New USAF tanker race about to begin

Yeah old thread, oh well.

We're not buying KC-10s because the DC-10 is no longer in production, therefore parts are no longer being produced for them. Boeing is still producing parts for the KC-135 because of the sheer number of them in use by the USAF, but the airlines are retiring the last of the DC-10s by next year. Only certain models are eligible for the KC-10 conversion, so there are a limited number they could convert.

Let's also look at performance figures. The MGTW for a KC-10 is 590,000 pounds, with 342,000 as fuel. With cargo, it has a 4400NM range, without cargo 11.500NM range.

Going with the 767-400 as the replacement, we get an MGTW of 450,000 pounds and a range of 5645NM. The fuel load and range will be increased in a KC version, because they'll take out cargo holds and add fuel tanks, and convert the passenger space to cargo.

So as you can see, we're not losing much by going with a new plane as opposed to more KC-10s. And we're getting a more reliable plane, with improved performance, and a longer "shelf life" ahead of it. All in all it's a good idea to replace the KC-10 AND KC-135 fleets with either the KC-767 or Airbus tanker.

Do I expect a "fair" race? Not really, but Boeing took a pretty good hit with the scandal over the KC-767, so that may hurt the program in the long run. It's pretty bad when they develop the plane for the USAF, and the first delivery is for a foreign military with no sign of the USAF ever getting them.

The A330 pretty much ended commercial sales of the 767 due to its greater efficiancy, does this have any relevance to the USAF tanker choice? Obviously Airbus will think it should but reality it wont, the USAF is not an airline and doesn't have to worry about such things. The A330 has greater range and capacity though but realistacally the only way I see it in service with the USAF is if a MAJOR flaw was found with the 767 (which there wont be of course, it is a perfectly sound aeroplane) and even then it wouls have to be tied in with someone else, ie 'Lockheed KC-330' or whatever. I would bet my house on Boeing winning this contract.

Oh, I'm with you on this waynos. I'll ALMOST guarantee that Boeing will get it, they just have to punish everyone for the fiasco that was the USAF tanker contract first.

posted by Zaphod58

Yeah old thread, oh well.

We're not buying KC-10s because the DC-10 is no longer in production. Boeing is still producing parts for the KC-135 because of the sheer number in the USAF. The MGTW for a KC-10 is 590,000 pounds, with 342,000 as fuel. With cargo, it has a 4,400 NM range, without cargo 11.500 NM range. [Edited by Don W]

Z58, are your numbers for range with and without cargo correct? It seems too large a variation. I suppose your second number would be “empty” other than the internal fuel load for the plane itself. But, then, I’m still having trouble with such a long range. Even empty. Would you elaborate, Z58?

Going with the 767-400 as the replacement, we get an MGTW of 450,000 pounds and a range of 5,645 NM. The fuel load and range will be increased in a KC version . . we're not losing much by going with a new plane we're getting a more reliable plane, with improved performance, and a longer "shelf life" ahead of it. It's a good idea to replace the KC-10 AND KC-135 fleets with either the KC-767 or the Airbus tanker.

The numbers show the KC10 about 140,000 pounds ahead of the 767 in payload. Based on what I think is a typical refueling this represents 10 events. If the KC10 fuel load vs MGTW is 64% then, if the same proportions apply to the 767, its maximum fuel load would be 288,000 pounds. Without regard as to how much of the load is internal fuel for the plane itself, it will take 11 767s to do the work of 9 KC10s. More flight crew and more ground crews needed. We look like we’re going backwards.

Do I expect a "fair" race? No, but Boeing took a pretty good hit with the scandal over the KC-767, so that may hurt the program. It's pretty bad when they develop the plane for the USAF and the first delivery is for a foreign military with no sign of the USAF ever getting them. [Edited by Don W]

Well, I’m not sure being a foreign firm will matter much. Does not Boeing already “outsource” 80% of its component work to companies in foreign countries? So what’s new? Based on % of content, I’m not sure a Boeing plane can fairly be described as an American product.

posted by Waynos

The A330 pretty much ended commercial sales of the 767 due to its greater efficacy .

I didn’t know that! I ride Delta almost exclusively - twice on a USAir trip I rode an Airbus product - and I’m thinking Delta is firmly committed to Boeing.

