Boeing 777 Crash Lands at San Fransico Intnl.
- Thread starter MacLeod
- Start date
If the a/c is in the right slope, the engine setting should be "approach idle" (may be known under different terms): not really giving thrust, but at high enough revs to give quick power for a go around. But there is a "target speed" for the approach, specified by Boeing. From what the NTSB has said, the airspeed may have been significantly below optimal approach speed, which could be why the approach profile came down short. A manual VFR approach, no ILS but with fine visibility, they should have had eyes on the visual approach indicators with plenty of time for a go around. I imagine the focus of the investigation will turn quickly to the flight deck crew, but it is way too early to rule out other factors.
My prayers go out to the victims' families and the survivors. This was such a tragic event.
It's also the third transportation accident in N. America this weekend along with
Ten Killed in plane crash in Alaska
http://www.bbc.co.uk/news/world-us-canada-23222244
and the run-away train in Canada
http://www.bbc.co.uk/news/world-us-canada-23231470
Ten Killed in plane crash in Alaska
http://www.bbc.co.uk/news/world-us-canada-23222244
and the run-away train in Canada
http://www.bbc.co.uk/news/world-us-canada-23231470
there does seem to come confusion in the media over the experience of the pilot flying and saying he was inexperienced.
He had over 9000 hours, ATPL and had flown into San Fransisco on numerous occasions. However this was his first time in a 777 and he was under the supervision of a captain with 3200 hours on type
He had over 9000 hours, ATPL and had flown into San Fransisco on numerous occasions. However this was his first time in a 777 and he was under the supervision of a captain with 3200 hours on type
That's kind of the big thought on my mind, why didn't the pilot have his eyes on the VASI lights? They certainly would have been a tip off to him that he was on the wrong slope and he was coming in way short of the runway. That's what's surprising to me, he wasn't really aiming for the runway, hell not even the apron area in the back of the runway he touched the ground on the TAXIWAY behind the runway. He F'd up big time and the VASI lights should have been telling him this.
VASI was off and had been for a few weeks due to runway construction designed to extend the apron and provide more room.
The NTSB Chairman said that PAPI was functioning at the time of the accident, but it's not now because some of its lights were taken out by the crash.
If VASI was off I suppose that's not too big of a deal, it's not at all airports and the pilot should still be able to use his instruments and own senses to know how he's landing. If the PAPI was up and functioning then, again, the pilot would have had visual indication to him to know if he was on the proper glide-slope for a landing. (But, again, even without it the pilot should have been able to safely land the plane using his knowledge and experience.)
It is very early to say, but it does seem as if this crash occurred due to some pretty darn severe pilot error. Either over-reliance on the abilities of modern-day planes to "land themselves" or inexperience on operating the plane.
And, again, this is just coming from the pictures and such I've seen, based on where the plane made contact with the ground vs. where it SHOULD make contact with the ground someone, or something, failed, big time.
The mass and weight of large transports makes them slow to respond to thrust changes and the movement of control surfaces. That would be dictated by physics and the engineers won't be able to design that out without some sort of science fiction technology like inertial dampers.
Turbines utilize heavy spinning cores that take time to change rotational rates. The higher the thrust the turbine can produce the heavier the core and the longer it takes to change its RPM, thus its thrust output.
Pulling the aircraft's yoke (stick on some planes) raises the wing angle of attack, increasing lift. This comes at the expense of making it harder for the wing to push its way through the air (slows the aircraft). If the angle of attack is too high the flow of air separates from the top of the wing (this is a "stall" short for "wing stall"). Lift is suddenly reduced when a stall occurs.
Lift functions in proportion to the wings speed through the air. Low speed results in reduced lift, causing a descent that has the same increased angle of attack that would occur if the pilot pulls back on the yoke. Note that for lift and drag the angle relative to the direction of the wing's motion through the air is relevant, not the angle relative to the horizon. Normally a pilot reduces lift by reducing thrust and pushes the yoke or stick forward to maintain the desired forward speed. For turbojet transports it might take a hundred miles to descend from cruise altitude to the destination airport.
The surfaces that extend from the front and trailing edge of the wing change the wing's effective width and upper surface shape to increase lift (with the expense of significantly increased drag). The added lift helps the plane fly at a lower speed, reducing the distance on the runway required to slow enough to turn off onto a taxiway.
The same physics dictating control response and engine RPM response would hold true for both the 747 and 777 (as well as other "heavy" planes like the DC-10, Lockheed L-1011, C-17 and large Airbus transports). Visual and radio aids for final approach would bring large and small planes in at the same foot of descent per horizontal mile traveled (even the turbo prop regional transports). In their most basic flight training pilots would be trained to monitor forward air speed and land using just the view of the rectangular runway out the windshield (perspective angle of runway sides, peripheral vision and basic depth perception)
The differences in instrumentation, few feet difference in cockpit height (above the nose wheel) and different engine count between a 747 and 777 shouldn't be enough so seriously affect a pilot's experience in the older model.
Turbines utilize heavy spinning cores that take time to change rotational rates. The higher the thrust the turbine can produce the heavier the core and the longer it takes to change its RPM, thus its thrust output.
Pulling the aircraft's yoke (stick on some planes) raises the wing angle of attack, increasing lift. This comes at the expense of making it harder for the wing to push its way through the air (slows the aircraft). If the angle of attack is too high the flow of air separates from the top of the wing (this is a "stall" short for "wing stall"). Lift is suddenly reduced when a stall occurs.
Lift functions in proportion to the wings speed through the air. Low speed results in reduced lift, causing a descent that has the same increased angle of attack that would occur if the pilot pulls back on the yoke. Note that for lift and drag the angle relative to the direction of the wing's motion through the air is relevant, not the angle relative to the horizon. Normally a pilot reduces lift by reducing thrust and pushes the yoke or stick forward to maintain the desired forward speed. For turbojet transports it might take a hundred miles to descend from cruise altitude to the destination airport.
The surfaces that extend from the front and trailing edge of the wing change the wing's effective width and upper surface shape to increase lift (with the expense of significantly increased drag). The added lift helps the plane fly at a lower speed, reducing the distance on the runway required to slow enough to turn off onto a taxiway.
The same physics dictating control response and engine RPM response would hold true for both the 747 and 777 (as well as other "heavy" planes like the DC-10, Lockheed L-1011, C-17 and large Airbus transports). Visual and radio aids for final approach would bring large and small planes in at the same foot of descent per horizontal mile traveled (even the turbo prop regional transports). In their most basic flight training pilots would be trained to monitor forward air speed and land using just the view of the rectangular runway out the windshield (perspective angle of runway sides, peripheral vision and basic depth perception)
The differences in instrumentation, few feet difference in cockpit height (above the nose wheel) and different engine count between a 747 and 777 shouldn't be enough so seriously affect a pilot's experience in the older model.
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