Hi GtE, I wonder how you factor in height asl in those calculations ?

Our flying club had recently fitted a new propeller to a C152, so myself and my passenger took it out to see if we could find any performance increase. We climbed to about 10,000ft where we found it just ran out of lift.. 50ft/min was all it would do. Pull back on the stick and it would descend (-300 f/m.).. Push forward and it would descend, any angle of bank and it would descend..
Whether this could be called a stall I don't know, but there was only one stick position that would give us a climb.... The engine was leaned out for max rpm, which I think was about 2300 rpm. The Indicated airspeed was about 60 knots. At a rough guess we would have run out of fuel before it would climb another 1000ft.


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I fly from a 600metre grass strip. There is no fence at the 24 end, just a footpath then a barley field. 06 has trees ~100metres short of the strip with a rough "grass" area between. I don't have a particular "threshold" speed other than controllably above the stall, approach speed is adjustable to suit the eyeballed rate of decent, radius of final turn, distance from threshold etc. If I can put it down very close (10metres in) to the threshold at 45knots I can get it stopped by 100metres in. If I go for 1.3Vso (52 knots) I'll end up at 250 metres in. I don't like using the brakes cos I don't have a safety wheel on the front and prefer to keep the prop out of the mud!

Yes, you ran out of a combination of lift and power (more of either, and you could have climbed more). You reached the service ceiling. If there were any stick position at which any climb was possible, the aircraft was not stalled yet. When you reached a higher altitude, and the stall horn was screaming to simply maintain altitude, you are near the absolute ceiling, and the stall. I have done this during flight testing in a Cessna 185 with a carburetted engine, on auto fuel. 20,800 feet. I could get to 21,000, but could not stay there, it would settle back stalled a few hundred feet. There are atmospheric corrections to reduce this to standard atmosphere if needed. If the service ceiling you obtained in the 152 with a new prop was 10,000 feet, I would not be very enamored of that prop.

Thank you G t E. I'll get an email off to you later today.

Let's get this straight?

You are trusted, with a passenger, to do an air test on a prop change and have excellent recall of numbers I'd have to look up in my post flight report, not to mention the relatively obscure concept of leaning for best power, but don't know about stalling in the landing configuration? I see why some people think you're a troll.

You clearly do have enough knowledge to look this stuff up in the same textbooks I've got on the shelf. Try this one... which has served me very well since I was an undergrad 30 years ago.

G

I think the issue here is knowing what the term means.... perhaps it just got lost in translation somewhere?

Landing configuration generally means, gear down, normal stage of flaps for landing, air brakes if fitted etc... NOT descending at x ft per min maintaining y kts, or z rpm!!

Its all about terminology. I am sure that the OP has done these, but perhpas under a different name.

The fence isn't, or doesn't have to be, a real fence. It's sometimes called screen height, and it's 15m high. If it was there it would be anyway. It's used in performance calculations. Take off consists of ground roll and an airborne sector. Would you believe to 15m?
Landing consists of an airborne sector which involves clearing a probably imaginary 15m fence, and touching down, followed by a ground roll. If you look in a flight manual for pretty much any light aircraft you should find all four of these distances given, and a factor to apply for different surfaces and wind conditions, altitude above sea level, and temperature.
Does that help?
Approach speed is also given, normally for MAUW. The takeoff and landing distances are calculated for the technique stated in the flight manual. Use something else and you are a test pilot.

I've come to this thread a bit late, but isn't the purpose of training to deal with a 'stall in the landing configuration' all to do with dealing with the aftermath of a mistake - which would be letting the speed decay away whilst close to landing. eg base to final turn or loss of concentration on final.

In other words you've set the plane up for landing (full flap, little or no power), you're less than a thousand feet above the ground, you f--k up, are you going to die or not ?

So by its very nature you're likely to be flying at 30, 40 or 50 knots. Testing this at 80 knots seems utterly pointless .

If only there was a term for such a measurement :hmm:

Tee Hee. Pontius, that was naughty.

:ugh::ugh::ugh::ugh: If you're not a troll you have a strong urge to become a statistic! Windshear? Engine failure on short final? insufficient braking action? A stable speed on finals gives a huge protection from all of the above. My day job involves stable approaches every time, as far as possible I do the same in my spare time. My aeroplane is a basic permit beast, but she's mine, she cost me good money and I like to protect her, me and anyone who flies with me.

SND

Troll "simulated glide path" my ass!

Looking around his other posts, possibly a keen aero-modeller with a sim package on his pc. Probably a teenager, a lot of his posts are similar to CapA330.

SND

This is all getting a bit technical.
Surely all the person wanted to see was how you reacted to being too slow on finals, with all the inherent dangers.
What you actually call it is irrelevent, however its important that you recognise the situation if it happens and that you can handle it.

Low and slow on final? - shove the nose down, instinctive reaction. (And also probably add some power.) Always pleases instructors, who seem to come across other behaviours from time to time?

Very common to hold the attitude and power out of it. Which is still being taught in the USA and all over Europe.

As its normally recovered from the none stalled, stall warning stage it works mainly because nobody is that great at holding an attitude. But there is also a possibility of the nose pitching even further up.

And its not just a SEP PPL thing, it goes all the way to type rated machines and pro pilots.

Stalling was done in type ratings but after that it wasn't given that much priority in training. In fact I don't think I did a stall for 10 years. EASA have now included it in the normal training cycle exercises along with upset training. So in a 3 year cycle you get 12 sim sessions and all the stalls are covered. The new pilots on there first SIMs after TR do revert back to SEP training and this causes quiet a few repeats. Habits formed in basic training are extremely hard to unlearn.

The other one which is seen a lot is full rudder to lift the wing in case of wing drop. Instead of rudder to stop yaw and aileron to bring the wing back to level. It really gets acrobatic when people use both aileron and rudder at full deflection to recover especially if the stick shaker then triggers they hammer the power leavers forward and then the over speed warner sounds. Then they lift the nose... In upset training you can have a 10 knot window between stall and over speed. Its thought that the common exercise of flying slow and using the rudder to keep the wings level and change the heading is root cause of this in Europe. USA until the airbus tail falling off just after 9/11 it was standard practise.

At the basic, the risk of a stall exists when the angle of attack is too high. The best way to reduce the risk of stall, is to reduce the AoA. If an aircraft manufacturer recommends powering out, that is theirs to do, but pilots should always remember basic principles.

No OEM that I am aware of recommends powering out.

It seems this powering out is pure pilot nonsense.

Unless you are too low to lower the nose too far! ;)

Yep that's the logic of the pilot nonsense.

You can't unstall an aircraft without reducing angle of attack. You only have to lower it a degree for you to unstall.

Ga aircraft do not have the power to defeat the induced drag of a stalled aircraft. If your that low that your going to hit the deck with the nosewheel first if you reduce the attitude you might as well hold it as it is and accept the arrival. Aka a short field on the horn landing with no flare and cut the power on touchdown. I suppose that isn't taught any more.

So the excuse for powering out is based on a stall in the last 10 feet of the approach. It wouldn't work anyway on a stalled aircraft.

Which leads into the approach profile are they flat 3 degree and powered up or are they doing a sensible single engine approach steeper with less power.

The ones usually advocating powering out are usually the ones with + huge amounts of speed extra. It's probably linked with all the hassle with power outs and hanging in the air doing a tap dance on the rudder while the engine thrashes itself and nothing much happens until they actually fail holding the attitude and the plane unstalls itself despite their intentions.