“ . . does this have any relevance to the USAF tanker choice? Obviously Airbus will think it should but it wont, the USAF is not an airline and doesn't have to worry about such things. The A330 has greater range and [load] capacity though but realistically the only way I see it in service with the USAF is if a MAJOR flaw was found with the 767 (which there wont be of course, it is a perfectly sound airplane) and even then Airbus would have to be tied in with someone else, i.e. 'Lockheed KC-330' or whatever. I would bet my house on Boeing winning this contract. [Edited by Don W]

I don’t know what would happen if America really had a real war. I’m still calling this Iraq thing the Second Punitive Expedition to Iraq. Back in those halcyon days of WW2, Korea and even in Vietnam, we actually made all of the “things” you need to go to war. Post Vietnam, America’s manufacturing base has been dismantled and shipped to Mexico, China, Malaysia and elsewhere. Post 1977, chosen by me when the Gang of Four was removed from power, or 1978, with the launch of the “New Long March” by the Chinese leadership. These steps came following the 4th Peoples Congress. My point is that we don’t make all of anything anymore. So who cares if Airbus isn’t headquarter in Seattle?

X58, A Silly Q1. Isn’t “M” for Maximum in MGTW sort of redundant? I mean, there is only one GTW.



[edit on 6/17/2006 by donwhite]

Answer 1: No. Because you have Gross Take Off Weight, which is what it's taking off at, and MAXIMUM which is what it CAN take off at.

The range figures are due to the added weight of the cargo. More weight means more power for take off and climb out, and to keep the speed up until some fuel burns off. If you look at fighters you'll see the same variance. The F-15 has a Ferry Range of about 3400NM, but a COMBAT Radius of only about 620 or so. More weight due to the weapons being carried. It's the same with the KC-10.

A KC-10 with a full load of fuel, and able to offload it all can "drag" 6 F-15/F-16s from Hawaii to the West Coast without assistance. A KC-767 SHOULD be able to drag 4-5, or possibly 6 as well, the same distance once the extra fuel tanks are added. Yes, you'll lose some cargo capacity, but during a fighter move there are usuall C-130s, C-17s, or C-5s that travel behind them, and the tankers haul necessary spares (ie. engines, tools, chocks, pins, crew chiefs). We hardly ever saw a KC-10 come in maxed out with cargo on a fighter drag.

I didn’t know that! I ride Delta almost exclusively - twice on a USAir trip I rode an Airbus product - and I’m thinking Delta is firmly committed to Boeing.

Certain Airlines will always have their preferences, our own BA is a committed Boeing fan too, however in the main the arrival of the A330 saw 767 sales drop of quite sharply away from those airlines that can be counted as 'loyal customers', which is why Boeing started out on the path that led to the 787. That doesn't mean 767's were suddeny rendered redundant, there are hundreds in service and they will remain so for many years but Boeing had to address the issue of future sales and appears at the moment to have done so much more cleverly than Airbus did with its A350.

So who cares is Airbus isn’t headquarter in Seattle?

Although you are quite right and there might be only slightly less US content in the KC-330 if chosen, the nominal nationalities of Boeing and Airbus does hold quite a bit of sway. The general public for instance aren't nearly so clued up about internationalism and the govt would be loathe to risk losing votes because it gave a big contract 'to the French' over 'good ole all-American Boeing'.

posted by waynos

“ . . our own BA is a committed Boeing fan, however the arrival of the A330 saw 767 sales drop off quite sharply which is why Boeing started on the path to the 787. Boeing had to address the issue of future sales and appears to have done so much more cleverly than Airbus did with its A350 . . the [US] govt would be loathe to risk losing votes because it gave a big contract 'to the French' over 'good ole all-American Boeing.' [Edited by Don W]

OK, Waynos, thank you for the good updates on airplanes. I have some more questions.

In Re the 787 and A350. Are these the super-planes capable of carrying 500-600 passengers? Are these planes using the newest fan jets of say, 55,000 lbs or more of thrust?

Next, I seem to recall that the 747 holds both the number of passengers carried and the maximum weight at take-off records. In the former, a typhoon in west Australia caused an evacuation and 700 + people (actual count was lost) flew out on one 747. In another story, but I don’t know the source, it was said a 747 had lifted off successfully weighing somewhat more than 1 million pounds. Both for the Guinness Book. Can you confirm or de-bunk either of both?

Last, I’m thinking I have heard the typical jet engine is set to run the turbine at 10,000 rpm max. i.e., 100% power is also equal to 10,000 rpm.
Q. How do you hold a pre-set turbine speed at maximum power on a jet engine (regardless of what the actual running rpm is)?


[edit on 6/17/2006 by donwhite]

The 787 and A350 are actual medium range transports that will carry about 300 people depending on configuration. The A380 and 747-8 are the 500 plus birds.

