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Birdstrikes In Engines Seems At All Time High  
User currently onlineflaps30 From United States of America, joined May 2009, 289 posts, RR: 0
Posted (2 years 8 months 2 days 9 hours ago) and read 3221 times:

There has been so much news lately about bird strikes in commercial jet engines causing damage and emergency landings especially since the days of the miracle Hudson River landing by US Airways. It makes me wonder if there is a plausible solution for this occurance? Is it possible to safeguard the engine in some way in order to make the engines immune to birdstrikes? Are the engine makers any closer to a solution? Is it possible to cover the engine intake area with some sort of thin mesh without disrupting the function of the engine? Seems like something needs to be done quickly before another disaster happens.


every day is a good day to fly
17 replies: All unread, jump to last
 
User currently offlineBMI727 From United States of America, joined Feb 2009, 15830 posts, RR: 27
Reply 1, posted (2 years 8 months 2 days 8 hours ago) and read 3153 times:

Quoting flaps30 (Thread starter):
There has been so much news lately about bird strikes in commercial jet engines causing damage and emergency landings

That is not the same as

Quoting flaps30 (Thread starter):
Birdstrikes In Engines Seems At All Time High
Quoting flaps30 (Thread starter):
Is it possible to cover the engine intake area with some sort of thin mesh without disrupting the function of the engine?

Not really.



Why do Aerospace Engineering students have to turn things in on time?
User currently offlinercair1 From United States of America, joined Oct 2009, 1349 posts, RR: 52
Reply 2, posted (2 years 8 months 2 days 8 hours ago) and read 3132 times:
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Quoting flaps30 (Thread starter):
There has been so much news lately about bird strikes in commercial jet engines

I think the "Miricle on the Hudson" has raised awareness so there is more reporting. It would be intersting to mine the FAA data and see - but you would need to normalize for # flights.

That said - there has been a significant effort in the US (and I assume elsewhere) to restore avian populations - and limit hunting - so there are more birds near airports.

Quoting flaps30 (Thread starter):
. It makes me wonder if there is a plausible solution for this occurance? Is it possible to safeguard the engine in some way in order to make the engines immune to birdstrikes? Are the engine makers any closer to a solution? Is it possible to cover the engine intake area with some sort of thin mesh without disrupting the function of the engine?

No viable methods. You can screen an intake (stealth aircraft do) but the screen is no where strong enough to withstand a bird strike and it does limit engine efficience and increase noise.

Lots of discussion about that in previous birdstrike threads search. For example look at the thread BirdStrike At LGA



rcair1
User currently offlinereadytotaxi From United Kingdom, joined Dec 2006, 3359 posts, RR: 2
Reply 3, posted (2 years 8 months 2 days 8 hours ago) and read 3132 times:

Have this today on the BBC site, Delta 1063.

http://www.bbc.co.uk/news/world-us-canada-17788229



you don't get a second chance to make a first impression!
User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 4, posted (2 years 8 months 2 days 5 hours ago) and read 2989 times:

My brother-in-law worked as an acoustic engineer in jet engine design for Pratt & Whitney for 30+ years. (He has a PhD from MIT in that field).

He said that commercial jet engine design was focused on trying to build the engine so that it could survive a bird strike. Screening and alterations to the intakes to keep birds out of the engines was unfeasable given the power and weight requirements of commercial aviation.

The US Airways flight was somewhat unique and unusual because of the number of large birds the plane struck at near the same time. Other aircraft of that type with those engines have struck birds of that size and had sufficient power to return safely to the airport.

Secondly, incidents are not significantly increasing from the past/ previous years.

Reporting of bird strike incidents in the new media is at an all time high.


User currently offlineEMBQA From United States of America, joined Oct 2003, 9364 posts, RR: 11
Reply 5, posted (2 years 8 months 2 days 4 hours ago) and read 2977 times:

The numbers have remained the same for many years. It's just reported more now post the USAirways event. Also its migrations season.. both spring and fall have spikes that are to be expected.


"It's not the size of the dog in the fight, but the size of the fight in the dog"
User currently offlinesoon7x7 From , joined Dec 1969, posts, RR:
Reply 6, posted (2 years 8 months 2 days 4 hours ago) and read 2929 times:

I pass the approach end of runway 6 at (ISP) every morning at sunrise and the same two Canadian Geese are hanging in the grass by the runway lights.They have been there in the area for about 2 months. Runway 24, the opposite direction, is favored by WN departures at this time every day. Just a matter of when.

