Given recent events this has been mentioned a lot. I’m not a pilot but an aviation enthusiast (whatever that means) and, um, did I miss something?
Isn’t the ability for a commercial airliner to land itself a huge accomplishment? Doesn’t it require pretty powerful computing power (like maybe “a neural-net processor, a learning computer”)? Wasn’t there any fanfare or press when this was put into operation? And when are they used? Pilots still always land manually, even in bad weather, don’t they?
This is almost Snopes material, so I don’t vouch for it, but a pilot for the Australian airline Ansett (which went broke last week, BTW), told my father “strictly off the record” that after testing a new Airbus, the airline sent a letter to the manufacturer saying, “The plane performed very well. The only criticism we have is that the “auto-land” feature gave a quite bumpy landing.”
They recieved a reply from Airbus saying, “Thank you for sharing your concerns, but the aircraft in question is NOT FITTED with an Auto-Land function”.
:eek:
This anecdote is entirely untrue. A pilot of a commercial airliner knows by heart every single control, ability, and nuance of the machine he flies. And autoland is not like there is a toggle switch on the dash with a post-it saying “Autoland” - it is programmed into the onboard computer, and requires a bit of setup to use.
Plus the fact that trying to let a plane land on its own sans autoland would almost certainly result in death for all involved.
Yeah, but it’s a great old joke. There used to be a book of these floating around that would get repeated at every flying-club bull session over and over again. They were usually presented as ‘true but funny maintenance log entries’. Like this:
Entry: Auto-land on this aircraft very rough.
Engineering Fix: Auto-land not installed on this aircraft.
Entry: Right Engine Missing.
Fix: Looked under wing. Found Right Engine.
Entry: Engine Rough when mag switched to left only.
Fix: Don’t switch mag to left only.
And so it goes. There are dozens of 'em. Lots of fun to repeat at Beer Call after a long day of trying to keep students from killing you in the airplane.
Correct me if I’m wrong, but doesn’t “autoland” require special equipment on the ground so that the plane can determine how close it is to the proper glidepath by picking up signals from ground transmitters near the runway? Sorta like the “autodrive” function that only works in the HOV lanes on I-5 near Burbank (or somewhere like that) because they’ve embedded transponders in the road.
Not really. An ILS approach is all numbers and computers love numbers. The computer knows exactly how high above the ground it is by following the glideslope and watching the radar altimeter. The localizer tells the computer exactly how far it is off track the plane is from the runway centerline, the DME tells it how far away the runway is. Airspeed, engine output are all digitized. Computers and airplanes work well together, it is much more difficult to get a computer to drive a car.
A full auto-land (Catagory IIIc ILS, decision height is zero) is usually only used when visibility is very near zero. Pilots don’t like to land under those conditions since once they do land they can’t find their way around on the ground.
There are other occasions where an airliner will use the autopilot to fly lower than is allowed for planes that don’t have an autopilot (200 ft usually), but the pilots will still actually land the plane manually. These are Catagory II, IIIa, and IIIb ILS’s.
Yes, the auto-landing can only be done on runways that have an ILS (instrument landing system). This is made up of two radar beams, one horizontal and one vertical. From these beams the instruments on the airplane can tell how many degrees off it is from the proper flight path.
DDG: Thanks for that. I just did a brief search and found a similar page. I’m going to reprint the list because I’m pretty sure there is no copyright on it. It’s just a bunch of collected items that I’ve seen reprinted everywhere:
Problem: “Something loose in cockpit.”
Solution: “Something tightened in cockpit.”
Problem: “Evidence of hydraulic leak on right main landing gear.”
Solution: “Evidence removed.”
Problem: “Number three engine missing.”
Solution: “Engine found on right wing after brief search.”
Problem: “DME volume unbelievably loud.”
Solution: “Volume set to more believable level.”
Problem: Dead bugs on windshield.
Solution: Live bugs on order.
Problem: Autopilot in altitude hold mode produces a 200 fpm descent.
Solution: Cannot reproduce problem on ground.
Problem: IFF inoperative.
Solution: IFF inoperative in OFF mode.
Problem: Friction locks cause throttle levers to stick.
Solution: That’s what they’re there for.
Problem: “Left inside main tire almost needs replacement.”
Solution: “Almost replaced left inside main tire.”
Problem: “Test flight OK, except autoland very rough.”
Solution: “Autoland not installed on this aircraft.”
Problem #1: “#2 Propeller seeping prop fluid.”
Solution #1: “#2 Propeller seepage normal.”
Problem #2: “#1,#3, and #4 propellers lack normal seepage.”
Problem: “The autopilot doesn’t.”
Signed off: “IT DOES NOW.”
Well, I can’t find a date for when jets started using autoland, but it seems to be fairly recent.>>>
The only barometer I have is that it must have happened sometime between the movies AIRPLANE and TURBULENCE (where the auto-land is a crucial plot device).
When googling around late last night trying to find a definate answer for this one, I found some information about the BAC Trident autoland systems from the mid sixties, but the link was outdated and I have no cite to present here.
Apparently, the Lockheed L-1011 was the first commercial airliner to be outfitted at the factory with the Category IIIa autoland, and was the first equipped with the 0 RVR, 0 DH Category IIIc autoland. Since the Tri-Star debuted in 1970, it seems that the technology had been progressing for several years before that.
Back in July 1971 ,on a British Airways ( or it could have then been BOAC) 747 flight from JFK to London I remember the captain saying, as we were coming into Heathrow, " ladies and gentleman I shall just sit here with my arms folded while the plane lands itself".
In the onslaught of coverage and special reports from the media over the last month, I seem to remember seeing a report saying that LAX was the only airport equipped to land planes on approach sans pilot intervention. The caveat to this being the plane had to be in LAX airspace to be able to do it. Not sure of the validity of this, I think I saw it on CNN.