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Why No Winglets/raked Tips On VC-25/32 Or E-4's?  
User currently onlineLHCVG From United States of America, joined May 2009, 1446 posts, RR: 1
Posted (4 years 5 months 6 days 4 hours ago) and read 6312 times:

As the topic says, why hasn't the AF installed winglets on these planes? To start with the obvious, I don't see expense being an issue, especially since these are VIP planes, and they are commercially-derived so they should be able to use pretty standard AP winglets. The only thing I can come up with is that it might have something to do with the security/defensive systems, but then again I can't come up with any particular capability that I know of that would impede (or be impeded by) a winglet.

23 replies: All unread, jump to last
 
User currently offlineStealthZ From Australia, joined Feb 2005, 5609 posts, RR: 45
Reply 1, posted (4 years 5 months 6 days 4 hours ago) and read 6306 times:
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Likely the main reason is that the operator is not driven by the same economic considerations as a commercial operator.

I believe the VC-25 and E-4 are based on the 747-300 wing and that was not available with winglets.(Pretty sure someone will come up with something more detailed)

Despite my opening statement a short browse of the DB will find many photos like --

View Large View Medium
Click here for bigger photo!

Photo © Chris Heaton



Cheers

[Edited 2009-11-13 12:30:37]


If your camera sends text messages, that could explain why your photos are rubbish!
User currently onlineLHCVG From United States of America, joined May 2009, 1446 posts, RR: 1
Reply 2, posted (4 years 5 months 6 days 1 hour ago) and read 6248 times:



Quoting StealthZ (Reply 1):
Despite my opening statement a short browse of the DB will find many photos like --

I did remember after posting about the VC-32's winglets. I'm confused as to why you couldn't add winglets to an older wing, though as upgraded Super 27's have winglets and definitely came way before winglets were popular. I considered the economics point, but then again the fuel savings on some of those long across the world flights, like the current Asia trip, would have to add up.


User currently offlineKC135TopBoom From United States of America, joined Jan 2005, 12060 posts, RR: 52
Reply 3, posted (4 years 5 months 5 days 10 hours ago) and read 6127 times:

As said by Stealth Z, the VC-25 has the B-747-300 wing, which is almost the same as the -200 wing. It does not have the required outboard stiffing and has one spar less than the outboard -400 wing (which is 10' longer). The E-4B has the standard B-747-200B wing, also not having the extra spar.

The E-4Bs will be retiring soon, and there are still rumors the 2 VC-25As will be replaced within the next 8-10 years with new 3-4 build B-747-8I-BBJ/VIPs.

All of the USN C-40As, except for the first 3 built airplanes are being upgraded, or built with the blended winglets. The USN does not want to pay for the extra modification the first three airplanes need to accept BWLs. All USAF C-40Bs and C-40Cs already have the BWLs as well as all 4 C-32As. the 2 C-32Bs are getting them, or may already have them.


User currently offline747classic From Netherlands, joined Aug 2009, 2009 posts, RR: 14
Reply 4, posted (4 years 5 months 5 days 8 hours ago) and read 6093 times:

Around 2000 the blended winglets of Aviation Partners are tested on a 747-200 freighter.
If my memory hasn't left me there were some flutter issues and further testing has not been done due lack of customers. The wings of later built 747-200 and -300 aircraft are both type 6 ( 833.000 lbs MTOW).
If installed on the VC25 (CF6-80C2B1 powered) the fuel consumption could be reduced by around 5% and would be at least equal or better than the 747-400. Local stiffening of the outboard wing would be necessary as on 767/757 and older 737's.
The E4B are already much older and powered by CF6-50E2 engines, so a retrofit with blended winglets will have to be earned back in a shorter time.

[Edited 2009-11-14 08:23:04]

[Edited 2009-11-14 08:24:05]


Operating a twin over the ocean, you're always one engine failure from a total emergency.
User currently offline747classic From Netherlands, joined Aug 2009, 2009 posts, RR: 14
Reply 5, posted (4 years 5 months 5 days 1 hour ago) and read 6008 times:

I found a picture of the 747-200F, used for test-flying the aviation partners winglets on the classic 747.
This is the only picture I can remember, but sadly the winglets are already removed.

View Large View Medium
Click here for bigger photo!

Photo © A J Best



Maybe somebody has some pictures of this aircraft with winglets.



