Why jet engines are NEVER protected in the front?!
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- Опубликовано: 29 окт 2019
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One of the most common questions I get on this channel is why we don't mount some kind of mesh, in front of the jet engines to protect them from birds and other debris.
In todays video I will try to crack this mystery in a few different ways.
I hope you will enjoy this episode my friends and continue to send in your questions to the channel. If i get enough, I will make a video about them!
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A huge "Thank You!" to the channels that were featured in this episode! See the awesome full versions using the links below:
okrajoe (Chinook engine)
• Video
marioyhector1 (testing the GE90)
• Real Flight video Boei...
An old school machinist was telling me that he knew a guy back in the day who’s job at pratt and whitney was to throw stuff into engines. Apparently they would throw turkeys, hammers, ladders and all sorts of other crap into them to see what happens. Sounded like an awesome job.
Shredding turkeys
throw a freight train into the engine
He should start a youtube channel as a spiritual successor to Blendtec's "Will it blend"
Not true. Not totally anyways. They shoot birds into them, 4lb maximum weight, and ice sheets and hail. No need to throw a hammer into it to find out what happens. They know what will happen...totally destroy the engine.
@@rak6080 I know a bunch of guys that worked there in the 70’s and they all tell the same stories, maybe its bs but that what they say.
This is all really quite simple: Attach a large plastic owl to the top of the jet engine. Birds in flight will see the predatory owl, and in initiate evasive maneuvers.
It would be moving so fast birds wouldn’t react fast enough.
Or you could equip all birds with TCAS and call it a day
I have a plastic owl on my balcony and it works great
BattleshipAgincourt Wooooooooooosh the Sound of the owl passing by
...or paint the front of planes to look like owls!
I think in the instance a mesh got hit hard enough that it broke or fragmented, the metal shards would create more damage than a bird.
He says exactly that at 6:50...
It might not have to be metal. It could be carbon strands that would just be combusted by the engine.
And it would most likely disturb the airflow
Absolutely true , There's a large number of negative factors that would occur putting a mesh screen in front of a jet engine ,
There are devices that put out high frequency sound waves that you wouldn't hear but birds will and it's uncomfortable to them so that would keep them away from the area , If you notice another thing , High tension wires on steel towers carrying 138,000 volts and higher , Birds will not sit on those kind of power lines because of induction surrounding the lines which is uncomfortable to them
If airports would implement the use of those devices that put out high frequency sound waves , It would reduce the risk of bird strikes and without doing any harm to the birds
If a bird goes through the engine it would probably have to be rebuilt anyways.
Side note: I'd imagine a mesh would make a great place for ice to begin forming thus further reducing the air ingested by the engine. You'd then have to design a system to deice the screen.
Just add a heating element.
like running heated liquid through the mesh?
how will that hold in case of bird strike?
@@amolbambode2959 no, just a filament wire presumably
@@ianc8999
lol... I wasn't gonna tell him...
@@amolbambode2959 no just run electricity through like those heat blankets to warm it up and prevent icing.
Answer basically starts at 4:13
Ovi Haliuc
You’re a life saver
And I was convinced before the five minute indicator came up. No mesh.
Blessing
thanks, i love his content. But he can sometimes ramble.
thanks homie
Why don't they just paint a sign near the air intakes warning the birds NOT to fly into the engines?
Most birds are illiterate
@@harbard642 most
Write it in pidgin English.
@@decam5329 Now that s so crazy...it could actually work
They should be taught sign language first
Actually the first blades row IS the mesh. It is designed to cope with that strikes and minimize possible damages to the rest of the engine.
Great videos! Congrats!
That makes a lot of sense. My initial thought when he said a mesh wouldn't work because it would reduce airflow, was thinking of putting a high-speed fan in front of the engine. That would push air into the engine, but any solid object that tried to get in would either bounce off the blades or get chopped into many pieces. And at high speeds a mesh would pretty much just slice up anything that it hit anyway, just like a fan blade. But apparently that's already been done, so it's not much of an idea.
@@jeremyandrews3292 There used to be a video on RUclips showing the aftermath of human ingestion at an aircraft stand. The centrifugal force pushed him to the outside of the main fan housing and pretty much shredded him throwing pinkish fat deposits and muscle around the housing and spread out behind the engine. I doubt any of him went through the engine. It was a video you wished you could unwatch and like so many RUclips removed them.
