Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 11:52
by Dragon029
https://www.aviationweek.com/defense/lo ... rade-f-35a

Lockheed Martin has started engineering studies focused on substantially extending the range of the F-35A by increasing the total onboard fuel capacity by 40% and improving the aircraft’s fuel efficiency, Aviation Week has learned. The studies would resurrect a long-abandoned plan to install external fuel tanks under the wings of the conventional takeoff-and-landing variant. The range-extension study also could benefit from proposed propulsion improvements, such as Pratt & ...


A 40% increase in fuel would translate to roughly 2x 540 gallon tanks.

By comparison, the tanks that some will recall having previously been designed and wind-tunnel tested were 426 gallon tanks, optimised down from a 480 gallon baseline tank design.

Israel was interested in integrating 600 gallon tanks; it's possible that with drag and separation optimisation this is the range-equivalent to the 600 gal tanks that they wanted.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 13:43
by taog
Lockheed confirms that it is now engaged in a study about the option for a 600-gal. fuel tank and a wing pylon that can be jettisoned. The tank is designed to be integrated on the inboard stations—3 and 9—on each wing, the company says. Although the pilot can restore the F-35A’s stealth signature to radar by jettisoning the tank and pylon, it is not clear how the radar cross-section is affected with the equipment attached to the wing.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 14:41
by marsavian
Basically what F-22 has.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 15:30
by sprstdlyscottsmn
Well, there goes any discussion at all of a Strike Eagle going farther. It was already close. With a 70k MGTOW the F-35A with two internal AIM-120s and two internal GBU-31s and two external 600gal tanks still has nearly 9,000lb payload remaining. You could slap on two more external GBU-31s and a pair of Winders and not even be close to MGTOW. Meanwhile, the Mudhen cannot carry more than two GBU-31s if it triple bags without going over MGTOW. If it double bags it can carry 4.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 19:18
by madrat
sprstdlyscottsmn wrote:Well, there goes any discussion at all of a Strike Eagle going farther.


Badda boom, badda bing!

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 20:14
by marsavian
Strike Eagle still carries more fuel with CFT and EFT, 31,500 lb with two 600gal and 35,500 lb with three 600gal whereas the F-35A with two 600gal is 26,000 lb.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 20:33
by marauder2048
sprstdlyscottsmn wrote:Well, there goes any discussion at all of a Strike Eagle going farther. It was already close. With a 70k MGTOW the F-35A with two internal AIM-120s and two internal GBU-31s and two external 600gal tanks still has nearly 9,000lb payload remaining. You could slap on two more external GBU-31s and a pair of Winders and not even be close to MGTOW. Meanwhile, the Mudhen cannot carry more than two GBU-31s if it triple bags without going over MGTOW. If it double bags it can carry 4.


I'm assuming that the increase in volume is only possible by virtue of not having to accommodate adjacent
external store separation/jettison.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 21:00
by sprstdlyscottsmn
marsavian wrote:Strike Eagle still carries more fuel with CFT and EFT, 31,500 lb with two 600gal and 35,500 lb with three 600gal whereas the F-35A with two 600gal is 26,000 lb.

As has been mentioned many times before, it also guzzles fuel at prodigious rates due to it's sheer weight and drag.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 21:02
by sprstdlyscottsmn
marauder2048 wrote:
sprstdlyscottsmn wrote:Well, there goes any discussion at all of a Strike Eagle going farther. It was already close. With a 70k MGTOW the F-35A with two internal AIM-120s and two internal GBU-31s and two external 600gal tanks still has nearly 9,000lb payload remaining. You could slap on two more external GBU-31s and a pair of Winders and not even be close to MGTOW. Meanwhile, the Mudhen cannot carry more than two GBU-31s if it triple bags without going over MGTOW. If it double bags it can carry 4.


I'm assuming that the increase in volume is only possible by virtue of not having to accommodate adjacent
external store separation/jettison.

I assume you are referring to a three-bag eagle carrying two GBU-31s to a two-bag eagles four? Is that is the case then the issue is purely weight.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 21:08
by wrightwing
marsavian wrote:Strike Eagle still carries more fuel with CFT and EFT, 31,500 lb with two 600gal and 35,500 lb with three 600gal whereas the F-35A with two 600gal is 26,000 lb.

