ATTN: Samnavy
10-29-2011, 11:40 PM
#21
Minimum speed to take off should be whatever the stall speed of the plane is plus a few knots for ground effect. Tactical aircraft don't brief that however because everything has a margin of safety. We brief rotate speed in the Hawkeye. We almost always take off at the exact same gross weight of 54k. Aircraft that have stores can have takeoff weights that vary by 30klbs+... for example, a Superhornet has catapult launch settings that go from like 34klbs to 68k... ie, he can take a cat-shot with zero weapons and almost dry tanks all the way up to full tanks and carrying 15k of weapons or a mix.
What is far a far more important number for tactical jets however is refusal speed. There comes a certain speed reached on takeoff that when you hit it, you must continue the takeoff. Prior to, you still have the option to abort. In the Hawkeye, our refusal speed does not take into account our ability to use reverse thrust in case the reason we're aborting is because of an engine issue... it's only using the brakes. Ie... if our refusal speed is 120kts, at 119kts, we still have enough runway left to stop the aircraft on the pavement using the brakes alone. At 120kts, if we attempt to abort and have no reverse thrust, we'll drive off the end of the runway. The term "Critical Field Length" comes into play here. CAVEAT... almost all military airfields have arresting gear that we can use to stop the plane, but you're not allowed to factor that in when calculating numbers.
Tactical jets obviously don't have reverse thrust, but Navy aircraft typically have a very robust braking system due to our typically short runways. Air Force aircraft on the other hand with their huge runways typically have very wimpy brakes.
As for shooting... the shooters prior to walking out on the flight deck to shoot have a rundown of all the planes that are going to fly that event. They know the side numbers of the planes, their loadouts, and weights. That information, along with current atmospheric data allows the shooters to make some basic calculations about what kind of wind they'll need to see over the deck to launch planes.
The thing about carrier flight ops is that all of the procedures are based around shooting planes while simultaneously defending the carrier from attack. Any time the ship is launching/landing, it has to drive in a straight line at a steady speed... that makes it very easy to attack, especially for a submarine. The idea is to land/launch as quick as you can and the turn. A typical land/launch cycle during the day might take 15 minutes... but at night, might last an hour. So, while the carrier is under flight ops, it's course/speed is predictable and it is most vulnerable. The shooters will actually tell the ship drivers how much wind they need over the deck... specifically, a minimum wind.
So if there is 10kts of wind out of the west on a specific day, but the ship only has seaspace to drive eastbound, and the shooters need 20kts of wind over the deck... the ship has to drive the screws to 30kts... which is hauling ***. How much wind the shooter needs depends mostly on the aircraft weights and the air temp/humidity/density.
So here's how it works. A plane rolls up to the cat and there is a guy on the deck who holds up a WEIGHT BOARD with the known weight of the aircraft on it which the pilot rogers and that guy then shows the shooter... that way the shooter knows the exact current weight of the plane.
The shooter then takes that weight and the current wind over the deck and references a chart called a "LAUNCH BULLETIN". The aircraft weight plus the wind over the deck tells the shooter how much power to give the catapult. Every plane has different charts, and the power of the cat is set for every plane on every shot real-time.
The shooter dials the power setting into the cat and then keeps a very close eye on the wind throughout the shooting process. If halfway through a shot the wind drops enough, the shooter will suspend the shot and "re-wind". In that pic, you can see the shooter, the deck operator with the launch bulletins in his lap, his "talker" who is in comms with the equipment operators belowdecks, and on the inside of the hatch, the boxes that show the shooter the current windspeed and atmospheric data.
The catapult has a power setting of 20-320. This does not equate to any speed, it just means that a setting of "20" is the minimum setting (ie, 1% power of the cat), and "320" (100% of catapult power) is the maximum. The dials adjust in even numbers. The power setting for that particular plane on that particular shot if the weight is perfect and the wind is exact gives the aircraft "SAFE SINGLE ENGINE FLYAWAY SPEED PLUS 15KTS". If you **** a motor on the stroke, you still have enough endspeed to safely fly the plane and execute a safe climbout.
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10-30-2011, 11:13 AM
#26
"Quality" is my first name.
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Sam, why not launch all planes at max cat speed?
And ever see one spill in the Ocean? What was the outcome? Was every rescued? What happened to a pilot if they fail a plane into the ocean?
Thanks for the explanation though. Was an interesting reading
And ever see one spill in the Ocean? What was the outcome? Was every rescued? What happened to a pilot if they fail a plane into the ocean?
Thanks for the explanation though. Was an interesting reading
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10-30-2011, 02:02 PM
#28
We did for the Army/Navy Football game... had a camera crew onboard for a week building footage for commercials and stuff. I took this video. The action is in the last 15 seconds. Bad day to be a football.
The shooters and the airboss will do a "boot shoot" at the end of their tour. Sometimes the Captain will if he's cool. Here are some shots and a video of mine. You prep a pair of boots ahead of time, but tradition requires you run the track barefoot... hence my socks. It's hot as ****.