Operating a twin over the ocean, you're always one engine failure from a total emergency.
User currently offline2H4 From United States of America, joined Oct 2004, 8955 posts, RR: 60
Reply 6, posted (4 years 5 months 5 days ago) and read 5988 times:
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HEAD DATABASE EDITOR



Quoting 747classic (Reply 5):
Maybe somebody has some pictures of this aircraft with winglets.



2H4



Intentionally Left Blank
User currently offlineJarheadK5 From United States of America, joined Nov 2005, 216 posts, RR: 1
Reply 7, posted (4 years 5 months 4 days 20 hours ago) and read 5953 times:



Quoting KC135TopBoom (Reply 3):
the 2 C-32Bs are getting them, or may already have them.

I don't know about getting them; that's outside my knowledge. But I can assure you the two C-32Bs do not have winglets currently installed.



Cleared to Contact
User currently offline747classic From Netherlands, joined Aug 2009, 2009 posts, RR: 14
Reply 8, posted (4 years 5 months 4 days 13 hours ago) and read 5892 times:

Thanks 2H4 for the picture of the winglet equipped 747 classic.
As you are a database editor, is it possible to have this picture in a higher resolution published in the Airliners.net photo data base?
IMO this will be an unique picture in the "real 747 classic" (747-100/SP/200/300) data base.

I am very interested in the APB winglet option on the 747-200/300 aircraft, because during the late nineties I was a member in the committee "Future of the KL 747-200/300 fleet".
The main objective was to make a business case for two scenarios :
- continue operation of the 13 747-200(SUD)/300 aircraft, together with the 747-400 fleet.
- replacement of all classic 747's by 747-400's.

After investigation of "aging aircraft" issues, it was finally decided that we would continue with the 747-200/300 fleet. But to continue, we had to upgrade the aircraft for the future navigational requirements and try to make them more fuel efficient. Also the requirement for dedicated freighters, supplemental to the large 747 combi fleet, came along.

Three (3) separate projects were studied and (partly) actually proceeded with :
- navigation update.
- freighter decision : new or converted 747 freighters.
- fuel consumption improvement.

The freighter discussion was the more easy one. All figures were favorable for conversion of our oldest 747-200(SUD) combi's into dedicated freighters. This resulted in 1998 in a unique project, producing the two first SUD freighters in the world.
The cockpit upgrade proved to be the most tricky one. The company decided not to choose the Boeing backed (more expensive) solution and choose another company.
In the end the cockpit modification dragged on for a few years, because of the sudden increased requirements from the FAA (Boeing !!!), regarding HIRF (High-Intensity Radiated Fields) for the LCD ADI,HSI and EDIS (engine display interface system).
The certification costs increased more and more and the remaining projects were put on hold by the board of directors.
Also the third project concerning the fuel consumption upgrade was put on hold. This would have to be achieved by installation of the APB blended winglets on the classic 747 fleet.
It was very promising :
- more than 5% fuel saving.
- slightly less noise was produced, enough to come in a different noise category at AMS (home base).
- PR, the aircraft looked very "new" with the very large winglets and not dated anymore.

But as described above, the odds were against us, caused by the over budget cockpit modification and the whole project was frozen and finally terminated.


IMO, winglets on the VC25 can never be a real business case because the utilization of both aircraft is far below normal airline figures. So, it's impossible to earn back the investment by fuel saving alone. You can do it for PR reasons. It will look magnificent and maybe APB will do the certification job for a "friendly" price, also for PR reasons.

However, it will be interesting to look at the possibility to increase the economic lifespan of both aircraft by installing the winglets.
New 747-8I aircraft, modified as air force one, will be far more expensive, than installing blended winglets.



Operating a twin over the ocean, you're always one engine failure from a total emergency.
User currently onlineLHCVG From United States of America, joined May 2009, 1446 posts, RR: 1
Reply 9, posted (4 years 5 months 4 days 7 hours ago) and read 5850 times:



Quoting 747classic (Reply 8):
IMO, winglets on the VC25 can never be a real business case because the utilization of both aircraft is far below normal airline figures. So, it's impossible to earn back the investment by fuel saving alone. You can do it for PR reasons. It will look magnificent and maybe APB will do the certification job for a "friendly" price, also for PR reasons.

However, it will be interesting to look at the possibility to increase the economic lifespan of both aircraft by installing the winglets.
New 747-8I aircraft, modified as air force one, will be far more expensive, than installing blended winglets.