Along with a higher drag index, and 2 engines.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 21:08
by marauder2048
sprstdlyscottsmn wrote:
marauder2048 wrote:
sprstdlyscottsmn wrote:Well, there goes any discussion at all of a Strike Eagle going farther. It was already close. With a 70k MGTOW the F-35A with two internal AIM-120s and two internal GBU-31s and two external 600gal tanks still has nearly 9,000lb payload remaining. You could slap on two more external GBU-31s and a pair of Winders and not even be close to MGTOW. Meanwhile, the Mudhen cannot carry more than two GBU-31s if it triple bags without going over MGTOW. If it double bags it can carry 4.


I'm assuming that the increase in volume is only possible by virtue of not having to accommodate adjacent
external store separation/jettison.

I assume you are referring to a three-bag eagle carrying two GBU-31s to a two-bag eagles four? Is that is the case then the issue is purely weight.


No the F-35. The reason why you had the early comparatively low fraction external fuel tanks was the need
to accommodate adjacent store separation typically JSOW or GBU-31. If that restriction is relaxed you
can design tanks that are both drag efficient and volume efficient.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 21:55
by sprstdlyscottsmn
Oh okay, I'm tracking. It may have borne out in testing that the separation issues were overcome by other means. We may never know.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 22:38
by magitsu
Very interesting tweets about the previous rejection of 426 gal efts.

Scott Williams (UK F-35 pilot):
"Interesting Steve. I chaired the government meetings that effectively removed the 426 Gal EFT requirement back in 2010. Fuel fraction wasn’t worth it back then. A 600 Gal option changes the ball game in that regard."

https://twitter.com/scottmox/status/1139175881707012097

"Difficult to justify if they are niche. The Fuel Fraction of 426 Gal obviously favored the B best and C worst. It was still only a 12% range increase for the B though! Deemed unanimously by all partner requirements officers to not be worth the effort."

https://twitter.com/scottmox/status/1139179249028534272

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 22:51
by sprstdlyscottsmn
My first iteration of performance modeling for the F-35A said the same thing. The 426 wasn't worth it.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 13 Jun 2019, 23:21
by sferrin
sprstdlyscottsmn wrote:My first iteration of performance modeling for the F-35A said the same thing. The 426 wasn't worth it.


Sounds like the fuel tanks they thought about putting on top of the SR-71's wing. Would have gave them, "about 80 more miles" so they passed.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 14 Jun 2019, 01:22
by weasel1962
sprstdlyscottsmn wrote:Well, there goes any discussion at all of a Strike Eagle going farther. It was already close. With a 70k MGTOW the F-35A with two internal AIM-120s and two internal GBU-31s and two external 600gal tanks still has nearly 9,000lb payload remaining. You could slap on two more external GBU-31s and a pair of Winders and not even be close to MGTOW. Meanwhile, the Mudhen cannot carry more than two GBU-31s if it triple bags without going over MGTOW. If it double bags it can carry 4.


1. Can't the Mudhen just take off carrying 4 GBU-31 but with less fuel then top up to max via tanker, if there is a need? The f-35A will need to burn more fuel before tanking i.e. tanker will need to be closer to the target.

2. F-35A carrying 2 external GBU-31s, 2 EFTs and 2 AIM-9L will generate drag and attendant max altitude restrictions i.e. impact range.

3. F-35A with 4 GBU-31s may not be close to the MTOW but its TWR is worse off than the Mudhen by virtue of the F-15EX's "fuel-guzzling" but more powerful twin engines. I don't think it would be realistic to assume the F-35A has a consistent performance across all weights. The heavier the loads, the higher the fuel consumption, the lower the altitude, the more fuel burn per nm, with a weaker engine pushing those loads. The F-15E suffers from it, same laws of physics apply for the F-35A.

The requirements of a dual-engine heavy fighter vs a single-engined cheap lightweight fighter is an established, well proven strategy. Much the same way as the F-16 is a fantastic plane but still better to leave it to the F-15 to deal with fighters, a dual engined PCA will be needed. That should be the priority compared to the beauty parade/sideshow of F-15 vs F-35. Once one agrees on the validity of the strategy, the F-15 becomes irrelevant because it is neither a single-engined LWF nor is it ideal as a dual engine HWF. That is where a cogent argument has not been made which has allowed the F-15 to sneak back in.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 14 Jun 2019, 06:29
by marauder2048
weasel1962 wrote:The requirements of a dual-engine heavy fighter vs a single-engined cheap lightweight fighter is an established, well proven strategy.