The MIG-29 and a few other military aircraft had "Anti FOD Screens" to protect the engine from foreign objects. They were eventually dropped as the performance hit wasn't worth the protection. The idea was that during war battle debris would be everywhere and you might have to operate from roads, temporary forward bases, and unimproved airfields.
I see them on model aircraft sometimes. The risk of ingesting FOD can be pretty high for models (depending on aircraft and runway), and while there is definitely a performance hit, most model jets can spare a little power.
I thought the Mig-29's FOD screens were pretty much only for take-offs and landings. I saw a Russian pilot explain that the Russian air force doesn't take meticulous care of its runways like the west does.
On the MiG-29 during takeoff and landings they use louvers on the top and the main ones are closed
The engine chops, blends the spices and cooks the bird then only teases you with the smell
There are videos of it. A bird comes in, a red mist is ejected at the back.
Finger lickin' good
Better than roadkill goulash!
@@NeedaNewAlias depends on the freshness of the ingredients. I do enjoy bird smoothies doh.
Colonel Sander's private jet did this.
I believe Sully said they were Canada Gooses (Canadian Geese?) - not seagulls.
When he said they hit a flock of seagulls, my mind started playing, "And I raaaan, I ran so far awaaaaay...."
Canadians with wings.
it was Canadian geese without a flight plan and were still getting bad press over this, lol
Much larger than seagull
The correct plural is "Canada geese" .
The "Miracle on the Hudson" plane was brought down by Canada geese. The NTSB report indicates that the Smithsonian identified the bird remains in the engine using DNA analysis. This species is a year round resident of New York City. Its year round range along the East Coast is from Maine to the northern part of Florida. The ingestion happened very close to the Bronx Zoo and Bronx River over the neighborhood I grew up in.
Yes, that is what I read as well. Cda Geese are sizeable birds!
I'm 99% sure this is correct. Those are a big breed of geese, from memory 7kg or something like that?? I've never seen them IRL but the geese I have seen would stand almost waist-high to a human, and I'm sure the Canada Geese are bigger than most. (A quick google would answer my question, I know lol). Point being, they're MUCH bigger than little seagulls or ducks or any birds like that which I imagine would be more common ones for planes to hit.
If Sully's plane had hit a flock of seagulls, even a very large number of them, it may well have been ok, as the birds would have disintegrated with much less resistance on the engine (and being lighter they would probably have gotten thrown out the bypass ducts as Petter described). For the Miracle on the Hudson, a flock that big, of birds that big, was just plain bad luck.
@@nicholasorr6051 I am surprised you never seen a Canadian geese. The are a vere invasive breed that have spread to many places in the last decades. For example; in Sweden it was virtually non existent 25 years ago and now they are everywhere. I hate them😠 they crap a lot and it doesn't look like regular bird crap, it looks like dog do.
@@nhytg376tgyuu765gjmg I live in New Zealand, so they haven't made it here lol.
@@nicholasorr6051 that's explains it.
When there’s a bird strike, generally the bird leaves the exit of the engine cooked to perfection with crispy skin. The jet engine is outfitted with herb and spice dispensers as well as exhaust ports for the airlines signature sauce. The chopped up bird parts are collected by a special net at the end of the engine where it is pulled into the fuselage through a hole. After which it can be served to the crew and passengers for dinner 🍲 😌
😂😂😂😂😂
Such a creative and hilarious comment. 😄
Hey, do you have a blond kid with a stuffed tiger? He’s been building those snowmen on my property again. 🫤
@@thebasketballhistorian3291 thank you ☺️ 🙏🏽
@@geoear air fryer 😋🍗
Actually, jet engines ARE covered by a steel mesh on ONE aircraft type (the F-117 stealth fighter) -- but the purpose is to absorb radar waves rather than stop birds or debris!
Tu-134, Tu-154 Soviet airliners have their engine intakes protected as well.
@@ukrainianregionalaviation1809 Not true -- I saw a Tu-154 up close at the exhibition center in Moscow, and it did NOT have ANYTHING of the sort!
su 33 also have screens, for land operations, not for carrier op... mig 29 have doors and intake on top...
Yes, but there was NO ice protection on the cowling or the mesh, so they could not fly through any icing conditions.
@@agentorange153 well, they could've taken it off. Or maybe you haven't heard that aircraft can have different configurations?
Me watching this video: "OK" ... "Got it" ... "Understood" ... "Makes perfect sense, please continue" ...
Mticj
Deez nutz
U really didn’t understand
*First time I ever found a material fact in error with MT. Sully didn't fly into a flock of Seagulls, but instead hit a flock of Canada Geese. Love the videos!*
Actually he did, but then he ran. He ran so far away.