That is where I was coming from initially. Obviously the VC-25s get very little utilization relative to commercial versions, so as you say making the horizon to earn back the cost extremely long relative to the life of the a/c. But then again, given the low utilization and the absolute babying that these planes receive in mx, I would think that adding winglets would pay off in the long term since I don't see a reason they NEED to replace the VC-25s any time soon. The old 707s served for what, 30 years (I'm not sure if JFK flew on the same one RR did though)? Unless the Air Force has some plan for radically new comm/security/defensive tech that could only be accomodated on a 748 vs the 742-based airframe.


User currently offlineZANL188 From United States of America, joined Oct 2006, 3433 posts, RR: 0
Reply 10, posted (4 years 5 months 4 days 7 hours ago) and read 5842 times:
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Quoting LHCVG (Reply 9):
But then again, given the low utilization and the absolute babying that these planes receive in mx, I would think that adding winglets would pay off in the long term since I don't see a reason they NEED to replace the VC-25s any time soon.

Airline economics simply do not apply to the military 747. Winglets would be added only if it made sense from an operational standpoint, ie. increased range or additional payload is needed.

Quoting LHCVG (Reply 9):
The old 707s served for what, 30 years (I'm not sure if JFK flew on the same one RR did though)?

Yes he did.



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User currently offline747classic From Netherlands, joined Aug 2009, 2009 posts, RR: 14
Reply 11, posted (4 years 5 months 4 days 6 hours ago) and read 5833 times:

Quoting ZANL188 (Reply 10):
Airline economics simply do not apply to the military 747. Winglets would be added only if it made sense from an operational standpoint, ie. increased range or additional payload is needed.

In this case I can't totally agree with you, because the VC-25 is also a PR aircraft in the whole world. It's the representation of the USA in the outside world, very important to be up to date (but seen the present economic situation not against all costs).

The addition of winglets will produce a "green" aircraft, with a fuel consumption comparable or better than the 747-400, with a low noise print, caused by the combination of a relative low MTOW and installed blended winglets for a steep climb out performance.
The need to replace it with a 747-8 will be less, because the performance differences between the two will be less.
The winglets will give it a modern, sleek appearance.


I can give a few figures from 2000, the year that the winglet tests on the 747-200 were done and a price indication in USD (pricelevel 2000).

According the CEO of Aviation Partners Boeing, Joe Clark, a fuel saving of more than six (6)% was achieved during this test flight. From the same source the following info was obtained (august 9, 2000) :

- We are currently in flight test on the 747-200 aircraft fitted with 14 foot (6 inch) high blended winglets. We have completed 6 hours of flying having cleared flutter and obtained preliminary data.
- We are presently changing the winglet configuration for our performance evaluation which will be completed around the end of September. Preliminary performance numbers are encouraging in the 6-7 % drag reduction area.
- Program go-ahead will then be evaluated and will most likely be determined by the extend of the structural modification to the wing. Our process for evaluation should be completed by the middle of October. If there is a program go-ahead given, certification and first deliveries should occur about 12 months later.
- We are flying a wing 6 configuration ( capable 833.000 lbs MTOW) and will certify the higher take-off weight if program go-ahead is given.
- Block fuel saving should be in the 6% plus area for flight durations of more than 6 hours.
- Winglet weight and structural modification should be between 1000 and 1500 lbs. increase total.
- We don't have the T/O or climb benefit yet but it will be significant, especially in high and hot situations.
- Noise reduction will be determined. We do know that throttle cut backs may be used and anticipate about a 6.5% reduction in size of the noise envelope foot print.
- Installation will be performed at an FAA repair station or dedicated installation center.
- Price of the winglet kit will be about USD 1,500,000. This is excl. installation and downtime. Installation can be done in the C-check to avoid downtime (2 weeks needed for winglet installation). Estimated downtime/labor/installationcosts : USD 300.000/aircraft.

[Edited 2009-11-15 10:50:50]


Operating a twin over the ocean, you're always one engine failure from a total emergency.
User currently offlineZANL188 From United States of America, joined Oct 2006, 3433 posts, RR: 0
Reply 12, posted (4 years 5 months 4 days 5 hours ago) and read 5824 times:
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Quoting 747classic (Reply 11):
In this case I can't totally agree with you, because the VC-25 is also a PR aircraft in the whole world.

Pretty unlikely VC-25 will be a launch customer for this mod unless there is a dire operational need and, at the moment, that need does not exist.



