Another post addressing the AP disconnect point on an ILS approach.
Yes, I hold a Private license.
Just a FlightSim question (not necessarily IRL question) - considering all the good & not so good aspects of MSFS, when are most disconnecting the AP on final ?
Dedicated to the TBM. I usually (always) fly the AP / APR all the way down to minimums, regardless of weather - guess I remain curious how long the AP will hold the guidance.
Repeatedly, as I get near minimums, quite often, the AP / APR / ILS guidance will fail - so just asking - those that try to fly really accurate approaches in the sim - when are you disconnecting and going to manual / hand flying ?
Usually for me in the sim (I only fly the FBW A320neo), is that if the APPR mode is still doing things right on the approach, I donāt see a reason to disengage AP. If things works well, I disengage AP at 100 ft callout for the manual flare.
Only when I start to see things like an offset localiser, or my glideslope is too high or too low, thatās when I disengage AP early and manual fly down the runway.
Even on RNAV approach which is not a precision approach, as long as my glide slope profile and my lateral tracking is still on-point, I also keep the AP on until 100 ft for the manual flare.
Feel free to explore my flight videos on Neo - YouTube channel. I donāt have a pilotās license unlike you, thoughā¦ so donāt take my flying too seriouslyā¦ Hahahah.
Usually when the runway can be seen visually the AP is turned off. There is no hard and fast rule on this method. In real life flying I do it the same way but there are also AP limitations for minimum altitude to have the AP engaged during enroute, precision, and non-precision approaches. Those numbers are usually lower than minimums for the approach so they are never reached.
So I also fly the A320FBW.
I turn off the autopilot at 1000ft radar altitude and then turn off the autothottle. Provided I can see the runway and itās not too windy.
This is probably how pilots do it in real life to keep their license.
Disengaging the AP immediately when getting the first glimpse of the approach lights and/or the runway is a common mistake, even IRL.
Especially in low viz you want to keep the AP engaged until you have a very clear picture of the runway, lights and attitude.
You can disengage the AP at the minimum altitude which is usually between 80-200ft, but if the viz is good enough, itās highly advisable to disenage it between 200-500ft.
The reason is simple. Since every approach is different and your aircraft reacts different to control inputs on each flight, itās a good idea to get a feel for the aircraft response in pitch and roll well before you start the flare.
Pulling the stick/yoke back for the flare and finding out that it was too much, is a bad moment.
Most airline APs arenāt certified for ops below 200ft unless conducting an LVO approach & landing. These LVO approaches are planned to be flown to an auto land, but may be hand flown below the minima when visual, ie 100ft for CAT II etc. As no MSFS aircraft has a working auto land system, technically the AP should be out before 200ft.
In real life, assuming good weather, 1500-1000ft is normal for a wide body, (domestic/regional guys tend to do way more sectors, are more proficient in hand flying, and hence disengage a lot earlier). Saying that Iāve seen the AP come out as high as 20,000ft.
Underway now KPBI to KEYW for RNAV 9 via CHETS. Having a blast flying - but my success on holding an approach is still ~ 70% in the sim - either ILS or RNAV, as the aircraft (when in failure) will yaw to the left and lose the GS. When it works - itās great.
A friend of mine flew the Q400 for Air Berlin. They were certified to fly on AP down to 60 or 80 ft (not sure anymore) and he said once that this aircraft was such an attention wh*** that on the 4th or 5th flight a day (!!!) they were so done and tired that they used the AP the whole legal time, as long as possible. He flies 767 freighters now and knowing him I guess he has much more hands-on time now
In the sim I fly for fun and except for required autolands or really low visibility I usually fly manually as much as possible. Even in the Airbus the AP is usually off below 10000 or even higher. There are also weather conditions that the sim aircraft canāt handle and I need to take over to stabilize. It really depends.
I fly mostly GA. I tend to cut the AP off at about 500 feet. Sometimes higher, depending on conditions. To quote Steveo Kinevo - āYou canāt let the airplane have all the funā. During IMC though, Iāll typically AP down to minimum,
Usually AP donāt disconnect on itās own unless something else is happening. Maybe your Landing assist is on, which conflicts with AP and APPR modes.
Still, my point is still valid, Landing assist is notorious for ignoring glideslope and path and has its own way of āassisting your landingā. Make sure everything in your assist settings are Off by setting them to Hard/True to Life.