Hmmm... the entire moving assembly of the pistons/connector/shuttle weigh about 12,000lbs. They're made of the most ungodly strong steel you can imagine. On the "no-load" setting where we shoot test shots with no planes attached, the assembly hits the brakes at about 200mph... and all that energy concentrated on an area the size of a fist when it makes contact with your nuts. You can't explain that.
It's all about fatigue. You could put every plane off the end at a 320 setting assuming you could build a nose-gear that wouldn't get ripped off... but then you'd be putting double/triple the stress on the plane that it needs. They need to last 25 years, so giving them just enough speed to safely fly provides maxiumum lifespan of aircraft and catapult parts. Goshawks (training jets) weigh 12k lbs. Tomcats could weigh as much as 72k lbs if I remember right.
A Hawkeye leaves the flight deck at about 140kts. A Hornet anywhere from 150-180kts. Hornets also have afterburners. The power settings for Hornets are different if they're going to be shot in blower. The settings are actually less for a blower shot than a regular shot even though blower shots are typically for heavier aircraft. The afterburner is helping the plane down the track. Remember that all the shots are based on getting enough speed for a SINGLE ENGINE shot. Hornets are "almost" centerline thrust, which means if they lose a motor on the stroke, it's not trying to push the plane sideways down the track. Hawkeyes have extreme assymetric thrust issues because the motors are so far apart, and the launch bulletins are all calculated for a worst case scenarios... ie, a Hornet doing a blower shot who loses a motor completely and loses the blower on the good engine, or a Hawkeye losing it's critical engine.
I've never witnessed a cat failure personally. They are VERY RARE. But... but my best friend died in 2007 off of Truman during carrier qualifications when their Hawkeye crashed immediately off the cat even though they had good speed... crash report had many causal factors, the cat was not one of them. My daughter is named after him.
With an ejection seat aircraft, rule #1 is that if you're going to pull the handle, do so in time to saver your life. I'm pretty sure the emergency procedures for a cold cat-shot for tactical jets or "not enough speed" off the cat are:
1. Select Afterburner.
2. Gear up.
3. Flaps to FULL.
4. Standby to eject.
In the Hawkeye, skip step 1 and insert "Pray" for #4.
This is a very famous video of an Intruder who had a hydraulic flight control failure off the cat. The pilot lived but the Navigator did not... you can see he hits the water without a full chute opening. The pilot manages to get one swing in the chute before impacting the water.
Here's another famous video of an old radial piston S-2 Tracker.
A Hawkeye leaves the flight deck at about 140kts. A Hornet anywhere from 150-180kts. Hornets also have afterburners. The power settings for Hornets are different if they're going to be shot in blower. The settings are actually less for a blower shot than a regular shot even though blower shots are typically for heavier aircraft. The afterburner is helping the plane down the track. Remember that all the shots are based on getting enough speed for a SINGLE ENGINE shot. Hornets are "almost" centerline thrust, which means if they lose a motor on the stroke, it's not trying to push the plane sideways down the track. Hawkeyes have extreme assymetric thrust issues because the motors are so far apart, and the launch bulletins are all calculated for a worst case scenarios... ie, a Hornet doing a blower shot who loses a motor completely and loses the blower on the good engine, or a Hawkeye losing it's critical engine.
I've never witnessed a cat failure personally. They are VERY RARE. But... but my best friend died in 2007 off of Truman during carrier qualifications when their Hawkeye crashed immediately off the cat even though they had good speed... crash report had many causal factors, the cat was not one of them. My daughter is named after him.
With an ejection seat aircraft, rule #1 is that if you're going to pull the handle, do so in time to saver your life. I'm pretty sure the emergency procedures for a cold cat-shot for tactical jets or "not enough speed" off the cat are:
1. Select Afterburner.
2. Gear up.
3. Flaps to FULL.
4. Standby to eject.
In the Hawkeye, skip step 1 and insert "Pray" for #4.
This is a very famous video of an Intruder who had a hydraulic flight control failure off the cat. The pilot lived but the Navigator did not... you can see he hits the water without a full chute opening. The pilot manages to get one swing in the chute before impacting the water.
Here's another famous video of an old radial piston S-2 Tracker.
Last edited by samnavy; 10-30-2011 at 11:21 PM.
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10-30-2011, 02:18 PM
#30
Hmmm... the entire moving assembly of the pistons/connector/shuttle weigh about 12,000lbs. They're made of the most ungodly strong steel you can imagine. On the "no-load" setting where we shoot test shots with no planes attached, the assembly hits the brakes at about 200mph... and all that energy concentrated on an area the size of a fist when it makes contact with your nuts. You can't explain that.
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10-30-2011, 03:10 PM
#33
Me shooting from the "BUBBLE". Something cool to watch for is immediately before I say "there's the squat" at :53 seconds. You'll see the nose of the plane dip down about a 6" as the pilot selects afterburner and the thrust fully compresses the nose strut. You'll also hear me use the word "COMBAT" a couple times. That doesn't mean this is a combat mission, but rather "COMBAT RATED THRUST" which is the technical term for afterburner. This plane is a FA18/F Superhornet 2-seater. You can see 3 large fuel tanks which drives the gross weight high enough that an afterburner takeoff is warranted.
