Author Topic: jets vs helicopters (Read 6573 times)

Just_A_Guy · « **on:** January 04, 2018, 17:34:15 »

i am deciding whether to do one or the other, please respond with pros and cons
which one makes more of a difference, gets deployed more?
thanks.

FJAG · « **Reply #1 on:** January 04, 2018, 17:46:04 »

Quote from: Just_A_Guy on January 04, 2018, 17:34:15

i am deciding whether to do one or the other, please respond with pros and cons
which one makes more of a difference, gets deployed more?
thanks.

Have you given up all your plans about being a "fire support officer" in the artillery?

Before anyone wastes any time responding to you on this it might be an idea if you told us a bit about yourself. I'm starting to have some doubts about you.

mariomike · « **Reply #2 on:** January 04, 2018, 18:10:02 »

Quote from: FJAG on January 04, 2018, 17:46:04

Have you given up all your plans about being a "fire support officer" in the artillery?

Perhaps so. The OP has started three new Pilot threads today.

Roger123 · « **Reply #3 on:** January 04, 2018, 19:54:25 »

Quote from: Just_A_Guy on January 04, 2018, 17:34:15

i am deciding whether to do one or the other, please respond with pros and cons
which one makes more of a difference, gets deployed more?
thanks.

I would suggest revealing a bit of information regarding your self, your situation, place in the application process, etc. Your decision about going jets or helicopters is pretty mute, seeing how that decision is far off into the future, based on the needs of the RCAF and your performance amongst your class,etc, assuming you get through, successfully, the lengthy and extensive pilot application process. You have no input, in an official capacity, with regards to your preferred airframe when you make your pilot application.

Eye In The Sky · « **Reply #4 on:** January 04, 2018, 22:03:11 »

The correct answer is it depends.

Good2Golf · « **Reply #5 on:** January 05, 2018, 01:10:13 »

Quote from: Eye In The Sky on January 04, 2018, 22:03:11

The correct answer is it depends.

Disagree.

The real answer is 'yes'.

SeaKingTacco · « **Reply #6 on:** January 05, 2018, 01:56:08 »

You know, helicopters have jet engines, so, does it matter?

medicineman · « **Reply #7 on:** January 05, 2018, 08:37:03 »

C17's are jets too...

MM

Remius · « **Reply #8 on:** January 05, 2018, 09:04:38 »

Jet packs. Plus they let you get to the coins and life ups on higher levels.

Oldgateboatdriver · « **Reply #9 on:** January 05, 2018, 09:53:34 »

If we are suggesting things with jet engines: What about a frigate or a destroyer?

Remius · « **Reply #10 on:** January 05, 2018, 10:23:43 »

Quote from: Oldgateboatdriver on January 05, 2018, 09:53:34

If we are suggesting things with jet engines: What about a frigate or a destroyer?

or those hand dryer things in public washrooms...

Ditch · « **Reply #11 on:** January 05, 2018, 10:37:26 »

Some tanks have jet engines too.... albeit none of ours.

SupersonicMax · « **Reply #12 on:** January 05, 2018, 10:43:03 »

Quote from: SeaKingTacco on January 05, 2018, 01:56:08

You know, helicopters have jet engines, so, does it matter?

To be accurate, you are referring to Turbine engines. Jet engines are a subset of turbine engines but turbine engines are not necessarily jet engines. All CAF helicopters are powered by turboshaft engines, a subset of turbine engines.

Jet engines uses the acceleration of the air mass going through the engine to produce thrust. The difference between the exhaust velocity and the intake velocity is directly proportional to thrust.

In a turboshaft engine (such as those in a helicopter) having any exhaust velocity is a waste of power that could be used to turn the rotor. Yes, there is residual thrust however, just like you don't consider your car to be powered by a jet engine, turboshaft helicopters aren't considered powered by jet engines.

But we disgress...

Baz · « **Reply #13 on:** January 05, 2018, 10:46:00 »

Quote from: SupersonicMax on January 05, 2018, 10:43:03

To be accurate, you are referring to Turbine engines. Jet engines are a subset of turbine engines but turbine engines are not necessarily jet engines. All CAF helicopters are powered by turboshaft engines, a subset of turbine engines.

And here I though he wanted to make electricity using one of these: http://www.opraturbines.com/en/OPRA-WEB---Products---Products/Mobile-Power/ (it does say "Electricity for military compounds in war zones"), but that would also be a turbine, not a jet.

SeaKingTacco · « **Reply #14 on:** January 05, 2018, 10:56:29 »

Quote from: SupersonicMax on January 05, 2018, 10:43:03

To be accurate, you are referring to Turbine engines. Jet engines are a subset of turbine engines but turbine engines are not necessarily jet engines. All CAF helicopters are powered by turboshaft engines, a subset of turbine engines.

Jet engines uses the acceleration of the air mass going through the engine to produce thrust. The difference between the exhaust velocity and the intake velocity is directly proportional to thrust.

In a turboshaft engine (such as those in a helicopter) having any exhaust velocity is a waste of power that could be used to turn the rotor. Yes, there is residual thrust however, just like you don't consider your car to be powered by a jet engine, turboshaft helicopters aren't considered powered by jet engines.

But we disgress...

What in the world makes you think accuracy is important in this thread?

