Forum: Modern Military Aircraft

If the goal of the KC-X program was to get tanker replacements flying, why no rush 10 years ago for a more affordable option based on a smaller airframe like either the 737NG or 757? Boeing even has the P-8 in about the same size class as the two aforementioned models. Airbus has the A320 and McDonnell has the MD-90 that could have been in a potential competition. All around, any of the models are in the same operational weight class of the KC-135E.

There are around three dozen Boeing 737's in the USAF already serving other roles, so its not like the USAF doesn't know what they can do or how much they cost to service. If the rush was to get KC-135E replacements with the KC-X program then it seems like they should have been looking at smaller airplanes than a 767!

F-16.net Sponsor

Two issues.
1) Size. The 737 may not be large enough to mount a fuel boom. That eliminates all USAF and larger Navy Aircraft. Fine for tactical Navy/Marines and international aircraft.
2) Fuel load. Even using the -900ER as a basis and the baggage compartment full of aux fuel tanks you still end up with less transferable fuel than the kC-130J.

The 737 is just plain too small and the 757 line has been shut down for a few years now, and there is no way restarting it would make sense financially when the 767 line is still running. I think the days of a pure tanker are over. The fact is that we are not going to be at war forever. If you build a 737 tanker, then that's all you have is a tanker, similar to what you have with the KC-135. sure it has a small cargo hold, but it's small, can only haul 6 pallets and no passengers when carrying those pallets. Plus it's hard and dangerous to get carog on an off the KC-135. The future tanker will need to not only be a tanker, but have the ability to carry large amounts of cargo and be able to be easily reconfigured for a variety of missions. I forsee the KC-767 eventaully having the ability to have a variety of roll on mission suites for missions such as Medivac, Recon, Electronic warfare, jamming, AWACS, Radio and Link relay, Airborne Command Post, etc. As the manned fighter and bomber force draws down there will be less need for a pure tanker, and the USAF would be wise to buy a tanker that has the size and flexibility to accomplish all of these other missions with a single airframe.

All around, any of the models are in the same operational weight class of the KC-135E.

Quote:

All around, any of the models are in the same operational weight class of the KC-135E.

B739ER max load available for fuel payload ~40 000kg
A321-200("HGW") max load available for fuel payload ~46 000 kg
KC-135R max fuel load ~90 000kg (still under MTOW)

Even the smaller fuel consumption of the small twins won't get these aircraft in the same class. KC-135R can off-load 50% more.

The reality is that the KC-135E aren't carrying nor are they offloading anywhere near that fuel. If I was talking the KC-135R that would be different. But KC-X is about replacing the least capable units in the current fleet. If the number of booms in the air is the limiting factor right now then by all means KC-X should have been more about the number of affordable similar in capability booms over the desired size of the replacement aircraft. Instead they opted for a design that surpasses KC-135R.

The reality is that KC-135Es are not off-loading anything. Last E model flow its last fligt in 2009. The Rs (and Ts) are the least capable units in the current fleet.

http://www.af.mil/news/story.asp?id=123169666

I get the models confused. The typical load on the least capable model is approximately 100,000 pounds of fuel to offload which it typically offloads 40-60% of its load. Seems like a waste to replace them with larger models.

I don't get the argument against upgrading the remainder of the KC-135E to the KC-135R standard for $3 billion. They are going to spend that amount per year on KC-X. They could have done that and added more frl mk32's to the fleet and kept the bulk of the 135's soldiering on another THREE decades. This whole KC-X program is looking more and more like pork barrel politics to keep Boeing from self destructing under their own weight.

737-class tankers would have given McDonnell Douglass somewhat of a lifeline if they had acted ten years earlier than the KC-X. And even today it gets the booms into the air sooner than the 767 is going to do. Less program size, smaller product, cheaper to operate units, and more units. Keeps the assembly lines going. Puts more booms in the air, which is the real problem today. And it gives the air force incentive to burn more time on the KC-135's that have long since been paid off. $4 million a year per plane is a lot cheaper than $210 million for each new KC-X plane and its $5-$6 million operating annual costs per plane.

Forum: Modern Military Aircraft

Why no 737NG-900 or 757-sized tanker competitions?