That was for an era before the advent of accurate munitions that can threaten fuel supply, storage and
distribution infrastructure on practically every US and allied airbase.

You can massively harden aircraft shelters and protect them with terminal defenses but no one has figured out,
short of mountain redoubt style bases with deeply buried pipelines, how to protect fuel supply, storage and
distribution to the same extent.

If you accept that the US and allies will be operating in a fuel limited environment then you don't want twins.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 14 Jun 2019, 07:54
by doge
I daydreaming...May I fantasize of a dreams match combination this "EFT" and the "ADVENT engine"? 8)

I try to play with numbers. 8)
With a current A's 18,000 lbs fuel, the radius is about 1,400 km. (Max radius currently revealed.)

If EFT increases fuel +40% by My roughly simple calculation, will be the radius about 2,000km further from there.

Furthermore+, ADVENT engine is advertised increase the radius by +30%, so by My sketchy simple calculation will be the radius about 2,600km further from there.
2,600km!! :doh: It's a crazy distance!! :doh: It's a long working hour, which make the pilot tired... :doh:
(This is my fantasize... 8) )

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 14 Jun 2019, 13:55
by sprstdlyscottsmn
40% more fuel will not mean 40% more range. Maybe 25%. 30% tops.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 15 Jun 2019, 15:00
by mixelflick
In for EFT's. Let's see some 600 gallon bags. Every other external store makes it look that much more deadly, hope these will too.

But really, why not just move to CFT's? That's where everything went on the legacy's. First the Eagle, then Viper and lately the Super Duper Hornet. And if anyone can come up with jettisonable CFT's, it's Lockheed..

Or Israel :)

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 15 Jun 2019, 15:25
by viper12
sprstdlyscottsmn wrote:40% more fuel will not mean 40% more range. Maybe 25%. 30% tops.


Fully concur. Using the range equation at fixed height, and assuming the 40% extra fuel doesn't create extra drag and the extra weight is only the extra fuel, I end up with a combat radius of 898.7nm for the mission profile with a 669nm combat radius on internal fuel, or a 34.3% range increase.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 15 Jun 2019, 15:37
by ricnunes
sprstdlyscottsmn wrote:40% more fuel will not mean 40% more range. Maybe 25%. 30% tops.


Absolutely! Now you just have to inform this to Saab :wink:

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 15 Jun 2019, 22:04
by wrightwing
viper12 wrote:
sprstdlyscottsmn wrote:40% more fuel will not mean 40% more range. Maybe 25%. 30% tops.


Fully concur. Using the range equation at fixed height, and assuming the 40% extra fuel doesn't create extra drag and the extra weight is only the extra fuel, I end up with a combat radius of 898.7nm for the mission profile with a 669nm combat radius on internal fuel, or a 34.3% range increase.

There's got to be some drag penalty, but the question is how much? If we're more conservative and stick with 25%, that's still 837.5nm. Of course when the next generation motors are available with a 30 to 35% range increase, then we're looking at numbers like 1088.75nm to 1130.63nm when using EFTs.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 15 Jun 2019, 22:39
by viper12
There's obviously some drag penalty, so a 34% range increase for 40% extra fuel is just impossible. The weight of the fuel tanks themselves isn't completely negligible either, as I guess 2 of them should weigh around 600 pounds, or roughly 2% of the F-35A's empty weight.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 16 Jun 2019, 21:48
by geforcerfx
I wanna say it was on this forum or from a family pilot friend that said the rule of thumb was EFTs usually only give 50-75% of there fuel, the rest is the drag and weight penalty.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 16 Jun 2019, 22:07
by spazsinbad
Rules of thumb generalisation? Some A4G profiles were better with two tanks rather than three - one had to do the math.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 17 Jun 2019, 08:26
by taog
Omg, LM also considers adding the CFT to F-35 lol

Image

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 17 Jun 2019, 13:52
by vilters
Simple economics.
If LM does not develop extra range, Israel will, because they are going to use it.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 17 Jun 2019, 19:27
by blain
So both Israel and LM are developing CFTs, or is this a joint venture. A key issue will be capacity. The shape of the top of the F-35 will limit capacity. The F-16I supposedly carries around 450 gallons per CFT. The SH's CFTs have a capacity of around 515 gallons. So the capacity of the CFTs might approach the capacity of the external tanks.