This is taken from the PORT catwalk and the shot is from Catapult-4... at that point in the stroke, he's doing about 100kts
I'm filming this one. It's a shot from the bow bubble shooting Cat-2, an FA18/E afterburner (COMBAT) shot.
You just miss the pilot "thumbs up" for the weight board, but the guy brings the board to the Shooter and he uses that number to reference the launch bulletins, and then set the catapult power via the 3 large ***** on the panel. Turn the volume up so you can hear what he's saying as he goes through the sequence.
You'll see at time 1:29, the guy on the flight deck throws his arm in the air... this is one variation on the signal for the pilot to now select afterburner. A deck operators combat signal is a point of pride. That one was pretty lame. Some guys get really wild. My signal was somewhat legendary.
I'm filming this one. This is TOPSIDE shooting, 2 shooters, the big guy is under instruction. They're shooting Cat-3. The guy pushing the buttons is actually in the catwalk directly to my right. You can see the shooters "COMBAT" signal at :27... lame.
This is taken from the PORT catwalk and the shot is from Catapult-4... at that point in the stroke, he's doing about 100kts
I'm filming this one. It's a shot from the bow bubble shooting Cat-2, an FA18/E afterburner (COMBAT) shot.
You just miss the pilot "thumbs up" for the weight board, but the guy brings the board to the Shooter and he uses that number to reference the launch bulletins, and then set the catapult power via the 3 large ***** on the panel. Turn the volume up so you can hear what he's saying as he goes through the sequence.
You'll see at time 1:29, the guy on the flight deck throws his arm in the air... this is one variation on the signal for the pilot to now select afterburner. A deck operators combat signal is a point of pride. That one was pretty lame. Some guys get really wild. My signal was somewhat legendary.
I'm filming this one. This is TOPSIDE shooting, 2 shooters, the big guy is under instruction. They're shooting Cat-3. The guy pushing the buttons is actually in the catwalk directly to my right. You can see the shooters "COMBAT" signal at :27... lame.
Last edited by samnavy; 10-30-2011 at 08:13 PM.
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10-30-2011, 07:46 PM
#36
Each catapult is manned by 7-8ppl on deck including the Shooter, and 6-7 belowdecks. There are 4 cats.
Each arresting gear engine is manned by 6-7 on deck and 5-6 belowdecks... there are 4 engines.
There are 7-10ppl in the tower including the Airboss.
There are 5-8 LSO's on the LSO Platform for landings.
During FULL flight ops, there are anywhere from 200-300 other people on deck who are driving tow tractors, chocking and chaining aircraft, directing aircraft, arming aircraft, fueling aircraft, providing safety oversight, performing maintenance on aircraft or just watching.
But at it's most basic level, the amount of people it takes to man a cat, hook up the plane, and then push the fire button takes about 40ppl.
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10-30-2011, 07:53 PM
#37
I should also mention that there are 2 ways of shooting. The first way is called "TOPSIDE" or "DECKEDGE". In this method, the Shooter is up on the flight deck calling the shots, making the hand-signals, and there is another guy standing in the catwalk actually pushing the buttons on the shooters signals. The shooter still retains full control of the evolution, it's just that the actual mechanical/electrical control of the circuits is being controlled by a guy operating a panel in the catwalk.
In the "BUBBLE" method, the Shooter is inside the... well, bubble. The Shooter pushes all the buttons and there is a guy on the flight-deck who makes all the hand-motions. There is a system of lights on the flight deck that as the shooter pushes buttons, the guy on the flight deck knows what hand-motions to do next.
I've got videos of both methods so you can see the difference.
In the "BUBBLE" method, the Shooter is inside the... well, bubble. The Shooter pushes all the buttons and there is a guy on the flight-deck who makes all the hand-motions. There is a system of lights on the flight deck that as the shooter pushes buttons, the guy on the flight deck knows what hand-motions to do next.
I've got videos of both methods so you can see the difference.
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10-30-2011, 08:51 PM
#39
"Quality" is my first name.
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During FULL flight ops, there are anywhere from 200-300 other people on deck who are driving tow tractors, chocking and chaining aircraft, directing aircraft, arming aircraft, fueling aircraft, providing safety oversight, performing maintenance on aircraft or just watching.
When you were in the bubble shooting the jets, why is everything audible. Why do you call the cross wind, squat etc? Can anyone else here you saying them out loud?
Can anyone override you via a button or switch or are you the point of no return guy? Are you accountable for the people on the deck if you launch and say they made a mistake? Do mistakes even happen with that much redundancy ?
Have you seen combat?
You read a lot of ground soldiers get messed up after blowing **** up like people. Do pilots just high five and walk around saying "i feel the need, the need for speed!" and not giving a crap cause they are so distanced from it all?
Is there such thing as dog fights anymore?
Anyone ever fall overboard by accident, by choice?
Which part of your day do you dislike the most when on a Carrier; favorite part?
Can you have sex with females on a Carrier and not get in crap?
Does the carrier ever rock due to waves? Is there such thing as a big wave to a carrier?
*can you tell im so Canadian and not military.....* Alex will vouch i ask him shitloads of Military questions.
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