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lamoey
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Posted: Aug 10, 2012 - 06:16 PM
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Sponsor
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Posted: May 23, 2013 - 6:55 AM
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F-16.net Sponsor
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cola
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Posted: Aug 10, 2012 - 11:38 PM
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Senior member

Joined: May 18, 2009 - 01:52 AM
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jeffb wrote:
It would have been nice to see the drop from a couple of angles and yeah, the down angle is quite pronounced isn't it. Although I notice that a lot of the F-18s show a similar 'droop' on their wingtip stations:
The "droop" is a leading edge twist (washout), a measure the wing designers use to battle wing (tip) stalling characteristic and employs reduced angle of incidence (AoI).
F15/16/18/22/35/Rafale/etc...use it too.
EF, for example, uses a "washin", which also employs wing's LE twist, but with increased root's AoI, instead. |
_________________ Cheers, Cola
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handyman
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Posted: Aug 11, 2012 - 08:31 AM
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Active Member

Joined: Mar 04, 2011 - 05:41 AM
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jeffb wrote:
The F-35, the answer to the question nobody asked.
What crauled up your butt? |
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jeffb
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Posted: Aug 11, 2012 - 10:17 AM
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handyman wrote:
jeffb wrote:
The F-35, the answer to the question nobody asked.
What crauled up your butt?
Listening to drivel like "internal carry brings capability to the troops" gets my goat, so sue me.
This morning I was just comparing the relative values of the F22@$180M for 450 units versus the F-35@$110M for 3000 units. If they don't build 3000 of these things they are going to turn out to be the worlds most expensive combat jet - ever - bar none. All to do a job that could be done by a block 50/60 F-16 or another platform which already exists. And to think they decided the F-35 was the way to go because the F22 was too expensive.
The Marines do need their STOVL jet though don't they. Or do they...
http://www.informationdissemination.net/2012/08/used-cars-and-f-35s.html |
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spazsinbad
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Posted: Aug 11, 2012 - 11:50 AM
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Elite 3K

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jeffb
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Posted: Aug 11, 2012 - 12:56 PM
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You're right, it is getting old.
Nuff' said. |
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arkadyrenko
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Posted: Aug 11, 2012 - 10:32 PM
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Joined: Sep 19, 2011 - 08:40 PM
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Back to JeffB's original question: was there side to side yaw on the bomb release? If there was, that could limit the release angle for internal weapons. (Which is acceptable)
I'm looking forward to the videos of:
1) 300 ft parachute retarded internal release. (Especially of a modified nuke...)
2) Toss bombing. (Which could come back with stealth planes, under certain tactical circumstances) |
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SpudmanWP
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Posted: Aug 11, 2012 - 11:13 PM
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| I did not see side-to-side, but I did see a little porpoising (initial angle is nose-down) before the JDAM stabilizes. This should not affect release angle as the BRU-67/68 ejects it with plenty of force. |
_________________ "The early bird gets the worm but the second mouse gets the cheese."
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munny
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Posted: Aug 12, 2012 - 12:06 AM
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Joined: Jan 13, 2010 - 01:39 AM
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jeffb wrote:
This morning I was just comparing the relative values of the F22@$180M for 450 units versus the F-35@$110M for 3000 units. If they don't build 3000 of these things they are going to turn out to be the worlds most expensive combat jet - ever - bar none. All to do a job that could be done by a block 50/60 F-16 or another platform which already exists. And to think they decided the F-35 was the way to go because the F22 was too expensive.
The Marines do need their STOVL jet though don't they. Or do they...
http://www.informationdissemination.net/2012/08/used-cars-and-f-35s.html
initially responding to geoffery, report button was less effort |
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jeffb
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Posted: Aug 12, 2012 - 02:54 AM
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Banned
Joined: Feb 16, 2010 - 08:00 AM
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munny wrote:
initially responding to geoffery, report button was less effort
Well we all know how you love to foster dissenting views Munny, but don’t get me banned just yet or you’ll rob Wrightwing of his nyah-nyah moment when the F-35 flies at greater than 20 degrees AoA.
But the post about costs versus capability was off-topic and I’ll cop to that, it’s just that, for me, that’s the twenty tonne elephant in the room.
Back on topic, Spudman is quite right and I image we all noticed that the store was deliberately pushed out nose down for entry into the slip stream. Do we know how sensitive the ‘porpoising’ effect is to stores weight? Will the same ejector force work equally as well for all the proposed stores or will the force need to be adjusted depending on the store.
Also, I imagine somewhere down the line they will have to test dropping the store and the ejector together in the case where the ejector fails. Has anyone seen a schedule for that stuff or is it all considered part of the current weapons drop testing? |
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johnwill
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Posted: Aug 12, 2012 - 05:40 AM
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Joined: Mar 24, 2007 - 09:06 PM
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jeffb wrote:
Back on topic, Spudman is quite right and I image we all noticed that the store was deliberately pushed out nose down for entry into the slip stream. Do we know how sensitive the ‘porpoising’ effect is to stores weight? Will the same ejector force work equally as well for all the proposed stores or will the force need to be adjusted depending on the store.
Also, I imagine somewhere down the line they will have to test dropping the store and the ejector together in the case where the ejector fails. Has anyone seen a schedule for that stuff or is it all considered part of the current weapons drop testing?
jeffb,
Of course the stores are ejected nose down. Down air loads are used to help get the store away from the airplane cleanly.
The slight porpoising exhibited is of no importance and is determined by pitch damping of the store design, not airplane design.
The same ejector force will not be used for all stores. Store mass and cg location determine the ejector force used and the balance between forward and aft ejector pistons forces. Every store will have its own unique ejector force requirements.
The store and ejector will never be dropped together, since the ejectors are bolted into the weapon bay brackets and cannot be dropped. If a wing mounted pylon can be ejected, it might be possible drop the pylon plus store in the case of a hung store. Whether that is a wise thing to do is for someone else to decide. |
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jeffb
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Posted: Aug 12, 2012 - 08:24 AM
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Banned
Joined: Feb 16, 2010 - 08:00 AM
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Thanks for your (patient) reply Johnwill.
I mentioned the nose down push because at some point they will need to see what happens if that part of the release fails or sticks. I don't know how much testing they've done of or the reliability number they've attach to the (relatively) new BRU-67 pneumatically powered ejectors given the limited corporate knowledge of their functioning but you'd assume that they'd have to take a look at these things.
I had also assumed, given the implications of a partially suspended and possibly partially armed weapon in a closed bay that some sort of conventional pyro-powered backup might have been included to ensure that any hung store within one of the bays could be got rid of safely. I (again) assumed that dumping the ejector with the store would be the easiest way to do that. Obviously they are confident that that issue will never occur or that if it does that they will simply bring the store back or that the back up release is part of the existing rack. |
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count_to_10
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Posted: Aug 12, 2012 - 03:12 PM
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Elite 1K

