Another Drone Pilot does it Again
05-20-2015, 05:28 AM
#1351
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05-20-2015, 06:25 AM
#1352
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We are not talking about low mass bullets flying at supersonic speed, the soft bullet would be deformed by blasting through the sound barrier and would no longer be small enough to penetrate. We are talking about medium mass object flying at subsonic speeds and constrained enough that it will not easily deform. For example on mythbusters they found no difference in shooting a frozen or thawed chicken through a windshield of an airplane. The damage is done by the impact not a hard object, the blender is not an equal comparison. That is a much lower kinectic energy situation with hardend blades, still the likely result is that the blades get bent from the engine, and dulled from the bones. The aircraft engine uses softer but much stronger blades and the damage is not caused by contact with hard objects but a sudden impact. Yes the motor will nick and cut the blades more than the chicken, but that is minor damage the engine will run through. It is total breakage and missing blades that will do the jet engine in, not cuts and nicks.
http://kwc.org/mythbusters/2004/02/m...icken_gun.html
http://mythbusters.wikia.com/wiki/Chicken_Gun_Myth
I personally doubt a jet engine could survive ingesting a 2-3 Kilogram drone with 4 hard metal engines and a 500 gram battery with only nicks and cuts on the blades but lets hope we never find out.
Last edited by Rob2160; 05-20-2015 at 06:46 AM.
05-20-2015, 07:38 AM
#1353
Mythbusters later revised their findings and determined frozen chickens are more damaging
http://kwc.org/mythbusters/2004/02/m...icken_gun.html
http://mythbusters.wikia.com/wiki/Chicken_Gun_Myth
I personally doubt a jet engine could survive ingesting a 2-3 Kilogram drone with 4 hard metal engines and a 500 gram battery with only nicks and cuts on the blades but lets hope we never find out.
http://kwc.org/mythbusters/2004/02/m...icken_gun.html
http://mythbusters.wikia.com/wiki/Chicken_Gun_Myth
I personally doubt a jet engine could survive ingesting a 2-3 Kilogram drone with 4 hard metal engines and a 500 gram battery with only nicks and cuts on the blades but lets hope we never find out.
Result of myth: when a chicken is flying that fast, it don't matter what temperature it is.
They did find that a frozen chicken did more damage, but the result for the higher speeds that a jetliner flies at made little difference. The high kinetic energy overwhelms any difference the hardness makes. The motors on such a small sUAV just don't weigh that much. The batteries would do more damage. But its the total combined weight that will determine the actual damage.
05-20-2015, 08:17 AM
#1354
Also, Mythbusters was using the windshield made for a Cessna 172 Skyhawk, not the pressure and impact rated material used in modern jetliners. As far as what will and won't damage an engine, I have seen a standard Bic pen destroy an F-14 Tomcat engine while running at ground idle. It takes little very little to unbalance an engine and an unbalanced engine will self destruct very quickly. If you need an example, look back to the Quantas Airbus plane that had an engine explode in flight and how much damage it caused and how hard it was for the crew, including extra high hour check pilots, to get it on the plane back on the ground safely https://www.youtube.com/watch?v=6LYcpVtaDD0
05-20-2015, 08:42 AM
#1355
An f-14 Tomcat is not an airliner engine, and not a fan jet. Airliners are rated to injest 5 KG birds and continue running. The fan helps as it tends to send the bird parts out away from the compressor inlet. Yes a missing blade can cause a large amount of damage, but it usually takes something larger than that. That is not saying it would never happen, only unlikely.
05-20-2015, 09:39 AM
#1357
Not really. My neighbor would go deer hunting at night regularly. And he was always in by the time the cops showed up. Trumbull spends most of its money on the Trumbull head weanies than on needed services.
05-20-2015, 09:42 AM
#1358
I can tell you that in many areas of the country including the pro gun states that firing a gun without a valid cause can wind you up in jail in fact you can't even fire a warning shot.
Unless you are at a legal gun range the only reason accepted for firing a gun is self defense and firing at mode airplanes wont qualify as self defense. Also legally hunting
in a area that is legal to hunt in would be about the only other reason you can fire a gun.
Unless you are at a legal gun range the only reason accepted for firing a gun is self defense and firing at mode airplanes wont qualify as self defense. Also legally hunting
in a area that is legal to hunt in would be about the only other reason you can fire a gun.
05-20-2015, 10:51 AM
#1360
I am well aware that you can sometimes get away with firing a gun that even holds true here in anti gun calif as the police can't be everywhere all the time. This discussion
started because a guy said he would shoot down drones and another said you could. IMO there is a big difference between shooting at someone's property in the daytime
where they will immediately call the police and report a crime and/or a description of the person firing or a general description of where the shots came from.
However in the nighttime hunting you talked about the police likely only showed up because someone called and reported hearing shots in a somewhat general area .
started because a guy said he would shoot down drones and another said you could. IMO there is a big difference between shooting at someone's property in the daytime
where they will immediately call the police and report a crime and/or a description of the person firing or a general description of where the shots came from.