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User currently offlineAeroweanie From United States of America, joined Dec 2004, 1606 posts, RR: 52
Reply 13, posted (4 years 5 months 3 days 21 hours ago) and read 5745 times:
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Quoting LHCVG (Reply 2):
I did remember after posting about the VC-32's winglets. I'm confused as to why you couldn't add winglets to an older wing, though as upgraded Super 27's have winglets and definitely came way before winglets were popular. I considered the economics point, but then again the fuel savings on some of those long across the world flights, like the current Asia trip, would have to add up.

It takes a lot of money to develop and certify winglets for an aircraft. When hull values on 747-200s dropped, API decided that their program was not financially feasible and it got canceled. Developing and certifying winglets for just the VC-25 and E-4 would result in extremely expensive winglets that would never earn back their development costs in fuel savings.

Quoting 747classic (Reply 8):
Thanks 2H4 for the picture of the winglet equipped 747 classic.
As you are a database editor, is it possible to have this picture in a higher resolution published in the Airliners.net photo data base?
IMO this will be an unique picture in the "real 747 classic" (747-100/SP/200/300) data base.

The picture was taken by an photographer working for API and they own the copyright.


User currently offline747classic From Netherlands, joined Aug 2009, 2009 posts, RR: 14
Reply 14, posted (4 years 5 months 3 days 17 hours ago) and read 5709 times:

Quoting Aeroweanie (Reply 13):
It takes a lot of money to develop and certify winglets for an aircraft. When hull values on 747-200s dropped, API decided that their program was not financially feasible and it got canceled. Developing and certifying winglets for just the VC-25 and E-4 would result in extremely expensive winglets that would never earn back their development costs in fuel savings

Part of the development/certification costs are already spent. De data from the test flights in 2000 are still available and valid.
Earning back all costs in fuel saving is impossible, i agree.
However, certification and installation costs of the winglets, can be easily earned back by further delaying the successor of the VC-25.
Producing a successor will be far more expensive, with little gain in performance achieved. The payload/ range difference between the VC-25 with winglets and the 747-8I will decrease, so will the economic need for replacement.
Estimated costs of a new 747-8I in "air-force one" livery will probably exceed USD 500 milj for only one aircraft.

[Edited 2009-11-15 23:14:08]


Operating a twin over the ocean, you're always one engine failure from a total emergency.
User currently onlineRevelation From United States of America, joined Feb 2005, 11919 posts, RR: 25
Reply 15, posted (4 years 5 months 3 days 11 hours ago) and read 5676 times:



Quoting ZANL188 (Reply 10):
Airline economics simply do not apply to the military 747. Winglets would be added only if it made sense from an operational standpoint, ie. increased range or additional payload is needed.

All it will do is add more wing surface area for the blue-suiters to buff and polish!



Inspiration, move me brightly!
User currently offlineRedFlyer From United States of America, joined Feb 2005, 4252 posts, RR: 29
Reply 16, posted (4 years 5 months 3 days 9 hours ago) and read 5660 times:



Quoting 2H4 (Reply 6):

Holy bent-wings, Batman! How tall are those winglets? They look to be on the order of 15 - 20 feet in height.



I'm not a racist...I hate Biden, too.
User currently offlineKC135TopBoom From United States of America, joined Jan 2005, 12060 posts, RR: 52
Reply 17, posted (4 years 5 months 3 days 8 hours ago) and read 5650 times:



Quoting LHCVG (Reply 9):
The old 707s served for what, 30 years (I'm not sure if JFK flew on the same one RR did though)? Unless the Air Force has some plan for radically new comm/security/defensive tech that could only be accomodated on a 748 vs the 742-based airframe.

Don't forget, the VC-25s are 1989 and 1990 airplanes, now 20 years old. It takes 8-10 years to develope a new Air Force-1. President Reagan started the VC-25 program in 1981. That year VC-137C 62-26000 was approaching 20, and 72-27000 was 10 years old. VC-137C 62-26000 retired in 1993, at 31, and 72-27000 retired in 1999.

Quoting 747classic (Reply 14):
Estimated costs of a new 747-8I in "air-force one" livery will probably exceed USD 500 milj for only one aircraft.

Apparently that is still cheaper than the VH-71A/Bs were going to be, per airframe.


User currently offline747classic From Netherlands, joined Aug 2009, 2009 posts, RR: 14
Reply 18, posted (4 years 5 months 3 days 7 hours ago) and read 5634 times:



Quoting RedFlyer (Reply 16):
How tall are those winglets? They look to be on the order of 15 - 20 feet in height.

14 feet and 6 inch.