User currently offlineplanemaker From Tuvalu, joined Aug 2003, 6418 posts, RR: 34
Reply 7, posted (2 years 8 months 2 days 3 hours ago) and read 2831 times:

Here is a link to an article on bird strikes from 2009 that says, 'Airplane collisions with birds have more than doubled at 13 major U.S. airports since 2000'...

http://www.birdstrikecontrol.com/new...-more-than-double-at-big-airports/


And here is the link to the FAA bird strike database...

http://wildlife-mitigation.tc.faa.gov/wildlife/


Of course there are options that can be taken to mitigate engine bird strikes but they all have a significant cost component. As has been discussed several times on other threads, aviation is far from being as safe as it could be... but the current cost/risk equation is acceptable.



Nationalism is an infantile disease. It is the measles of mankind. - A. Einstein
User currently offlinezippyjet From United States of America, joined Sep 2001, 5533 posts, RR: 13
Reply 8, posted (2 years 8 months 2 days 3 hours ago) and read 2785 times:

Like with deer and other critters, as we expand out into their habitat and chuck all kinds of goodies in our trash they have a feeding/grazing buffet moment. In addition with climate change (to the deniers there's a river in Egypet) just look at this past winter less winter, a breeding frenzy for animal friends including tweedy birds and there you have it. And with JFK and for that matter the other two NYC metro airports so close to major bodies of waters the birds fly. We've even seen an increase at BWI with the Chesapeake Bay within a 25 minute drive.


I'm Zippyjet & I approve of this message!
User currently offlineSPREE34 From United States of America, joined Jun 2004, 2264 posts, RR: 9
Reply 9, posted (2 years 8 months 1 day 22 hours ago) and read 2595 times:

No more strikes, just more reporting. If one hadn't been reported earlier in the week, we wouldn't have heard about the latter.


I don't understand everything I don't know about this.
User currently offlineRaptor1090 From United Arab Emirates, joined May 2011, 82 posts, RR: 0
Reply 10, posted (2 years 8 months 1 day 18 hours ago) and read 2478 times:

Quoting flaps30 (Thread starter):
Is it possible to safeguard the engine in some way in order to make the engines immune to birdstrikes? Are the engine makers any closer to a solution?

Jet engines are already designed to 'ingest' birds in a strike so as to not harm the engine. So even after a bird strike the engine remains operative, at least for a long enough time to get the aircraft to the ground.
http://www.youtube.com/watch?v=y2OS2pwrZTI
http://www.youtube.com/watch?v=rSafRuLB0c0


User currently onlineflaps30 From United States of America, joined May 2009, 289 posts, RR: 0
Reply 11, posted (2 years 8 months 1 day 11 hours ago) and read 2321 times:

Quoting Raptor1090 (Reply 10):
So even after a bird strike the engine remains operative, at least for a long enough time to get the aircraft to the ground.

Thats not always the case. Most of the time the engine is immediately shut down.



every day is a good day to fly
User currently offlineRWA380 From United States of America, joined Feb 2005, 3454 posts, RR: 5
Reply 12, posted (2 years 8 months 1 day 10 hours ago) and read 2294 times:

Quoting rcair1 (Reply 2):

I think the "Miricle on the Hudson" has raised awareness so there is more reporting. It would be intersting to mine the FAA data and see - but you would need to normalize for # flights

I think you are spot on, couldn't have said it better myself. With instant media outlets littered around the world, and having to fill the many days of news broadcasts, I'm sure it's just the increased exposure by the media, and our instant access to it.



AA AC AQ AS BD BN CO CS DL EA EZ HA HP KL KN MP MW NK NW OO OZ PA PS QX RC RH RW SA TG TW UA US VS WA WC WN
User currently offlinercair1 From United States of America, joined Oct 2009, 1349 posts, RR: 52
Reply 13, posted (2 years 8 months 1 day 10 hours ago) and read 2288 times:
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Quoting Raptor1090 (Reply 10):
Jet engines are already designed to 'ingest' birds in a strike so as to not harm the engine.

Not really and not for large birds like Canadian Geese. What they are designed to do is remain contained - no stuff coming out the sides at you - they do shed stuff out the back - and maybe produce thrust at a reduced level. Even with a small bird - they are damaged, they may continue to operate, but they are contained. However, I think the standard procedure in modern aircraft would assume there are other engines operating and you should shut down the damaged one to prevent further damage.