However in the nighttime hunting you talked about the police likely only showed up because someone called and reported hearing shots in a somewhat general area .
05-20-2015, 01:27 PM
#1361
An f-14 Tomcat is not an airliner engine, and not a fan jet. Airliners are rated to injest 5 KG birds and continue running. The fan helps as it tends to send the bird parts out away from the compressor inlet. Yes a missing blade can cause a large amount of damage, but it usually takes something larger than that. That is not saying it would never happen, only unlikely.
05-20-2015, 02:08 PM
#1362
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OK, This Clown that landed on the White House Lawn, is getting what he deserves. Wish it were more.
http://www.foxnews.com/politics/2015...cmp=latestnews
http://www.foxnews.com/politics/2015...cmp=latestnews
05-20-2015, 02:20 PM
#1363
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An f-14 Tomcat is not an airliner engine, and not a fan jet. Airliners are rated to injest 5 KG birds and continue running. The fan helps as it tends to send the bird parts out away from the compressor inlet. Yes a missing blade can cause a large amount of damage, but it usually takes something larger than that. That is not saying it would never happen, only unlikely.
05-20-2015, 05:39 PM
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Per the Mythbusters conclusion.
Result of myth: when a chicken is flying that fast, it don't matter what temperature it is.
They did find that a frozen chicken did more damage, but the result for the higher speeds that a jetliner flies at made little difference. The high kinetic energy overwhelms any difference the hardness makes. The motors on such a small sUAV just don't weigh that much. The batteries would do more damage. But its the total combined weight that will determine the actual damage.
Result of myth: when a chicken is flying that fast, it don't matter what temperature it is.
They did find that a frozen chicken did more damage, but the result for the higher speeds that a jetliner flies at made little difference. The high kinetic energy overwhelms any difference the hardness makes. The motors on such a small sUAV just don't weigh that much. The batteries would do more damage. But its the total combined weight that will determine the actual damage.
That would do very nasty things to a jet engine or cockpit windscreen impacting at 300 Kts.
05-20-2015, 05:46 PM
#1365
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A jet engine is just that, a jet engine. They have blades in the front, which narrow down to the compressor stage. There is where the problem occurs. The blades already fractured by a foreign object other than AIR, chicken or what not , will not go into the compression state. The fractured blades with the other foreign object then enter the compression stage, when that takes place, the engine will self disstruct, implode within itself creating an engine failure. Jet fighter, bomber, Airliner, jets engines operate on the same principal, air in air out. Any object sucked into those fan blades with create havoc in that engine.
https://www.youtube.com/watch?v=L1jZvlFmqQU I have personally experienced four bird strikes while flying jet aircraft, 1. did no damage to a wing leading edge, only blood stains, 2, No damage to a windscreen, it happened at low speed on landing, 3 and 4 went into engines causing minor damage to the compressor blades which needed replacing.
We also had an incident where the engine ingested several medium size pieces of iron ore gravel - though smaller than the birds, they did far more damage and the engine had to be replaced.
Last edited by Rob2160; 05-20-2015 at 05:57 PM.
05-20-2015, 07:41 PM
#1366
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Also, Mythbusters was using the windshield made for a Cessna 172 Skyhawk, not the pressure and impact rated material used in modern jetliners. As far as what will and won't damage an engine, I have seen a standard Bic pen destroy an F-14 Tomcat engine while running at ground idle. It takes little very little to unbalance an engine and an unbalanced engine will self destruct very quickly. If you need an example, look back to the Quantas Airbus plane that had an engine explode in flight and how much damage it caused and how hard it was for the crew, including extra high hour check pilots, to get it on the plane back on the ground safely https://www.youtube.com/watch?v=6LYcpVtaDD0
It started as "Queensland and Northern Territory Aerial Service".
Last edited by Rob2160; 05-20-2015 at 07:55 PM.
05-20-2015, 08:29 PM
#1367
A jet engine is just that, a jet engine. They have blades in the front, which narrow down to the compressor stage. There is where the problem occurs. The blades already fractured by a foreign object other than AIR, chicken or what not , will not go into the compression state. The fractured blades with the other foreign object then enter the compression stage, when that takes place, the engine will self disstruct, implode within itself creating an engine failure. Jet fighter, bomber, Airliner, jets engines operate on the same principal, air in air out. Any object sucked into those fan blades with create havoc in that engine.
Not news to me. These engines are tested with birds that are much larger than a 5 pound sUAV and they keep going.
05-20-2015, 10:20 PM
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It sounds good in theory and I wish it were true in all cases but facts prove otherwise - foreign object ingestion can and does cause engine failures.
The FAA certification standard for a large bird strike (above 1.85Kg - 4.07lbs) in a turbine engine does not require the engine to continue producing power.
