Question for anyone in carrier aviation.
- Thread starter Houston
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Nihon_Ni
Well-Known Member
No, they aren't normally defueled when taken below. They only time they would normally be defueled is when there's some maintenance action that requires it for access. The hangar deck has a overhead foaming fire protection system, sort of like a sprinkler system in an office building, but it puts out foam instead of water which extinguishes fuel fires. On my ship there was a huge fire door in the center that cut the hangar in half. The lane for that door always had to be clear, and the doors would close in a few seconds when activated. There was someone on duty there 24/7/365 who watched the hangar deck and would close the door and at the first sign of fire.
Flyinthrew
Well-Known Member
In addition, aircraft on Naval vessels are fueled with JP-5 (now technically named F-44, but nobody calls it that) rather than JP-8 or Jet-A. The flash point of JP-5 is somewhere between 20 and 25 degrees celsius higher than that of Jet-A so it is inherently safer.
When you fly onto the ship from a shore base the fuel is supposed to get tested for flashpoint before it is allowed to be taken below.
When you fly onto the ship from a shore base the fuel is supposed to get tested for flashpoint before it is allowed to be taken below.
NATO calls it the F-44 name. Those F prefixes are all the NATO designations for the various aviation fuels.
killbilly
Vocals, Lyrics, Triangle, Washboard, Kittens
Dumb question....can a modern fighter jet engine burn both? I'm guessing yes because I've seen USN aircraft at civilian FBOs (presumably buying fuel) and now I'm wondering if the civilian FBO keeps JP-5 on hand or they just burn whatever's handy.
Yes. If we in the AF, in my birds, operated prolonged from a USN/USMC installation, there would be a minor fuel control adjustment made is all.
Flyinthrew
Well-Known Member
Our digital engine controller is quite good at adjusting for different fuels with no input from the pilot. You can take off with JP-5, hit a USAF tanker with JP-8, then an Omega with Jet-A+ and it makes no difference. There is a very large table of approved fuels. There’s one Russian fuel that has a table note that says it’ll chug at high altitude and low power settings. My assumption is that it’s made out of vodka and plutonium.
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Separate subject. Was slumming around the boneyard checking stuff out and taking pics. What are you guys doing with the 50+ GR7/9 airframes sitting disassembled in the boneyard here? Parts, or actual aircraft being brought onto the line?
Lawman
Well-Known Member
Helicopters as well.
Really the Blackhawk, Seahawk, and Apache are all running the same 701 series GE engines. The only changes are to the assembly section of the engine.
Land based operations run JP-8 for the Army, but we can run 4 or 5 with no change in actual aircraft function, only a change in calculated fuel and performance rates. With the all glass cockpit that’s as simple as a button push telling the computer what it’s eating.
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killbilly
Vocals, Lyrics, Triangle, Washboard, Kittens
trafficinsight
Well-Known Member
The sabreliner at state (A T-39A) had a selector on the fuel control with detents labeled JetA, JP-(something) and.... Avgas.
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Yes the older non-FADEC birds had to be manually adjusted to long-term use of approved alternate fuels. For the A-10, if I remember right (am going back 15 years here), that was at the 3rd refueling. For a once or twice refueling when stopping at a USN/USMC base, it was no issue. But if we were temp duty there and operating out of there, then Mx made the adjustment. As was stated earlier, newer digitally controlled engines do it all magically.
///AMG
Well-Known Member
If you have a spare 20 mins OP, watch the video "trial by fire" about the Forrestal fire. Doesn't cover defueling but it does contain a detailed analysis of shipboard fuel based fire fighting efforts gone wrong. As a legacy of that accident, everyone who deploys on an aircraft carrier (aircrew included), is required to attend actual hands on firefighting training every 4 years or basically at least once every sea tour. I just went a week ago for a refresher, and fought a large propane fire simulating a fuel fire on a flight deck around a burning aircraft fuselage, with a standard navy hose. There is a much more robust fire fighting syllabus for ships company/Damage Control folks where they run around in an enclosed space with full breathing apparatus and gear fighting their way out of multiple blazing rooms. But for aircrew and random cats and dogs, we still get this familiarization course, primarily because with Forrestal, the initial responders were all dead within a couple minutes, and the firefighting effort was left to folks with no formal training, which resulted in some significant errors ultimately.....errors that almost cost the Navy a capitol ship.
Flyinthrew
Well-Known Member
Those are for parts. There is enough that is non-common about them that we can't mod them and slap them on the line. And to be quite honest, we haven't felt the effect quite as much as we thought we would down at the operational level. It's the whole "we have 300 of Part X, but Part Y is the one that keeps breaking. We have one of Part Y. There are 7 in rework, but the test bench is out of calibration." The acquisition and supply people need a mirror to slap their own asses.