So tl;dr
1. engines are designed to keep working in the event of a bird strike
2. it would restrict airflow to the engine
It's like saying if I cover my bed with a mosquito mesh and sleep inside, I'll suffocate to death
@@basalticlife1861 With many enough mosquitoes, it would be true. Fortunately, no place on earth is that bad.
3. mesh could fail and it or parts of it could enter the engine. Because the mesh has to be really strong, its parts would cause heavy damage. And the stronger you make the mesh, the more it will weight.
If the birds cover the entire mesh, just put the engine into reverse and it will blow the birds off!
Or maybe install a viper there that will deal with ice also
You didn't watch the video did you, otherwise you'd understand why the mesh is not viable, even when it's 100% clear. So having it covered with birds (or any other FOD) is irrelevant.
Gary XHLC
r/woooosh
The plane will fall out of the sky if you reverse engines in mid flight.
Efrain Rosso
r/woooosh
I would suspect icing could be an issue with mesh over the intakes as well.
Could probably line it similar to how your rear windshield defroster on your car is set up. Or make the mesh a straight up heat coil outright.
@@Zeromaus or use bypass air like leading edges of aero surfaces. Not sure if I would want to chance that.
@@Zeromaus YEAH---MADE OF POLYCARBON. BESIDES, THINK OF ALL THOSE CHICKEN BURGER'S, ALREADY DE-FEATHERED.
probably, and also the engine would have a lot of trouble with the turbulend air
Jesse, maybe this pilot's next video should be on why the wings don't already have those "hot wires" like a car rear window?
if birds accidentally fly into the engine, then just remove the engine lol
This is the exact same energy as that girl that said "if you are homeless... Just..
Buy a home"
I actually had a flight delayed for that. It’s kinda off putting that they found it after everyone was in their seats. Glad the second guy to check everything saw it I guess lol
Enrique Barroso yeah but it’s a joke
What if u eliminate the birds?
Yeah, this is 🅱️ig 🅱️rain time
Rolls-Royce did lots of experiments on this in the 1950s - a good friend of my brother was the official RR photographer who documented it all. Apart from the drag, in the appropriate conditions, you can get a lot of icing - and big chunks of ice build up on/behind the mesh, break off then get fed straight into the turbine blades.
better explanation with sources than the 10 minute long video
Heating mesh?
@@yasarpeker7457 A mesh capable of holding a heating element that could keep the mesh hot enough would not only cost a friggin fortune per engine, but also seriously hamper the efficiency of the engine in question.
@@Skyfighter64 fortune (?! ) instead of lives.
@@yasarpeker7457 I'm a realist, not an idealist. You try to take every risk it of aviation entirely, which is naturally an impossible task, is going to be too expensive for anyone to operate airplanes at all, taking away the most powerful mode of long range human transportation ever created. Worse, the number of lives you would save annually to the failure you are trying to prevent, by meshing the engine inlets would be virtually nill, because few of the airline fatalities we do see are directly attributable to bird strikes in the engine.
You need powerful laser guns mounted on the aircraft to automatically target and destroy any bird in the vicinity of the aircraft.
Lasers are the answer.
Nah get a .950 JDJ machine gun
Wipe out the entire global bird population. Problem solved
@@goomanhlr5697 the bullet will hit the plane , lasers are the answer
This could only be applied to military aircraft.
Unless you meet the birds in the fog or they are behind a cloud.
One small detail - although it doesn't change the gist of the video: the Miracle On the Hudson was caused by a migratory flock of Canadian Geese (which are much larger than seagulls.)
They also apologized as they were ingested by the engines, giving confirmation that they were, in fact, Canadian.
Actually they're Canada Geese, not Canadian Geese.
The Canada goose has two reactions: Apologize like a polite Canadian, or drop the gloves, square up,pull your shirt over your head and start punching like a hockey player.
Yes they were Canada Geese but no they were not migrating. The incident happened January 15 when birds are not migrating that time of year. Canada Geese are known to not migrate anymore as large cities have enough food year round for them to eat, therefore these geese were just a local flock that are not migrating anymore, this creates a lot of problems as they over populate an area like New York year round
@@KnightsWithoutATable Lest we forget!
This video explained the question quite simply and effectively, especially the tennis racket example, thank you very much.
Things getting stuck against the mesh and stopping air flow was my first thought; but everything else you explained also makes perfect sense.
