Why does the C-130 military transport plane use propellers instead of jet engines?
In: Engineering
It does this for fuel efficiency, purposes. The plane flies slower flights at a lower altitude . Since the plane is designed for the transport and airdropping of heavy cargo loads across longer distances it does not need a jet engine that uses lots of fuel but allows the plane to fly extremely fast for short distances which a jet
fighter with a jet engine needs to do.
They C-130 does have jet engines, turboprops to be exact. Turboprop engines have the performance and characteristics required for cargo aircraft.
Because the c-130’s job isn’t to fly fast, it’s to fly slow and take off and land from short runways.
The other reasons mentioned in this thread, but also: the C-130 dates to 1954. We had jet aircraft, but only since about 1944, so this was a transitional time. All of our newer cargo aircraft (e.g. C-5, C-17) are jets, but they are also larger, with a different role.
Props are more efficient since they move a large amount of air. It’s easier to move a large amount of air a little, than move a little bit of air very fast. Both will create thrust, but the former takes less energy. Think about the amount of air a box fan moves at its lowest speed versus a bunch of smaller computer fans at high RPMs.
Also, turboprops sound cool.
I did a tour of the factory where they make the wings for the a400m, the successor to the c130. One of the reasons they said they use propellers is because one of the things it needs to be able to land on a runway it can’t turn around on, and propellers mean it can reverse down a runway to be able to take off again.
The question showed up in my news feed today. Are you on the same feed? https://www.slashgear.com/1676242/why-does-c-130-use-propellers-instead-jets/
It’s efficient, making it useful for maritime patrol and taking off from shorter runways (they were even capable of landing on carriers). If you want to transport an enormous amount of stuff you use a C-5.
Because propellers are more efficient at slow speeds than jetse engines.
Jet engines are also very sensitive to Foreign Object Damage (FOD) where dust, debris etc gets sucked into the engines on a dirty runway.
Propellers have no such concerns.
Also, you may not be aware, but there are two different types of prop driven planes.
Those with reciprocating piston engines similar in principal to what you’d find in a car, and those with turbine engines which we call turbo-props.
A turbo-prop is just a propeller that is connected by a shaft to the main shaft of what is basically just a jet engine. It’s just that instead of using the hot gas ejected out the back of the turbine for thrust, you use a propeller instead.
(Helicopters use the same principal).
So, the real reason for using props on the C-130 isn’t any of the reasons listed so far.
The C-130 was designed from the outset to be able to perform logistics missions anywhere. So that means it has to be able to operate from unprepared surfaces, such as dirt/gravel roads. Landing and taking off from those types of surfaces would kick up a significant amount of debris. The turbine blades in jet engines are extremely sensitive to ingesting debris, whereas propellers are not.
Additionally, prop engines are significantly easier to work on in an environment without dedicated support facilities, making the aircraft more reliable in the long term for where its missions tend to occur.
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