Sxmarbury33 From United States of America, joined Oct 2000, 447 posts, RR: 0
Reply 3, posted (13 years 10 months 2 days 2 hours ago) and read 2079 times:
I dont know why there is a flap and gear inhibit on the GPWS. I mean i could understand the thinking behind it but if you know that you are doing a flyby cant you just ignore the warnings. Also donsnt it inhibit the sink rate woop woop pull up warnings i might want some of those depeneding on what i was doing.
Avt007 From Canada, joined Jul 2000, 2132 posts, RR: 4
Reply 4, posted (13 years 10 months 2 days 2 hours ago) and read 2021 times:
Flap override is available on the Dash 8 for training purposes, allowing flapless landings without that annoying voice. Other a/c have various mode inhibit switches, but no one switch inhibits all modes, unless you call the circuit breaker a switch! BTW, I don't recall ever seeing a gear override for the gpws. Gear warning horns, yes, but not gpws.
Bigmikenice From , joined Dec 1969, posts, RR:
Reply 9, posted (13 years 10 months 1 day 21 hours ago) and read 1833 times:
Yeah you wish that Islandsflug shot was real. Tell me how the horizontal elevator casts a shadow, but not the rest of the plane on the ground? If it was real that plane would have you running for the port-o-potty cuz you would have just crapped your Hanes.
Big777jet From , joined Dec 1969, posts, RR:
Reply 11, posted (13 years 10 months 1 day 18 hours ago) and read 1783 times:
On December 1, 1984. I was the first passenger on Delta's Boeing 757 in Birmingham, AL. Pilots wanted to fly low pass on the runway before climb out to Atlanta.
It was fun! I never forget about the adventure first flight 757.
Goingboeing From United States of America, joined Dec 1999, 4875 posts, RR: 15
Reply 12, posted (13 years 10 months 1 day 18 hours ago) and read 1766 times:
The only thing I'd question is the altitude of the "low pass". The AF A320 that crashed was supposed to make a "low pass" at 100 feet, which the pilot thought he was at. He was shocked to see on the video that he was about 30 ft off the ground. Seems to me the plane in the first post is a tad lower than he should be.
Turbulence From Spain, joined Nov 1999, 963 posts, RR: 19
Reply 17, posted (13 years 10 months 1 day 5 hours ago) and read 1598 times:
The shadow of the Islandsflug plane is not the closer black asphalt. It is a little further, and if you open the large photo and look carefully enough, you'll see the perfect shadow of the whole airplane.
The 320 that crashed was not supposed to do a low pass. Have a look at the video: it has the gear down, and a landing attitude (nose up). The low passes (exhibition ones) must be with the gears up, in order to avoid wheel contact with the ground, and for granting an optical effect. Otherwise, from afar, people would think the low pass was a "touch&go" instead. Also, low passes are flown horizontally, for pilots and tails "health".
The 320 crash was a misprogrammed autoland.
Discussions on "low passes" have been held here. The "secret", if any, for doing them is the "ground effect". The wings lift the plane, but below a minimum altitude, the airflow under the wing gets "compressed" between the wing and the ground, thus increasing lift substantially.
The next time you fly, pay attention to something: a very short while after the main gear lifts, a slight sensation of "descent" can be felt. It is the critical moment when, increasing the distance from the asphalt, the "ground effect" is lost, resulting in a slightly lesser sustemptation. As far as I understood, this is a critical moment strongly related to Vr (therefore Vr being always higher than stall speed, if I am not mistaken), and taken care of, because below a certain speed, the airplane can get airborne without being able to keep up there and fall down again. Maybe a pilot could enlighten us better about this very special moment. In that other forum, someone wrote that the airplane would be able to fly a little sooner than it really does, but it is "kept" on the ground until the lift generated by clear speed is higher than the lift generated by the combination of speed and ground effect.
This is also why Formula 1 cars carry inverted wings: they would not fly because they do not have the proper propulsion, but they would lift from ground, due to speed alone.
The Europeans will remember the Ford Sierra (predecessor of today's Ford Mondeo in Europe/Contour in USA), the 1986 model SR Cosworth, 2door version, and the huge aileron mounted on the trunk, (the 4door's aileron was quite smaller). By then I was a mechanic at the biggest Ford workshop in BCN, and drove the first one in the whole Spain. OK. Without that aileron, the Sierra Cosworth was unable to go above 180 km/h (115mph) safely because the rear wheels were loosing the capacity of solidly transmitting 220 HP to the ground...
Back to the topic, and not being too sure if I made my explanation clear enough, this ground effect is the reason why flying so low is safe: the ground effect prevents the airplane from falling lower than it is.
Back in time, there was also a post about "ekranoplanes"
See that the "thing" is not touching the water, in spite of what, the water below is waving and being sprayed. See also how small the "wings" are.
wich are boats that "sail" at 500 km/h (315 mph) or "fly" at few feet from the water, the truth being that they do not do one thing neither the other: they take advantage of ground effect.
And the section entitled "The Captains Version" states:
"Captain Asseline flew the aircraft manually. He had been instructed by Air France to overfly the airfield at 100 ft above ground. When he increased throttle to level off at 100 ft, the engines did not respond. So after some seconds he got worried and thought there was something like a short-circuit in the completely computerized throttle control. So he pulled the throttle back all the way and forth again. By that time the aircraft had touched the trees.
After the accident, Captain Asseline was very astonished when he saw on an amateur video tape that the gear was only 30 ft above ground when the aircraft was passing over the runway. He affirms the altimeter of the Airbus A320 indicated 100 ft. "
Turbulence From Spain, joined Nov 1999, 963 posts, RR: 19
Reply 20, posted (13 years 10 months 9 hours ago) and read 1444 times:
I have heard and read many negative comments about airdisaster, mainly accusing them of beeing too "sensationalist" about crashes. I don't trust them too much.
But the facts are clear: compare the attitude of the airplanes of two photos above with the one of the 320 video. Do not match AT ALL.
Low passes are done every while (not every day), without passengers. Writing "safe" as I did does not necessarily mean "appropriate for commercial use".
L-188 From United States of America, joined Jul 1999, 30101 posts, RR: 58
Reply 21, posted (13 years 10 months 9 hours ago) and read 1435 times:
Hell, If that Islandsflug airplane was a Piper or a Cessna I would say that he was practicing a soft field takeoff.
For those of you not in the know, for a soft field takeoff you hold the stick back untill you get airborne, Not at a set airspeed. This lightens the weight on the tires as quickly as possible and keeps you from digging into the surface you are lifting off from.
As soon as you break the surface you push the stick slightly forway to lower the nose as you gain airspeed. This step is needed because you are right on the stall margin when you lift off with this technique.
The fastest way to do this is to get the airplane level as quickly as possible, because of ground effect increasing with airspeed the airplane will want to climb. So the nose down pitch keeps this from happening allowing the speed to come up faster.
It is pretty fun to do this when you take off.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
CV990 From , joined Dec 1969, posts, RR:
Reply 23, posted (13 years 10 months 4 hours ago) and read 1377 times:
I remember a few years ago reading an article about a Northwest 707 making a very low flypast in a way that it flipped small airplanes that where parked in a grass runway, that was really not a low but a "mow" flypast!!!
I think with a 737 it makes a nice effect but it doen'st really put your addrenaline pumping, with a 707 or a widebody I would like to experience that!!