Another consideration for why a protective mesh makes sense for a Chinook: they lack the bypass ducts of a turbo fan, so any FOD is going straight through the core of the engine.
Also being a military helicopter it is likely to land in places with plenty of debris which may be made airborne by the rotor down wash.
@@bigbadjohn10 also true!
Chinooks fly much slower, are lighter than commercial airliners and are essentially a turbo-prop aircraft so the volumetric flow of air being drawn into the engine is much much lower.
Helicopters don't have engines to produce thrust and so they can't have a bypass duct. Turbines on helicopters are turboshaft engines, delivering power to a transmission which then drives the rotors. It's a completely different type of engine and approach to the propulsion of the aircraft.
My favorite anti-FOD device is the gravel kit fitted to some 737-200's operated in Alaska and Canada
Yeah....you saw sam chui video ?
I build and test jet engines for a living. Mentour Pilot is spot on here. This video is 100% endorsed by Jet City Turbines.
This is an excellent explanation of a question I also get all the time.
Thank you once again CAPT for a great vid/info. I've often wondered about this.👍 Makes so much sense!!
Excellent video as always, very informative. The US Airways Flight 1549 was hit by a flock of Canada Geese, not seagulls. The point discussed is still the same though.
I really like how you take people's ideas and seriously consider them and then explain different scenarios of why it could work, but could have bad consequences, or why they wouldn't work. It's great that you give respect to the people who think of these things!!!
when they designed the first turbojet engines, they did not think of the fan. someone told them, damn!
Just mount one of those stupid plastic owls on the intake.
And if that plastic owl happens to come lose , what do u think will happen . Same scenario ...plastic bits straight into the engines . Even before it falls down , it will get sucked in .
@@ed4all33 wooosh
@@cerdon4076 oopsie
@@ed4all33 lol is okay
@@cerdon4076 whewwww ...generally i am quite quick on the uptake . It must have been one of those days ...when everything went over my head :))
Conical mesh, solving the problem of the birbs getting stuck in front of the protection.
Also, they could try flashlights at the tip of the or something of the sort to warn off the poor birds, too.
A cat sticker on the front of the engine
That helps...Lion Air has never had a crash due to bird strikes.
Meow ?
Keep up the good work Mentour.
This makes perfect sense. I went to Edwards Air Force Base driving an 18 wheeler once to pick up some fuel bowsers and before I could get anywhere near the place where they were, I had to get all the rocks out of the treads of all 18 tires. There was another guy that escorted me around the base that helped me. He said those rocks could come out and get on the runway and a jet might pick it up. So, here we are with screw drivers and pliers getting the rocks out. About a 45 minute job for 2 people.
It wasn't the 1st of April was it???
😛
Hmm... wouldn't the rocks fall out of you added more air? Curious.
One of the reasons the AF is big on FOD walks (foreign object damage). The airmen spread out and walk down the flight line picking up anything on the taxiway/runway. When you have completed your work on an aircraft you have to account for everything you took out to the line. Nothing worse than being the one responsible for the screwdriver that got sucked into an engine.
@@ilenestrong7471 "lost a screwdriver "(quote)
No... that would mean that the rest of your tour - was to be spent peeling potatoes from morning to night! Haha
Beter have a 45 min job for two than a multi day operation for 10 aviation engineers.
Wire mesh will restrict too much airflow, will decrease performance by a good bit. Good video lots of things are considered here, this is what most engineers are faced with everyday when engineering things. I always trust the engineers as they have looked at all the factors and got the best solution.
I think a cone shaped mesh that can be retractable after certain altitude/speed could be useful on takeoff and landing. Cone shaped will displace foreign objects away from the engine, being retractable will eliminate the drag for most of the flight (like landing gears)
Astronomical costs, added systems, added maintenance, added inspections, added weight, added fuel consumption, and safety of flight issues with in-flight failures. Not to mention the system itself would pose a FOD hazard to the engines with the mounting hardware.
Why is _[a thing]_ on airplanes done _[the way it's done]_ instead of _[some other way]?_
The answer is ALWAYS "To reduce drag". Some stealth airplanes have mesh in front of the engines to reduce radar reflection off the compressor blades, and those airplanes are MUCH slower because of it. Also, if anything hits the engine at 500 miles an hour, a mesh screen isn't gonna do shit. And if anything hits the engine at _low_ speed, who's going to volunteer to go outside to clean it off? It's simply more expedient to build the engine strong enough to eat birds rather than trying to prevent them from getting sucked in.
