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Engine failure video

Old 10th Nov 2021, 03:58
  #81 (permalink)  
 
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Originally Posted by 172_driver View Post
How about this one - slow below best glide speed to steepen the approach angle!?

Never taught it to my students. But tried it a few times on my own and worked like magic.
Discuss.
I wouldn't recommend this technique as a standard procedure. One need only ask themself how many times have they been doing a practice engine out scenario where they discovered that they were no longer at their best glide speed which they had been targeting. All this because they were busy doing a cause check or busy doing a shutdown procedure or busy assessing how their positioning with their chosen landing area was working out, etc. There are plety of distractions during this procedure and speed is inevitable going to end up off target sometimes. Best to have a fair bit of margin above the stall to account for this.
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Old 10th Nov 2021, 07:29
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Posters on this thread seem to me to be about 50/50 split between knowledgeable, helpful folk and Walts/trolls. Folk with a bit of experience can tell the difference, but I do worry about any body else reading it.
ATB
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Old 10th Nov 2021, 07:44
  #83 (permalink)  
 
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Originally Posted by sagan View Post
Later on figured out he stalled the fin. It was nasty.

.
We lost several photo flying KZ 7s in the 60s for that reason.
You are low and slow, kick the rudder to get a strut out of the photo, the fin stalls and the rudder locks out. On the 7 the only way out of this was a full stall.
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Old 10th Nov 2021, 12:12
  #84 (permalink)  
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the fin stalls and the rudder locks out
I have no experience, and therefore no comment about the KZ 7. Over the years, and with different flight test programs, I have found that a very few airplanes can be flown to this extreme condition. Certain Cessna 180/185's can get there, particularly as floatplanes. I've done it in a King Air B200, for which it is a know characteristic, and a certification special condition. In the case of these types, recovery can be accomplished with appropriate use of the rudder - it just was not a positively state as other types. But, the rudder did not "lock", or it would not be certified. In both cases, this was powered flight, idle power flight was more benign. The turbine DC-3 will exhibit unfavourable rudder forces with very large rudder deflections, which is alarming. The DC-3 was certified before today's more modern standards - I consider it an exception, for which competent training is pretty important. I have slipped 172's with flaps extended, and experienced the burble in pitch which is warned as an "avoid". Again, manageable within normal pilot skills, as long as you just keep flying it. I have never made any version of a 150 loose positive directional stability, and I have the most experience on them.

During testing of a modified Cessna Grand Caravan last winter, the authority required that I demonstrate a stall to the break from a 75% power climbing 30 degree bank turn in each direction, with full rudder applied in each case. (Yes, this is about a spin entry). The airplane handled it just fine, no rudder lock, benign recovery attitudes.

I find a sideslip to be a very useful tool for descent control, and have done it in many types with no difficulty nor alarm, though no, I would avoid it in a DC-3!
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Old 10th Nov 2021, 12:42
  #85 (permalink)  
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Originally Posted by Pilot DAR View Post
... I have slipped 172's with flaps extended, and experienced the burble in pitch which is warned as an "avoid".
Can you elaborate ?
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Old 10th Nov 2021, 12:55
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The position out the wing (the wing station) of the outboard end of the flap corresponds poorly with the outboard end of the horizontal stabilizer. In a slip, the wake off the outboard end of the flap can impinge on the H stab, and blanket part of it, and perhaps induce some elevator motion, which will create unexpected momentary pitch control forces, and some pitching. It's more surprising than a real problem, but it is a thing. It varies with models of the 172, some are worse than others, but it was the cause of the "avoid slips" placard common to most 172's. It's also a thing with C 170B's. It's worthy of understanding, and an imperfection with the design, but it did pass certification, and is manageable. C 150/152 don't suffer, as their flaps don't reach as far out the wing. 18x don't seem bothered by it (I've tried all of them!).
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Old 10th Nov 2021, 13:18
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Originally Posted by Heston View Post
Posters on this thread seem to me to be about 50/50 split between knowledgeable, helpful folk and Walts/trolls. Folk with a bit of experience can tell the difference, but I do worry about any body else reading it.
ATB
Why donít you assist the people you worry about by telling them who the trolls are.