There is a debate on the 1549 case that the FADEC (Full Authority Digital Engine Control) prevented the engines from producing all the thrust they could have given the need. The FADEC noted problems and limited fuel flow/throttle. The system is designed to note problems and limit damage in the engine. It does not consider if there is a case where the pilot would accept damage to produce thrust in the short term ("I don't care if I'm shelling the engines - get me back to the runway"). Some claim that had the pilots of 1549 been able to override the FADEC and go to maximum available thrust they could have made one of the airports- though that is a risky proposition - how do the pilots know how long a damaged engine will continue to operate as it tears itself apart. Then again - ditching in the Hudson was pretty risky proposition too.

It is an interesting debate - not one I'm ready to conclude anything on. IIR - some WWII fighters had a battle or pursuit or 'getaway' position on the throttle/boost where the pilot could push past a soft limit (wire or something) and get more power for a period of time, but likely damage the engine doing so. This may be incorrect, I can't name any particulars, but I seem to recall that.



rcair1
User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 14, posted (2 years 8 months 1 day 10 hours ago) and read 2258 times:

Quoting rcair1 (Reply 13):
some WWII fighters had a battle or pursuit or 'getaway' position on the throttle/boost where the pilot could push past a soft limit (wire or something) and get more power for a period of time, but likely damage the engine doing so. This may be incorrect, I can't name any particulars, but I seem to recall that.

The fighter pilots I've talked called it WEP "War Emergency Power" and it was a detent in the throttle which required a specific extra side movement or such to engage.

It basically pushed the engine manifold pressure to the maximum possible given the fuel flow and air available. It moved the engine into areas which were certain to cause damage to those pistons, bearings and rods. The aircraft could have a total of about five minutes of WEP before damage started to occur, if the engine was in top condition.

More than that and soon the pilot would be flying a glider, not a fighter.

Quoting rcair1 (Reply 13):
Some claim that had the pilots of 1549 been able to override the FADEC and go to maximum available thrust they could have made one of the airports- though that is a risky proposition -

In my opinion Sully's 'miracle' was not the landing/ ditching - it was making the decision so very quickly that ditching in the Hudson was the only option for the aircraft. Had he not made the decision so quickly, the plane would have gone down in an area of buildings with like a huge loss of life. Every A320 captain should have been able to do the dead stick ditching. The decision to go for ditching was where his experience and leadership saved all those lives.


User currently offlineN62NA From United States of America, joined Aug 2003, 4593 posts, RR: 7
Reply 15, posted (2 years 8 months 1 day 8 hours ago) and read 2230 times:

What I find interesting is that the number of engines per aircraft are at an all time low, i.e. everything flying today is for the most part a twin jet, hence less "opportunities" per plane to ingest a bird.

User currently offlinercair1 From United States of America, joined Oct 2009, 1349 posts, RR: 52
Reply 16, posted (2 years 8 months 1 day 7 hours ago) and read 2175 times:
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Quoting rfields5421 (Reply 14):
In my opinion Sully's 'miracle' was not the landing/ ditching - it was making the decision so very quickly that ditching in the Hudson was the only option for the aircraft. Had he not made the decision so quickly,

I agree. That is why I'm not a big proponent of the people who say the FADEC limiting power was an issue. That could have just gotten them into more trouble - by relying on power in a failing engine they may have tried to make it, and 'just not quite' achieved it. I noted it as a interesting debate/discussion. In Sully's words - returning to LGA would have been an "irrevocable decision" and had he done so and realized he could not make the airport, he would have had no options. (NTSB report, pp 54)

The claim that FADEC limited power is not supported by the NTSB report which does discuss research into advanced FADEC systems that can diagnose engine problems and inform the pilot of what mitigating actions can be taken to restore power. Research was done in both military and civilian engines, but never completed or commercialized. The NTSB notes that had this capability existed, it would not have informed the pilots of ways to mitigate power loss and regain limited power, but, on the contrary, would have informed the pilots that thrust could not be restored because the engines were too damaged. The crew then would not have wasted time attempting re-lights.

In fact, the actions to re-light were not useful because combustion was not extinguished during the event - the combustion in the engines did not go out - so re-light was not applicable. Indeed, combustion did not cease till the crew turned off the engine master ignition switches as part of the re-light process. The current FADEC does not provide this information to pilots, so they followed the appropriate procedure. They had no idea the engines were still turnin' and burnin' even though they were not producing thrust.

The advantage of advanced FADEC diagnoses in this case would not have been to restore power, but to allow the crew to ignore the re-light process and focus on ditching.

Regarding Sully's decision - it was the correct one.
This is born out by the simulations the NTSB performed afterward. In simulations they found that pilots could make a return to the airport - just barely and 50% of the time - provided they turned and headed there the immediately they hit the birds. No time for any diagnoses or decision making. In the simulations, the pilots were fully briefed before the simulation and turned to the designated airport immediately after lost of engine power. They knew what was happening and did not diagnose - just turned.

