US Debating Aerial Tanker Types, Mix
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It has been a long road for the USA’s aerial tanker replacement competition. After the Darlene Druyun scandal and the linked but separate withdrawal of Boeing’s KC-767 lease proposal, the USA continues to examine its options. Some reports note that the existing tanker fleet of “more than 490” KC-135 Stratotankers (USAF figure, out of 732 built until 1966), derived from Boeing 707s, and 59 KC-10 Extenders derived from McDonell Douglas DC-10-30CFs, may be able to perform until 2040. Yet a combination of procurement momentum, steadily increasing and future-uncertain maintenance costs, and the impact of an unforeseen fleet-wide grounding for the USAF’s aging Boeing 707s continue to push the competition ahead.
With a Phase One buy of around 175 aircraft, whose unmodified civil versions cost well over $100 million each, this could easily become a $100 billion program by the time all is said and done. Meanwhile, studies like “Brittle Swords: Low-Density, High-Demand Assets” [PDF] highlight the dangers and potential false economies of under-investment.
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In the wake of the USAF’s recent RFI, industry-watchers are paying attention again. Boeing’s latest 10K investors’ report noted that the likelihood of KC-767 tanker orders coming in before the civilian 767 production line runs out had “diminished”; Boeing added that the decision to “complete 767 production” could come before the end of the 2006 calendar year. Meanwhile, some observers believe the EADS Airbus/ Northrop-Grumman KC-30 (A330 MRTT) tanker may have become the competition front runner – but new options like the larger 777 or A340 are being bandied about, and military opinions differ re: the preferred size and mix of the USAF’s future tanker force.
The latest news is the release of the KC-X RFP, amidst uncertainty over the EADS/Northrop Grumman team’s willingness to compete.
Tanker Questions: Timing and Force Mix
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The question becomes twofold: what to replace the existing fleet with, and when to do so.
The subject of when is easiest. Air Force Chief of Staff Gen. T. Michael Moseley has told reporters that service officials have signed off on a Request For Information and passed it on to Deputy Defense Secretary Gordon England. The RFI is expected to be issued within a month, and many observers expect a September 2006 deadline for responses. Inside Defense and other media outlets report that the tanker program may have adequate congressional support to move forward, though there is a potential conflict with the perceived need for more C-17 transports given limited funds.
The question of what to replace the existing fleet with is far less clear. A RAND report discarded a number of alternatives, and leaves the USAF looking at manned derivatives of commercial aircraft, in the medium to large size range.
Within that narrow field, however, one finds a divergence of views. Service officials have admitted that the Pentagon has yet to finalize its tanker replacement requirements. That has left industry relying on internal projections, largely based on the requirements the Air Force highlighted during the failed 2002 KC-135 replacement effort. Indeed, after the House Armed Services Force Projection subcommittee member Rep. Gene Taylor [D-MS] asked them for their personal opinions, two different Air Force officials gave two different perspectives.
Deputy USAF Chief of Staff for Acquisition Lt. Gen. Donald Hoffman, told the subcommittee that “It should be a new aircraft, a commercial derivative, and I think we ought to buy one kind… The first 100 (should) all look the same…[and] should all be medium” His second choice for recapitalizing the tanker fleet was to modernize the current KC-135 fleet, which involves re-engining some aircraft, and adding extensive electronics and avionics refits plus multi-point refueling systems across the board. Some smart innovations and refits are already ongoing.
On the other hand, Air Mobility Command Vice Chief Lt. Gen. Christopher Kelly told the committee that he would prefer some mix of medium- and large-sized aerial tankers, much like the current fleet mix of KC-135 (mid-size) and KC-10 (large size, 1.95 times the capacity) aircraft.
Given their roles, both Gen. Kelly and Gen. Hoffman are likely to have some say in the USAF’s acquisition plans.