Well back in this thread, I mentioned the potential importance of using a slip(yes it is a forward slip) when appropriate..

I was well aware that there are occasional rare cases of aircraft types that one wants to avoid using this procedure(such as the C170B with Ďbarn doorí flaps), a type I used to fly. That is why I stated in that post ďif safe to do so in aircraft typeĒ, which in my opinion would be most of the light single engine propeller types(and the 767-200 for those who know the story).

You may have to dig around to find out how a particular type behaves. A type club can be very useful as that is where I learned about C170B handling characteristics in a slip, which can be deadly due to stalling the horizontal stab.

Last edited by punkalouver; 10th Nov 2021 at 14:51.
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Old 10th Nov 2021, 13:46
  #88 (permalink)  
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Originally Posted by Pilot DAR View Post
The position out the wing (the wing station) of the outboard end of the flap corresponds poorly with the outboard end of the horizontal stabilizer. In a slip, the wake off the outboard end of the flap can impinge on the H stab, and blanket part of it, and perhaps induce some elevator motion, which will create unexpected momentary pitch control forces, and some pitching. It's more surprising than a real problem, but it is a thing. It varies with models of the 172, some are worse than others, but it was the cause of the "avoid slips" placard common to most 172's. It's also a thing with C 170B's. It's worthy of understanding, and an imperfection with the design, but it did pass certification, and is manageable. C 150/152 don't suffer, as their flaps don't reach as far out the wing. 18x don't seem bothered by it (I've tried all of them!).
Ah. Thanks. It's good to finally have an explanation for that placard and a warning of what to expect if it's ignored.
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Old 10th Nov 2021, 18:02
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I seem to remember that a C152 would go down like a lift with full flap, IAS about 5 KT above full flap stall speed, idle power, and side-slipped as hard as possible. Total control was retained throughout. I have no idea what the rate or angle of descent was, but it seemed very steep indeed, especially with a good headwind.
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Old 10th Nov 2021, 18:44
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Originally Posted by sagan View Post
Just a quick note re side slipping Cessna's with full flap.
Had an instructor demonstrate a fairly vigorous side slip in a 150. This was over 35 years ago and was to show me how to 'fix up' a stuffed practice forced landing into some paddock.
Lost control at around 200ft, flick rolled and ended up near enough inverted.
After he recovered and during the awkward flight of shame back home I asked what happened...
'No idea' was the reply....
Later on figured out he stalled the fin. It was nasty.

.
Iím thinking the instructor showed you a forward slip.



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Old 10th Nov 2021, 19:54
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From the handling, I see side and forward slip as just names. I got my PPL on an aircraft without flaps or airbrakes. Most of my flying has been on an aircraft with airbrakes, not flaps. I can stop a slip without taking my hand off the throttle, so I seldom used the airbrakes. Only recently did I encounter the term "forward slip".
The distinction is like that between "Stop:sign-braking" and "Red-light-braking" which I don't think driving instructor has ever taught.
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Old 10th Nov 2021, 19:59
  #92 (permalink)  
 
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Originally Posted by Rozy1 View Post
Iím thinking the instructor showed you a forward slip.


is there a difference ? All the aircraft and its fin knows is the relative airflow, which in both diagrams would be 180 degrees to the flight path, and have the same effect on the aircraft, except one is from the left and one from the right. The path over the ground is irrelevant to aerodynamics.
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Old 10th Nov 2021, 21:11
  #93 (permalink)  
 
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Yes, there is a difference! Can you not see the picture?

