3. Aeronautical - General Stuff

Question 1

What are the main Heath and safety concerns in Aeronautical?

Answer 1

The engineers are exposed to machines and fieldwork that may be harmful

Question 2

What are some of the properties needed in aircraft materials?

Answer 2

• Very good strength to weight ratio
• Formability
• Durability
• Stability at high temperatures (engine)
• Good specific strength
• Ease to join
• Corrosion Resistance

Question 3

How are materials cent stable at high temperatures?

Answer 3

Titanium alloys and Nickel base super alloys (e.g. Nimonic) are used. Chromium or cobalt is added to maintain strength and resist corrosion at high temperatures. They also have a good creep resistance.

Question 4

What are some legal and ethic problems in the aeronautical field?

Answer 4

The question of intellectual property and who it is owned by.

Designs can be patented, but the question of making it available for others is also there if it is very important to the safety of people.

Some aircraft parts are sold on the black market and it is important not to buy them as it can be dangerous.

If an engineer finds a problem they need to tell people and make sure it’s fixed.

Question 5

Outline the main occurrences in thee jet age hot to the 1960’s

Answer 5

✈️1938: First turbo jet engine.
✈️1943: The British Gloster Meteor was made, the first fighter aircraft.
✈️1944: German Messerschmitt Me 262 Subwalbe had a swept wing.
✈️Vietnam war produced jets that moved at twice the speed of sound.
✈️1960’s: General Dynamics F-111 was the first to use variable geometry wing (swing wing) technology. This is needed to deal with the shock waves of high speed travel. For low level flight the wings are swept forward for more lift, on transonic speeds its partially swept back and for Mach 2 the are swept more to create a delta wing.

Question 6

Outline the main occurrences in the jet age after the 1960’s.

Answer 6

✈️Saab AJ37 Viggen (Thunderbolt): Swedish needed STOL (short take of and landing) tech and a rapid climb rate, Mach 2 performance and manoeuvrability that was cheap (no swing wing). This was done by using a delta wing and forward canards.
✈️VTOL (vertical take off and landing): British Aerospace Harrier used a single turbo fan with 4 outlet nozzles.
✈️Stealth technology: B-2 “flying wing” have radar absorbing materials and the surfaces are designed to minimise radar reflection.

Question 7

Outline important occurrences in the commercial aircraft world.

Answer 7

✈️1949 Brittish Havilland Comet: 36 seats, swept wings, pressurised cabin, 4 jets in wing roots and aluminium stressed skin with a top speed of 800 km/h. One of its failures lead to the discovery of fatigue cracking, new adhesives and the rounding of windows.
✈️Boeing 707: 4 turbojet engines slung beneath the wings. Carried 180 passengers.
✈️Boeing 747: jumbo jet. Has 4 high bypass turbofan engines, complex high lift devices and advanced wings. 2001 Airbus A380 was the only one that could carry more passengers.
✈️1969: British Aerospace Concorde provided supersonic commercial travel. (The one that looks stupid) but was very costly and not popular.
✈️2005: Airbus A380
✈️Boeing 787 Dreamliner: focuses on efficiency not size with a highly fuel efficient and light weight design. Extensive use of composites eg aluminium alloy airframe.

Question 8

What are some current projects and innovations aeronautical engineers are working on?

Answer 8

• Reduce weight
• Increase lift
• Alternate energy sources