Autoland vs. manual

[peter]

It appears that the vast majority of landings are manual vs. autoland in the "real" world. I am 50% - 50%. Can someone advise why in actual 744 most landings are manual vs. autoland. Why not use the technology.

Peter
First Officer - Globe Cargo
#1848

[nwadc10]

Typically the autoland is more of a stiff landing compared to a pilot landing. The autoland system doesn't care so much about pax comfort as it does sticking the plane on the ground early in the touchdown zone. Additionally, the landing is the most challenging part of the flight which is right up the alley of the Type-A personallity pilots typically have. In other words, we'd rather do the landing ourselves because it's fun Now that's a full autoland. Most pilots will fly the ILS using the autopilot until the runway is in sight at which time the autopilot is disengaged and a manual landing is made. There is also a requirement to accomplish a number of takeoffs and landings within so many days to maintain currency on the aircraft.

With that said, there are three levels of automation: flight director on/autopilot on, flight director on/autopilot off, and flight director off/autopilot off (aka "raw data"). Pilot should maintain proficiency in all levels of automation which means sometimes the pilot flying will takeoff with no flight director and no autopilot to maintain proficiency flying raw data, just like flying a 172.

I can't speak for 747 operations of course, but what I typically do is hand fly from takeoff to 290 kts. By that I mean we've climbed thru 10000' and accelerated from 250 kts to 290kts. On a visual approach I'll disconnect the autopilot and remove the FD anywhere from on the downwind or base leg to 500' AGL..depending on how lazy I feel that day

[John Khan]

I'm sure most of you have heared of the 747 Captain (the airline will remain nameless) who made an autoland landing at Heathrow and complained in the defect book....

"Autoland selected, landing very firm and to the right of the centerline, not satisfactory."

The engineer who checked it out then wrote.....

"Autoland not fitted on this aircraft."

John

[hawkeyeted]

In addition to Justin's comments, there are some legal issues too. Three things need to be satisfied in order to perform a full autolanding; the Aircraft, the Pilot, and the Runway must all be certified for the given category (Cat II or CAT IIIa/b/c). One can't just pull up to an ILS beacon and just couple up an autoland.

The aircraft must have certain equipment operational in order to be able to autoland, and this may change midflight if one of those critical systems breaks airborne. The pilot must also have a minimum number of hours and passes under CAT II/III conditions to be able to autoland.

Additionally, it costs money for airports to maintain those certifications. Typically, an airport will certify as few runways as possible and only to the lowest minima it needs to get away with. It's wasted dollars to certify all runways to Cat IIIb mins when the typical weather only requires Cat II and traffic during those periods require only one runway.

An interesting note specific to the 747; all CAT II and below landings (visibility less than 2,400 feet) will be AUTOLAND. Reason? The 747 is so long and the cockpit so high, it is possible for the cockpit to remain in the goo as the aircraft crosses the threshold and the aircrew lack the visual cues to safely land the aircraft.

[Kevin Hester]

these are numbers off the top of my head but I believe the autoland lands the 744 at around -150 to -200FPM. After a few manual landings, it dosent take that much to do a better job than that.

even I think that can be a little hard on the main gear sometimes depending on your weight.

[PetriSuni]

Maybe it's just me but I think that -150 FPM is NOT a hard landing...It's actually very good, if an autoland can achieve -150 FPM.
By what I've heard autolands on many birds land MUCH harder than -150 FPM.

Petri

[nwadc10]

Maybe it's just me but I think that -150 FPM is NOT a hard landing...It's actually very good, if an autoland can achieve -150 FPM.
By what I've heard autolands on many birds land MUCH harder than -150 FPM.

Petri

I don't know the numbers but I agree with this statement. From all that I've heard about autolands, they are much harder than a pilot would do. -150 isn't a bad landing at all.