It's not just aviation fuels, NATO uses F- codes for all their fuels. You don't want to put F-76 into any aircraft. The military is mostly single-source fuel on JP-8/F-34 for aircraft and ground vehicles. Navy uses JP-5/F-44 and F-76 for their peculiar "fear of shipboard fire" needs. Ships with embarked Marine units also carry MOGAS (regular automotive fuel that you can buy at the gas pump) and there are severe restrictions when fueling using MOGAS. Any MOGAS not stored in the internal "MOGAS" fuel tank has to stored on jettison racks external to the skin of the ship. The Marines have an annoying habit of putting empty MOGAS containers on the jettison rack, and leaving the full MOGAS containers next to the jettison rack where it can't be jettisoned in the event of a fire. So we get on their case about it and some poor Pfc or LCpl ends up getting to rearrange MOGAS containers the jettison rack properly.
The overhead sprinkers in the hangar bay have remote and local controls. The remote controls are in a location called "CONFLAG" and there is at least one CONFLAG station for each section of the hangar bay which can be sectioned off by doors. The conflag stations also control the ventilation for their area and the hangar section door. On amphibious assault ships, there are several vehicle decks, where the M-1 tanks, LAVs, AAVs / rolling stock are stored and fueled before they go ashore via LCU/LCAC landing craft. Since there is more F-76 than there is JP-5/F-44, the vehicles and LCUs get fueled with F-76. LCACs get JP-5. There are sprinkler systems and the associated CONFLAG station for each vehicle bay and in the well deck where the actual landing craft is stored / launched / recovered.
It is kind of neat to see the mess generated by the overhead sprinklers - they have to be tested at least once per workup cycle for certification to handle/operate aircraft usually right after leaving the shipyard - so in the days before the sprinkler test, each sprinkler head is wrapped up with a collapsible plastic tube that drops from the sprinkler head to the hangar bay floor. So while the hangar bay bulkheads are spared from the test, the deck bears the brunt of the testing.
The flight deck also has sprinkler heads embedded in the flight deck, and the island structure is also has its own separate sprinkler system. Though the sprinkler system on the flight deck and island is a dual purpose fire fighting and NBC system compared to the one in the hangar bay. The system is also tested as part of certification to handle/operate aircraft. Either way after the system is used/tested, it is followed up with a fresh water washdown.
The AFFF system that feeds the flight deck / hangar / vehicle deck sprinklers comes from several HiCap AFFF systems located throughout the ship. It's a station that contains several thousand gallons of AFFF concentrate (6- to 10,000 gallons is what my failing memory tells me). and when it's activated it feeds the concentrate along with water from the fire main to the sprinkler heads. If there's a failure of the HiCap station or you run out of AFFF concentrate, you can draw from another station or there will be racks of 5 gallon jugs AFFF concentrate located throughout the ship and outside each repair locker. Though if you're down to using the 5 gallon jugs, life will suck for the fire attack teams as a single 1.5-inch fire hose will eat a single 5-gallon jug of AFFF concentrate every minute. a 2.5-inch flight deck fire hose will eat a 5-gallon AFFF concentrate jug every 30 seconds.
The main difference between the fire fighting trainer for shipboard fires vs the fire fighting trainer for land-based fire fighters is that you start at the top and work your way down, i.e. from the damage control deck down the engine room. So you start at the top of the 4-story fire fighting training tower, and you have to drag all the hoses you are going to use all the way down to the ground floor, and then fight the fire in the engine room / ammunition magazine / storeroom locker, etc. So the attack teams carry the hose over the shoulder and you can actually use it for support to go down the steep ladder. You have to station someone at each level to guide the hose down the access trunk as you go down the ladder.
During one firefighting training session, we had to hose down the "bombs" to keep them cool during an adjacent flight deck fire. So after keeping the bombs cool, we send one guy to check that the bombs are still cool. He was supposed to say something to the effect that the bombs were cool. But he decided to be a smart ass and said the bombs were still hot. So we let him have it and drenched the bombs with more fire main and didn't give him a chance to get out of the way.
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///AMG
Well-Known Member
I'd really never thought about the fact that the AF gas we always got was probably not the "shipboard" type, until I had to do some random govt gas card training or something. Apparently, per the letter of the law, the jet has to be defueled if you get JP8 or Jet A. I don't know if that is actually true, and it certainly isn't in practice. Possibly the Navy/USMC only KC-135's carried JP5, but I know for a fact that the dual capable KC-10 was carrying whatever they brought with them from that place they fly from over there......considering they would reconfigure and give USAF gas with us on the wing, presumably from the same tanks. Not a tanker (ha actually I am now) guy, so maybe there is something I'm missing.
Pilot Fighter
Well-Known Member
I don't recall the details but I think the procedure is written in a way that rarely does anything have to be done unless you come aboard with an unusually high volume of JP8 or JetA and the aircraft is being brought downstairs.
I think it's do nothing if it's under a certain percentage full, dilute if it's above a certain percentage full, defuel or defuel and dilute if it's above a certain percentage full.
Waiting for a grape to correct me.
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Lawman
Well-Known Member
Man you guys have a lot of rules/procedures that would never work in the Army just because of the people you usually find in the 3-5 platoon.
Pilot Fighter
Well-Known Member
I'm not sure if there's any evidence this one is working.