Operating a twin over the ocean, you're always one engine failure from a total emergency.
User currently offlineFlighty From United States of America, joined Apr 2007, 8200 posts, RR: 3
Reply 19, posted (4 years 5 months 2 days 19 hours ago) and read 5571 times:



Quoting KC135TopBoom (Reply 17):
Don't forget, the VC-25s are 1989 and 1990 airplanes, now 20 years old. It takes 8-10 years to develope a new Air Force-1. President Reagan started the VC-25 program in 1981. That year VC-137C 62-26000 was approaching 20, and 72-27000 was 10 years old. VC-137C 62-26000 retired in 1993, at 31, and 72-27000 retired in 1999.

Given that the -8I is probably the right aircraft, it is only a matter of time.

Still, I feel that a midlife refresh would be pretty adequate for the VC-25. Problem is, military contractors would just charge $500 million for the rehabilitation, as they did with the E4-B. Then you don't save any money versus the new aircraft. It's funny how that works these days.


User currently offline747classic From Netherlands, joined Aug 2009, 2009 posts, RR: 14
Reply 20, posted (4 years 5 months 2 days 10 hours ago) and read 5524 times:



Quoting KC135TopBoom (Reply 17):
Don't forget, the VC-25s are 1989 and 1990 airplanes, now 20 years old. It takes 8-10 years to develop a new Air Force-1.

Due the decrease in fuel consumption with the blended winglets (better than 747-400) the decision point and actual in service date for a successor can be pulled backwards. The need for a new follow on aircraft decreases as the difference in operating costs declines.

Fuel consumption original VC-25 = 100% (base value)
Fuel consumption 747-400 = 96% (-4%) - 400 winglets (-3%) , FADEC (-1%)
Fuel consumption VC-25W = 94% (-2%) - blended winglets (-6%)
Fuel consumption 747-8 = 81% (-15% lower than 747-400)

SFC Difference between original VC-25 and 747-8 = 19 %
SFC Difference between VC-25W and 747-8 = 13 % ( difference reduced by 30%)

Total economical lifespan 30 years of VC25 and 747-8
An increase in lifespan with 3 years (10%) is a very low estimate.

Calculation : Purchase of one VC-25 successor USD 500.000.000
Interest 3% : Delay in purchase will earn USD 15.000.000 every year.
Total financial earning in 3 years : USD 45.000.000.

Not taken into account : Inflation (pos), difference in fuel consumption (neg) and maintenance(neg).
Let's assume USD. 10.000.000 (neg) to compensate for this in 3 years time.

Total earning by delaying purchase with 3 years :
USD 35.000.000.

IMO you can easily buy a set of winglets, incl. certification, for this amount of money.

[Edited 2009-11-17 05:34:28]


Operating a twin over the ocean, you're always one engine failure from a total emergency.
User currently offlineRedFlyer From United States of America, joined Feb 2005, 4252 posts, RR: 29
Reply 21, posted (4 years 5 months 2 days 10 hours ago) and read 5516 times:



Quoting 747classic (Reply 20):
IMO you can easily buy a set of winglets, incl. certification, for this amount of money.

You forgot one very critical calculation: Government decision-making = a fortune in wasted taxpayer money.  Wink



I'm not a racist...I hate Biden, too.
User currently onlineLHCVG From United States of America, joined May 2009, 1446 posts, RR: 1
Reply 22, posted (4 years 5 months 1 day 17 hours ago) and read 5426 times:



Quoting ZANL188 (Reply 10):
ie. increased range or additional payload is needed.

Not to split hairs here, but doesn't decreasing fuel burn by definition increase range by a similar amount? I'm no engineer, but if you save x gallons, doesn't that dictate you gain y miles of range based on the fact that you get z MPG (effective, I realize this is airplane and not a car)?


User currently offlineXT6Wagon From United States of America, joined Feb 2007, 3320 posts, RR: 4
Reply 23, posted (4 years 5 months 1 day 13 hours ago) and read 5400 times:



Quoting LHCVG (Reply 22):
Not to split hairs here, but doesn't decreasing fuel burn by definition increase range by a similar amount? I'm no engineer, but if you save x gallons, doesn't that dictate you gain y miles of range based on the fact that you get z MPG (effective, I realize this is airplane and not a car)?

Not allways. If you put 5 tons of wieght on a plane to make it burn 5tons less fuel... range will go down as will the operating cost (at max fuel takeoffs). So its all in how you reduce fuel burn. Most will increase the max range as adding wieght quickly murders shorter flight economics, so any 1:1 offset won't sell.


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