Rather than trying to prevent debris from entering, jet engines are designed to ingest a certain amount of debris without issue. They are capable of swallowing whole chickens and passing them out the exhaust cooked to perfection, sliced, deboned and pureed.
It would be folly to attempt to build a screen; even at landing speeds, the goose would simply go through the screen like a potato through a french fry cutter.
This must've been one heck of a goose or an entire flock.
That statement makes no sense at all. Scaring them is far less inhumane than sucking them into a jet engine. I did not mention this in my original message but the thought did come to mind about harming/killing birds in addition to the plane damage and human lives lost. It's a bad situation all the way, and with all the technology we have these days, you'd think they would have developed something by now to keep these birds from getting sucked into the engines.
They sell these whistle devices to put on cars to scare deer away, isn't there some way to do something like that to get the birds away from the planes?
I know what propane cannons are, I heard them once, and they are sort of annoying, but why not just fire them before a plane takes off, and not all day long.
Sorry, geese are more important than humans. Remember the days of Arafat? The cats were more important than the Israeli children Arafat's men were killing!
I think others have explained why screens are not such a good runner. I suspect that the problem is that there are obese geese that side of The Pond!
Seriously, it does make me wonder about whether the incredible tests that the engine manufacturers do are now adequate. I've not checked to find out how close to the airport that the apparent strike occurred. I do know from professional experience that the airports and local regulators here in the UK are rightly concerned about environmental developments close to airports that will encourage avian friends!
Since *each* engine ate one, there obviously had to have been at least two geese. Fox News reported that it was a flock large enough that it showed up on radar.
You mean every 6 minutes? or at some airports every 3.5?
I would expect they know migratory flyway/patterns of the geese and adjust accordingly.
Last month the FAA reduced the number of flights arriving/departing Laguardia to a max of 71 per hour. That's one landing or takeoff every 51 seconds.
Canada geese haven't been migratory for decades. They form a year-round population in nearly every urban area in the eastern third of the U.S.
Well I just have this big urge to set some facts straight on this thread, from someone who knows; :)
They still use sound-makers, at least at the airports I'm familiar with here in the NE to scare the birdies away. A guy in a pickup with a blank but loud rifle has a go at it every now and then at KHFD. BUt they don't have much of an effective range and certainly wouldn't have any effect on birdies 2 miles out and a few x000 feet up, which is where these guys were.
Whether or not this was a crash, well "crash" is not a technical term; But this technically / legally was an "aircraft accident", and the aircraft did receive "substantial damage", all of which are precisely defined. "Substantial damage" is incurred when the damage affects the "performance or flight characteristics... and would normally require major repair or replacement of .. [a] ... component". The very fact that both engines failed due to birdie impact qualifies this as both an accident and substantial damage. [FAR 830.2].
A transport multi-turbojet glides quite well with no power. I'm not familiar with the A320, but am with the B737, which has a glide ratio pushing 20:1. That's when cleaned up -- no flaps, no gear. A little problem with that is the speed required to maintain that L/D ratio is circa 200Kts, kinda too fast to hit pavement with landing gear, much less anything bumpier like water. So when dirty and slow, the glide ratio deteriorates (a lot), but you are by no means falling like a rock.
A landing in the water, as this was, is most certainly a "ditching". Nothing critical of how this was executed, that's just what a water landing is called...
And no (mainstream at least) pilots practice ditching in a simulator, although power failures are of course routine proficiency exercises for the simulator. Ditching technique and guidelines are discussed as part of training and proficiency, but I'm not aware of any "land on the water mode" in a simulator.
A multi-engine jet on [a normal] final approach by no means has its engines producing essentially zero thrust, and they had better not be turned off. A jet will be in a very high drag configuration on approach what with gear and flaps of all types hanging out, and a non-trivial amount of power is required to manage the descent rate. Also, power is carried since it minimizes an already significant lag in response to throttle on a jet -- they take time to spool up. You might need that to manage any need to go around, wind shear, turbulence, etc, so carrying power is done in no small additional part to minimize response time to a power-up command.
Jet engines are not held in place with a single shear pin.
I'm not aware of any engine departures [that ended without a major crash]... and would suspect that such an event would probably upset the CG into an unflyable configuration esp on tail-engine aircraft, and/or mess up some critical control systems.
Like I said, I'm not familiar enough with the A320 to be authoritative, but I do understand that it is aerodynamically unstable and requires fly-by-wire in order to introduce the stability required to make it flyable (and certifiable). Doesn't matter much I think... stability either comes from aerodynamics or the systems..
And now, in my opinion. Without detracting from the tremendously fortunate outcome and the contributions by the flight crew, this wasn't the case of steely nerved coordination like you might need to get a Greyhound bus up on its two wheels, banked over on the side, riding only on a single rail in order to cross a railroad bridge over a deep chasm.
I'd attribute the successful outcome of this in order of:
- a darn good configuration of luck -- this was the right place at the right time and the right conditions to make a happy ditching like this occur. I guess it had a bit of bad luck -- would've been a better outcome to set it down on a piece of asphalt with numbers on both ends, but that being out of the possibility, it was fine that the water was smooth, the hidden wires were not there, and massive rescue capacity was seconds away.
