An utterly daft question about aircraft carriers
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An utterly daft question about aircraft carriers
I was just watching a documentary on WW2 aircraft carriers, and sitting near the stern were a number of piston aircraft warming their engines up.
For no particular reason I wondered if you could get a bit more speed out of the carrier if you put all the aircraft on deck, tied them down, and gave the engines a bit of power?
I mean, say each piston fighter has about 1,500hp, and you can get twenty on the deck then that's another (inefficient admittedly) 30,000hp to help move the ship.
How about jet aircraft on a modern carrier? Less likely to overheat though hot air ingestion for the aircraft near the back would be a bother.
</daft though of the day>
For no particular reason I wondered if you could get a bit more speed out of the carrier if you put all the aircraft on deck, tied them down, and gave the engines a bit of power?
I mean, say each piston fighter has about 1,500hp, and you can get twenty on the deck then that's another (inefficient admittedly) 30,000hp to help move the ship.
How about jet aircraft on a modern carrier? Less likely to overheat though hot air ingestion for the aircraft near the back would be a bother.
</daft though of the day>
Pinwheel
Jet powered aircraft were no use, but propeller powered aircraft were considered a valuable resource by the fisheads driving the aircraft platform.
Operation Pinwheel used propeller powered aircraft strategically placed on the flightdeck and suitably tied, lashed and chained down, to aid the ship in close quarters manoeuvering. They replaced tugs which probably were on strike, or not big enough to provide motive thrust.
I last saw this in Melbourne in the early '70s when the tug company went on strike. The AEOs hated it as they saw it as an abuse of airframes/engines.
So, no they couldn't aid the ship in going faster, but could help you get alongside. Oh, and the stokers were known to burn a bit of jet fuel in the ship's boilers as well!
Operation Pinwheel used propeller powered aircraft strategically placed on the flightdeck and suitably tied, lashed and chained down, to aid the ship in close quarters manoeuvering. They replaced tugs which probably were on strike, or not big enough to provide motive thrust.
I last saw this in Melbourne in the early '70s when the tug company went on strike. The AEOs hated it as they saw it as an abuse of airframes/engines.
So, no they couldn't aid the ship in going faster, but could help you get alongside. Oh, and the stokers were known to burn a bit of jet fuel in the ship's boilers as well!
Watch 'the Bridges of Toko Ri' with William Holden for an early scene in the movie that shows this 'Pinwheel' evolution using chained down piston fighters to assist in docking.
The Co of the squadron goes over the head of the Captain to complain directly to the Admiral of the abuse to his fighters engines.
With diastrous results to his career..
A fun flick though with some great airborne scenes on and off the carrier.
The Co of the squadron goes over the head of the Captain to complain directly to the Admiral of the abuse to his fighters engines.
With diastrous results to his career..
A fun flick though with some great airborne scenes on and off the carrier.
The Australian carrier HMAS Melbourne was docked on a 'stinking' hot day in 1980 or '81 at Station Pier, Melbourne, using Grumman Trackers chained to the deck for the 'pinwheel' manoeuvre (The 'wharfies' were on strike as usual). A miniature 'Bridges at Toko Ri' scene was subsequently played out between engineers, pilots, flight safety officers and ship's crew regarding alledged exceedence of aircraft engine operating temperatures. But that's naval aviation; the ship comes first (aircraft are just another weapons system).
I had a tour of the USS Nimitz in the '70s when she was anchored in Spithead.
I recall being shown the lower hangar deck which had an engine running bay at the aft end where jets could do runs without affecting flight ops. There were shutter doors to open at the back and side and shut off the rest of the hangar.
I think an F14 or F18 at full re-heat should help the ship along, but with two neuclear reactors I doubt it needs any help.
I recall being shown the lower hangar deck which had an engine running bay at the aft end where jets could do runs without affecting flight ops. There were shutter doors to open at the back and side and shut off the rest of the hangar.
I think an F14 or F18 at full re-heat should help the ship along, but with two neuclear reactors I doubt it needs any help.
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On the subject of aircraft carriers, I understand that there is a time-honoured procedure (pre-GPS) which enables aircraft to locate and return to a moving mother ship without the ship having to emit signals to alert the enemy. How does this work ?
Last edited by ReverseFlight; 11th Jan 2010 at 14:41.
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Intrigued by the post about finding the carrier, I rang my friend, ex RN and a helicopter pilot.
"Ah yes" he says, "I know that one. It's simple".
"Plot your circle of uncertainty centred on where you think the carrier is. 25 miles radius would usually be right for a jet, 1 mile for a chopper.
Then, find out the wind direction and speed at 5,000 ft above the sea. Plot the point on the circle's circumference precisely upwind of the centre. Then fly round from that point, clockwise and observing inwards, at 5,000 ft in ever-decreasing circles until you find the carrier. Anything else you want to know?"
"How do I find out the wind direction and speed?"
"Call the bleedin' carrier, of course."
He's retired now. He once dropped my gun* into the sea - after converting to a Wessex - when some one said "What's the time?" and he answered "Eight Bells", whatever that means. He explained later that the hook release button was where the PTT used to be.
PS That's gun as in 105mm gun, not gun as in 9mm peashooter...
"Ah yes" he says, "I know that one. It's simple".
"Plot your circle of uncertainty centred on where you think the carrier is. 25 miles radius would usually be right for a jet, 1 mile for a chopper.
