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CPL flight test slow flight (Cessna172)

Posted: Wed Dec 13, 2017 6:45 pm
by TopGun1234
For those of you that have done the CPL flight test in a Cessna172, does the examiner tell you a specific speed to fly it at? I’ve heard one instructor say yes and another say no, just pick any configuration and fly it at 5 KTS above stall.

If the latter is correct, what is the best configuration you chose for slow flight (and to do the 30o turn in slow flight)?
I’ve been doing 45kts with 20o flaps.

Also Vs0 vs Vs1 (C172) : is Vs0 defined as being at full flaps?

Thanks,

Re: CPL flight test slow flight (Cessna172)

Posted: Thu Dec 14, 2017 9:55 am
by lhalliday
The flight test guide says "near-constant stall warning or aerodynamic buffeting".

At one time slow flight was done to a speed specified by the examiner, but that changed years ago. They wanted people to fly airplanes, not chase needles. The examiner will still specify the airplane configuration.

...laura

Re: CPL flight test slow flight (Cessna172)

Posted: Thu Dec 14, 2017 10:10 am
by photofly
There's nothing in any guidance to say that the examiner chooses the configuration, and in fact the candidate chooses the configuration. You are welcome to demonstrate flight at minimum controllable airspeed with any flap setting.

For the stall demonstration and recovery the examiner will specify a scenario, eg. stall in the departure configuration, or landing configuration.

Why do we have two threads on the same topic at the same time?

Re: CPL flight test slow flight (Cessna172)

Posted: Thu Dec 14, 2017 3:28 pm
by TopGun1234
I think because my initial thread needed approval and wasn't showing up as posted so I resubmitted. In any case MOD: please delete.

Re: CPL flight test slow flight (Cessna172)

Posted: Sun Dec 17, 2017 8:39 pm
by DCL415
From the flight test guide:
Ex. 11 Slow Flight
Description:
At an operationally safe altitude that would allow recovery from an inadvertent stall at or above 2,000 feet AGL or the minimum altitude recommended by the manufacturer, whichever is higher, the candidate will establish and manoeuvre the aeroplane in flight near minimum controllable airspeed. The candidate may increase airspeed slightly while turning or in turbulence conditions.
In my understanding of near minimum controllable speed, is that speed near the stall with a margin of safety. And to achieve that speed you need FULL flaps. Any configuration that is not full flaps will not minimum controllable speed.
Thats how I understand it and how I am preparing my commercial flight test

Re: CPL flight test slow flight (Cessna172)

Posted: Sun Dec 17, 2017 10:00 pm
by CpnCrunch
DCL415 wrote: Sun Dec 17, 2017 8:39 pm In my understanding of near minimum controllable speed, is that speed near the stall with a margin of safety. And to achieve that speed you need FULL flaps. Any configuration that is not full flaps will not minimum controllable speed.
Thats how I understand it and how I am preparing my commercial flight test
I chose to do it with 10 degrees of flap, as that seems the most reasonable configuration for flying in slow flight. I take it to mean "minimum controllable speed in a given configuration", and that's what my instructor assumed. From the examiner's guide:

"Flight near minimum controllable airspeed: flight on the backside of the power curve at a
speed at which a stall is imminent if there is a significant increase in angle of attack, load factor or
a reduction in power while maintaining control and altitude with some buffeting or with the stall
warning intermittently activated."

"“Slow Flight” is defined as the range of speeds between the airspeed for maximum endurance and a speed
immediately above the stalling speed with full power. It is also known as flight on the back-side of the
power curve, requiring more power to go slower."

I don't see any practical reason behind trying to get the lowest speed possible...the idea of the exercise is to be able to control the plane just above the stall. Of course the examiner might want you to use 20 or 30 degrees of flap, but I think that would be more to do with showing that you can control the plane in slow flight in the landing configuration.

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 18, 2017 8:17 pm
by DCL415
As it happens a lot of times those guides depend on who is interpreting them. Both examiners that work in our FTU interpret it as full flaps, so we train for that.
It has all to do with landing configuration, because the aircraft that we fly has 3 flap positions, retracted, take off and landing.

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 2:26 am
by rotorspeed
I read on transport canada guide it's 1.2 x' s vso
Which would be 49 knots

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 8:55 am
by rvdungen
Any examiner that demands flaps obviously didn’t read the FTG very well. In examiner workshops it’s embarassingly bad how some examiners run a flight test.

The guide itself makes no mention of required configuration like landing or missed approach only that the stall warning needs to nearly continuous and a stall is prevented. With flaps you must lower the airspeed further to maintain the stall warning which makes the airplane more difficult to control. Not to mention complicating the recovery with flap retractions. If an examiner requests flaps I suppose you could oblige but it’s terrible flight test strategy to do so otherwise.

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 2:55 pm
by PilotDAR
With flaps you must lower the airspeed further to maintain the stall warning which makes the airplane more difficult to control.
I see it differently. I would like to see that the pilot is comfortable controlling the aircraft down to the slowest speed which could be encountered within its normal operating regime. This could include a 1.2Vso full flap approach to a short runway.

"Difficult" to control? No, just must be controlled. If the pilot is reaching the control stops, and thereafter running out of control, then perhaps the exercise is going too far. Otherwise, I like pilots to remind themselves that the control travel limits are there for a reason. It may be that the pilot requires a momentary application of full aileron (with coordinated rudder, I certainly hope!). That's a good exercise. Too many pilots are afraid of applying full control.