Tanker Questions: Competitors
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Michael Kennedy, the Associate Director of RAND’s Project Air Force, also testified before the Force Projection subcommittee:
“Which one is best depends on specifics of mission mix and other issues and it literally — all the analysis we did shows them to be approximately equally cost effective… I can tell you what I think the best are and I can tell you in terms of size: Boeing 767, Airbus 330, Airbus 340, [Airbus] 300 and Boeing 777.”
The Northrop-EADS team has primarily pitched the conceptual KC-30 tanker aircraft, based on the A330-200 MRTT selected by Australia and Britain. The aircraft has a maximum fuel capacity of over 246,000 pounds. Even with a full fuel load, the aircraft has the capacity to carry 43 metric tonnes of cargo. The aircraft could also carry up to 272 passengers instead.
This might allow a fighter squadron to deploy right along with its personnel and some of its key equipment, carried in the same refueling aircraft that escort the squadron’s fighters as they fly over. This gives the squadron the ability to quickly ramp up to a combat-level sortie rate after arrival.
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Boeing has chiefly touted its KC-767 aircraft, which has entered service with Italy and will soon begin deliveries to Japan.
“Global Tanker Transport” team members include Finmeccanica’s Aeronavali, GE and Pratt & Whitney for engine choices, Honeywell, Rockwell Collins, Smiths Aerospace, and Vought Industries. On March 10, 2006, Boeing continued its preparations by naming Mark McGraw its VP of Tanker Programs, under Boeing Integrated Defense Systems’ recently-created Precision Engagement and Mobility Systems unit.
The KC-767 carries about the same fuel payload as the KC-135 (161,000 pounds without auxiliary fuel tanks, or 202,000 pounds with auxiliary fuel tanks). Like the A330, it can also carry passengers and cargo at the same time. In the cargo configuration, maximum cargo capacity is 35 metric tons or 19 standard military 463-L pallets; in the passenger configuration, 200 passengers can be accommodated; and in the Combi configuration 10 cargo pallets and 100 passengers can be carried.
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Defense analyst Loren Thompson of the Lexington Institute notes to the Everett Herald that pundits have also talked about a tanker based on the 777; but he says that the Air Force has not formally asked Boeing to develop one, so Boeing hasn’t done much work on a design. He also believes the 777 is too large. On the other hand, he notes that a faction inside the Air Force that thinks the 767 is too small. The Pacific theater is larger, and characterized by great distances between bases and potential targets. The A330 is larger than the 767, and despite the 767’s fuel efficiency, Thompson said that “over a wide range of distances, the A330 delivers more fuel.” A 777 alternative might go over better with that constituency as a substitute for the KC-767, or even as a complementary aircraft that covers the large size range in a dual force mix. Airbus, meanwhile, will likely include its four-engine A340-200 as a second option. It is likely to be at a disadvantage in that size class, however, for the same efficiency-related reasons that the A340 is losing to the 777 in the commercial market.
Air Force Chief of Staff Gen. T. Michael Moseley told reporters the next day on Capitol Hill that service officials have signed off on a version of the RFI and passed it on to Deputy Defense Secretary Gordon England, and the document is “up there on his desk.” Its release is expected within a month or so, yet the RFI will likely contain few actual requirements, sticking instead to broad goals. A forthcoming capabilities development document (CDD) will add further detail, but a senior official confirmed to Inside Defense that a full RFP wasn’t expected until September 2006 (UPDATE: it would be delivered in January 2007).
One characteristic that seems certain to be common to both aircraft proposals – aside from the capacity to be refueled in the air themselves – is a boom and drogue combination on every aircraft.
boom & drogues
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The US Navy, the US Marines and NATO aircraft have traditionally used the hose and drogue air refueling method, which extends from pods on the wings and is picked up by an extensible tube the emerges near the front of an aircraft. Aircraft using hose and drogue refueling include US Navy F/A-18 E/F Super Hornet and USMC AV-8B Harrier Plus aircraft, the French Mirage F-1, and England’s Eurofighters.