Then, find out the wind direction and speed at 5,000 ft above the sea. Plot the point on the circle's circumference precisely upwind of the centre. Then fly round from that point, clockwise and observing inwards, at 5,000 ft in ever-decreasing circles until you find the carrier. Anything else you want to know?"
"How do I find out the wind direction and speed?"
"Call the bleedin' carrier, of course."
He's retired now. He once dropped my gun* into the sea - after converting to a Wessex - when some one said "What's the time?" and he answered "Eight Bells", whatever that means. He explained later that the hook release button was where the PTT used to be.
PS That's gun as in 105mm gun, not gun as in 9mm peashooter...
Last edited by Capot; 11th Jan 2010 at 16:48.
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Watch 'the Bridges of Toko Ri' with William Holden...
A fun flick though with some great airborne scenes on and off the carrier.
A fun flick though with some great airborne scenes on and off the carrier.
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While we are talking about aircraft carriers I have another question, with apologies to Brian Abraham who told me the answer but in my dotage I have forgotten.
The moder carrier flight deck is, I think, at 15 degree angle to the centreline of the ship. Now with the carrier doing perhaps 20 to 30 knots into a not inconsiderable headwind at times and with a jet at something like 130 knots on approach to land. Does the pilot make any allowance for crosswind? Is there any crab angle applied and if so is it removed prior to touchdown or does the undercarriage have to take some lateral strain as well as vertical?
The moder carrier flight deck is, I think, at 15 degree angle to the centreline of the ship. Now with the carrier doing perhaps 20 to 30 knots into a not inconsiderable headwind at times and with a jet at something like 130 knots on approach to land. Does the pilot make any allowance for crosswind? Is there any crab angle applied and if so is it removed prior to touchdown or does the undercarriage have to take some lateral strain as well as vertical?
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"Aim for the crotch" -- the intersection of the angle deck with the straight deck. That axiom works for normal situations, and only slight corrections need be made.
Ideally, the wind is down the angle. Often when the ship has to make its own wind, it is "axial" -- down the straight deck -- requiring more correction.
Ideally, the wind is down the angle. Often when the ship has to make its own wind, it is "axial" -- down the straight deck -- requiring more correction.
HMAS Melbourne only had a 5 degree angle. To recover aircraft, the 'fish heads' would steer the ship so that the wind was down the angled deck. In calm winds, as Intruder alluded to, the wind would be axial causing turbulence off the ship's 'island' (and a whiff of stack gas through the open overhead hatches if you were in a Tracker). Calm conditions on a moonless night were, to my mind, the most challenging for getting back on board!
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Captain Dart and Three Wire, I remember at the end of a day out on HMS Ocean in which my father was serving, based in Malta just prior to leaving for Korea, when the Captain angled the Fireflies and Sea Furys at the stern to assist the tight turning cricle before picking up her mooring buoy.
The sound was thunderous and spine tingling!
GF
The sound was thunderous and spine tingling!
GF
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Does the pilot make any allowance for crosswind? Is there any crab angle applied and if so is it removed prior to touchdown
This results in an approach where just prior to the threshold you make a small correction that results in the wind being "right on the nose" at touchdown. If you don't, it doesn't really matter as the hook has found the arrestor cable and you have stopped! The glide slope 'crab' is slightly right, and unlike a land based crosswind approach, when you take it off there is no x-wind, rather your runway is moving 15 degrees right of heading at the ship's speed through the water.
The whole situation is unfamiliar to non carrier trained pilots, as the wind-speed into which they are landing is comprised of two components made up by the actual wind-speed and the ships speed. So your GS at touchdown will be TAS minus wind-speed, minus relative ship-speed. In this situation the cross-wind factor is maximum on a calm day with the ship steaming, but as the relative angle between the wind direction and the ships heading doesn't exceed 15 degreees, the x-wind factor is negligible.
mm43
Further to 'The Bridges at Toko-ri', does anyone remember a scene in the original movie where the character played by William Holden stands with his nose inches away from where the below-deck component of the catapult shuttle stops after each launch? When he stopped flinching he figured he had got his nerve back. My purchased DVD of the film does not include the scene; does anyone remember it??
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Great post, Capot. Thanks to you and your friend - actually a good friend of mine who flew in the Marines in the Vietnam war forgot the details of the procedure and I'm sure this will help jog his memory. 
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Reverseflight - the RN use something called Outhouse (at least for rotary operations). Outhouse is a moving datum which has a set course and speed - this is given to the crew before they depart. The Ship then guarantees to remain within a specified distance (I forget the numbers) of the moving datum. The helicopter crew always know, therefore, roughly where the Ship will be on their return. If not emcon silent, they can then use ESM to find the ship.
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On the subject of aircraft carriers, I understand that there is a time-honoured procedure (pre-GPS) which enables aircraft to locate and return to a moving mother ship without the ship having to emit signals to alert the enemy. How does this work ?
At the briefing the Fisheads would give the ship's MLA (Mean Line of Advance) and you could predict where the ship would be by taking the recipricol of the course and adding 5 knots.
Example: Cod Face says he's going to go 180 at 10 kts. Therefore, after one hour you would search 360 at 15 nms from the launch position.
A truly excellent means of locating the boat was to combine the calculation above with poor weather. If, in the example above, there was a fog bank 20 nms north of 'Mother', then you could put money on the fact that the Fisheads would have piled on a bit more speed to ensure they were cloaked in fog ready for your recovery.