TY for the answer. 4 min into the video I still didnt have an answer so I went looking in the comments
@@LesAventuresDeTigRRe brilliant! I love your comment 🤣🤣🤣
Very well said.
The F-117 really isn't that slow. Despite the designation, it's a bomber, not a fighter. Its speed is comparable to other aircraft of comparable role designed without afterburners. Also, the whole airframe was kind of terrible because it was what could be done.
I'm sure the mesh didn't help but it doesn't seem as big a difference as you imply.
If I understand the Miracle on Hudson situation correctly, there was another problem compounded on top of the bird strike, specifically that they only just took off and didn't have enough airspeed to restart engines mid flight. Had this happen when they were faster, I think it is possible, if not likely, they'd be able to restart at least one engine.
Sir: For many years, Alouette Helicopters (Alouette 2's & 3's to my certain knowledge) used a metal mesh induction air guard to avoid ingestion of birds, twigs, stones & any other impedimenta. In later years they used "Elephant ears" (large square aluminum or fibreglass housings that contained filter media, but were mainly used in desert conditions. Russian MI-8 & Mi-17 choppers also used induction screens, depending where geographically they were operating. Obviously, owing to drag considerations , jet transports do not use them. A secondary consideration I suspect is in the case of a foreign object
ingestion, the possibility of breaking the screens free & having them ingested into axial compressor stages, with subsequent destruction of those stages & possible disintegration of the entire engine.
I very much enjoy your videos Sir.
Thanks Captain. I've always wondered this 👍🏻
I think cactus 1549 impacted canada geese, not seagulls
I think because Mentour Pilot said it, we need to change the Wiki to Seagulls, Mentour Pilot is always right.
@@GWRProductions-kg9pt Obviously you do not understand the concept of dry humour....
Yes mentor pilot said so he has spoken they were Canadian seagulls
A huge flock of canada geese so dense the flight crew had spotted over 7 miles away bit still chose to fly at them.
@@byteme9718
Sully and Jeff saw the geese split seconds before hitting them!!!
Go watch the movie called SULLY
The tennis racket is fantastic! Your videos are always entertaining and educational, thank you!
Modern (military) tanks have flexible plates covering them which can detect an incoming anti-tank projectile and explode (sort of like a car airbag) which can deflect the projectile. Perhaps an integral shield that can instantly deploy when a significant bird flock will hit the engines. Of course it could cause the engine to stall, but it would quickly re-deploy and the engine could be started again without damage.
I just pictured an image of an engine ingesting a big metal screen.... 😳
And that's invariably what would happen if a portion of the mesh were to break off. The engine would suck the entire mesh (and probably also the engine cowling) into the nacelle.
Peter S Thinking the same thing here...metal fatigue for sure.
I did, too. Scarier than any bird!
They wouldn't use chicken wire
It should be a honeycomb structure made of carbon fiber. Give it a steep conical profile so birds slide off to the side.
The DC-9's I worked as a ramp agent had meshes infront of their engines.
Of course when the DC-9 was produced fuel efficiency wasn't nearly as important as it is now.
Thanks, clear explanation, covered all the aspects of the issue.
I used to work for Rolls Royce Military Engine Group in Bristol, UK. The engines were tested in test cells with inlet screens to prevent ingestion of debris, however we were prohibited from running at certain conditions of low temperature and high dew point. This was based on previous experience where the mesh iced over in an instant and the entire structure was sucked into the engine causing extensive damage. Obviously it is not practical to limit aircraft operations in this way, so a mesh is not practical.
and yet again i find myself nodding at my monitor in acknowledgement every time he says "okey?" and "alright?"
I wish I could handle a second language as well as the presenter speaks English.
@@peteacher52 In Sweden we start to learn english very early in school :)
I googled your username, and I'm impressed, but I'm also disappointed with the formulation of the word. It _should_ be pneumonoultramicroscopivulcanisiliconicosis.
Good informative video. The Hudson accident was not due to a flock of seagulls but Canadian Geese.
I hear that are very big, solid birds. Never seen one in real life.
those Canadian!!
Canada Geese, not Canadian Geese....
I have often wondered about this myself. How about engineering jet engines to easily shred an ostrich without blinking an eye? Or equipping commercial airliners to emit a hellish terrifying noise that only birds can hear that scares them off? Or even better: a noise that causes them to drop from the sky to their feathery dooms?
Very good and clean explanation of issues involved!
Easy way to experience the difference a protective grill/mesh makes, take the front one off of a desk fan. 20-30% diference at least.
