Artist’s concept of an Airbus A310 with a Kepplair KIOS retardant delivery system. Kepplair image.A company in France is designing a retardant delivery system for an Airbus A330. With variants of the original aircraft capable of transporting 247 to 400 passengers, Kepplair Evolution’s plans call for the A330 air tanker to be able to carry up to 9,000 gallons, just shy of the 9,400-gallon capacity of a DC-10 very large air tanker.
In collaboration with Pr Dominique Legendre of the Toulouse institute of fluid mechanics (IMFT), Kepplair has built a 1/3 scale prototype of their KIOS system which they say validated the concept of the patent by specifying the control to be implemented to guarantee a constant flow. As part of the maturation program managed by IMFT and Toulouse Tech Transfer, further tests are being carried out to confirm the scaling up.
The aircraft would be considered to be multi-role with the ability to carry about 100 passengers while configured as an air tanker. With removal of the tanks it could transport about 250 (12 hand crews). The exact numbers could vary depending on the wishes of the owner.
“The aircraft will keep a very high capacity [of passengers] with the system installed,” David Joubert, President of Kepplair Evolution told Fire Aviation. “The main deck is 45 meters long and the system only uses 15 meters and we will design it in order to maintain a certified communication corridor between the front and the rear of the aircraft. Moreover, the lower cargo hold keeps more than 75 percent of its maximum capacity.”
Mr. Joubert said the cost of converting the first aircraft to install the KIOS system would be between 12 million and 20 million Euros ($13.7 million to $23.0 million US dollars) depending on the level of multi-role capacity and country of certification. “Of course the first prototype is always more expensive than the following units,” he said.
The system is “semi-pressurized” to help force the retardant out of the system, but there is reportedly less pressure than in other pressurized systems. Two other retardant systems use compressed air, the Modular Airborne FireFighting System (MAFFS) used to covert a military C-130 into an air tanker, and the one formerly in the 747 Supertanker. The KIOS system supposedly minimizes gas-liquid mixing, in order to decrease the liquid dispersion in the air and the number of very small droplets which result in a fine mist more subject to being blown off target or captured by a timber canopy, preventing some of the retardant from reaching the fuels on the ground.
There would be virtually no major modifications on the external structure of the aircraft except for the exit points of the four retardant nozzles, thus reducing aerodynamic drag, fuel consumption, and conversion costs.
Diagram of an Airbus A330 with a Kepplair KIOS retardant delivery system. Kepplair image.In order to maintain appropriate weight and balance of the aircraft even if there is a partial failure of the retardant delivery system, the four tanks totaling about 9,000 gallons will be mounted close to the center of gravity above the front part of the wing. But due to this being above the landing gear and the fuel tank, the liquid ejection nozzles will have to be moved farther to the rear.
Dominique Legendre (L) and David Joubert at the 2020 Aerial Firefighting Conference in Sacramento, CA. Credit, Mr. Joubert.The system is being designed to produce eight levels of retardant coverage, including 8 gallons per 100 square feet, the maximum typically used on wildfires.
Ryan Becker led the US Forest Service’s Aerial Delivery group from 2002-2015, including the qualification test programs for seven different models of air tankers. He also established the 15-person organization that carried out the Aerial Firefighting Use and Effectiveness (AFUE) study. Since he has known about Mr. Joubert’s work for a number of years, we asked him about the effort to convert an A330.
“[David Joubert’s] paid close attention to the fundamental design principles for tanking systems, and if they’re able to build what they have planned, I’m confident the tank will be good,” Mr. Becker wrote in an email. “I’m not a pilot or aeronautical engineer, so I can’t comment knowledgeably on the suitability of the A330 for the role, but I will say that the trend toward higher drop speeds with newer platforms is one that needs more investigation. We’d have better information on that if the FS hadn’t shoved AFUE under the bed.”
Mr. Joubert said they are speaking with an investment firm in order to finance the company and the building of the first full-scale prototype.
“Our goal is to be ready before the [2024] Paris Olympic games,” he said.
Below is a video describing the system, produced by Kepplair Evolution.
10 Comments
Well, since it’s French, perhaps they could configure it to also drop —
Cheese.
Just a thought…
Welp….Airbus gave Boeing and McD ( which Boeing owns) a run for its money. So with a few loose A330 airframes France might just give Europe a little push forward in the VLAT world
Ten Tanker /9,400 ga . . . !
947 (B747 19,800 ga, of some continuing unwarranted controversy) . . . !
Il-76 /13,000 ga . . . !
A330, 9,000 ga . . . !?
Next VLAT . . . ??
Prob is not tanker size . . .
It’s CalFire, USFS . . . attitude . . .
The Airbus 330 would probably make a excellent VLAT. What I find of interest is the tanking system. Going back to the early 1970’s the external tank mounted under the fuselage of commercial airliners seems to have been proven as a successful retardant delivery system i.e. Ten Air Carrier
This is just one example. There are several variant of retardant tanks being mounted under or around the aircrafts airframe. The current internal tanks design by various operators has also been successful. What is the advantage of a new retardant tank system? Retardant has its own values, weight and viscosity. Pumping to heights in the aircraft will require the air tanker base to have the ability to do so. What works with water is not so with retardant when it comes to gating.
I don’t see the platform being good considering all the flying “protections” built into Airbus aircraft that would need to be disabled for normal drops. I don’t think Normal or Abnormal Law would allow it…maybe Abnormal Alternate or Direct, but not sure a certification office would allow modification to disable Normal Law without a massive flight test program. Your talking about completely changing the flight control logic in a fly-by-wire aircraft where the pilot is never in direct control of the aircraft unless many systems have failed.
Spot on. Given the Airbus engineering /design, a tanker version would have to be an entirely “new” aircraft as far as the flight control system is concerned. Routine hands on flying isn’t part of the Airbus engineering design philosophy.
The protections provided by normal law are there to keep the airplane from exceeding the fight envelope. On a retardant drop you can still maneuver as much as you would ever need and should be well inside the envelope of an Airbus in normal law. Flaps extended with gear up is certainly an abnormal condition at low altitude, which would trigger a GPWS warning, “TOO LOW TERRAIN” or “TOO LOW GEAR.” Fortunately, Airbus already provides an switch that inhibits all GPWS modes.
The flight controls of an Airbus are different, but an A330 tanker should not need to operate outside of the normal flight envelope, which means laws and their associated protections are not a factor preventing its use as a tanker. If you’re not trying to stall, overspeed, or bank beyond 67°, you’re fine in normal law. In fact, I think the protections would provide a level of safety never seen before in aerial firefighting. Heavyweight go around ? TOGA power and max aft stick, the airplane won’t stall. Windshear? Downdraft? Same.
From the previous posts, maybe the answer is a autonomous night delivery of retardant air tanker.
Can we perhaps borrow one – just for a short time – to try it out?
I have a hangar we can use.
Hmm… not necessarily a “not a chance” but certainly there should be some skepticism.
From what I can see, it appears to be another tank design that looks great in straight and level testing or dropping uphill. Haven’t we already seen the effect of exit nozzles being that far aft of the tanks (i.e. Evergreen 747, GST, Tronos Version 1 for Neptune, etc.)?
The problem with these tankers wasn’t necessarily the platform. (As proven by Neptune, if you fix the tank flaws, the platform’s not bad) The problem is how to get retardant “up hill” through the tank system and exit at the back during a downhill drop; which, I might add, is nearly all drops.
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