DarkKnight Posted January 9, 2016 Share Posted January 9, 2016 will there ever be a solution to the drag inducing pylons? Quote Link to post Share on other sites
Joe Hegedus Posted January 9, 2016 Share Posted January 9, 2016 If you're referring to the pylon orientation on the Super Hornet, the answer is, "most likely, no." Way too much expense involved in not only the redesign, but also in retrofitting the entire fleet and redoing pretty much the entire test program. Not likely to happen. Quote Link to post Share on other sites
11bee Posted January 9, 2016 Share Posted January 9, 2016 If you're referring to the pylon orientation on the Super Hornet, the answer is, "most likely, no." Way too much expense involved in not only the redesign, but also in retrofitting the entire fleet and redoing pretty much the entire test program. Not likely to happen. The time to have implemented this change was immediately after it was identified during initial testing. Given that the S/H program is getting close to the end, something this major isn't in the cards. To me, it is just a big sign applied to every aircraft that states - "Our Engineers Screwed Up". Quote Link to post Share on other sites
janman Posted January 9, 2016 Share Posted January 9, 2016 Okay, out of curiosity (and since the type could very well end up being our next fighter), what does this "pylon orientation" or "drag inducing pylons" mean in practise? Quote Link to post Share on other sites
11bee Posted January 9, 2016 Share Posted January 9, 2016 Okay, out of curiosity (and since the type could very well end up being our next fighter), what does this "pylon orientation" or "drag inducing pylons" mean in practise? Others can answer in more detail but if something adds drag to an airframe, the end result is typically less speed / range. Add weapons / tanks that are also canted outwards and the effect is magnified accordingly. Not something you want on an aircraft that is already regarded as somewhat of a mediocre performer. The S/H has plenty of positive attributes but sheer kinematic performance isn't one of them. Quote Link to post Share on other sites
TaiidanTomcat Posted January 9, 2016 Share Posted January 9, 2016 If you're referring to the pylon orientation on the Super Hornet, the answer is, "most likely, no." Way too much expense involved in not only the redesign, but also in retrofitting the entire fleet and redoing pretty much the entire test program. Not likely to happen. Yep. Not good for sales either, it would be like admitting there is a problem Quote Link to post Share on other sites
nfiler Posted January 9, 2016 Share Posted January 9, 2016 There is a very good reason for the offset pylons. Clean separation of bombs and tanks. The slight increase in drag is insignificant compared to the more important issue of weapons separation. Quote Link to post Share on other sites
habu2 Posted January 9, 2016 Share Posted January 9, 2016 Not good for sales either, it would be like admitting there is a problem As opposed to ignoring the (drag) problem? There is a very good reason for the offset pylons. Clean separation of bombs and tanks. The slight increase in drag is insignificant compared to the more important issue of weapons separation. Agree. Someone post a link of that Hornet dropping a tank and taking out the A-4 chase plane..... Quote Link to post Share on other sites
Kirk Taylor Posted January 9, 2016 Share Posted January 9, 2016 A friend of mine's son is an engineer with Boeing in St. Louis. He told me many years ago the reason for the angled pylons on the Super Hornets. Without going into a lot of detail ( classified info ) he said there was a "perceived " separation problem with a certain store/weapon that is not widely used. The pylons were canted as a quick fix and most people involved were not happy about it. Make of it what you will, but that is what I was told by someone in the loop. Fifteen plus years later and the program winding down, I think the Super Hornet operators have accepted the drag penalties and range reduction. If you look at pictures of Super Hornets in OIF and OEF, you'll notice that they are flying with some of the pylons removed. Kirk Taylor Quote Link to post Share on other sites
Joe Hegedus Posted January 9, 2016 Share Posted January 9, 2016 There is a very good reason for the offset pylons. Clean separation of bombs and tanks. The slight increase in drag is insignificant compared to the more important issue of weapons separation. That is, unfortunately, a fair amount of conjecture. Without going into details that shouldn't be discussed in an open forum, there were exactly zero stores dropped from a Super Hornet without toed pylons, and the wind tunnel analysis that was used as the basis for the change showed a problem with 2 stores in 2 loadings, with no validation of the models done to see whether or not they were predicting accurately what would go on below the jet. To this day, no one can say with any certainty whatsoever if it was really necessary to toe the pylons. Oh, and the 2 stores that were predicted to be problems STILL had problems with the toed pylons - is that because they were problematic before, or because the problems were induced by the "fix"? We'll never know the answer to that. We do know, however, that toeing the pylons introduced a host of new problems to the mix. Quote Link to post Share on other sites
Check Six Posted January 9, 2016 Share Posted January 9, 2016 Yep. Not good for sales either, it would be like admitting there is a problem Wasn't the Super Hornet's final pylon orientation an almost arbitrary solution? Kind of like, "O.K., we're having issues with the pylons being placed in a more conventional manner. Let's just place them at X degrees outward as a functional solution. Next". Quote Link to post Share on other sites
Joe Hegedus Posted January 9, 2016 Share Posted January 9, 2016 Someone post a link of that Hornet dropping a tank and taking out the A-4 chase plane..... :bandhead2:/> That event is completely irrelevant to anything dealing with SH pylon orientation. And the Hornet didn't drop a tank, it was a jettison test of a partially-loaded VER. Quote Link to post Share on other sites