Yeah, and imagine the difference at 550MPH.
Indeed, and cleaning the desiccated insects from your radiator fins vastly improves the cooling efficiency of the system.
@@peteacher52 My sisters car was overheating, took a look at the radiator to find a plastic bag stuck in there, car ran fine after removing it.
Ice buildup would be my biggest concern with putting screens over the engine intakes, the high surface area of the intake screen combined with the low air temperature would be a breeding ground for ice
Also, Sullys plane hit a flock of Canada geese, not seagulls
Came here to say exactly that.
You hit enough large birds like Sully did ,you will have a flame out.
I had that thought /question too. Seems like ice chunks would do significantly more damage than even large birds.
@@mhkeith829 it's more in regard to the loss of power caused by the ice blocking the screens
I'd be conerned about ice also..
I reallly wondered a lot for a long time why they didnt put a mesh out there! Thanks for answering the question
Thank you for covering this topic. This has been my question for a long time.
Sukhoi Su-27 has retractable mesh protectors in the jet intakes to prevent foreign object ingestion during taxi and takeoff.
Neal Scroggs because Russians don’t like KFC smell!
The Y-32 used a mesh on the inlet, though this was an attempt to reduce the radar cross section of the massive intake, not protect the engine.
Peter, you've done it again!!! I was totally fascinated....AGAIN!!!!
Decades ago , my father use to work for General Electric . One weekend they had a family weekend were workers & their family’s could come to the factory,s & tour the plant , my father happen to be one of the workers who built the blades on the jet engines ( what shreds birds first on jet engines). It was way cool to see how every step it take’s to make each part step by step . Back in the day GE use to use a real chicken ( dead of corse ) to test bird strikes in their engines & that was a cool sight to see , by the late 80 the quit using them & supplemented a dummy chicken . I even got to see how they test engines in a high altitude test , they would submerge parts of the engine in water then run it . Outside of the building , it would create gigantic plumes of water vapor that you could see for miles , if you knew about GE & what they built (jet engines) & stuff , when you would drive by the GE plant & seen one of these big plumes you knew what they were doing . Very interesting.
A mesh system in front of the engine would restrict too much airflow being ingested. Jet engines are deceivingly insane at ingesting large volumes of air, something like a large house worth of air volume every second. Image the tension required on that mesh screen to handle those kinds of airflows. If you encounter icing, the entire mesh surface would be an excellent surface for ice to form on thus restricting the inlet even more. Electrically heating the mesh would require A LOT of power to keep ice from forming. What if the mesh fails after a bird strike, well now you're back where you started and probably worse now that you have a metal mesh being ingested. The best measure we can take for bird strikes at this moment is prevention.
The intake of the engine is a spinning fan. Instead of installing a mesh infront of the intake fan, perhaps installing another fan, infront of the intake fan, might work? The first fan would spin at the same speed as the intake fan, thus eliminating drag concerns. The blades of the first fan can be engineered (i.e., angle, shape) in a way that minimizes biomass intake, and maximizes deflection. Something like three, wide, propeller blades. And whatever biomass still happens to get through to the turbines will have already drastically been reduced because of this dual-fan solution. Just a thought.
@@tonyr1736 Firstly, fans create turbulence in the air that goes through them, and turbulent intake reduces the efficiency for any other fan placed close behind. That's why wind turbines are always staggered and far apart from one another and why doubled-up propellers are rare. A fan in front of the turbofan would reduce the tubofan's ability to create flow and thrust.
Secondly, if the blade angle of the front fan was such as to deflect incoming mass (birds or air makes no difference) it means it would be pushing *against* the flow, completely starving the engine behind.
Kimon Froussios Very good points.
@@tonyr1736 it's a delicate balance between scavenging power from the turbine to power the main fan for thrust and leaving some thrust from the exhaust. Most of the power from turbofans is already sent to the main fan, any "redirection" of power to additional fans would require a larger turbine, larger engine, more weight, more fuel, etc etc, a secondary fan in front would demand too much additional power. Cool idea though!
Engines would also be much noisier. Props and fans are less noisy when they're biting into clean, or non-turbulent air.
A question I've always had in my mind. Thanks of answering!
LoL just imagine those meshes getting sucked into a jet engine!
That WOULD be unfortunate
Thats another fine mesh you got me into!
I was surprised why nose cone shaped meshes were not included in engine design, though this explanation does make sense as far as engine efficiency goes.