The USAF’s standard air fuel transfer method is through the boom and receptacle air refueling technique, which drops a long refueling boom from the back of the plane. Boom-refueled aircraft include the Australian F-111, and the USAF F-15 & F-16. Future aircraft such as the Joint Strike Fighter will be developed for the optional installation of either refueling, system, according to the customer country’s operational requirements.
Other key elements from the October 22, 2002 tanker requirements document include the ability to operate two drogue refueling hoses at once, and possibly the requirement that the tanker be able to carry different kinds of fuel. A 2002 Congressional Research Service report notes that the ability to carry different fuels would greatly enhance the aircraft’s ability to simultaneously fuel both USAF aircraft operating on JP-8 fuel, and Navy and Marine Corps aircraft which operate on a JP-5 fuel that is less prone to ignition. Navy and USMC aircraft using JP-8 must very nearly empty their tanks prior to landing, then have their fuel systems flushed upon landing, to avoid contaminating the carrier’s fuel supply.
Ongoing Developments
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Jan 30/07: USAF issues the KC-X RFP, and its news release language stresses the capability-based angle. Will the RFP itself be enough to induce Airbus’ participation? Yes. DID has the RFP documents… plus all subsequent updated to the program.
Jan 26/07: Flight International reports that Northrop/EADS may pull out of the KC-X competition after the RFP is released on January 30th. See full DID coverage.
Dec 16/06: USAF releases revised draft KC-X RFP. Among other things, it declares certain costs related to ongoing World Trade Organization litigation as unallowable expenses under USAF contracts. Sue Payton, the Air Force senior acquisition executive, says the release of the final RFP is expected in January 2007, and that her goal remained to complete the source selection process by the end of FY 2007.
Nov 14/06: InsideDefense.com publishes “Army Eyes USAF Tankers for Network Tech.” US Army and Air Force officials are exploring whether they will put Warfighter Information Network-Tactical (WIN-T) payloads on their aerial tankers in order to free up satellite resources. WIN-T will be the local bandwidth backbone for the Army’s Future Combat Systems, and UAVs may not be qualified to carry the relay equipment. By off-loading traffic from satellites, more bandwidth would be available for other services and leasing costs associated with using commercial satellites would go down. The idea is currently at the concept discussion and exchanges level.
Oct 13/06: KC-X tanker recapitalization program announced as #1 procurement priority for USAF.
July 19/06: Jane’s reports that EADS plans to contest the USAF’s request that contractors disclose whether they will use government launch aid for the tanker project. In their response to the USAF RFI, EADS officials said they would not address the issue since military programmes are funded by governments. EADS also noted that requests for information about launch aid are “unprecedented” in military contracts, while co-CEO Tom Enders has said that “we are not getting stuck with traditional methods of funding.”
With respect, a more… nuanced approach might have been better.
April 26/06: USAF Issues Replacement Aerial Tanker RFI
Appendix: The RAND Studies
RAND has studied this issue before. The first study was in 2003, titled “Investigating Optimal Replacement of Aging Air Force Systems.” In 2004, they issued a brief release titled “Options for Replacing the Air Force’s KC-135 Tanker Aircraft and AWACS, JSTARS, and Rivet Joint ISR Aircraft.” In 2006, they revisited the issue. Note that some of their conclusions differ from or do not include options examined in the 2002 Congressional Research Study of the KC-767 tanker lease deal. As RAND noted in its most recent 2006 Analysis of Alternatives study #MG495:
“The primary cost metric for assessing recapitalization timing is the present value of both operating the KC-135s until they are retired and acquiring and operating the replacement fleet. Delaying or slowing down recapitalization raises the former part of this cost, both because the KC-135 fleet is operated longer and because KC-135 costs are projected to rise as the fleet ages. Delaying or slowing down recapitalization lowers the latter part of this cost because there is a present-value benefit to delaying the costs of acquiring and operating the replacement fleet…
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It adds:
The most cost-effective timing policy (start and duration of recapitalization) in this case is the one that minimizes the total life-cycle costs for both the remaining KC-135s and the replacement tankers. However, all this assumes that there is no sudden decrease in the availability of the KC-135 as a result of unforeseen technical difficulties…”
RAND would go on to point out that unforseen technical difficulties associated with aging aircraft were a significant and unknowable risk if the USA decides not to replace its current fleet. The current KC-135 fleet entered service between 1957-1965, and most of these planes would be 60 years old even by 2020. The KC-10s are far fewer in number, but entered service in the early 1980s.