I'm not sure what the actual RPM for a fan section is, but a lot of your power comes from the fan. If you look at the 777 engine, which is rated at 100,000lbs or more of thrust, it's actually a pretty small engine. A huge portion of your power comes from the fan section. The big fan compresses the air and packs it into the combustion chamber. The more air you can get into there the more power you can get. That's why the old KC-135A, and B-52A-G would inject water into the engines on take off. The water would cool the air, allowing it to compress into the chamber, and give them more power. Now you get the same effect by using the giant fan sections. You can keep them limited to a set RPM, and get the same effect based on the fan section size, number of blades, number or turbines, etc.

It was an El Al 747 that holds the record. It was 1087 people in one flight.

"In a record-breaking airlift, the Israeli Air Force, aided by El Al, brought 14,000 Ethiopian Jews from Addis Ababa to Israel - 1,200 of them in one 747 - within 33h just days before the capital fell to rebel troops."
"Some of the flights were performed by a specially configured El Al 747, carrying 1,200 passengers. The top-secret Operation Solomon began on 24 May when an air force C-130 Hercules brought the first group of high-ranking Israeli officers and experts to Addis Ababa International Airport. The airlift was completed a few hours before the first rebel units reached the airport area."
"The group, head by deputy chief of staff Gen Amnon Shahak, set up a command post in the airport while Israeli special forces and paratroops secured the runway and airfield perimiter. An Israeli mobile air traffic control unit performed advisory control, parallel to that given by the airport's tower."
"By noon on 24 May preparations were complete and the green light was given for the first aircraft to land. In the next 24h 18 air force C-130s and eight Boeing 707s aided by nine El Al aircraft - three 747s, four 767s and two 757s - flew 14,000 Jews from Addis Ababa to Tel Aviv's Ben Gurion Airport. All El Al aircraft had their logos covered."

www.geocities.com...

The actual figure was 1087 though, not 1200.

[edit on 6/17/2006 by Zaphod58]

I’m not anti-Semitic, but I could not resist. Sorry.

posted by Zaphod58

The 787 and A350 are medium range transports that will carry about 300 people . . the A380 and 747-8 are the 500 plus birds . . the 777 engine is rated at 100,000 lbs or more of thrust, it's a pretty small engine. A huge portion of power comes from the fan section. You can keep them limited to a set RPM and get the same effect based on the fan section size, number of blades, number or turbines, etc. [Edited by Don W]

OK, Z58. I’m about 1 generation behind in jet engine power. But you still have not dealt with my inquiry. How do you regulate the speed of the rotating parts of a jet engine when on full power? I can understand somewhat if you limit the amount of fuel injected, the whole thing will run slower which is equal to less than 100% power. But when you are taking off from a carrier deck, for example, how do the engineers limit the speed of the engine? A runaway jet engine will explode due to centrfical force, bearing failure and etc. So do you have a small hand brake for the shaft? Next to the throttle?

It was an El Al 747 that holds the record. It was 1087 people in one flight.

"In a record-breaking airlift, the Israeli Air Force, aided by El Al, brought 14,000 Ethiopian Jews from Addis Ababa to Israel - 1,200 of them in one 747 - Some of the flights were performed by a specially configured El Al 747, carrying 1,200 passengers . The actual figure was 1087 though, not 1200. [Edited by Don W]

Wow! 1,087 is still a whopping record!

Any idea on the gross takeoff weight of a 747? How about the Shuttle transporter? What's the rated GTW - Maximum, that is.


[edit on 6/17/2006 by donwhite]

The OFFICIAL MGTW is 875,000lbs. But I've launched an E-4 at 880,000 before. They used what they call a ducted engine on those to get more power. They added a fan section to the engine so it gets more air compressed into the engine. Boeing did that with the 747-300/400 series.

Jet engines aren't really regulated to a certain RPM though. Some engines will run at a higher RPM than others. It's all controlled by the throttle settings in the cockpit. There is a bench jet engine that is capable of 10,000 RPM, but actual jet engines can run at 54,000 RPM or around there.

According to the 2004 Jane's the MTOW of the 747-400 is 910,000lbs (the heaviest of the lot, other engine fitments have slightly lower MTOW's), this compares with an MTOW of 710,000lbs in the 747-100 according to the 1969 edition.

I can't help with the the throttling question though, I'm no technician.

posted by Zaphod58

The OFFICIAL MGTW is 875,000lbs. But I've launched an E-4 at 880,000 before . . Jet engines aren't really regulated to a certain RPM though. Some engines will run at a higher RPM than others. It's all controlled by the throttle settings in the cockpit. There is a bench jet engine that is capable of 10,000 RPM, but actual jet engines can run at 54,000 RPM or around there. [Edited by Don W]

Thank you Z58. Last Q. Did you mean 5,400 or 54,000 rpm?

I meant 54,000RPM. There are test stand engines that have been measured at over 100,000RPM.

Would a tanker version of the C5/C17 be feasable?