- secondly, and I think this is where the flight crew should really get the kudos -- was the decisive decision making at the right time. Deciding to ditch in the Hudson is by no means an easy barrier to cross
-- but when the other options aren't there, one needs to make the hard choice and stick to it.
- and oh yeah, flying skill. Honestly, and I'm sure I'll be debated, but a gentle ditching given all the other factors above, I'd really expect from a competent pilot. Slow the thing down, keep the wings level, and nose up, real up, but don't stall it. Yeah, it does kinda sound like a soft-field landing, albeit one without power available.....
Having said that I've never ditched an aircraft (but landed one many times).
Happy home repairing and thanks for clearing up my three-wire dryer mystery:)
T
The pilot was also a glider pilot and flies gliders as a hobbie which was his ace up his sleeve , so to speak...The space shuttle is the biggest glider in the world...All landings are dead stick.....The pilot did an AMAZING job.......
Good points. We often forget about the shuttle not being powered.
Glide ratio for anyone not familiar, is how far forward the plane will go for every foot down. 20:1 means that a plane at 3000 feet altitude can go
60,000 feet or about 11 miles. A glider can be about 50:1 or 60:1, but they don't carry 150 passengers. A Cessna 150 is only about 7:1, the shuttle 4.5:1As for the crew, the Captain certainly did a great job and was cool about it, but the rest of the crew, cockpit and cabin, are to be commended for what they did for preparation and evacuation.
Not to take away from the accomplishment, but every pilot is, to a small extent, a glider pilot.
One of the first things taught in flight school is how to maneuver a plane with the engine turned off (and do all the other stuff, like call "Mayday," look for a landing spot, deal with soiled trousers, etc.). I still remember my instructor, whose name was Sneaky Bastard, surreptitiously turning off the fuel supply!
Cough-cough, pop, fizz.... silence!
I wept.
Hey, ever land a glider on water?
As for the Azores Glider:
"Without engine power, control of the aircraft depended on the last backup, a ram air turbine, which supplied limited power to hydraulic and electrical systems. While Piché flew the plane, DeJager monitored its descent rate ? around 2000 feet (600 metres) per minute ? and calculated that the plane had about 15 to 20 minutes left before they had to ditch the plane in the water.
The crew flew the plane a few more minutes, until sighting the air base. Piché then had to execute a series of 360 degree turns to lose altitude. Although they successfully lined up with Runway 33, they faced a new danger. The plane was on a final descent, going faster than normal. Although they had unlocked the slats and deployed the landing gear, the airspeed was 200 knots, compared to the preferable
130-140 knots.At 06:45 UTC, or 02:45 EST, after 19 minutes without engine power, the plane touched down hard 1,030 feet down Runway 33 with about 200 knots (370 km/h). The aircraft bounced back into the air but touched down again 2,800 feet from the approach end of the runway and came to a stop 7,600 feet from the approach end of the 10,000 foot runway. With the operation of the emergency brakes, several tires burst. Fourteen passengers and two crew members suffered minor injuries during the evacuation of the aircraft. Two passengers suffered serious, but not life-threatening injuries. "
At 32000 feet altitude and an airspeed of 330 knots he had something like 150 miles of "stretch", for a glide ratio of some 25:1. This was a A330 with twice the capacity of the A320-200 (306 people on board) and 361 sq M of wing, compared to the A32 with 122 SqM of wing., so LIKELY a lighter wing loading.
Note they did several 360 turns to lose enough altitude to land on the island. and STILL landed significantly "hot".
My pants were wet. Does that count?
Pucker marks on the seat?
on 1/16/2009 5:51 AM (ET) Jimw wrote the following:
When I worked with flight engines at Pratt and Whitney, all flight engines had anti-icing features built into the blades (some of the compressor blades were hollow and hot air circulated through them). This solved the engine icing problem. The icing problem is with the aircraft body itself.
We would NEVER put any "thing" in front of the engine for fear of ingesting the "thing" and destroying the engine. A structure like a screen and its supports has the potential for completely destroying any jet engine.
Bird strikes are a very common event, particularly around airports. Engines are designed to absorb bird strikes and tested against bird strikes. At Pratt we had a steam powered catapult "chicken gun" which was used to fire chickens into the inlet of a jet in a test stand. The chicken was shot in at about 300 mph, and the engine was expected to keep on running at power. For the design to be certified the engine model had to pass this test.
I do not recall any requirement for tests with multiple chickens.
In the very early days (say around 1955) the chicken was alive. After the SPCA etc. threw a hissy fit the test was changed so that the chicken was killed before being shot into the engine. No one wanted us to scare the chicken to death.
HTH,
EJ in NJ
Kurt Ullman wrote:
on 1/22/2009 7:35 AM (ET) Ernie Willson wrote the following:
Don't they just go to the supermarket and buy chickens from the butcher?
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