A question for you jet engine experts

[Tailspin]

My understanding is that the birds did not fail the engine on the US Air airbus, but ingesting them caused the engine management software to register such an anomaly that it rolled power back to idle on both engines. The engines did not fail per se.

I agree with EA. A lot of us from the industry believe that had Sully been in a late model 737, he wouldn't be the hero he is today...but nobody would have gotten their feet wet either. i.e. he could have gotten it back to LGA. That is not just Boeing propaganda.

[bdk]

Everything I have read in industry seems to cuncur with this opinion.

[jtramo]

...........and Airbus brags about how well their airplane floats.........

[ZeamerB17]

Thanks, everyone - I guess I have my answer. I still think with the technology we've got there should be some way to keep birds out of engines ... but then, I don't know nuthin'. Maybe some of those deer whistles for birds ...

[davidbray]

Thanks, everyone - I guess I have my answer. I still think with the technology we've got there should be some way to keep birds out of engines ... but then, I don't know nuthin'. Maybe some of those deer whistles for birds ...

Deflector Shields to Maximum Captain.


And I seem to have read exactly what everyone has said about the Airbus' engines, it wasn't the birds damaging the engines (they still would have produced enough power to get them back to an airport) it was the electronics getting the bad readings and shutting things down for safety. My question now is would there be an override of some sort that they could have used with more time?

[warbird1]

Thanks, everyone - I guess I have my answer. I still think with the technology we've got there should be some way to keep birds out of engines ... but then, I don't know nuthin'. Maybe some of those deer whistles for birds ...

There is, it's called radar. There is radar technology that exists now that can track large flocks of birds with pretty accurate results. The FAA is real hot on that now, especially in the aftermath of the Hudson incident. I've heard that the big issue is just like everything else that could make life better - money.

[Cubs]

Here goes my opinion before the moderator moves this to the Off-Topic Discussion. Wait, I have a warbird connection to this thread. I am dubious about FADEC. In General Aviation piston engines they make for much more efficient operation. However, the pilot is no longer in control.
How would a pilot react if during the flight a passenger reached up and pulled the throttles to idle. Well, thats essentially what happened in the Hudson River incident. Someone (thing) besides Sully decided to control the engines. Oh, the warbird connection. I read where an F-18 crashed and pilot killed while taking off from a carrier.
The reason: a data plate on some component exposed to the airflow disturbed the readings on a sensor. The computer interpreted this as a stall condition and applied DOWN elevator, even though the pilot had the stick aft on the catapult launch. He wasn't in control. His stick inputs were merely suggestions to Gizmo the black box. Maybe there should be a button or something that can override the software. One of the Eclipse VLJ's nearly crashed because of a software
code that rolled the remaining good engine to idle. The pilot can override this by going to a certain page on a screen, select a certain drop down menu, 'click' Restart, and let the computer restart.... Oh, and he has time to do all this ? With his head down, looking at a monitor. Who thinks this stuff up?

[jtramo]

Thanks, everyone - I guess I have my answer. I still think with the technology we've got there should be some way to keep birds out of engines ... but then, I don't know nuthin'. Maybe some of those deer whistles for birds ...

There is, it's called radar. There is radar technology that exists now that can track large flocks of birds with pretty accurate results. The FAA is real hot on that now, especially in the aftermath of the Hudson incident. I've heard that the big issue is just like everything else that could make life better - money.

First off, the engineers and computer geeks are infinitely smarter then mere pilots, so no there is no manual over-ride available to the pilot nor will there ever be. They designed the stupid out of the airplane. (stupid=pilot)

Second, bird radar? That is a huge waste of money. First, we will end up getting constant "watch out" calls in most areas due to the fact that birds are native to the air. Then after the call you have to look for and actually find a flock of birds the size of a Frisbee or smaller while you travel at 250+mph. Its hard enough to spot other (comparatively huge) aircraft let alone a flock of 1-9lb birds. You only see birds at the last second. It may have saved England in 1940 but it wont save us from birds.

The moral of the story, apparently bird strikes only cause dual engine failures once every 100 yrs, so lets not spend the entire FAA budget on pet rocks and Monorails.

[warbird1]

Thanks, everyone - I guess I have my answer. I still think with the technology we've got there should be some way to keep birds out of engines ... but then, I don't know nuthin'. Maybe some of those deer whistles for birds ...

There is, it's called radar. There is radar technology that exists now that can track large flocks of birds with pretty accurate results. The FAA is real hot on that now, especially in the aftermath of the Hudson incident. I've heard that the big issue is just like everything else that could make life better - money.

Second, bird radar? That is a huge waste of money. First, we will end up getting constant "watch out" calls in most areas due to the fact that birds are native to the air. Then after the call you have to look for and actually find a flock of birds the size of a Frisbee or smaller while you travel at 250+mph. Its hard enough to spot other (comparatively huge) aircraft let alone a flock of 1-9lb birds. You only see birds at the last second. It may have saved England in 1940 but it wont save us from birds.