I was thinking about nose cone shaped meshes and some big inlet bypass with laser separator detecting objects and hit it to prevent from entering compressor stage.
@@pawelpablo898, the problem is the speed, a 100g bird hitting the aircraft at cruising speed (around 800 km/h) have roughly the same energy of a .30 Winchester hunting rifle bullet.
@@nejiniisan1265 100 gram birds at 41,000 feet are pretty rare.
@@Markle2k
Yes usually they're much bigger but a fly a little lower :)
Rüppell's Griffon Vulture - 37,000 feet 6.4 to 9 kg (14 to 20 lb)
Common crane - 33,000 feet. ...
5.4 kg (12 lb)
Bar-headed goose - 27,825 feet. ...
1.87-3.2 kg (4.1-7.1 lb)
Whooper swan - 27,000 feet. ...
11.4 kg (22-25 lb)
Alpine chough - 26,500 feet. ...
191-244 g (6.7-8.6 oz)
Bearded vulture - 24,000 feet. ...
4.5-7.8 kg (9.9-17.2 lb)
Andean condor - 21,300 feet. ...
11 to 15 kg (24 to 33 lb)
Mallard - 21000 feet. ... 0.72-1.58 kg (1.6-3.5 lb)
@@Markle2k, yeah, I mentioned the 100g just to give an overall idea. If you consider a 7kg vulture, you have a canon ball hitting the plane.
Regarding engine FOD protection, B737-200 Gravel Kit mods are quite interesting. A vortex dissipator is fitted below each engine intake.
I believe I have a fix for this situation. The mesh should be conical in shape. The length between the nose of the mesh and the engine intake should measure at least 8 times the diameter of the engine intake. (No space here to show the math, but you can figure it out). The advantage of this design is that drag is cut in half, larger area between the engine blades and the mesh mean more air available for the engine, less chance of bird blocking airflow as it will either be pushed aside because of the cone shape, or if it does get stuck there is plenty of room for air to enter the engine from non-affected areas of the cone. Thanks for the video.
There are another challenges too. Icing, for example.
Heating elements would take care of that.
@@watershed44 technically yes. However, given how low temperature is up there and the sheer air mass that would pass this mesh in a second, that has to be a very powerful heater. All the energy to power it has to come from somewhere. This ultimately means wasted fuel.
@@ScramblerUSA look at an F-84F intake, it has retractable ice screens...
If memory serves the Air Florida crash in the Potomac in 1982 was attributed to pilots not deploying anti-icing devices in the engines and the wings.
The EPR sensor was iced over subsequently giving the pilots an inaccurate reading of the EPR. They didn't even turn the anti-icing on. They were in a Florida frame of mind and disregarded the dangerous Washington DC winter weather.
I need to say I actually saw 74 gear talked about this, but you actually seems talking about this more than he did before I proceed this new video.😜
Willy Kang ever wonder why 74 gear has no hair? See previous video.
R/engrish
English please?
no habla whatever the hell that is
WTF? What are you typing? LMFAO
The Mesh on the Chinook was needed due to where the helicopters were last operating, in rocky Deserts where they were taking in smaller rocks that would kill the engine. I remember this happening to several of the helicopters in the early part to where they had to add a part that was like yes you are going to need this for the machine to stay working when you went there that needed to be looked at.
Top class channel. Presented in a very logical way so that anyone can understand it. Very interesting.
You're only talking about flat meshes. What about a cone shaped mesh? It would reduce the force of a direct impact, have a wider surface area to allow more air in, and it wouldn't cause any obstruction as the bird would fly off to the side. Thoughts?
That's what the chinook uses
Still the added mesh makes a lot of drag
@@lukej557 you can make it foldable. it's needed only for a tiny fraction of a flight, that wouldn’t cause much extra fuel consumption, would it?
What tiny fraction of the flight are you talking about and Idk
if goose can dent an airplanes nose, mesh wouldnt stand a chance.
"We're gonna have to put it down on the Hudson. And someone get me a bucket of chicken wings, that smell is making me hungry"
In those 90 seconds where Sullenberger landed, he was really eating KFC. He could've landed much sooner. One of those facts that's not widely known.
Hello sir ,i hope this comment finds you doing fantastic 😄.
I really like the way you explains things taking the concept from the basic to technical aspects .
Your vedios are very much helpful to me . Thanx a lot to uh.
Could you pls make a podcast on head wind/tail wind/cross wind .
An important aspect of engineering is not only identifying how to design something to perform a function, but also identifying all the various ways things can and will go wrong.