The other issue will be whether the CFTs would preserve the low observability of the F-35. Israel might not have the ability to test RCS. If the CFTs are not low observable then it might make tactical sense to carry external tanks on long range missions and then drop them once entering enemy territory.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 17 Jun 2019, 21:02
by spazsinbad
"So both Israel and LM are developing CFTs, or is this a joint venture...." Both are in a joint venture and have been for years. What has been developed so far for Israel is not clear. One may speculate until someone elaborates on EFTs/CFTs.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 19 Jun 2019, 07:37
by doge
It seems to increase the "Range" by 40%....!! :shock: ...(spot)...But unfortunately, the F-35's maximum Range is not revealed... :doh: (The day when we can know the MAX range, when will it come... :roll: )
http://www.airforcemag.com/Features/Pag ... Suite.aspx
Lockheed Looking at Extending the F-35’s Range, Weapons Suite
6/17/2019​​––BRIAN EVERSTINE
LE BOURGET, France—Lockheed Martin is looking at dramatically increasing the range of the F-35 by adding external fuel tanks while also planning to expand the suite of weapons the aircraft can carry.

Adding 600-gallon fuel tanks to the strike fighter would provide about a 40 percent increase of range, said Greg Ulmer, Lockheed vice president and general manager of the F-35 program, June 17 at the Paris Air Show.

“There’s several customers that are interested in extending the range of the airplane,” Ulmer said, without specifying which countries.

Early in the program, the plan was for the F-35 to carry 480-gallon drop tanks on the inboard wing stations, but that requirement was dropped due to the aircraft’s significant internal fuel volume.

The aircraft is largely ready for external tanks. There are 12 stations on the strike fighter for weapons pylons; wing stations three and nine—the two closest to the fuselage—are “already piped to accept fuel on the wings,” Ulmer said. Lockheed is now analyzing how to best integrate tanks and the impact that would have on the stealth signature of the jet.

Additionally, for the Block 4 upgrade Lockheed is looking at increasing the internal payload from four weapons to six. The upgrade will also expand the suite of weapons it can carry, adding Small Diameter Bomb II, the Advanced Short Range Air-to-Air Missile, the Joint Strike Missile, and the Advanced Anti-Radiation Guided Missile, among others. This could eventually include future externally carried hypersonic missiles, Ulmer said.

There is no set timeline for the integration of the weapons or the external tanks.

The Pentagon and Lockheed last week announced a “handshake deal” on Lot 12 with options for Lots 13 and 14 at a total of $34 billion for 478 aircraft, including foreign partners and customers.

The deal would put the cost per F-35A at about $80 million. Under Secretary of Defense for Acquisition Ellen Lord told reporters the Defense Department “worked very hard” to get to that level. Over the past 18 months, the government and Lockheed have undertaken a data-driven review of the supply chain and manufacturing process to find these savings. Going forward, the DOD wants to “continue to realize efficiencies” in manufacturing and sustainment to get the mission capable rate of the aircraft to rise and lower the cost per flight hour.

Lockheed is trying to reach a goal of $25,000 per flight hour by 2025, and has a new life cycle sustainment plan with the Defense Department to try to reach it, though there is not a contractual requirement for the goal, Ulmer said.


I also found an article that mentions CFT.
http://www.nationaldefensemagazine.org/ ... s-for-f-35
PARIS AIR SHOW NEWS: Lockheed Planning Major Increase in Range, Other Capabilities for F-35
6/17/2019 By Jon Harper
PARIS — The Lockheed Martin-built F-35 joint strike fighter will receive additional capabilities in the coming years including significantly enhanced range, weapons capacity and manned-unmanned teaming options, a company executive said June 17 at the Paris Air Show.

The fifth-generation aircraft is expected to play the role of “quarterback” and be the centerpiece of future military operations, Pentagon officials have said.

The Defense Department is buying the A variant for the Air Force, the short takeoff and vertical landing B variant for the Marine Corps, and the aircraft-carrier based C variant for the Navy. It is the largest acquisition program in Defense Department history.

But the program is a multi-national effort. Nine original partner nations have funded its development and produce components including: Australia, Canada, Denmark, Italy, the Netherlands, Norway, Turkey, the United Kingdom and the United States. Foreign military sales customers include Israel, Japan and South Korea. Belgium has also elected to procure the plane.