I disagree that it's a waste of money. The bird radar would be useful for large, migratory flocks of birds like the kind that forced the USAir flight down. I don't think it is intended nor would be useful for isolated birds here and there. As an example, if a very large flock of birds were to transgress the departure corridor of a major airport, departures could be stopped for the minute or two it would take for the flock to pass. That's how you use such a system. It would not be useful if ATC used it to call out the birds, like they do other air traffic. Once you're at altitude, you are much less vulnerable to birds, and you have more options. I think where bird radar would be most useful would be during the vulnerable portions only at low altitude - departures and arrivals.

[warbird1]

On a related note, Sully has called it quits and retired from US Air with his final commercial aviation flight today:

http://aero-news.net/index.cfm?ContentB ... 9ac4a0a4e&

[engguy]

. Keep in mind that a jet engine is basically a long hollow compression ignition (diesel) engine.

And lets not forget volcanic ash, there was a pretty new KLM 747 that had all four choked out by Mt. Redoubt burping several years ago in Alaska, they were lucky to get a couple restarted and made ANC with badly frosted windshields and ribbons for a radome from the abrasive ash plume.

As Mudbone might have said 'stay away from that boy, that's machinery'

A jet engine is NOT a compression ignition engine like a diesel. It is lit by an ignition system ie spark igniter, and continues to run because of a constant supply of fuel to the combustion chambers, I would classify it as a continuous ignition engine, as there is no break in the fuel supply, or air supply. This fact alone explains why they will always consume more fuel than an intermittent or cyclic engine like the otto or diesel cycle engines of equal power density.
Screens on the air induction area of the engine, would like others say collect ice, and them selves be a hazzard to the engine like if a portion broke off or was broken off by the bird or what ever it is that hit it. They would present not only an air restriction thus power loss to the engine, but also increased drag on the aircraft, thus lowering the fuel economy. They would not protect the vanes and blades from small debris, like dust or sand, small rocks etc. If it was able to be done I'm sure all the major aircraft manufactures and engine builders would have done it years ago.

[Steveo05196]

i spent 6 years in the army and crewed apaches for 4 years and chinooks for 2 more and our engines had some fod protection. the apache engine had an area at the front of the engine where it swirled the air and forced all the dirt and debris to the outside and through a duct overboard. but of course thats for small stuff and wont help for birds. the chinook engine had fod screens on the front of the engine that prevented ingestion of debris and would have protected from birds but it made some big power losses in the process. but i assume you arent able to put anything like that on turbofans. just on helicopter engines.

[Randy Haskin]

Second, bird radar? That is a huge waste of money. First, we will end up getting constant "watch out" calls in most areas due to the fact that birds are native to the air. Then after the call you have to look for and actually find a flock of birds the size of a Frisbee or smaller while you travel at 250+mph. Its hard enough to spot other (comparatively huge) aircraft let alone a flock of 1-9lb birds. You only see birds at the last second. It may have saved England in 1940 but it wont save us from birds.

The moral of the story, apparently bird strikes only cause dual engine failures once every 100 yrs, so lets not spend the entire FAA budget on pet rocks and Monorails.

Surprise! It's all ready here. I've been using it for a decade in the USAF:

Using NEXRAD (WSR-88D) Weather Radars to track the movements of birds, AHAS represents the most comprehensive method of remote sensing of birds today. These radars were originally built to track storm cells and chart precipitation returns. Now they are being used to keep planes away from birds. The system actually takes the weather out of the picture leaving biological targets. AHAS uses the radars to monitor bird activity in near real-time and as a feedback tool for the forecasts that AHAS produces for the flight crews. AHAS is the dynamic version of the BAM. It takes weather into account and calculates where the big birds are going to be. The AHAS is now available online. Coverage includes the entire continental United States.

[jtramo]

I would love to have arrivals and departures stopped in the NY area for flocks of birds that are constantly present. The delays on a clear day are enough to make me cry. If there is a single cloud in the sky they start a ground stop program let alone a few birds. Heck, a grade school kid was directing traffic at JFK yesterday! Thats what we have to work with! I would also love to see the budget for this bird radar.

"Sorry folks, we have to hold here on the ramp as some birds have been identified on the bird radar. We have to wait while they exit the departure area (5 miles) at 5kts airspeed. Sorry you will miss your connections but that flock of birds is deadly!"

"Holding? What for, its clear and a million!?"
"Well there is a flock of birds in the arrival area so we have to go into holding."
"Yeah but we are burning 3000lbs of fuel an hour here!"
"Yeah sorry, advise when ready to copy holding clearance."

In all honesty, I suppose if it keeps one more Bus out of the Hudson I guess its worth it. I would vote on a manual override on the FADEC for an emergency restart instead! Or Boeing's!

[Randy Haskin]

I would also love to see the budget for this bird radar.

First, the program identified above uses commercial NEXRAD radars -- the ones that feed you the weather picture on the internet and the TV news -- and runs that data through software owned/operated by the DoD.

Second, the cost is minuscule compared to losses of and damage on US military tactical aircraft that fly low and fast.

It's an accurate -- and useful -- tool that the military uses when determining where and when we'll conduct training operations.

I can't speak to how it could be implemented to help commercial operations avoid birds.