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#11
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Well at least you read data, CTR. Now read the tilt rotor data with the
same vigor! Just as I left off the minor load reduction for the 53 (2 tanks at 800 lbs each, not the mysterious, non-existant 3,000 lbs), I left off the wing tip tank weight for the V22, and did not discount the payload by the 2,000 lbs shown on the Navy web site. As a little exercise for you, now that you are finally reading data, find these V22 reductions and reduce the V22 payload, too. Don't make too much of your new found knowledge, CTR, note that my chart shows the CH53E carrying 5000 lbs to 900 nm, and so does the Sikorsky data (which I gave you, BTW). My chart is quite accurate, thank you, CTW. I do admire how you decided to take over this debate by continually trying to find the 'missing" 3,000 pounds, but you never discuss the fact that the V22 carries 2,000 lbs less than I show! Nice work, CTR. Nick "CTR" wrote in message oups.com... Nick, You need to look a little closer at the data from Sikorsky at : http://www.sikorsky.com/file/popup/1,,185,00.pdf Did you even notice those steps in the load range curve? Or didn't you read your own data? Those drops in load capability correspond with the added weight of the external and internal fuel tanks required to meet the 1120 KM range. These steps in load carrying capability total over 3,000 LBS (why does that number sound familiar). So if you plan to fly the CH-53 over 470 KM you need to add over 3,000 LBS of fuel system hardware. This of course reduces the CH-53 paylod capability by ..... (pause for added drama) over 3,000 LBS. So how sure are you about the rest of your data? Have fun, CTR |
#12
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Nick,
You are getting closer to accepting the real payload value for the CH-53. I got you to accept 1600 LBS for the external tanks. Now how about the added internal aux tanks? How do you explain the approx 1500 LBS step at 470 KM in the Sikorsky data?. Could it posssibly be the weight the internal aux tanks?. While you are re-looking at the Sikorsky data, take a look at the air refueling load/range line. Note that the Air to Air hardware has its own weight penalty. So with internal tanks, external tanks and the refueling probe installed the CH-53 payload is only 30,000 LBS, not 36,000 LBS, BTW, the retractable V-22 probe is included in the weight you show. Your chart is decieving because it infers that the same CH-53 that lifts a load of 36,000 LBS can also fly 1,120 KM. That is why I stated in a earlier post "Correct your empty weight up by 3100 lbs if you plan to use the 1120 KM self deployed range then you will be accurate". Next, when have I I tried to defend, justify or repute the V-22 HELICOPTER mode load/range data you quote. I just assumed that you were using the worst possible values you could find anywhere to make your case. Still trying to understand a V-22 cruising in hover mode at 10,000 ft instead of flying as an airplane. Can you explain why a Tiltrotor would do that? Also I never heard of wing tip tanks on a V-22. The MV-22 has additional internal tanks in the fuselage, Do you mean sponson tanks? Finally, to Dave Jackson, welcome to the sling fest. Have fun, CTR |
#13
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CTR,
It is clear that you have no idea how to read a payload-range chart, why are you even debating? The chart shows all possible missions, each range point on the curve is a specific mission. The 36000 lb payload can be carried 1 mile, the 5000 lb payload can be carried 900 miles. If there is no payload, the distance is over 1100 miles. Your ****-poor attitude leaves you unable to learn here. The chart I provided is a simplification, quite accurate, of the Sikorsky chart. You are doubly a fool, you are wrong, and you do not know what you are talking about. You are simply not equipped to discuss this. The tip tanks are described on the Navy web site, and in the V-22 flight manual I have read (and you clearly have not). That Navy web site shows the V22 having 6000 lbs of payload at 485miles. Spot that on my chart and see that I have given them closer to 8,000 lbs of payload, and they still suck as compared to a helicopter. When you mention the fuel probe, you grasp at straws, the probe is also in the H-53E weight, wake up and smell the coffee. If you were not so beligerant, you might learn something. Why dont you email me and we can go slowly in private? Nick "CTR" wrote in message oups.com... Nick, You are getting closer to accepting the real payload value for the CH-53. I got you to accept 1600 LBS for the external tanks. Now how about the added internal aux tanks? How do you explain