I Broke My A2A 172 :)

[Mithras 87]

My first proper failure, fantastic.... full throttle up from Cape Canaveral airbase to view some freeware scenery for NASAs VAB. Almost straight away oil pressure light came on, I flinched, looked at the dial for zero oil pressure. Panicked ... The engine cut out ... I knew my drill, I'd run through some lessons on FSX and watched You-Tube videos on emergency descents and landings, I trimmed for best glide speed, dropped some flaps, did 180 and dropped back onto the runway with the stall horn squealing in my ear.

 

Brilliant! ;)

 

What a plane!

[CrownCityMisfits 58]

Awesome. These moments make the Accusim aircraft worth every penny.

[PinkJackal 86]

If you are low, you'll never, never turn back to runway. You'll search for a good landing spot in front of you, turning back can stall your plane.

That's the first think I've learned on flight school!

[Mithras 87]

Oh I was quite high by then, almost 1000', but I see what you mean, that sharp turn will just bleed off airspeed...

[BeechPapa 32]

Oh I was quite high by then, almost 1000', but I see what you mean, that sharp turn will just bleed off airspeed...

 Yep, and the plane isn't going to be level when it stalls, so it will most likely be a stall/spin accident, very close to the ground, with no chance of recovery. If you err, the result is violent and ugly. It's called "the impossible turn" but the possibility of making it is sometimes up for interpretation and practice (see video). 

 

That said, when Captain Sullenberger landed in the Hudson, he was 3,000 ft up I think, and it was later demonstrated in a simulator that a 180 degree turn back to La Guardia was actually possible. But commercial airline rules mimic the "impossible turn" rule in GA, and dual engine failures are not to be followed up by u-turns to the airport. Sticking with the hard and fast rules, and picking from the remaining logical options saved passengers that day.

 

[Lewis B 14]

Great to hear your are enjoying the simulation. Its got quiet the life span built into it with some things statistically very very rare to occur (mechanical system failures over pilot error for example). Also with the time modeled sat not being used, even if you stop flying it for a few months and come back to fly the simulation it should prove interesting during the pre-flight and first engine start right away depending on how you left her when last parked up. ^_^

 

Also regarding 'The impossible turn' we have a topic on that at the moment, and its already apparent the differences between gliders and powered aircraft which i thought an interesting thought.

 

Heres the link, unfortunately due to the nature of the video we had to remove it as it was too graphic for our younger forum users;
http://a2asimulations.com/forum/viewtopic.php?f=64&t=40658

 

thanks

Lewis

[twojastara 85]

Nice video BeachPapa!

Below is another one from real world practice. VERY experienced pilot makes "impossible turn" on 300ft AGL in C152:

 

VIDEO:

ftp://ppaero.pl/Impossible%20turn%20-%20www.ppaero.pl/C152+-+Symulowana+awaria+silnika+po+starcie+z+Babic+-+czesc+2-HD.mp4

 

Theory is that if you make it with 45 degree bank and just above stalling speed your altitude loss will be smallest.

 

But of course if you exceed your bank just few degrees or lose too much speed you will end up in deadly spin.

[BeechPapa 32]

Thanks for the link, Lewis! I have often googled aviation phrases or terms (not sim-specific) only to find an A2A thread discussing the matter. You guys have an enormous storehouse of aviation info, and the linked discussion is a good example. Without seeing the video, I can imagine the horror it entails… lucky for us we can practice this from the safety of a computer. 

 

Great video, Twojastara. DL link is much appreciated. That was very well done, and the included GPS track shows just how steep the recovery needs to be. Even despite that roller-coaster pitch angle, the stall horn is going off like Miles Davis. Very scary, and shows just how dangerous this maneuver can be.  Come to think of it, I have no idea what a survivable turn back altitude is for any of my sim planes, I should get practicing…   

[Oracle427 45]

Stalling in a turn does not lead to a spin. You can easily enter a spin from a wings level stall if you are uncoordinated. The stress of making a fast turn back to the runway might be the last straw that makes one skid the turn while also trying to stretch the glide. If you use the rudder and ailerons correctly, you can't spin.

