. A private named Paul Arnold flew it. The plane only reached 80 meters (262 feet) high after a 200-meter (656-foot) takeoff run. This was because the stabilizer (part of the tail) was set incorrectly. Later that day, after the stabilizer was adjusted, Mallinckrodt flew it again. This time, he reached 900 meters (2,953 feet) from a shorter takeoff. Pilots said the plane handled well and was stable in the air.
On January 19, Mallinckrodt took the J 1 for its only "high performance" flight test. He flew a 7-kilometer (4.3-mile) course at altitudes between 200 and 300 meters (656 and 984 feet). During this flight, Mallinckrodt reached a top speed of 170 km/h (106 mph).
The military was interested in Junkers' design. So, they compared the J 1 to the popular Rumpler C.I biplane. The J 1 was 30 km/h (19 mph) faster, even though the Rumpler had a more powerful engine. However, the Rumpler was much lighter because it was made of wood and fabric. This meant it could climb much faster than the J 1, which was heavier due to its experimental steel structure.
Specifications
Data from Wagner and Nowarra (1971). German Combat Planes: A Comprehensive Survey and History of the Development of German Military Aircraft from 1914 to 1945.
General characteristics
- Crew: one
- Length: 8.64 m (28 ft 4 in)
- Wingspan: 12.92 m (42 ft 5 in)
- Height: 3.11 m (10 ft 2 in)
- Wing area: 24.34 m2 (262.0 sq ft)
- Empty weight: 920 kg (2,028 lb)
- Gross weight: 1,080 kg (2,381 lb)
- Powerplant: 1 × Mercedes D.II 6-cyl. water-cooled in-line piston engine, 90 kW (120 hp)
Performance
- Maximum speed: 170 km/h (106 mph; 92 kn)