More than 400 of the fighter jets have already been delivered, and Lockheed Martin projects that number could eventually increase to more than 3,500. A technology refresh slated for the 2023 timeframe is expected to add significant capability to the platforms, said Greg Ulmer, vice president and general manager of the F-35 program at Lockheed.

“We talked to several customers about how do we extend the range of the airplane,” Ulmer told reporters during a briefing. “We're looking at conformal fuel tanks as well as external fuel tanks on the airplane to increase the range” by about 40 percent. The F-35A currently has a combat radius of about 590 nautical miles.

Ulmer said the range could be extended for all three variants.

Other capabilities are slated to improve. By the time of Lot 15 production, Lockheed aims to increase the internal weapons bay capacity from four to six missiles and integrate new weapons into the aircraft. The fighter could potentially externally carry new hypersonic weapons that the Pentagon is pursuing, he noted. Hypersonics can travel at speeds of Mach 5 or faster and are highly maneuverable, posing a major challenge to enemy air defenses.

New sensor fusion capabilities could facilitate multi-domain operations such as missile defense, Ulmer noted.

“We've done some experimentation here and seen some very strong results as well, and that will only improve” with the technology refresh, he said.

The sensing and communications capabilities could enable the jet to team with unmanned systems, he added.

“The data sensor fusion approach to the airplane as well as our relationship with our brethren at the Skunk Works [division of the company] I think very well align relative to unmanned teaming and the F-35's ability to play in that realm,” he said.

Lockheed is planning other classified upgrades to the aircraft, which Ulmer declined to discuss.

During the Block 4 technology refresh, new capabilities will be added over time, he noted.

After the hardware technology refresh in the 2023 timeframe, “you'll see year over year over year we're going to have an incremental update in terms of the capability that hardware provides,” Ulmer said.

Under pressure from the Pentagon, Lockheed Martin has been working to bring F-35 costs down. Last week, Undersecretary of Defense for Acquisition and Sustainment Ellen Lord announced that the department and Lockheed had reached a “handshake agreement” for the low-rate initial production Lot 12 contract with options for Lots 13 and 14.

The $34 billion agreement for Lots 12 through14 will include the delivery of 478 aircraft — including 157 for Lot 12 — for the U.S. military services, partner nations and foreign military sales customers, Lord said in a statement.

The agreement will result in an estimated 8.8 percent cost savings from Lot 11 to Lot 12 F-35As, and an average of 15 percent unit recurring flyaway cost reduction across all variants from Lot 11 to Lot 14, she noted. For Lot 11, the price tag for the F-35A was about $89 million.

“This framework estimates the delivery of an F-35A for less than $80 million in Lot 13, one year earlier than planned,” Lord said. “This agreement symbolizes my commitment to aggressively reduce F-35 cost, incentivize Industry to meet required performance, and to deliver the greatest capabilities to our warfighters at the best value to our taxpayers.”

Operation and sustainment costs of the joint strike fighter have been a major concern for Lord and others. Ulmer said Lockheed aims to bring the cost per flying hour down to $25,000 by 2025.

Some negative publicity for the program emerged last week when Defense News reported that different variants of the aircraft have a number of category 1 deficiencies including potential problems associated with operating in extreme temperatures, cabin pressure spikes, the logistics system and the peeling of stealth coating at speeds greater than Mach 1.2.

Ulmer said the company has plans in place or is developing plans to resolve those issues.

F-35 Program Executive Officer Vice Adm. Mat Winter told Defense News that none of the deficiencies represent any serious or catastrophic risk to pilots, the airframe or missions.

Meanwhile, the U.S. government has threatened to boot Turkey out of the F-35 program if it moves forward with plans to purchase Russian-made S-400 air-defense missile systems. Ulmer said the program has not been affected by the current standoff.

“Right now the program of record stands,” he said. “Turkey still remains … a partner on the program. We're still producing the Turkey aircraft. We're still procuring material from Turkey,” he said.