the approx 1500 LBS step at 470 KM in the Sikorsky data?. Could it posssibly be the weight the internal aux tanks?. While you are re-looking at the Sikorsky data, take a look at the air refueling load/range line. Note that the Air to Air hardware has its own weight penalty. So with internal tanks, external tanks and the refueling probe installed the CH-53 payload is only 30,000 LBS, not 36,000 LBS, BTW, the retractable V-22 probe is included in the weight you show. Your chart is decieving because it infers that the same CH-53 that lifts a load of 36,000 LBS can also fly 1,120 KM. That is why I stated in a earlier post "Correct your empty weight up by 3100 lbs if you plan to use the 1120 KM self deployed range then you will be accurate". Next, when have I I tried to defend, justify or repute the V-22 HELICOPTER mode load/range data you quote. I just assumed that you were using the worst possible values you could find anywhere to make your case. Still trying to understand a V-22 cruising in hover mode at 10,000 ft instead of flying as an airplane. Can you explain why a Tiltrotor would do that? Also I never heard of wing tip tanks on a V-22. The MV-22 has additional internal tanks in the fuselage, Do you mean sponson tanks? Finally, to Dave Jackson, welcome to the sling fest. Have fun, CTR |
#14
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Nice input., Dave. The Vintokryl is a good alternative, and it compares
quite nicely with the helicopter. The payload was 36,000 lbs and the horsepower was about right (13,000 HP) so it lays on the line with a single rotor helicopter, and far above a tilt rotor. Dr. Mikheyev gave a paper at a conference that I was at and espoused that configuration. I will dig up some details (maybe email Dr. Mikheyev) and post the comparison. I think that payload was done with a rolling takeoff, as the gross weight was eyewatering, and the hover performance was much poorer than a single rotor helo (wing drag costs about 10% of total payload, but the wing adds about 20 knots of cruise speed). The program was cancelled, reportedly because of the aeroelastic problems between the rotors and wing. That is also the reason why the early tilt rotors were not successful, and why the V22 is a testament to the dynamic analysis technologies designers have today. Note that both the KA-22 and the CH-53E have the same horsepower as a V22, but carry twice as much payload as the tilt rotor, even though the V22 has a much more efficvient structural design, due to the fact that it was designed 40 years later. If a helo were designed with the same tools, the V22's payload would look even worse. Nick "Dave Jackson" wrote in message news:IbHZe.556210$s54.151893@pd7tw2no... Nick, Would it be fair to toss a third rotor configuration in to the competition? How about the Side-by-Side Kamov KA-22 "Vintokryl: http://www.vstol.org/wheel/VSTOLWheel/KamovKa-22.htm ~ Speed of 192 knots [record] ~ Payload of 36,343 lbs [record] ~ Gross weight of 65,036 lbs This is a 44-year-old helicopter. Just think of what could be done with today's engines and composite materials. I think that it's a slam-dunk for the Vintokryl. Dave "Nick Lappos" wrote in message ... Just to keep the juices flowing, and get this newsgroup buzzing again, try this: http://webpages.charter.net/nlappos/...comparison.pdf |
#15
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Nick,
Now don't get snippy just because the holes in your case are causing your myopia and prejudice to become evident. Your have distorted facts to make your case by "simplifying" your data. Yes I know how to read a load range curve, and it is obvious that you know how to distort one. Note that I am kind enough to call you an inadvertent liar instead of questioning your intellect. Its the mission remember? Look at the air refueled line on the Sikorsky chart. Now follow it to the vertical axis of load. Now read the load. Is it 30,000 LBS? So you need to add approximately 6000 LBS equipment to the CH-53 to perform this mission correct? For the V-22 to perform the same mission how much equipment do you need to add? 0 LBS! Why can't you just be fair in your comparison instead of distorting facts. I already said that the twice the speed and twice the range clams of the V-22 guy were stretch of the facts. Why can't you be better than them and keep your case honest? And take this off line? Not until the civility of this discussion drops to name calling. Then I drop out both on and off he group. Have fun, CTR |
#16
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Again your lack of knowledge shows through, CTR. You do not know how to