In 8 of the 15 valid simulation runs, the pilots made the runway. However, in these simulations the pilots turned immediately after loss of power and only 50% of the time made it.
Regarding those simulations Footnote 88, pg 50, in the NTSB Report states:

88 "The immediate turn made by the pilots during the simulations did not reflect or account for real-world considerations, such as the time delay required to recognize the bird strike and decide on a course of action."

In the simulation where they introduced a real world delay of 35 seconds for recognition and decision making process - the aircraft did not make the runway.

Footnote 89, page 50 states:
89 "The 35-second delay accounted for real-world considerations, such as the time delay required to recognize the extent of the engine thrust loss and decide on a course of action."

I add that from the AB checklist - when you are attempting re-light you are supposed to wait 30 seconds after turning engine master switches off before turning them back on. The 1st officer stated he was not sure he waited that long. I think a 35 second diagnosis/decision process is actually quite fast.

It is a debate that cannot be answered as we do not know what 'coulda, shoulda, woulda' happened if the FADEC could have been coaxed into allowing the engines to exceed temps/pressures but produce power. What we do know is that the crews rapid decision making followed by a concrete course of action resulted in the best result. The NTSB concluded that the engines were too damaged to provide thrust in any case.

The NTSB conclude:
"Therefore, the NTSB concludes that the captain’s decision to ditch on the Hudson River rather than attempting to land at an airport provided the highest probability that the accident would be survivable."

Quoting N62NA (Reply 15):
What I find interesting is that the number of engines per aircraft are at an all time low, i.e. everything flying today is for the most part a twin jet, hence less "opportunities" per plane to ingest a bird.

I don't think it is quite this simple.

First - you need to look at inlet area on twins and quads (or triples I suppose) if you are going to look at the probability of ingestion.

For instance, a 777 (the largest fan twin) has an fan diameter of 128 inches (GE90-115B) for an inlet are of 25,731 sq inches (total for both engines).
The AB340, picking the RR trent 500, total area for all 4 engines is 29,369 sq inches - or 14% greater, not 2x.
Looking at the 747-8 with GE engines (larger diameter), 38,351 sq inches - 49% more than the 777
The AB380 with Trent 900 - pretty much the same as the -8

So, while there are 4 engines, for a given 'rough size' of aircraft, the ingestion area is not 2x. The probability per engine is lower.

You'd also really need to look at things like exposed core area because it is really core ingestion that kills the engine.

Current certification requires a 2.5 lb bird in the core, and 3 2.5 lb birds in the fan area. The core requirement is not enforced for smaller engines (like the AB320). 1549 ingested an 8 lb bird in each core - well beyond any certification limits.



rcair1
User currently offlinercair1 From United States of America, joined Oct 2009, 1349 posts, RR: 52
Reply 17, posted (2 years 8 months 1 day 7 hours ago) and read 2168 times:
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Quoting rcair1 (Reply 2):
I think the "Miricle on the Hudson" has raised awareness so there is more reporting. It would be intersting to mine the FAA data and see - but you would need to normalize for # flights.

That said - there has been a significant effort in the US (and I assume elsewhere) to restore avian populations - and limit hunting - so there are more birds near airports.

While reviewing the NTSB report on US 1549, for my previous post, I re-found data about bird population that refutes my contention that this is about awareness and media coverage.

From the NTSB report, page 63

"The number of wildlife strikes annually reported in the United States increased significantly from 1990 to 2007. (109) According to a USDA report, various reasons account for the increase in wildlife-strike reports.(110) For example, airports have large areas of grass and pavement, which are attractive habitats to birds for feeding and resting. In addition, modern turbofan-powered aircraft have quieter engines and, therefore, are less obvious to birds than older and noisier turbine-powered and piston-powered aircraft. Additionally, commercial aircraft operations in the United States have increased by about 2 percent per year since 1980. Further, research has shown that various government-sponsored programs initiated over the past 40 years, such as pesticide regulation, wildlife refuge system expansion, wetlands restoration, and land-use changes, have resulted in increases in populations of many wildlife species in North America.(111)."


The graph on page 64 is very interesting.
While migratory Canada Geese population has increased from ~ 1million in the 70's to about 1.75M in the 2000s (eyeball Average) the

resident Canada Geese population has increased from 250,000 in 1970 to 4,000,000 in 2008.

That is a 16x increase.

Given these factors - I rescind my comments about it being "news media". There are more bird strikes.



rcair1
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