I am trying to manually land the plane with auto throttle disabled. The way I understand is this plane auto trims so you don’t have to keep pressure on the stick. However, when I push the throttle forward, the airspeed increases instead of decreasing rate of descent.
Isn’t this the mechanism of autopilot glideslope approaches? I mean, the autopilot will control pitch to chase the glideslope and you need to change the power to support. If you are above, it will pitch down so remove power (rate of descent increases). If you are below, it will try to pitch up so add power ( rate of descent decreases). I guess another way to look at this, if you remove power, the plane pitches down to maintain airspeed increasing its rate of descent; and if you add power, the plane pitches up to maintain airspeed decreasing its rate of descent. I think that’s how it works, just not sure if the chicken or the egg comes first.
If above is correct, how can you make the A320 perform this way?
I think it does both. I always land ‘manually’ without auto-throttle. And if I gas it up, it will first increase the speed and then adjust the pitch (probably sort of simultaneously, but you see the pitch effect a bit later). But that’s with autopilot still on and a captured glide slope. Perhaps it’s the delay between the two that’s getting to you?
I’m trying to see how I could land the A320neo when I only have 700 feet height from ground and 2 Nm from the runway. This comes after flying with Managed speed, altitude and heading to the very last waypoint and not having a glideslope or a glidepath. I want the autopilot to continue to maintain lateral navigation, but I need to adjust my vertical speed so I don’t overshoot or undershoot the runway. I need to keep the Vapp at around 150. Incidentally at that height and that distance from the runway is about a 3.2 degree slope I think. So I am trying to figure a glide slope approach without a glide slope in the simplest way possible.
If a plane behaves passively with throttle changes by pitching up and down with or without autopilot ( just as a consequence of physics if it is trimmed for speed), then all I need to do to control vertical speed is manage power with the throttle. But I think the a320 is trimmed for pitch. I don’t really understand the concept yet I guess of trimmed for speed. Trimmed for pitch makes more sense as you don’t want the nose of the plane to be bobbing up and down on approach as you adjust power to land. Passengers would be more accomodating of speed changes which is expected anyway.
So how can I convert this thrust power to vertical speed? I can’t hold the speed unless I use the autothrottle. And If I use the autothrottle, i can’t use the throttle to control vertical speed. I am left with holding the speed with autothrottle and manually inputting vertical speeds in the autopilot and then looking out the window, then adjust the vertical speed in the autopilot and then look out the window, and then… It would be nice if I can just pull the stick or the throttle and observe the effects and then be able to react faster. I don’t really want to change the pitch or airspeed, just vertical speed. Is there a way?
The manual throttle will affect airspeed first and then vertical speed later. So there is indeed a delay. By the time I get to the right vertical speed this way, the airspeed would not be at 150.
HI, that would be the correct procedure for GA but not for the A320 fly by wire system.
If you want to manual-land the plane disconnect the autopilot keeping the auto-trhottle active.
The A/T will keep the speed in your VREF speed which is usually around 145 knots.
Then you control the V/S with pitch, which is usually around -700 to -900 before flare.
The throttles are not touched until about 20ft above when the aircraft barks “retard” which is not an insult to your landing abilities but a signal to put the throttle on idle
So as a short summary:
A/T should be on the whole time.
Use pitch to control the rate of descent
At about 30ft above ground start the flare procedure
At about 20ft above put the throttles back to zero
After touching down the spoilers will be deployed if they were armed, if not armed they will deploy when you trigger the reverse thrust.
If you want to increase/decrease v/s you need to increase/decrease the pitch attitude.
That’s the primary way with an immediate effect.
If you use only power for v/s control, the effect will be delayed as you have noticed.
That’s correct since that’s increasing/decreasing speed the primary use of the throttle.
I’ve never understood the discussion of using pitch or power to control the glide path (the decades old method 1 vs method 2 discussion).
If you need to apply signifcant changes to your glidepath and/or speed, you have to use both, pitch and power.
Reverse with unarmed spoilers works on the real A320.
I’ve tried multiple times, but they don’t extend on the MSFS A320 if not armed when selecting reverse.
btw. IRL and in the sim I prefer either AP and AT on for the approach, or AP and AT off.
Awesome. I just got done watching a couple of landings from Baltic Aviations and saw the same thing. The auto throttle was on and it held the speed while the stick was used to control descent rate by varying pitch. This is very different from a Cessna where you control the descent rate with the throttle.
I Think the plane was also holding a steady course against wind in HDG mode on final approach in the manual landing video.
I don’t think the plane was flared. The throttle was set to idle at ‘retard’. Is the flare optional?
In an airliner, the flare is definitely not optional. Landing with 700-800 frpm VS will likely break the aircraft and cause minor injuries to the pax.
Edit:
Th reason it probably appears as though there was no flare, is because it is a much more precise maneuver than wht is usually done in the GA world.
2° additional pitch up is all that is usually required to achieve the proper landing attitude. 3° pitch up and you’re probably climbing again, at least untill you run out of airspeed completely.
This small pitch change is somtimes difficult to see from cockpit videos.
No. Neither one happens. In the long run, over the years, the structure will suffer.
800fpm on a 3deg glide path means a touchdown speed of 160kts…that’s pretty fast.
E.g. Vref on the A320 CEO varies between 106 and 136kts
Where I work, we had a couple of aircraft grounded due to hard landings. These were caused by the introduction of a HUD to a fleet without previous experience using such devices. Some crew were missing their flare prompts and landing at exactly the vs rates I mentioned.
A hard landing doesn’t necessarily comes from a no-flare landing.
The even worse case, which is usually the cause for a hard landing, is a too late flare.
Which aircraft type are you talking about?
FYI Part 25 aircraft have been demonstrated by test and analysis to be able to withstand a 600fpm landing rate at the maximum landing weight and any pitch angle possible. It’s an airworthiness requirement.
The 600fpm is a minimum do it may be higher. Realistically, structural buckling of the fuselage may be a concern.
Regarding OPs question. Airliners are not power-pitch controlled on approach speed like smaller aircraft, there’s far more momentum which is why this idea of using power to control descent rate and trim to control airspeed doesn’t work on an A320. And manually controlling an A320s thrust by disengaging the auto throttle is poor practice (although entirely possible). You handful but delegate airspeed control to the aircraft at all times until the flare.
I disagree. Don’t know about the NEO, but on the CEO and e.g. the A330 auto thrust is really bad if there’s turbulence and/or changes in wind speed/direction.
This might be of target but If I arm Autobrake and arm the auto spoiler on approach, I assume that when I touch down the reverse thrust will deploy without any further action on my part. If I don’t arm the auto brake but arm the spoiler the reverse thrust still deploys Is that correct?
Not sure if I understand you correctly. Reverse can never deploy on its own, regardless of spoiler state/position.
Autobrakes aren’t connected to the spoilers or reverse.
@PZL104 disregard the auto spoiler part of the question I didn’t mean to confuse anyone. Basically what I wanted to know is if I arm the auto brakes on approach and when I touchdown, the reverse thrust will deploy automatically. Correct? Or do I still need to perform a specific action?
No. The thrust reversers can’t deploy automatically.
You need to select reverse on your own by either using e.g. the reverse toggle, or the reduce throttle command.
On the A320 you can confirm this by looking at the small reverse levers on the thrust levers which are moving upward and a green REV message which appears on the upper ECAM display.