read this technical data, and are not equipped to understand it. You have not yet found the shortfalls of the V22 in the data, because you are too biased to even try, yet you still seek the myhhical 3,000 lbs, now grown to a mythical 6,000 lbs. You misunderstand the refuel line, also. The aerial refuel line shows the maximum weight at which the CH-53E is approved to hook up with the tanker, CTR, and in no way infer that any equipment has been left off. The CH-53E weights shown INCLUDE the USMC shipboard mission equipment, and represents the weight of the hundreds of in-service CH-53E aircraft. As I have stated, the helicopter, either a Black Hawk or a CH-53E outlifts a tilt rotor by a factor of TWO to ONE, and goes the SAME range and you have done nothing credible to shake that proof. Any distortions you think you have found are in your understanding of HOW to measure these aircraft, not the way I have done so, but you think I must somehow be biased. The fact that you have not tried to understand the "extra credit" I have given the V22 shows that you are the biased one here. Let me ask, what qualifications do you have to be so misunderstanding of this technical data? Nick "CTR" wrote in message oups.com... Nick, Now don't get snippy just because the holes in your case are causing your myopia and prejudice to become evident. Your have distorted facts to make your case by "simplifying" your data. Yes I know how to read a load range curve, and it is obvious that you know how to distort one. Note that I am kind enough to call you an inadvertent liar instead of questioning your intellect. Its the mission remember? Look at the air refueled line on the Sikorsky chart. Now follow it to the vertical axis of load. Now read the load. Is it 30,000 LBS? So you need to add approximately 6000 LBS equipment to the CH-53 to perform this mission correct? For the V-22 to perform the same mission how much equipment do you need to add? 0 LBS! Why can't you just be fair in your comparison instead of distorting facts. I already said that the twice the speed and twice the range clams of the V-22 guy were stretch of the facts. Why can't you be better than them and keep your case honest? And take this off line? Not until the civility of this discussion drops to name calling. Then I drop out both on and off he group. Have fun, CTR |
#17
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Both articles discuss the pros and cons of alternative rotor configurations etc. However, they give absolutely no consideration to Active Blade Twist. Imagine a group of Roman generals sitting at the local winery have a couple of glass of libation. They have come from watching the gladiators at the coliseum and are discussing the pros and cons of different sword shapes. They are so engrossed in this discussion that the fail to give any consideration to the little oriental person in the corner who is busy mixing potassium chloride, sulfur and charcoal. Active Blade Twist is the essential precursor for Generation II rotorcraft. It is significantly beneficial for all configurations. However, the Interleaving configuration could well become the medium/heavy lift rotorcraft of the future, and for this configuration, Active Blade Twist is mandatory. |
#18
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Nick,
Lets keep to the facts and lighten up on the name calling. 1) On slide 4 of your presentation you state the CH-53 max payload as 36,515 LBS. From slide 5 you show the max ferry range to be approximately 1,100 KM. In the Sikorsky data you referenced however, to achieve both these points the CH-53 has to be reconfigured by adding or removing external and internal aux fuel tanks. The external tanks by your own statement weigh 1,600 LBS. I extrapolated from the Sikorsky curve the internal aux tanks to weigh approx 1,500 LBS (please supply a wt. if you disagree). The V-22 does not require aux tanks to meet this range. Therefore to be an unbiased comparison you need to subtract the weight of the aux tanks from the max payload value. .Or conversely not use the range provided by these aux tanks 2) From the Sikorsky data, any mission requiring air refueling reduces the CH-53 range by 6,000 LBS. From this same chart I assumed that was due to the combined weight of aux tanks and refuel hardware. You stated that this in a inflight performance restriction. Either way, does not this large drop in payload deserve at least a foot note on slide 4 and 5. Especially since the V-22 does not suffer from this restriction? 3) To make your case you are willing to use the best performance data for the CH-53 with or without added aux tanks and not bothering to note the air refuel drop in payload. However when asked to consider the increase in V-22 maximum gross to 60,500 pounds (STOL) from the 52,600pounds (V/STOL) you dismissed this as being unrealistic. Data source Naval Helicopter Association. 