Good2Golf · « **Reply #15 on:** January 05, 2018, 15:04:27 »

Quote from: SeaKingTacco on January 05, 2018, 10:56:29

What in the world makes you think accuracy is important in this thread?

Response-theme mis-read. Perhaps an OT to INT O is in Max's future?

Eye In The Sky · « **Reply #16 on:** January 05, 2018, 15:40:28 »

Quote from: Good2Golf on January 05, 2018, 01:10:13

Disagree.

The real answer is 'yes'.

Damn! I didn't think of that one!

Colin P · « **Reply #17 on:** January 05, 2018, 17:03:58 »

Quote from: SupersonicMax on January 05, 2018, 10:43:03

To be accurate, you are referring to Turbine engines. Jet engines are a subset of turbine engines but turbine engines are not necessarily jet engines. All CAF helicopters are powered by turboshaft engines, a subset of turbine engines.

Jet engines uses the acceleration of the air mass going through the engine to produce thrust. The difference between the exhaust velocity and the intake velocity is directly proportional to thrust.

In a turboshaft engine (such as those in a helicopter) having any exhaust velocity is a waste of power that could be used to turn the rotor. Yes, there is residual thrust however, just like you don't consider your car to be powered by a jet engine, turboshaft helicopters aren't considered powered by jet engines.

But we disgress...

leave it to the british

https://en.wikipedia.org/wiki/Jaguar_C-X75
https://www.livescience.com/49567-rocket-powered-bloodhound-car-photos.html

medicineman · « **Reply #18 on:** January 06, 2018, 08:42:50 »

Quote from: SupersonicMax on January 05, 2018, 10:43:03

To be accurate, you are referring to Turbine engines. Jet engines are a subset of turbine engines but turbine engines are not necessarily jet engines. All CAF helicopters are powered by turboshaft engines, a subset of turbine engines.

Jet engines uses the acceleration of the air mass going through the engine to produce thrust. The difference between the exhaust velocity and the intake velocity is directly proportional to thrust.

In a turboshaft engine (such as those in a helicopter) having any exhaust velocity is a waste of power that could be used to turn the rotor. Yes, there is residual thrust however, just like you don't consider your car to be powered by a jet engine, turboshaft helicopters aren't considered powered by jet engines.

But we disgress...

Spoil sport...

MM

Good2Golf · « **Reply #19 on:** January 06, 2018, 10:00:58 »

Quote from: medicineman on January 06, 2018, 08:42:50

Spoil sport...

MM

And not even accurately spoiling.

Otherwise we would have seen a more accurate breakdown of the turbo machinery by function, including: turbojet, turbofan, geared turbofan, turboprop, ducted turboprop and turboshaft. No turboshaft engine/system extracts 100% thermodynamic power from the fuel to output at the shaft, there is always unextracted energy in the exhaust, sometimes on the order of 5-10%. In the case of a large turboshaft engine such as the Honeywell T55-L-714 on the CH-147F Chinook, this can actually approach a quarter ton of thrust (sounds more impressive than 500 lbs) per engine, not an insignificant amount of true jet thrust...exhaust being ejected at much greater speed at the exhaust plane than the air that entered the engine's inlet. Furthermore, those who were wondering why the Chinook's exhaust is shaped the way it is (a linearized expanding bell), is amongst a number of functions, a divergent nozzle downstream from the power turbine which effectively reduces the overall nozzle pressure ratio - NPR (see NASA's Glen Research Center's information paper on Turbine Nozzle Performance for reference) thereby maximizing the speed increase of the exhaust flow, and associated (residual) thrust of the engine(s). Interestingly, that puts a CH-147F Chinook's T55 per/engine output at twice the maximum jet thrust as the Microturbo SA (France) TRS-18 turbojet used in the BD-5J micro jet, albeit about 35 times less thrust than a CF-188's GE F404 engine. Jet thrust is jet thrust, after all.

Now, back to the thread's response theme...should we include additional jet thrust from the helicopter if the crew ate at Taco Bell before the flight?

Nerf herder · « **Reply #20 on:** January 06, 2018, 10:03:02 »

Quote from: Ditch on January 05, 2018, 10:37:26

Some tanks have jet engines too.... albeit none of ours.

Thank sweet zombie Jeebus....

Regards

dapaterson · « **Reply #21 on:** January 06, 2018, 10:06:45 »

Quote from: Good2Golf on January 06, 2018, 10:00:58

should we include additional jet thrust from the helicopter if the crew ate at Taco Bell before the flight?

Friends don't let friends eat at Taco Bell.

medicineman · « **Reply #22 on:** January 06, 2018, 13:31:34 »

Quote from: Good2Golf on January 06, 2018, 10:00:58

Now, back to the thread's response theme...should we include additional jet thrust from the helicopter if the crew ate at Taco Bell before the flight?

Taco Bell = Taco Smell

MM

Sent from my iPhone using Tapatalk

Dimsum · « **Reply #23 on:** January 06, 2018, 14:29:23 »

Quote from: Good2Golf on January 06, 2018, 10:00:58

Now, back to the thread's response theme...should we include additional jet thrust from the helicopter if the crew ate at Taco Bell before the flight?

At least you can open the cabin and rear doors in a helicopter, to either a) quickly ventilate the cabin and/or b) throw the offender out.

News:

Author Topic: jets vs helicopters (Read 6573 times)