Another dumb plane question....

[Waynester]

If you strapped down an F18 or current top line fighter to the stern of a stationary aircraft carrier..Nimitz for example, would it be able to move it utilizing it's max thrust..re-heat etc...?

Or if you could strap down numerous planes to the carrier, what would or could happen?

It always occurred to me that when an aircraft lands on the deck and hooks the line it goes to max thrust (incase it misses the cable) and i always wondered if it 'adds anything' to the ships forward motion.

There...told you it was dumb.

At least there isn't a conveyor belt involved!

[TheEnd]

F=ma

apply a force, and you'll get movement, but on such a big mass, it won't be too fast.

[AlexKP]

TheEnd said:

F=ma

apply a force, and you'll get movement, but on such a big mass, it won't be too fast.

Exactly as The End says, and appropriately, that should be the end of the discussion!


(Somehow I doubt it though...)

[Waynester]

TheEnd said:

F=ma

apply a force, and you'll get movement, but on such a big mass, it won't be too fast.

Didn't think it would be much, just wondered if one plane could do it and if so what speed could the carrier achieve with a squadron strapped to it's deck..engines & afterburners at max!

[Waynester]

anonymous said:

[redacted]

Boo!!!

[Swilly]

Id imagine a better way of describing it would be the conservation of momentum.

sum of momentum before = sum of momentum after the event.

A small fast moving object impacting on a large slow moving object would have a total momentum equal to the sum of the two separate bodies. i.e. the aircraft carrier would speed up a tiny amount (ignoring all other environmental factors of course)

[XB70]

That reminds me of a related question that I always wanted to know about.

On the pad, an orbiter (about the size of a medium range Airbus - they are MASSIVE) is secured to the external tank at three points. Quite a load.

When the Shuttle Main Engines ignite, they are run to full power (a couple of squillion horspower) and, for a few seconds, does the load on the three anchor points shift such that it is not trying to stop the orbiter from moving up when a few moments before, it was holding a dead weight from falling down.

Cue SRB firing - massive load shift on the attachment points as the SRB's outpower the SME's but as the SME's are 'assisting' in moving the Orbiter relative to the external tank/boosters through the takeoff, is the 'stress' less on the attachment points are that point rather than at a) when no engines are firing and b) the moment when the SRB's kick in?

That being said, astrobat managed to hold onto the external tank at the last launch...what a ride for the little critter

Edited by XB70 on Saturday 28th March 19:05

[Darkslider]

What if there was a conveyor belt on the aircraft carrier?

[Bushmaster]

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

[Jasandjules]

Bushmaster said:

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

Uh, arrestor hooks snaps off and shatters the plane.........

[Waynester]

Bushmaster said:

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

I guess you could say one is pulling the other is pushing. Either way the effect should be the same..yes?

They may be easy to answer, and a bit silly, but i love these sort of questions. Anything involving engines at max gets a thumbup from me.

[samdale]

Jasandjules said:

Bushmaster said:

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

Uh, arrestor hooks snaps off and shatters the plane.........

even if the wire held and the plane didn't shatter theres no way the plane has enough power to accelerate a 22000 tonne ship up to the same speed it's going. the plane would slow down and fall like a sack o' st

[Bushmaster]

samdale said:

Jasandjules said:

Bushmaster said:

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

Uh, arrestor hooks snaps off and shatters the plane.........

even if the wire held and the plane didn't shatter theres no way the plane has enough power to accelerate a 22000 tonne ship up to the same speed it's going. the plane would slow down and fall like a sack o' st

Or if the hook were strong enough, the plane would 'hover' just over the deck...well until the engines overheated anyway..

[thunderbelmont]

No so dumb, and as has been stated in previous posts, there is an effect on the forward motion of the vessel.

Thankfully, the aircraft always land from Stern to Boughs, were it the other way, the Admiral's coffee may fall of the desk when the string goes taut!

As the manual states..

You know when the landing gear is up and locked when it takes full power to taxi to the terminal.

If the wings are moving faster than the fuselage, it's probably helicopter, and therefore unsafe.

When one engine fails on a twin-engine airplane, you always have enough power left to get to to the scene of the crash.

[samdale]

Bushmaster said:

samdale said:

Jasandjules said:

Bushmaster said:

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

Uh, arrestor hooks snaps off and shatters the plane.........

even if the wire held and the plane didn't shatter theres no way the plane has enough power to accelerate a 22000 tonne ship up to the same speed it's going. the plane would slow down and fall like a sack o' st

Or if the hook were strong enough, the plane would 'hover' just over the deck...well until the engines overheated anyway..

surely it couldnt get off the deck at that speed... (c. 30kts)
eta, unless you mean aiming its jets towards the deck with the same effect as a VTOL system..

Edited by samdale on Saturday 28th March 19:47

[Waynester]

samdale said:

Bushmaster said:

samdale said:

Jasandjules said:

Bushmaster said:

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

Uh, arrestor hooks snaps off and shatters the plane.........

even if the wire held and the plane didn't shatter theres no way the plane has enough power to accelerate a 22000 tonne ship up to the same speed it's going. the plane would slow down and fall like a sack o' st

Or if the hook were strong enough, the plane would 'hover' just over the deck...well until the engines overheated anyway..

surely it couldnt get off the deck at that speed... (c. 30kts)

The aircraft would still need sufficient forward motion to generate lift.
Towing the carrier by F14/15/18 et al is clearly ridiculous. It's staying on the deck and pulling the cable that was meant, though surely it would likely...eventually break the cable or the aircraft.

[Defcon]

Aircraft carriers tend to hold engine testing cells on their aft.

From http://www.aerospaceweb.org/question/dynamics/q030...

"While in college, one of my classes visited an aircraft carrier in port where we received a tour of the Aviation Intermediate Maintenance Department (AIMD) that includes the jet shop. One of the other students asked the obvious question, "How fast does one of these jet engines make the ship go?" The crewman we spoke to said every group that visits asks the same thing. He went on to explain that even the most powerful engine they worked on, the General Electric F110 used on the F-14 Tomcat, couldn't come close to affecting the ship's speed. It would take 36 of these engines operating at maximum afterburner to nudge the ship just enough to break the force of friction! "

[Mr Dave]

samdale said:

Jasandjules said:

Bushmaster said:

I wonder what would happen if instead of hooking up to the catapult, an F-18 hooked up to the arrester wire prior to take-off.... plane goes to full power, wire goes to full stretch..... plane drags ship along....?

Uh, arrestor hooks snaps off and shatters the plane.........

even if the wire held and the plane didn't shatter theres no way the plane has enough power to accelerate a 22000 tonne ship up to the same speed it's going. the plane would slow down and fall like a sack o' st

22,000 tonne ship would be a pretty small carrier, the Nimitz class are over 100,000 tonnes fully loaded I think.

With 40,000 ish lbs of thrust from an F/A 18 on full reheat I dont think that it will be moving much.

[Waynester]

Defcon said:

the General Electric F110 used on the F-14 Tomcat, couldn't come close to affecting the ship's speed. It would take 36 of these engines operating at maximum afterburner to nudge the ship just enough to break the force of friction! [/i][/b]"

Amazing!

[Bushmaster]

A lot of ships seems to be powered by derivations of aircraft jet engines i.e the LM2500 gas turbine:

http://www.fas.org/man/dod-101/sys/ship/eng/lm2500...