Hint- look at the ground path and the angle between said ground path and the leading edge of the wing.
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Old 10th Nov 2021, 22:42
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Sitting at 10 knots above the stall on the approach? Your operating outside the normal envelope of the aircrafts operation, itís called Loss of Control
( I)

Originally Posted by henra View Post
And this is why many here -after acknowledging the good judgement- suggested that a carefully executed sideslip, after having made sure that sufficient energy is available to reach the runway even if the engine completely quits, would have been the icing on the cake.
Slipping is only one option. S Turns and diving the height off are two other ways of varying the glide path and should be easily accomplished by any FI.
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Old 10th Nov 2021, 23:48
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Had an instructor demonstrate a fairly vigorous side slip in a 150. This was over 35 years ago and was to show me how to 'fix up' a stuffed practice forced landing into some paddock.
Lost control at around 200ft, flick rolled and ended up near enough inverted.
After he recovered and during the awkward flight of shame back home I asked what happened...
'No idea' was the reply....
Later on figured out he stalled the fin. It was nasty.
Rather than stalling the fin I'd suggest you got too slow and stalled, where upon the aircraft snap rolled., An instructor with student in similar circumstances in a 152 said recovery took 500'.

One author has said in a typical Cessna 152/172/182, depending on the amount of slip, the airspeed can easily be off by 20%, which means the energy is off by 40%. This is enough to cause real trouble. Location of the static source induces errors.

Last edited by megan; 10th Nov 2021 at 23:59.
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Old 11th Nov 2021, 00:07
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Originally Posted by Maoraigh1 View Post
From the handling, I see side and forward slip as just names. I got my PPL on an aircraft without flaps or airbrakes. Most of my flying has been on an aircraft with airbrakes, not flaps. I can stop a slip without taking my hand off the throttle, so I seldom used the airbrakes. Only recently did I encounter the term "forward slip".
The distinction is like that between "Stop:sign-braking" and "Red-light-braking" which I don't think driving instructor has ever taught.

Yes they are names, but there is a difference. I think most people, even pilots, intuitively think of the slip as a side slip because the side of the airplane is headed towards the runway, not the spinner/longitudinal axis. Just my guess as to why so many get it backwards.

A lot in aviation is taught incorrectly. Like two molecules leaving the leading edge, then because of a rendezvous they have set up at the trailing edge, the one on the top of the wing goes faster. I have heard lift described thusly from more pilots than I care to admit.
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Old 11th Nov 2021, 00:08
  #97 (permalink)  
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A miss is as good as a mile.

Any landing you can walk away from is a good landing.

Any landing that you can fly away from is a great landing.

Nobody panicked even if they didn’t nail the landing.

Once you become a glider, your options are limited, and although all private pilots train for engine out emergencies, it’s hard to get over the instinct that altitude is good.

Once upon a time, a man spun in and landed his single engine plane inverted in a field, with his family onboard, near where I lived because he thought that it was better to press on regardless at the edge of an approaching hurricane rather than sit it out and await better weather the following day.

The plane looked pretty good, aside from being upside down and somewhat crunched. No survivors.
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Old 11th Nov 2021, 00:28
  #98 (permalink)  
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Forward slip vs side slip versus crab landing…

If you land with your landing gear at an angle to the runway, you risk the sideways force collapsing them under the plane.

Always best to land with the plane aligned with the runway.

I have landed with strong steady crosswinds in a forward slip on approach according to the above diagram, which I was told was a crab landing, then switched to a side slip in order to keep the landing wheels aligned directly with the runway, albeit with plenty of rudder which meant that the upwind wheel touched down first, and the other main touching down second when speed/lift dropped sufficiently.

I have also done S turns on approach if I wanted to burn off speed/time/landing distance, but only when there was another plane ahead of me on the runway/approach.

Yes, this pair could have done S turns/weave back and forth to burn off speed/distance, but they may not have had the time/leisure to think it through and it may not have reduced their altitude fast enough.
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Old 11th Nov 2021, 00:40
  #99 (permalink)  
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Also, in terms of “slips” when you are not trying to land…

If you want to go from point A to point B in a crosswind, you will be pointing into the wind in order to maintain heading to your destination, so you will be flying “sideways” relative” to the ground.

It reduces your net speed over the ground, which increases your fuel consumption for a given flight, but otherwise crosswinds are only a major problem when you try to land.

Hat, coat, door…
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Old 11th Nov 2021, 01:28
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Wind correction angle is not a slip.
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