4) When you admitted to an error by omitting the CH-53 externat aux tank weight, you said your case was still sound because you also made an error on the V-22 data. Maybe in PPRUNE two wrongs make a right. But in a professional technical paper two wrongs just call into question all data that is presented. If you data is wrong (even if it is minor), admit the mistake, correct it and check the rest of your data for other errors. Finally, if you plan to just post this presentation on the web to have online bull sessions, your presentation and attitude is great entertainment. But if you plan to submit this as a paper or presentation to a professional society, don't bias the facts and loose the attitude dude. Have fun, CTR PS I have 25 years of Aerospace engineering experience on many verticle lift aircraft including the AV-8B Harrier, won multiple awards for best paper by both AHS and SAE and have seven patents in the field of aerospace technology. How about you? |
#19
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It is hopeless, CTR. You refuse to read the chart properly, and you refuse
to admit your inability to do so. You are hopeless. I only pray that you do not fly aircraft, you would be dangerous if you did. Nick "CTR" wrote in message oups.com... Nick, Lets keep to the facts and lighten up on the name calling. 1) On slide 4 of your presentation you state the CH-53 max payload as 36,515 LBS. From slide 5 you show the max ferry range to be approximately 1,100 KM. In the Sikorsky data you referenced however, to achieve both these points the CH-53 has to be reconfigured by adding or removing external and internal aux fuel tanks. The external tanks by your own statement weigh 1,600 LBS. I extrapolated from the Sikorsky curve the internal aux tanks to weigh approx 1,500 LBS (please supply a wt. if you disagree). The V-22 does not require aux tanks to meet this range. Therefore to be an unbiased comparison you need to subtract the weight of the aux tanks from the max payload value. .Or conversely not use the range provided by these aux tanks 2) From the Sikorsky data, any mission requiring air refueling reduces the CH-53 range by 6,000 LBS. From this same chart I assumed that was due to the combined weight of aux tanks and refuel hardware. You stated that this in a inflight performance restriction. Either way, does not this large drop in payload deserve at least a foot note on slide 4 and 5. Especially since the V-22 does not suffer from this restriction? 3) To make your case you are willing to use the best performance data for the CH-53 with or without added aux tanks and not bothering to note the air refuel drop in payload. However when asked to consider the increase in V-22 maximum gross to 60,500 pounds (STOL) from the 52,600pounds (V/STOL) you dismissed this as being unrealistic. Data source Naval Helicopter Association. 4) When you admitted to an error by omitting the CH-53 externat aux tank weight, you said your case was still sound because you also made an error on the V-22 data. Maybe in PPRUNE two wrongs make a right. But in a professional technical paper two wrongs just call into question all data that is presented. If you data is wrong (even if it is minor), admit the mistake, correct it and check the rest of your data for other errors. Finally, if you plan to just post this presentation on the web to have online bull sessions, your presentation and attitude is great entertainment. But if you plan to submit this as a paper or presentation to a professional society, don't bias the facts and loose the attitude dude. Have fun, CTR PS I have 25 years of Aerospace engineering experience on many verticle lift aircraft including the AV-8B Harrier, won multiple awards for best paper by both AHS and SAE and have seven patents in the field of aerospace technology. How about you? |
#20
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Hello Mr. Lappos
Would it be fair to toss a fourth rotor configuration in to the competition? www.diskrotor.com George "Dave Jackson" wrote in message news:IbHZe.556210$s54.151893@pd7tw2no... Nick, Would it be fair to toss a third rotor configuration in to the competition? How about the Side-by-Side Kamov KA-22 "Vintokryl: http://www.vstol.org/wheel/VSTOLWheel/KamovKa-22.htm ~ Speed of 192 knots [record] ~ Payload of 36,343 lbs [record] ~ Gross weight of 65,036 lbs This is a 44-year-old helicopter. Just think of what could be done with today's engines and composite materials. I think that it's a slam-dunk for the Vintokryl. Dave "Nick Lappos" wrote in message ... Just to keep the juices flowing, and get this newsgroup buzzing again, try this: http://webpages.charter.net/nlappos/...comparison.pdf |
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