 

This is why you should always brief yourself on what to do if your engine fails just before you take the runway. Know what you are going to do at specific altitudes.

 

Turning back to the runway from 1000 feet high should be somewhat easy unless you have a short field and/or a strong tailwind. 300 feet is crazy! Wow!

[twojastara 85]

Stalling in a turn does not lead to a spin. You can easily enter a spin from a wings level stall if you are uncoordinated.

 

Thanks for your comment because it made me to read more about this topic and I have learnt something new :P However I disagree with your statement.

 

Coordinated turn will reduce weight imbalance which will eliminate one possible cause for spin. However, you can anyway enter spin even being in coordinated turn, because during it the upper-wing will have little more relative airspeed then the lower wing (because of being in a turn) thus at critical airspeed lower wing will stall before the upper one.

 

Quotuing link below:

The increase in drag yaws the aeroplane toward the down-going wing, which may further delay the stall of the up-going wing as a result of increased airspeed. This process, where yaw causes roll, which causes yaw, is known as autorotation.


 

http://www.caa.govt.nz/fig/advanced-manoeuvres/wing-drop-stalling.html

[Oracle427 45]

Okay I thought about what I said and can agree that stalling while being in a turn, even a coordinated turn, is more likely to result in a spin entry than a wings level stall. However, the technique to recover and prevent a spin remains exactly the same.

 

Being uncoordinated can trigger a stall that goes directly into an incipient spin. Skidding a turn increases the difference between the angles of attack felt by the inside and outside wings exactly as you noted above. Additionally, a descending skidded turn is the worst combination, which is exactly what one might find themselves in during a engine failure and turn back to the runway. So the moral is no stall no spin and keep those feet alive the rudder.

 

For an example of how effective the rudder is at stopping a spin see this video. These are loads of fun to practice.

 

[ZachLW 37]

My first proper failure, fantastic.... full throttle up from Cape Canaveral airbase to view some freeware scenery for NASAs VAB. Almost straight away oil pressure light came on, I flinched, looked at the dial for zero oil pressure. Panicked ... The engine cut out ... I knew my drill, I'd run through some lessons on FSX and watched You-Tube videos on emergency descents and landings, I trimmed for best glide speed, dropped some flaps, did 180 and dropped back onto the runway with the stall horn squealing in my ear.

 

Brilliant! ;)

 

What a plane!

Too cool!  I spent hours upon hours teaching students "ABCDE" when the engine sputters/stops.  It's neat to see someone with no real world training (or so I assume) self learning basic emergency procedures and techniques.

 

Emphasis on the ABC.

 

Airspeed;  Pitch & Trim for best glide.  In most well rigged C172s (all models) trimming all the way to the trim up stop will give you hands off best glide.  Remember how you're trimmed when practicing because the go-around can be a real bear.  Not sure if the trim trick works in the A2A 172, I don't own it.

 

Best field for landing.  Field length, obstacles (houses, power lines, ditches), with plowed rows, no danger to people on ground, etc.  Use slips before flaps and don't come up short or long!

 

Checklist.  Now that we're flying the airplane (Aviate, Navigate, Communicate) we can worry about the checklist if there's time.  Memory items (in bold) and then to the checklist.

 

Declare your emergency if you have time and need to.  Use common sense.  DON'T shout on unicom or tower as I've had students try to do.  Make a position report and state your emergency if you think you should.  Maybe transmit on 121.5 as well.

 

ELT.  Manually activate the ELT if you believe you're going to bend it up pretty bad.  If I'm unconscious I want to be found.

 

I've had several engine failures.  All but one was a partial power loss.  That prompted me to train partial power losses to my students.  I would pull the throttle off to 1300-1600 RPM and say "you lost a jug!"  Fun times!

