Since I don’t have a real Cessna to fly, what is IRL the final approach speed of a 172 (ideally the version in the sim)?
I took 65kts over the threshold as a reasonable guess but may have been doing it entirely wrong the whole time!
The POH says
- 60-70 flaps up
- 55-65 flaps 40
using the standard 1.3 x Vso rule, flaps 40 approach would be 47kts. The handbook gives a pretty solid safety margin.
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Thanks a lot!
Spoilers ARE used in flight, airliners often use spoilers in flight. Airliners that have high aspect ratio wings can float down the runway, the 737 800 can float on a bit if you let it. Aircraft with high aspect ratio wings produce less drag and extra lift. Your MSFS A320 has a high aspect ratio wing, (10+). Aircraft can either be stalled onto the runway or flown on, it depends on the type of aircraft and the conditions.
The TBM has a high aspect ratio wing, if you want to learn more about this aircraft and it’s performance I have a link for you .Charles
Just tried the same thing with the King Air.
By the book
- 135 kts
- 2.3nm x 1000ft
- Feathered
From 5000 ft I got 10.5nm no wind.
Although they don’t visually model feathering, it made a big difference to the glide.
Unfeathered, I got 3.5nm / 1000ft. That seriously supports your theory of no prop drag. In fact I was still producing significant thrust at idle power, prop fine.
Other than the lack of braking in the air and no beta, I actually like the way the King Air flies.
In the developer mode you can see the thrust produced, it never goes negative with a windmilling prop.
On the TBM it doesn’t matter a thing if you select flight idle with the engine off, feather in high or low idle or even full reverse. The prop spools up when selecting reverse but no change in drag 
.
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How did you arrive at that. Did you use 36 kts stall speed for flaps 40 at 2300 lb for say a C172N? But that is 36 KIAS, which is 44 KCAS. 1.3 x 44 = 57 KCAS which is about 54 KIAS. So the low end of the 55 - 65 KIAS recommendation gives no margin on top of the standard 1.3 x, which is as I would expect it.
Running the same calculation for the C172S at 2550 lb flaps 30 stall speed is 48 KCAS, 1.3 times that is 62 KCAS or 59 KIAS. Recommended approach speed by the book is 60 - 70 KIAS with flaps 30, so no additional margin at the low end there either.
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This part of the discussion was about the flare and you usually don’t use speed brakes in this case.
On most aircraft the use of speed brakes and flaps is restriced or even forbidden.
Carrying just 4kts more than the minimum of 61kts in calm weather is perfectly fine. 
The 737 has a pretty heavy nose down tendency when you chop the thrust levers to idle, its not gonna float much by itself. On the A320 this nose down tendency is artificially induced in the landing FBW law.
We have had a whole discussion about stalling aircraft onto the runway, I can’t talk about taildraggers but really landing in a fully developed stall is not a proper technique, an approaching stall or stall warning during the flare is NOT a stall. The flare should bring the aircraft in the correct landing attitude, keeping the aircraft off the ground until stall unnecessarily extends the landing distance.
Sure the TBM and also Kingair have high aspect ratio wings, they also have big props creating drag in the flare more than compensating for the lower induced drag. Flying with flaps and slats out during landing doesn’t increase the wings drag efficiency either… You have to look at the aircraft as a whole, not just the AR of the wings.
Regarding spoilers, ground spoilers are obviously not used during flight, flight spoilers or speed brakes whatever you wanna call them are but neither is used during the flare, and thats what this discussion is all about.
Right.
For example:
B737 since classic spoilers restricted above Flaps 10 as Flaps 15 is considered a landing flaps setting for abnormals like OEI.
A320 I believe no spoilers above Flaps Conf 2, as 3 and 4 are landing configs. But there is actually no point in using spoilers with config 2 as it produces a lot of drag already.
747 I believe no flaps higher than Flaps10, Flaps 20 is a landing setting too.
I guess other aircraft are similar, as soon as the flaps are in any landing setting the use of spoilers is prohibited.
Wouldn‘t make any sense anyway, why reduce the stall speed to increase it again? Just dangerous.
Stalling (or nearly stalling) onto the runway is correct procedure in glider planes or some other tail draggers as long as you do not want to do a main wheel touch down. You hold it off the runway and increase the pitch until you basically have a tail strike, your tail wheel hits the ground first. This limits the pitch and your wings can‘t create enough lift anymore to keep you in the air, so the mains touch down too. A fully developed stall would require a much higher AOA and many aircraft tend to drop a wing, way too dangerous for a landing. I saw this happen once during my glider training when I started flying and t her pilot really felt it, that‘s for sure.
I‘ve learned to use this technique in a C172 or DR400 too but of course not so far that the tail hits the ground… rather you float in ground effect until the speed has dropped far enough that the plane sits down. I personally don‘t like this, all above in high wing airplanes, as I feel like I lost control and became a passenger. Usually I rather fly the 172 more like the heavier Skyvan and just break the descent. The downside is a faster touchdown, up to 10 knots.
Other than gliders and taildraggers as you are saying I don’t see any purpose in a technique like that, it only extends the landing distance and reduces controllability. As soon as you reach the correct landing attitude just put it down 
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Also the phrase “stall” is used incorrectly in a lot of cases IMO, a stall means exceeding critical angle of attack, thats the exact definition.
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I was referring to flight spoilers and not ground spoilers. Ground spoilers only deploy when the wheels make contact with the runway when they are armed. Of course the A320, (for instance) has multi-function, spoilers which work as flight spoilers or speedbrakes, roll spoilers and ground spoilers when the wheels land on the runway. Charles
Maybe the planes are in general too light, hence the easy veer-off after touchdown, this might also cause a prolonged glide. The weight numbers may be correct but the physical effect of weight under 1G may not.
I am familiar with the concept of spoilers but thanks for the explanation 
.
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We’re on the same page ^^ However I was tought to land so. You’re slower… but you also float along.
The whole spoiler issue is off topic, but its an interesting discussion.
The Embraer E-jet I’m rated on also retracts spoilers upon selecting flaps 2 expect in one condition:
When steep approach is selected, 2 spoiler panels are extended partially to 15/20 degrees depending on the model for a neutral control column. So when pitching up they temporarily retract while pitching down they further extend. This way they will also partly retract upon starting the flare. Pretty clever feature. I guess the A318 has some similar system for steep approaches.
So there is an exception to the “spoilers are not used during flare”.
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but that’s an automatic mode, isn’t it? you wouldn’t touch the spoiler lever below 1000 ft (just a number now) or a certain configuration?
Its an automatic mode indeed, there is a steep approach button in the cockpit (its an option) you need to press upon intercepting the glideslope. You won’t touch the spoiler lever at any point indeed.
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