Joined: Mar 10, 2012 - 03:38 PM
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jeffb wrote:
Thanks for your (patient) reply Johnwill.
I mentioned the nose down push because at some point they will need to see what happens if that part of the release fails or sticks. I don't know how much testing they've done of or the reliability number they've attach to the (relatively) new BRU-67 pneumatically powered ejectors given the limited corporate knowledge of their functioning but you'd assume that they'd have to take a look at these things.
I had also assumed, given the implications of a partially suspended and possibly partially armed weapon in a closed bay that some sort of conventional pyro-powered backup might have been included to ensure that any hung store within one of the bays could be got rid of safely. I (again) assumed that dumping the ejector with the store would be the easiest way to do that. Obviously they are confident that that issue will never occur or that if it does that they will simply bring the store back or that the back up release is part of the existing rack.
It isn't so much that things like this need to never occur, it's more that they need to be infrequent enough that losing an aircraft to them falls bellow the noise of general accidents. |
Last edited by count_to_10 on Aug 12, 2012 - 06:07 PM; edited 1 time in total
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johnwill
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Posted: Aug 12, 2012 - 05:23 PM
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Elite 1K

Joined: Mar 24, 2007 - 09:06 PM
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jeffb wrote:
Thanks for your (patient) reply Johnwill.
I mentioned the nose down push because at some point they will need to see what happens if that part of the release fails or sticks. I don't know how much testing they've done of or the reliability number they've attach to the (relatively) new BRU-67 pneumatically powered ejectors given the limited corporate knowledge of their functioning but you'd assume that they'd have to take a look at these things.
I had also assumed, given the implications of a partially suspended and possibly partially armed weapon in a closed bay that some sort of conventional pyro-powered backup might have been included to ensure that any hung store within one of the bays could be got rid of safely. I (again) assumed that dumping the ejector with the store would be the easiest way to do that. Obviously they are confident that that issue will never occur or that if it does that they will simply bring the store back or that the back up release is part of the existing rack.
Concerning hung stores, you can be sure the ejector rack manufacturer has met all the stringent requirements for reliability. There are many qual tests conducted, including vibration, thermal, inertial, structural, electrical, etc. to help assure reliable operation. Does that prevent a hung store from ever happening? No, but nothing is perfect, is it?
Hung stores are serious business, especially for the Navy and Marine Corps, so great effort is expended to prevent them and to minimize the bad effects of an occurrence. |
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spazsinbad
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Posted: Aug 13, 2012 - 01:10 AM
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Elite 3K

Joined: May 05, 2009 - 10:31 PM
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Just to illustrate the SLDinfo penchant for MILspeak as indicated on previous page of this thread, here is a classic example. They have no sense of irony and sadly no editor/proofreader willing to make sense of stuff like this:
http://www.sldinfo.com/dynamic-defense- ... aper-2012/
"...In short, Japan is in the throes of change, and how their approaches intersect and impact on those of the United States and the allies will go a long way towards shaping the shape and effectiveness of a 21st century Pacific strategy."
They can and should do better than this. Otherwise some interesting ideas undone by some poor writing shaping.  |
_________________ RAN FAA A4G: http://tinyurl.com/ctfwb3t http://tinyurl.com/ccmlenr http://www.youtube.com/user/bengello/videos
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