[Great Ozzie 101]

Theory is that if you make it with 45 degree bank and just above stalling speed your altitude loss will be smallest.

This sounds like a recipe for disaster.

 

 

However, you can anyway enter spin even being in coordinated turn, because during it the upper-wing will have little more relative airspeed then the lower wing (because of being in a turn) thus at critical airspeed lower wing will stall before the upper one.

 

The lessons is "To carry out a stall from straight and level flight (and the turn) recovering from a wing drop with minimum altitude loss."

 

The paragraph you quote from in your link is discussing the possibility that flaps were extended at unequal amounts (rigging etc). Quoting your article:

 

The wing that reaches the critical angle first (at about 15 degrees) will stall first, losing lift and causing a roll at the stall. This often happens because of poor pilot technique where the aeroplane is out of balance at the stall, or aileron is being used. (emphasis added)

 

Quotuing link below:

From your link:

 

If the aeroplane is reluctant to drop a wing at the stall, alter the power and flap combination (refer CFI) and relax rudder pressure to simulate the pilot's failure to maintain directional control. Alternatively, a gentle turn may be required (5 degrees angle of bank).

 

There is nothing underhand about these techniques, as permitting the aeroplane to yaw or stall in the turn are possible causes of a wing-drop stall.

 

----------

 

From The Airplane Flying Handbook (FAA-H-8083-3B)

 

An airplane will stall during a coordinated steep turn exactly as it does from straight flight, except that the pitching and rolling actions tend to be more sudden. If the airplane is slipping toward the inside of the turn at the time the stall occurs, it tends to roll rapidly toward the outside of the turn as the nose pitches down because the outside wing stalls before the inside wing. If the airplane is skidding toward the outside of the turn, it will have a tendency to roll to the inside of the turn because the inside wing stalls first. If the coordination of the turn at the time of the stall is accurate, the airplane’s nose will pitch away from the pilot just as it does in a straight flight stall, since both wings stall simultaneously.

 

To enter a spin, you must have *both* a stall and a *sufficient* yaw moment.  A coordinated turn, by definition, has the yaw canceled out.

 

[ZachLW 37]

Thanks for your comment because it made me to read more about this topic and I have learnt something new :P However I disagree with your statement.

 

Coordinated turn will reduce weight imbalance which will eliminate one possible cause for spin. However, you can anyway enter spin even being in coordinated turn, because during it the upper-wing will have little more relative airspeed then the lower wing (because of being in a turn) thus at critical airspeed lower wing will stall before the upper one.

 

Quotuing link below:

http://www.caa.govt.nz/fig/advanced-manoeuvres/wing-drop-stalling.html

 

I think maybe you're misinterpreting some key points.  The only reason a "weight imbalance" (I'm assuming lateral) would cause the spin would be because of correction of over banking tendency. Correcting over banking tendency would of course mean the lower wing would have a higher AoA because of the downward deflected aileron.  More lift, more drag, greater angle of attack on the inside wing.  I'm tying to still wrap my head around what you mean by weight imbalance.

 

Many argue if over banking tendency even exist, so we typically throw that abstract and negligible effect out of teaching.  Maybe I'm missing what you're arguing?  At any rate, if the ball is in the middle, no spin.  Simple as that in GA airplanes.

[twojastara 85]

Well, OK Guys ^_^

It seems that I had different expectations of what stalling in a coordinated turn looks like. From that quote from Airplane Flying Handbook it seems that it is less violent - no spin until poor pilot technique.

Thanks! I have learnt something new again :lol:

 

What I meant by "weight imbalance" is that there is some lateral force? lateral momentum? I guess I am using wrong term since English is not my first language.

 

This sounds like a recipe for disaster.

 

Yes it is! It takes lots of experience to do that correctly. But I mean that pure theory says that in 45 degree bank and minimum speed you will have the lowest altitude loss in a turn.

 

I am now finishing my PPL and if I would had engine loss at less than 500ft I wouldn't even try to do this turn. Just land ahead...