Joe Hegedus Posted January 9, 2016 Share Posted January 9, 2016 Wasn't the Super Hornet's final pylon orientation an almost arbitrary solution? Kind of like, "O.K., we're having issues with the pylons being placed in a more conventional manner. Let's just place them at X degrees outward as a functional solution. Next". Arbitrary? No,it was the simplest of 3 proposed "fixes" to the alleged "problem". Quote Link to post Share on other sites
Finn Posted January 9, 2016 Share Posted January 9, 2016 Ever since things started dropping off planes there were problems due to all sorts of reasons, here is a video showing a few: i remember one time we were dropping Mk-82 Snakeyes from CF-18s and several a/c returned with their external tanks punctured by the opening fins of the bombs which was due to delivery method being used on that mission. All other times there was no problem just that one time. Jari Quote Link to post Share on other sites
Check Six Posted January 9, 2016 Share Posted January 9, 2016 Arbitrary? No,it was the simplest of 3 proposed "fixes" to the alleged "problem". Ah; O.K. Wasn't the alleged problem how, whatever was hanging on the pylons, fell in a 'less-than-desirable-way' from said pylons? BTW; Baltimore born here; GO O's !! Quote Link to post Share on other sites
Par429 Posted January 9, 2016 Share Posted January 9, 2016 Hey- So the store separation engineers were just making stuff up? (I'm one of them, BTW) There were thousands of hours spent in the wind tunnel during the development of the SH measuring flowfields and separation characteristics of weapons. The wind tunnel techniques used at the time were very good, if not perfect indicators of what should be expected in flight. The wind tunnel tests indicated a problem, should the results have been ignored? It would have been great to go test some weapons separation characteristics from a straight pylon aircraft to get some validation of the wind tunnel results, but that's a pretty expensive and time-consuming thing to do. The toed pylons are a compromise between different and competing engineering requirements. This happens all the time, every day in aircraft programs. Phil Quote Link to post Share on other sites
habu2 Posted January 9, 2016 Share Posted January 9, 2016 ... Without going into details that shouldn't be discussed in an open forum, there were exactly zero stores dropped from a Super Hornet without toed pylons, and the wind tunnel analysis that was used as the basis for the change showed a problem with 2 stores in 2 loadings, with no validation of the models done to see whether or not they were predicting accurately what would go on below the jet. Confirming, that's exactly the way I heard the situation described. Oh, and the 2 stores that were predicted to be problems STILL had problems with the toed pylons - is that because they were problematic before, or because the problems were induced by the "fix"? We'll never know the answer to that. We do know, however, that toeing the pylons introduced a host of new problems to the mix. That part I did not know... :(/> That event is completely irrelevant to anything dealing with SH pylon orientation. You're right, that wasn't a SH, the topic just triggered my memory of the old video... Quote Link to post Share on other sites
Check Six Posted January 9, 2016 Share Posted January 9, 2016 Hey- So the store separation engineers were just making stuff up? (I'm one of them, BTW) There were thousands of hours spent in the wind tunnel during the development of the SH measuring flowfields and separation characteristics of weapons. The wind tunnel techniques used at the time were very good, if not perfect indicators of what should be expected in flight. The wind tunnel tests indicated a problem, should the results have been ignored? It would have been great to go test some weapons separation characteristics from a straight pylon aircraft to get some validation of the wind tunnel results, but that's a pretty expensive and time-consuming thing to do. The toed pylons are a compromise between different and competing engineering requirements. This happens all the time, every day in aircraft programs. Phil 'Arbitrary' was the wrong word. Very wrong word . Compromise is much more appropriate. So are you a fellow former McDonnell Douglas employee too? I worked at the San Diego facility from 1990 until McD was sold to Boeing. Quote Link to post Share on other sites
DarkKnight Posted January 9, 2016 Author Share Posted January 9, 2016 well as a layperson angling the pylon seems the worst choice, you decrease speed and range and increase drag and radar cross section, why not skeletalize or split pylons or something? Im not an engineer Quote Link to post Share on other sites
Collin Posted January 9, 2016 Share Posted January 9, 2016 Medals for drone aircrew and Hornet pylons....slow news day? Cheers Collin Quote Link to post Share on other sites
spejic Posted January 10, 2016 Share Posted January 10, 2016 There's a document called the "F/A-18E/F Trajectory Improvement Study" by Dale R. Chaddock which I found on the web a while back. It should give you an understanding of why they did what they did and what other options they considered. Quote Link to post Share on other sites
Check Six Posted January 10, 2016 Share Posted January 10, 2016 Medals for drone aircrew and Hornet pylons....slow news day? Cheers Collin Quote Link to post Share on other sites
Check Six Posted January 10, 2016 Share Posted January 10, 2016 There's a document called the "F/A-18E/F Trajectory Improvement Study" by Dale R. Chaddock which I found on the web a while back. It should give you an understanding of why they did what they did and what other options they considered. I think I read the Cliff's Notes of that study a few years ago. Quote Link to post Share on other sites
B2Blain Posted January 10, 2016 Share Posted January 10, 2016 I hate the pylon orientation. That's why I correct the angle of the pylon's on my SHs. Quote Link to post Share on other sites
Flankerman Posted January 10, 2016 Share Posted January 10, 2016 I hate the pylon orientation. That's why I correct the angle of the pylon's on my SHs. Thereby making an inaccurate model ??? Ken Quote Link to post Share on other sites
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