Key points in the study included:
- New-design tankers – i.e., aircraft developed from the drawing board to be aerial tankers – are not cost-effective. The additional effectiveness of such specialized design features wasn’t seen as offseting their higher R&D, production, and possibly maintenance costs as well.
- Unmanned tankers are not cost-effective. These systems would offer no cost advantages or military advantages over manned tankers.
- Stealthy tankers are significantly more expensive than non-stealthy tankers, although they offer some effectiveness benefits… It is a military judgment whether the expense of penetrating tankers is justified by the additional military advantage.
- The most cost-effective tanker replacement alternative is a fleet consisting of new commercial derivative tankers in the medium to large size range (300,000 to 1,000,000 pounds maximum gross takeoff weight).
- The candidates in this range include tankers based on the Airbus 330, the Airbus 340, the Boeing 767, the Boeing 787, the Boeing 777, and the Boeing 747
- A mixed fleet consisting of more than one of these alternative candidates also has comparable cost-effectiveness, so there is no reason to exclude a priori an Airbus-Boeing mixed buy on cost-effectiveness grounds.
- Commercial-derivative tankers that are either smaller (Boeing 737 or Airbus 321) or larger (Airbus 380) are not cost-effective, even in mixed fleets that include other candidates in other size categories.
- The specific cost-effectiveness of each of these alternatives is highly sensitive to their “green” aircraft price, that is, the price charged for the part of the aircraft that is common with the commercial version.
- Acquiring used aircraft as tankers is not as cost-effective as acquiring new aircraft, introduces potential issues of electronic survivability in a nuclear environment, and would only meet between 10-25% of the total requirement based on market availability. RAND said this alternative could not be completely excluded, but neither was it seen as attractive.
- The study does not appear to have considered options like refurbishing additional DC-10s to KC-10 status, and option noted in the Congressional Research Service report.
- There is no compelling reason for the Air Force to outsource aerial refueling, that is, to purchase aerial-refueling capability from private companies instead of providing it organically.
- RAND adds its belief that: “The opportunity for commercial employment of assets [i.e. leasing of the tankers for commercial use when not in use by the Air Force, as Britain plans to do) should be neutral across potential suppliers of aerial refueling, whether private or government…” (in English: should cost the same and make the same, whether the government operated them or a private company did so)
- Again, the 2002 congressional Research Report appears to disagree, noting that the Navy has contracted for this service with satisfactory results, at a significant cost reduction.
- A fleet in which all the aircraft have cargo- and passenger-carrying capability has a present value of life-cycle cost about 6 percent greater than that of a fleet in which none of the aircraft have cargo- or passenger-carrying capability; as well as additional military utility and flexibility.
RAND’s Project Air Force added that if the existing US tanker fleet is considered adequate, the decision of when to replace the KC-135s should be based on considerations other than present-value life-cycle costs – but there are good arguments both for immediate and for delayed recapitalization:
Three possible considerations would favor earlier tanker recapitalization:
- Concern about the technical risk of continuing to operate the current fleet of KC-135s.
- If a constraint exists re: how large the annual tanker replacement procurement budget can be, it’s better to start early and spread it over time.
- Even if the KC-135 is considered adequate, a replacement fleet may offer other flexibility benefits from the ability to transport troops and light equipment as well to the ability to offer both boom and drogue refueling options at the same time, allowing it to handle more types of aircraft at once.