The "touch" for flying a single in the slow flight regime becomes a valuable skill, when it could be necessary to manage a twin, flying at Vmca, with one engine shut down.

The ability to fly with smooth control application at 1.2Vso, and thereafter, stall the aircraft nicely, while maintaining roll and yaw control, is a great skill for the flare of many landings. As an examiner, I would want to see this skill demonstrated by every candidate pilot, at all flap settings.

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 4:01 pm
by rotorspeed
I've noticed when I do it in the 172 I do it without the stall warning. When holding the nose up to keep altitude instructor told me to ad power when nose starts to want to drop. I then set the rpm to 1850 with no stall warning, no flaps is this correct? If one of the examiners could reply

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 4:59 pm
by C.W.E.
As an examiner, I would want to see this skill demonstrated by every candidate pilot, at all flap settings.
That way you can better judge the candidates flying skills ability.

To only use one configuration is only part of the test.

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 7:55 pm
by photofly
The problem is, as an examiner, you’re constrained by the flight test guide. Glaringly absent from the slow flight section is a anything about configuration changes.

We can all make up what we’d *like* to see...

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 8:23 pm
by rotorspeed
So do you have to hear the stall warning. No one answered that question

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 8:42 pm
by PilotDAR
So do you have to hear the stall warning
Noting that there are a few types which do not have audible or any stall warning system, but agreed that the 172 does. If the target speed is 1.2Vso, you're right in the speed range for the warning. It is a design requirement that the stall warning may not be sounding at a speed faster than 10MPH/kts faster than the stall speed in that configuration, and the warning must be present at 5MPH/kts faster than the stall. If the stall speed were 50MPH, 1.2Vso would be 60MPH, so the stall warning really should not be sounding, certainly not steadily.
We can all make up what we’d *like* to see...
It's true... I'm only an examiner to the extent that I might recommend a candidate pilot for a float endorsement. I agree that slow flight is not an element of the standards for a float endorsement. I'd be checking the skill was present with the candidate at some point during the training and assessment. Call me old fashioned...

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 8:52 pm
by photofly
The Pilot Examiner manual has this to say, on the subject of warning horns:
Flight near minimum controllable airspeed: flight on the backside of the power curve at a speed at which a stall is imminent if there is a significant increase in angle of attack, load factor or a reduction in power while maintaining control and altitude with some buffeting or with the stall warning intermittently activated...
and
The objective of flight near minimum controllable airspeed, at a safe altitude, is to assess the candidate’s competency to sense the decrease in wing performance resulting from operations at high angles of attack, identify a condition that could lead to an imminent stall and to control the aeroplane while avoiding a stall. Flight near minimum controllable airspeed with the stall warning intermittently activated or with buffeting while maintaining control and altitude presents the best situation for identifying slow flight...

That should answer the question about what the examiner hopes to see (or hear) during the exercise.

it’s a good document. Everyone interested in flight tests should read it.
https://www.tc.gc.ca/media/documents/ca ... H_2017.pdf

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Dec 25, 2017 9:11 pm
by rotorspeed
Thanks for the reply. My instructor always has me enter slow flight in the clean configuration, then asks after to add flaps I wonder if there is a Vs speed.miltiple such as the 1.2 x' s Vso I set the rpm to 1850 clean and say I'm in slow flight. I don't hear stall warning. I hope this will be ok with examiner.another thing someone mentioned earlier that when you add flaps you slow down. I have been taught with flaps nose down and add power to compensate for drag

Re: CPL flight test slow flight (Cessna172)

Posted: Tue Dec 26, 2017 12:40 am
by rvdungen
I think there is some confusion between instructing and examining. Absolutely teach your students to be the best pilot they can be and put them through the entire slow flight speed range in all available configurations. Do the same with stalls. When examining I’m looking for no critical errors or deviations that would make the aim of the exercise impossible to have been met. That is what Transport Canada has set for the criteria to meet the skill requirement for the license. Just like the old joke - what do you call the guy who finishes last in medical school? He finished after all.

Also be careful to not hose these students under the false pretences of making safer pilots either. There comes a point where more training benefits the instructor more than the student.

Stall warning does not need to be continuous during slow flight but it should be intermittent to on rather than intermittent to off considering turbulence. That’s right in the standard guide and if the instructor doesn’t know that, show them.

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Jan 01, 2018 8:52 am
by Oldguystrtn2fly
In reading this, I have seen reference to the flight test guide. Is there a flight training guide? Is there a set of rules that instructors are required to follow when training a new pilot?

Re: CPL flight test slow flight (Cessna172)

Posted: Mon Jan 01, 2018 11:28 am
by Big Pistons Forever
Oldguystrtn2fly wrote: Mon Jan 01, 2018 8:52 am In reading this, I have seen reference to the flight test guide. Is there a flight training guide? Is there a set of rules that instructors are required to follow when training a new pilot?
CAR 405.14

Flight Training Program Requirements

405.14 Flight training that is conducted using an aeroplane or helicopter shall be conducted in accordance with the applicable flight instructor guide and flight training manual or equivalent document and the applicable training manual on human factors.