However, Lockheed is looking at potential alternative sources of supply and will follow the direction of the U.S. government as it relates to Turkey’s involvement in the program, he added.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 21 Jun 2019, 09:22
by spazsinbad
THread starter (like others unsubscribed) could only quote the visible - here is 'some of'? the invisible...
Dragon029 wrote:https://www.aviationweek.com/defense/lockheed-martin-proposes-40-fuel-capacity-upgrade-f-35a
Lockheed Martin has started engineering studies focused on substantially extending the range of the F-35A by increasing the total onboard fuel capacity by 40% and improving the aircraft’s fuel efficiency, Aviation Week has learned. The studies would resurrect a long-abandoned plan to install external fuel tanks under the wings of the conventional takeoff-and-landing variant. The range-extension study also could benefit from proposed propulsion improvements, such as Pratt & …

Lockheed Martin Proposes 40% Fuel Capacity Upgrade for F-35A
https://www.pprune.org/military-aviatio ... st10499217
13 Jun 2019 Steve Trimble

“Lockheed Martin has started engineering studies focused on substantially extending the range of the F-35A by increasing the total onboard fuel capacity by 40% and improving the aircraft’s fuel efficiency, Aviation Week has learned.

The studies would resurrect a long-abandoned plan to install external fuel tanks under the wings of the conventional takeoff-and-landing variant. The range-extension study also could benefit from proposed propulsion improvements, such as Pratt & Whitney’s Growth Option upgrade offer for the F135 engine........

Not all customers wanted to rely on the range provided by internal fuel capacity alone, though. When the U.S. State Department approved the Israeli export configuration in 2011, the F-35I included external fuel tanks. But the impact on the cost and schedule for the aircraft forced Israeli officials to defer the requirement.

Nonetheless, work continued on the project within Israel’s aircraft industry. In April, Israel Aerospace Industries (IAI) and Elbit Systems’ Cyclone subsidiary confirmed that they had completed initial design studies on different fuel tank designs. IAI studied a conformal fuel tank design, while Cyclone examined a design for a 600-gal. external fuel tank. The latter would likely help preserve the F-35I’s stealthy profile on radar.

Lockheed confirms that it is now engaged in a study about the option for a 600-gal. fuel tank and a wing pylon that can be jettisoned. The tank is designed to be integrated on the inboard stations—3 and 9—on each wing, the company says. Although the pilot can restore the F-35A’s stealth signature to radar by jettisoning the tank and pylon, it is not clear how the radar cross-section is affected with the equipment attached to the wing.

Given that the 18,500-lb. internal fuel capacity of the F-35A is equivalent to 3,000 gal., adding two 600-gal. external tanks on an F-35A would raise overall fuel volume onboard to 4,200 gal., or 25,700 lb. That still falls short of the 35,500-lb. capacity for an F-15E configured for a ferry flight but should dramatically increase the single-engine fighter’s endurance.

“While exact ranges depend on mission profiles, our studies show a significant increase in both range and loiter time—or mission persistence,” a Lockheed spokesman says.

So far, the company has completed feasibility studies and conducted initial analysis, as well as early design of the range-extension upgrades. The industry-funded work was done in advance of an approved customer requirement, but Lockheed plans to present the range extension as a candidate upgrade through the Continuous Capability, Development and Delivery framework for the F-35’s follow-on modernization program, also known as Block 4.

The remaining work required includes detailed design and qualification of the fuel tank and pylon, as well as software integration, flight testing and airworthiness certification, Lockheed says.”

Source: http://aviationweek.com/defense/lockhee ... rade-f-35a

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 22 Jun 2019, 00:20
by citanon
Lockheed has been talking up other possibilities on the F-35 upgrade path too:

https://www.defensenews.com/digital-sho ... ers-grows/

Also in TR3, Lockheed plans to move to an open-architecture backbone for the F-35, which will allow it to more quickly boost the jet’s capabilities with new software.

“You’ll see year over year over year we’re going to have an incremental update,” Ulmer said. “Rather than biting it all off [at one time] and waiting for a big-bang tech insertion, we’re going to trickle that out.”


Multidomain command and control is another potential area of expanse. Again, Ulmer did not provide many details, but acknowledged that Skunk Works has conducted experiments with how the F-35 gathers and shares information, and that they have seen “very strong results.”

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 22 Jun 2019, 02:00
by spazsinbad
citanon wrote:Lockheed has been talking up other possibilities on the F-35 upgrade path too:
https://www.defensenews.com/digital-sho ... ers-grows/
Also in TR3, Lockheed plans to move to an open-architecture backbone for the F-35, which will allow it to more quickly boost the jet’s capabilities with new software. “You’ll see year over year over year we’re going to have an incremental update,” Ulmer said. “Rather than biting it all off [at one time] and waiting for a big-bang tech insertion, we’re going to trickle that out.”