It only requires the damage to be contained within the engine and not result in further damage to the aircraft / airframe.
http://rgl.faa.gov/Regulatory_and_Gu.../ac33.76-1.pdf
Even forgetting about the engines, impact damage anywhere on the airframe can also result in a crash e.g. the Concorde - which was brought down by a 10lb piece of rubber hitting the wing.
05-21-2015, 04:03 AM
#1369
OK, This Clown that landed on the White House Lawn, is getting what he deserves. Wish it were more.
http://www.foxnews.com/politics/2015...cmp=latestnews
http://www.foxnews.com/politics/2015...cmp=latestnews
05-21-2015, 04:32 AM
#1370
Tell that to Sullenberger..
It sounds good in theory and I wish it were true in all cases but facts prove otherwise - foreign object ingestion can and does cause engine failures.
The FAA certification standard for a large bird strike (above 1.85Kg - 4.07lbs) in a turbine engine does not require the engine to continue producing power.
It only requires the damage to be contained within the engine and not result in further damage to the aircraft / airframe.
http://rgl.faa.gov/Regulatory_and_Gu.../ac33.76-1.pdf
Even forgetting about the engines, impact damage anywhere on the airframe can also result in a crash e.g. the Concorde - which was brought down by a 10lb piece of rubber hitting the wing.
It sounds good in theory and I wish it were true in all cases but facts prove otherwise - foreign object ingestion can and does cause engine failures.
The FAA certification standard for a large bird strike (above 1.85Kg - 4.07lbs) in a turbine engine does not require the engine to continue producing power.
It only requires the damage to be contained within the engine and not result in further damage to the aircraft / airframe.
http://rgl.faa.gov/Regulatory_and_Gu.../ac33.76-1.pdf
Even forgetting about the engines, impact damage anywhere on the airframe can also result in a crash e.g. the Concorde - which was brought down by a 10lb piece of rubber hitting the wing.
http://lessonslearned.faa.gov/ll_mai...41&LLTypeID=10
Last edited by Sport_Pilot; 05-21-2015 at 04:41 AM.
05-21-2015, 04:47 AM
#1371
Like this.
https://www.youtube.com/watch?v=L1jZvlFmqQU I have personally experienced four bird strikes while flying jet aircraft, 1. did no damage to a wing leading edge, only blood stains, 2, No damage to a windscreen, it happened at low speed on landing, 3 and 4 went into engines causing minor damage to the compressor blades which needed replacing.
We also had an incident where the engine ingested several medium size pieces of iron ore gravel - though smaller than the birds, they did far more damage and the engine had to be replaced.
https://www.youtube.com/watch?v=L1jZvlFmqQU I have personally experienced four bird strikes while flying jet aircraft, 1. did no damage to a wing leading edge, only blood stains, 2, No damage to a windscreen, it happened at low speed on landing, 3 and 4 went into engines causing minor damage to the compressor blades which needed replacing.
We also had an incident where the engine ingested several medium size pieces of iron ore gravel - though smaller than the birds, they did far more damage and the engine had to be replaced.
Hard sharp gravel will damage nearly all of the blades, but likely the engine ran long enough to land. With a sUAV the engine is not sharp and soft metal, not hard carbon steel. I believe the battery would do more damage as it is likely longer than the space between the blades and will toss around till it lines up so that it is lying parallel to the blades. Or it will pass though when the blades cut it. Then the battery acids will damage the blades. Still I doubt this would cause a certified airliner engine to lose all thrust.
05-21-2015, 04:58 AM
#1372
I guess it also depends on the size of UAV we are talking about. - a small Phantom or Blade 350QX will do less damage than a larger machine. I have a UAV almost 1 meter across that weighs 4.5 Kilograms (10lbs) - most of the construction is metal, the motors are 150 grams each and it carries a 1 kilogram battery.
That would do very nasty things to a jet engine or cockpit windscreen impacting at 300 Kts.
That would do very nasty things to a jet engine or cockpit windscreen impacting at 300 Kts.
05-21-2015, 06:05 AM
#1374
Now how do we Educate the Educatable and prosecute the ones that don't care about regulations.
05-21-2015, 06:26 AM
#1375
Okay guys, we are all forgetting one simple fact:
A BIRD'S BONES ARE THIN WALLED AND FRAGILE, A QUAD'S ARMS ARE NOT.
The plastic or aluminum of the quad's structure is much more durable than a bird's skeleton so the blade damage will be much more severe than a bird being sucked through. Going back to the "Bic" pen, it takes much more force to break the pen's outer tube than it does to break a much larger bird bone
A BIRD'S BONES ARE THIN WALLED AND FRAGILE, A QUAD'S ARMS ARE NOT.
The plastic or aluminum of the quad's structure is much more durable than a bird's skeleton so the blade damage will be much more severe than a bird being sucked through. Going back to the "Bic" pen, it takes much more force to break the pen's outer tube than it does to break a much larger bird bone
Last edited by Hydro Junkie; 05-21-2015 at 06:30 AM.