They struck a flock of seagulls and had to run.... run so far away....
Great video as always technically impossible to counteract bird strikes the easy bypass engines are going. Love your explaining of the way it has to be!
Thank you!
Perhaps research into bird's of prey sounds transmitted from the aircraft at a frequency's that birds can receive it warning them of imminent danger, which only needs to be operated automatically whilst the aircraft is at a lower altitude, just a thought?
Learnt a lot from this. Thank you very much.
I've wondered this! Will listen with interest! :)
Pilot after bird strike: "I'm salivating, but feeling bad at the same time because it's soooo wrong..."
helicopters do not fly as fast as jet planes.
Optical Clarity a few weeks ago an A321 landed in a cornfield in russia minutes after takeoff.
Must have smelt popcorn in the cabin
You guys crack me up!
"A Flock of Seagulls..." (sings) "i ran (flew) so far away..." lol i instantly thought of this song when you said that haha....
See the early East German passenger jet attempt - Baade 152. The prototype had mesh cones. However, it never did get to production. Also during early testing phase the B-58 was fitted with mesh cones but it was never intended to be on operational units.
mesh as a pre-grinder :D
Cube then mince.
No bird shall survive this thread.
Tjena Petter!
I have a similar question. In a live stream the other week, you talked about the wear and tear of the wheels. They have to accelerate from zero to 250 (or so) km/h in a split second at touch-down and this puts a lot of stress son them. Why not have some mechanism that speeds up the wheels just before touch-down. It could be created by the wind, by a spring wound up during landing gear deployment or by an electric motor.Thanks for a good RUclips channel and app. as well.
Regards from Lund, Sweden.
Dan
IMHO a bit of the rubber shaped in appropriate curves and the wind could spin up the wheels. Put a set of rubber half arcs on the side or the wheel. The C shape has much more air resistance from the one side than from the other.
There was research into that, but the conclusion was that the small gain in tire wear is not worth the added weight of the mechanism.
This is another fine mesh you've gotten me into!
Thank you for making this video. I have wondered this question on my life. It seems something like a loud screech, or some kind of horn would work better than a mesh, assuming that there was time to sound the alarm soon enough to scare the birds out of the way, and also be loud enough to make the passengers poop their pants. 😅
The bird protection device for the jet engines could be made by a cone shaped "mesh" in order to deflect incoming birds. It could be made retractable and radar activated only when birds are detected.
But where do you put the mesh when it's not in use? I'll create a lot of drag (when not in use) and require a lot of mechanical parts just for a shield. It'd be easier to put a flickering light or paint a flashy image on the engine to scare birds away.
"We made this mesh to prevent FOD."
*Jet sucks up mesh*
"Hmm... that didn't work. I guess the solution is to put a solid over over the intake..."
Very interesting channel. Nice work mate
7:20 Aw man, they struck A Flock of Seagulls?! I love that band.
Kentucky Fried Chicken. Was hungry for knowledge, now hungry for some food. LOL.
I laughed really hard when you said "they fire birds into the engines". I just imagine a huge Canon, with a room sized magazine filled with pigeons, parrots, geese, ducks etc, being fired full auto into the engine.
lmfao i laughed at that too
Yup, that's fairly close to the procedure.
When they shoot geese into jet engines, they aren't just testing whether the engine keeps producing power or not, they are testing how well an engine's design keeps a disintegrating engine's debris from blowing holes in the wing or fuselage.
@@johnstuartsmith are the geese alive or killed beforehand?
@@sh0gun570 yes
hello, in your video of the sully situation you said he hit canadian geese not seagulls, thank you for all your videos I really love learning all about plane stuff
Canada Geese…not Canadian
And actually, on military helicopters, we have mainly dust/sand centrifugal filters. It really helps a lot in desert ops =) And on helicopters, restricted inlet airflow in not a big problem, unlike for airplanes, wich partially rely on ram air pressure to add some compression ratio to the engine at high speeds.
2:20 before the content comes that im here for.
As a pilot you should know how precious time ist.
81 birds already hit the dislike button
Now 13 of them
A bunch of old birds
Now 19, but the thrust from the like button is making up it.
Now 20
25 now! 😂
Some of the early turbojet engines with centrifugal compressors actually did have a mesh over the inlet into the compressor. The Rolls Royce Nene engine was one example of an engine with a screen.
Wow, thanks for this interesting video, I have always asked myself why not put a mesh infront of an engine, now I understand why not.
Really scientific explanation from a professional, thanks for your great video.