Multidomain command and control is another potential area of expanse. Again, Ulmer did not provide many details, but acknowledged that Skunk Works has conducted experiments with how the F-35 gathers and shares information, and that they have seen “very strong results.”

MORE on that here: viewtopic.php?f=62&t=27390&p=422416&hilit=hypes#p422416

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 00:56
by weasel1962
Israeli news claiming CFT effort will be part of Blk 4.
https://i-hls.com/archives/92629

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 01:00
by SpudmanWP
Keep in mind that "Block 4" comprises 4 parts and spans most of the 2020's.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 01:09
by spazsinbad
weasel1962 wrote:Israeli news claiming CFT effort will be part of Blk 4.
https://i-hls.com/archives/92629

Looks like the info came from 'popularmechanics' so it is filled with speculation. Have not all the items in this 'report' been reported upon in various places elsewhere on this forum? I may or may not provide links. Meanwhile...
"...Ground Control Collision Avoidance System (GCAS)
This system will help pilots avoid the dangers that come along with disorientation. The system will utilise the aircraft’s sensors to alert the pilot if the jet is on a collision course. If the pilot doesn’t respond to the aircraft’s warning, then the aircraft will automatically change its flight course to a safer one. This technology would have saved the life of Japanese fighter pilot Akinori Hosomi, who lost his life after crashing his F-35 into the Pacific Ocean.…" [not possible if he was dead already from a medical event]

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 01:21
by weasel1962
spazsinbad wrote:Looks like the info came from 'popularmechanics' so it is filled with speculation. Have not all the items in this 'report' been reported upon in various places elsewhere on this forum? I may or may not provide links.


Don't recall where its stated in this forum that CFT/EFT will be part of Blk 4. Certainly not in this thread.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 01:41
by spazsinbad
weasel1962 wrote:
spazsinbad wrote:Looks like the info came from 'popularmechanics' so it is filled with speculation. Have not all the items in this 'report' been reported upon in various places elsewhere on this forum? I may or may not provide links.


Don't recall where its stated in this forum that CFT/EFT will be part of Blk 4. Certainly not in this thread.

I'll later be looking for that reference later - if someone else does not find it first. Just a generalisation BTW about article.

Whether we like it or not articles referred to often have many other references to other F-35 capabilities such as this one:
"...Some of the modifications that could become available in Block 4 include capabilities like conformal or external fuel tanks that could extend the jet’s range by more than 40 percent, or the auto-ground collision avoidance system that is set to roll out this month — six years earlier than expected...." F-35 Block 4 22 Jun 2019 viewtopic.php?f=62&t=27390&p=422416&hilit=external+conformal+tank%2A#p422416

21 Jun 2019: viewtopic.php?f=54&t=55676&p=422354&hilit=external+conformal+tank%2A#p422354

19 Jun 2019: viewtopic.php?f=54&t=55676&p=422205&hilit=external+conformal+tank%2A#p422205

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 10:06
by weasel1962
Just checked. The source was a LM briefing on 17 Jun at the Paris Air Show. Not exactly "just" speculation.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 10:40
by spazsinbad
weasel1962 wrote:Just checked. The source was a LM briefing on 17 Jun at the Paris Air Show. Not exactly "just" speculation.

Don't you know what 'generalisation' means? Popular Mechanics is a crap magazine for Military Aviation Information.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 10:49
by weasel1962
Noted your view on popular mechanics. Its not a question of who reports it, of which there are several. The source as mentioned is an LM briefing on 17 Jun during the Paris Air Show i.e. LM.

Re: Lockheed Proposes 40% F-35A fuel increase with EFTs

Unread postPosted: 01 Jul 2019, 13:39
by spazsinbad
weasel1962 wrote:Noted your view on popular mechanics. Its not a question of who reports it, of which there are several. The source as mentioned is an LM briefing on 17 Jun during the Paris Air Show i.e. LM.

I have no clue what this dispute is about. Please enlighten me. All I have done is highlighted where EFTs are mentioned.

We seem to have something crossed here. Just pointing out other sources for info about possible EFTs/CFTs is not OKAY?