Fail operational sure would be nice, but it must be about one of the biggest ticket options on the 737. I'd imagine it's more than SFP.

Are you asking if a single-channel approach will do an autoland? If, so, no. There will be no flare and no retard of the thrust.

Actually backwards - most NG operators do not have the fail operational system and do have fail passive. Any 757, 767, 777, 747-400, Airbus etc are always fail operational, so overall fail operational is probably more common. With regard to the original topic, a single channel approach is not an autoland, you're basically just flying straight down into the ground, there's no FLARE or ROLLOUT modes. Plus in the real world this would be a huge violation because you have no redundancy in the autopilot channels.

That's weird cause my NGX autolands on single channel. No flare / rollout modes announced, but it does flare and rolloutIs it just me? no big deal really, just curious

Hi Dazz must be your expert landing capabilities after shutting down autopilot

Hi Dazz must be your expert landing capabilities after shutting down autopilot

Haha, no no, it's A/P on all the way to the ground

AP on NG is coded for the flare, so it will do also in single channell mode. It's illegal, but also the real one opefully will do if someone is crazy to let it do.There are 2 autopilots for cross check, for continous monitoring and calculation.The difference between a single (not admitted) channell or dual channell is the indication of the flare/rollout that is not announced in the single channell.As I stated, also without indication, the AP is coded to do it and will do if not disconnected. If it is alone, and it is calculating wrong things also the results will be wrong... An explanation about FMC...Some users often use "set the FMC" or "program the FMC". The B737 is still an airplane, not a flipper, it can fly and autoland as well with FMC inoperative. All necessary inputs can be selected without it. FMC is an aid for the navigation, not the most important item. ;)In the autoland phase no outputs from FMC are needed, you need to put speed on MCP, you need to select flaps from the lever, you need to manually tune radios, you need to push buttons on the MCP, buttons, selectors, switches that speaks with the flight control computers directly.. :)

I really dunno, but I guess that 85% of real pilots disconnect the A/P and perform manual landings, except of course when low visibility f..i. heavy fog etc.. is involved.

With regard to the original topic, a single channel approach is not an autoland, you're basically just flying straight down into the ground, there's no FLARE or ROLLOUT modes.

AP on NG is coded for the flare, so it will do also in single channell mode.The difference between a single (not admitted) channell or dual channell is the indication of the flare/rollout that is not announced in the single channell.

Which is right? Don't think you are both saying the same thing.

From boeing manual:

Single Channel FlareAutomatic flare is for dual channel approach, however, since it is part of the A/P design, it can function during single channel approaches. The flare mode does not annunciate on the FMA in a single channel approach. The autopilot should be disengaged manually when the airplane reaches the decision height.

But it is true that no flare is made in the classics

AP on NG is coded for the flare, so it will do also in single channell mode. It's illegal, but also the real one opefully will do if someone is crazy to let it do.There are 2 autopilots for cross check, for continous monitoring and calculation.The difference between a single (not admitted) channell or dual channell is the indication of the flare/rollout that is not announced in the single channell.As I stated, also without indication, the AP is coded to do it and will do if not disconnected. If it is alone, and it is calculating wrong things also the results will be wrong...

So the MEL for RADALT states that you can't use the A/P and A/T for approach - at all! Not just dual-channel, but it's gone completely. Hmmm. That would make sense in light of what Andrea is saying. However, my MEL for the -400 says the same. Interesting.

Radio altitude is one of the needed inputs for autopilot. without it autopilot is unable to land as the baro altitude is not an useful data for landing.

Radio altitude is one of the needed inputs for autopilot. without it autopilot is unable to land as the baro altitude is not an useful data for landing.

RADALT is definitely needed for autolands, you are correct, of course. Therefore, it makes sense that if the NG is coded for autoland, even with single channel, that the RADALT would be needed for any ILS approach. However, I wonder why it is needed for an ILS on the -400.

Also on the NG the approach on course logic needs a valid radio altitude and a value less than 1500 feet, 1500ft is also the altitude used for VOr to approach change, flare logic uses itself a radio altitude. A lot of autopilot logics are LRRA related.With a single lrra failure (for MEL dispatch: 2 lrra installed, 1 maybe inop) approach is still possible with the not affected autopilot, autopilot affected by the loss of radalt cannot be used to approach, but still avaiable for other flight phases.As the other AP is still capable of flare, it will do alone if not disconnected, but, pilots must monitor AP operations because are we sure that radalt is correct? are we sure tat GS and LOC data received are correct? Are we sure that FCC is working correctly alone?