Two possible considerations favor later tanker recapitalization:
- Future circumstances that are likely to offer a better alternative, or lower requirements for an aerial tanker fleet (unlikely), technical and doctrinal developments that allow new design alternatives (for instance, a cost-effective seaplane option that could itself be refueled in the water by Navy ships instead of returning to base), etc.
- The existence of critical near-term financial constraints on spending that would make a major near-term acquisition program very unattractive.
You can read the entire report by clicking the link below.
Additional Readings & Sources: Aircraft
- USAF – KC-135 Fact Sheet
- Air Force Technology – KC-135 Stratotanker Air-to-Air Refuelling Aircraft, USA
- KC-10.Net – KC-10 Extender
- Boeing – Global Tanker: KC-X Competition. Lists both a 767 and 777 option. This article offers a good comparison.
- Air Force Technology – KC-767 Tanker Transport Aircraft, USA
- Aerospace Technology – Boeing 777 Twin-Aisle Twinjet Airliner, USA
- Northrop Grumman & EADS – KC-30 official site. The planes would be assembled in Mobile, AL, and the Northrop Grumman – EADS consortium promises that “More than 50 percent of the aircraft’s content – from engines to avionics and systems – will come from American companies.”
- Air Force Technology – A330-200 Future Strategic Tanker Aircraft (FSTA) – Multi-Role Tanker Transporter (MRTT), Europe
- Aerospace Technology – Airbus A340-200 and A340-300 Wide-Bodied Four-Engine Airliners, Europe
Additional Readings & Sources: News & Analysis
- Lexington Institute (Nov 28/06) – Fate of Huge Tanker Program Could Hinge on Cargo Role. “The wild card is cargo-carrying capacity, because if the request for proposals sets a modest goal, that will tend to favor the 767, and if it sets an ambitious goal that will tend to favor the A330. With cargo thresholds potentially driving the competitive outcome, Congress will be watching closely for any sign of bias. If it doesn’t like what is sees, tanker modernization could be delayed yet again.”
- Special Operations Technology (Nov 19/06) – KC-X. Very good summary of all of the tankers’ envisaged roles and key capabilities, then adds: “Equally important as the strategic KC-X program, if not more so, is an ever-growing urgency to bring relief to the AFSOC tanker aircraft. The KC-Xs will keep the MC- and HC-130s topped off, but they too need attention.”
- Flight International (March 14/06) – US Air Force Divided Over New Tankers
- RAND (2006) – Analysis of Alternatives (AoA) for KC-135 Recapitalization
- USAF (March 10/06) – Analysis of tanker fleet alternatives released
- Inside Defense (March 8/06) – Tanker Debate: Medium, Large, or Both?
- Everett Herald (March 8/06) – Tanker talk filled with uncertainty
- USAF (March 3/06) – Air Force seeks new tanker
- Boeing – 10k for period ended December 31, 2005
- Boeing (June 8/05) – First Boeing 767 Aircraft for Japan Tanker Program Arrives in Wichita. Due for delivery in December 2006.
- DID (March 17/05) – British AirTanker Deal May Go Private
- Boeing (Feb 24/05) – Boeing Rolls Out First KC-767 Tanker for Italian Air Force
- EADS (Dec 20/04) – Australia Becomes First Customer for A330-200 MRTT
- RAND (2004) – Options for Replacing the Air Force’s KC-135 Tanker Aircraft and AWACS, JSTARS, and Rivet Joint ISR Aircraft
- Congressional Research Service (Sept 2/03) – The Air Force KC-767 Tanker Lease Proposal: Key Issues for Congress [PDF format] Includes a good overview of the key issues, and a very clear explanation of the proposed lease’s somewhat involved structure.
- RAND (2003) – Investigating Optimal Replacement of Aging Air Force Systems (C21A and KC-135)
