Rapidly onboard JP-5 to USS Abraham Lincoln

[Donald]

So it seems the Navy is in a hurry to rapidly onboard fuel the the USS Abraham Lincoln in San Diego.

The fuel depot can onboard fuel at the rate of 300,000 gallons/hr but I guess with other ships in port needing fuel the fuel depot cannot pump fast enough.

So the Navy hired two barges to shuttle fuel from the ship to the fuel depot until all 1.7 million gallons of JP-5 are onboarded.

And I get annoyed at the Mobil station if I have to wait for a free diesel pump.

https://www.navalnews.com/naval-new...braham-lincoln-for-urgent-pacific-deployment/

 

[FowVay]

Those darned jets! They make a nuclear aircraft carrier that can go 20 years without needing a top-off but those little stinger thingys that fly around drink fuel like a sailor drinks rum.

 

[wwillson]

Those darned jets! They make a nuclear aircraft carrier that can go 20 years without needing a top-off but those little stinger thingys that fly around drink fuel like a sailor drinks rum.

Read "Tanker Pilot" and you'll have a whole new appreciation for how much fuel military jets consume.

 

[97prizm]

Read "Tanker Pilot" and you'll have a whole new appreciation for how much fuel military jets consume.

I met an SR-71 Blackbird pilot 20ish years ago when he came and spoke at my EAA chapter. He said the Blackbird burned fuel so fast you could cut the back end off a fuel truck and it wouldn't flow fast enough. Tanking up was fun as a KC-135 would have to full throttle while refueling the Blackbird to keep the Blackbird from stalling in flight.

 

[ka9mnx]

Our F16's burned about 1200 gallons, yes the AF uses gallons, in less that two hours in combat style flying.

 

[SubieRubyRoo]

I met an SR-71 Blackbird pilot 20ish years ago when he came and spoke at my EAA chapter. He said the Blackbird burned fuel so fast you could cut the back end off a fuel truck and it wouldn't flow fast enough. Tanking up was fun as a KC-135 would have to full throttle while refueling the Blackbird to keep the Blackbird from stalling in flight.

Considering a KC-135 has a cruising speed of ~460 knots, even though I don’t have personal experience flying the SR-71, I’m going to say whoever told you that was pulling your leg harder than an F-14 pulled an arresting gear cable under full afterburner.

 

[wwillson]

I met a B1B pilot that said the highest fuel flow he ever saw was a sea-level with full AB which was 398,000 lb/hr. That's 60,000 gallon/hr.

 

[97prizm]

Considering a KC-135 has a cruising speed of ~460 knots, even though I don’t have personal experience flying the SR-71, I’m going to say whoever told you that was pulling your leg harder than an F-14 pulled an arresting gear cable under full afterburner.

Apparently refueling the Blackbird was difficult as seeing out of the cockpit was limited and the fueling port was behind the cockpit.

 

[Astro14]

Considering a KC-135 has a cruising speed of ~460 knots, even though I don’t have personal experience flying the SR-71, I’m going to say whoever told you that was pulling your leg harder than an F-14 pulled an arresting gear cable under full afterburner.

The issue is not the cruising speed in knots of true airspeed, the issue is the refueling speed in indicated air speed.

At 35,000 feet, as a nominal altitude, the speed of the KC 135 is going to be about 260 indicated knots. That’s going to require the SR 71 to fly a very high angle of attack.

At that high angle of attack, the air speed on the receiver aircraft is difficult to control because they are on the backside of the lift over drag curve. L/D.

To keep the SR 71 receiver at an angle of attack where it is speed stable is going to require the tanker to fly at an indicated air speed of closer to 300, perhaps 350, indicated.

But, that requires being at relatively low altitude, which is less efficient, the receiver aircraft has to descend farther in order to refuel and climb farther in order to get back on mission profile.

There is a balance there, and it is not as simple as it might seem.

 

[Astro14]

Those darned jets! They make a nuclear aircraft carrier that can go 20 years without needing a top-off but those little stinger thingys that fly around drink fuel like a sailor drinks rum.

Yes, those pesky little airplanes. I have heard surface warfare officers say how great the carrier would be, if they could only get rid of those pesky little airplanes.

 

[Donald]

I think I read that afterburner is 10x the fuel usage for only 2X the thrust. And that planes taking off from a carrier are so loaded with ordnance that they have little fuel in their fuel tanks and pretty much must immediately fuel from a tanker after takeoff. During a sortie run a tanker is the first plane to take off, then all the fighter jets.

 

[Hohn]

Read "Tanker Pilot" and you'll have a whole new appreciation for how much fuel military jets consume.

My Academy roommate and his wife (a classmate of mine) are tanker drivers-- or were. She's flying for Alaska now and he's running the 225th ADS:

https://www.wads.ang.af.mil/About-U...-p-huhmann-225th-air-defense-group-commander/

They have stories.

 

[Astro14]

I think I read that afterburner is 10x the fuel usage for only 2X the thrust. And that planes taking off from a carrier are so loaded with ordnance that they have little fuel in their fuel tanks and pretty much must immediately fuel from a tanker after takeoff. During a sortie run a tanker is the first plane to take off, then all the fighter jets.

Don’t know where you read that - but that’s simply not the case.

Full fuel - always.

Ordnance as needed.

So, a Legacy Hornet, weighing 28,000 empty, was often taking off at 50,000+ - the difference being fuel and ordnance. The internal fuel of an F/A-18C was about 11,000#. Each drop tank was 2,000#. Typically two drops, sometimes 3, sometime 1.

That said, having extra gas for a mission helps, so, they will often “top off” overhead before going on mission, but one tanker has, perhaps, 10,000# of give, so, you’re not “filling up” those overhead, just giving them a bit extra, or it would be one tanker for every mission airplane, which is silly.

 

[Donald]

Don’t know where you read that - but that’s simply not the case.

Full fuel - always.

Ordnance as needed.

So, a Legacy Hornet, weighing 28,000 empty, was often taking off at 50,000+ - the difference being fuel and ordnance. The internal fuel of an F/A-18C was about 11,000#. Each drop tank was 2,000#. Typically two drops, sometimes 3, sometime 1.

That said, having extra gas for a mission helps, so, they will often “top off” overhead before going on mission, but one tanker has, perhaps, 10,000# of give, so, you’re not “filling up” those overhead, just giving them a bit extra, or it would be one tanker for every mission airplane, which is silly.

Good to know. It's also possible (but how likely??) that at 72 I just remembered wrong.

 

[ka9mnx]

That said, having extra gas for a mission helps, so, they will often “top off” overhead before going on mission, but one tanker has, perhaps, 10,000# of give, so, you’re not “filling up” those overhead, just giving them a bit extra, or it would be one tanker for every mission airplane, which is silly.

Right. When I was in the Desert, our jets were fully loaded with munitions and fuel. On take off when reaching the end of the runway they would do a "military" take off. That's pulling the jet into a vertical climb with full "augmenters" (AF doesn't call them afterburners). They immediately hit the KC-135's for a top off. We were in a hostile zone.