ACS standards for PPL checkride - how close?

AndyMac

AndyMac

Pre-takeoff checklist
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I was up on Friday with my CFI in pretty blowy conditions, and holding altitude was a bear. My question is for you DPEs, so I can properly prepare.

Do you want (require?) full flaps for slow flight? Our Cessna 150 has 40 degrees of flaps, and it makes the plane a slave to the wind. Oh sure, she'll climb with full power, but only barely. I think 30 or even 20 deg would be more appropriate to demo slow flight, but what does this green student pilot know?

Also, how strict is that altitude allowance? If we're getting bumped around, is it (theoretically) enough for me to be reacting to being off altitude, or should I just discontinue for a smoother day?

Thanks in advance!
 
As the 150 can have trouble maintaining altitude with full flaps, simply explain that to the DPE. You can't be asked to do something impossible.

The altitude tolerance is for a "normal day". You are expected to take prompt corrective action for any deviation.
 
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Per the ACS, for slow flight you need to demonstrate control of the airplane at speeds that would result in a stall warning (horn, buffeting, etc.) if you make any increase in angle of attack, reduction of power or increased load factor. You need to be within 100 feet of assigned altitude and 10 degrees of assigned heading. So, can you get the Cessna down to a speed 5-10 knots above stall warning and safely demonstrate control of the aircraft to the ACS?

The main purpose of the slow flight exercise is to simulate proper control of the aircraft at landing speeds when you are low, slow and at greater risk of stalling than in normal cruise. Since you usually have full flaps for landing, this is usually part of the maneuver. But it's not etched in stone as long as you can meet the requirements of the ACS for this maneuver. Sometimes in gusty winds, I don't deploy full flaps.

https://www.aopa.org/news-and-media...light-training-magazine/checkride-slow-flight

https://www.faa.gov/training_testing/testing/acs/media/private_airplane_acs_change_1.pdf (page 41)
 
Do what you think is right and explain what you're doing and why. Explanations can go a long way toward giving you forgiveness for minor issues. I've surely benefited from that practice.
 
Excellent feedback - thanks all. I appreciate the sounds advice, 1st hand experience, links to relevant deep dives and validation that I’m (probably) not crazy for worrying about it. I love this forum.


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AndyMac said:
I was up on Friday with my CFI in pretty blowy conditions, and holding altitude was a bear. My question is for you DPEs, so I can properly prepare.

Do you want (require?) full flaps for slow flight? Our Cessna 150 has 40 degrees of flaps, and it makes the plane a slave to the wind. Oh sure, she'll climb with full power, but only barely. I think 30 or even 20 deg would be more appropriate to demo slow flight, but what does this green student pilot know?

Also, how strict is that altitude allowance? If we're getting bumped around, is it (theoretically) enough for me to be reacting to being off altitude, or should I just discontinue for a smoother day?

Thanks in advance!
Click to expand...

I typically have my students demonstrate slow flight with 20 degrees of flaps for the reasons you mention. Anything more that 20 degrees really doesn't lower the stall speed much and just adds lots of drag requiring you to perform the maneuver at a higher power setting and potentially making it more difficult or impossible to maintain altitude.

The slow flight demonstration teaches and demonstrates a lot of concepts...for example..
When to use power to control Airspeed
When to use power to control Altitude
When to use Pitch to control Airspeed
When to use Pitch to control Altitude.
How little pitch affect altitude at low speeds.
How easily you can change speeds at low speeds with little affect on altitude.
How to divide your attention inside and outside the airplane.
How flaps affect trim and power configuration of the airplane.
left turning tendency at high power, low speed configurations
How the airplane requires more power to fly slower when on the back side of the drag curve.
demonstrates the skill needed to change airspeeds without changing Altitude, like when entering the traffic pattern.
I am sure there is quite a bit more...

The hardest part of slow flight is the transition from cruise to slow flight while maintaining heading and altitude.
for the PPL you should slow down to within 10kts of the stall warning going off.
as far as how strict the dpe will be, generally as long as you promptly recognize the deviation and apply appropriate control inputs you will do fine.
if you stay 120ft below your target altitude for a full minute and never add more power (if possible) then you may have an issue convincing the examiner that you know how to, and have the skills to perform the maneuver.
if you are 120ft low, full power and holding your airspeed you should be fine as you did all you could do to recover from the low altitude situation.

Brian
CFIIG/ASEL
 
brcase said:
I typically have my students demonstrate slow flight with 20 degrees of flaps for the reasons you mention.
Click to expand...

Your post identifies so many of my own thoughts but fleshes then out is really useful and specific ways - thank you.

This above was very helpful validation. I really did feel like we were scraping the backside of the power curve at 30 degrees with full throttle.


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YOU decide your weather minimums for the practical test. If YOU decide to take the flight portion of the test with winds or turbulence shame on you.
 
EdFred said:
Ask the DPE before you even get in the plane as part of the oral.
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@AndyMac -- What Ed is saying here. Once the oral part of the exam is complete, DPE's will explain how the flight will go and any specific items that are a part of their action plan.

If you have any questions about a maneuver, this is a good opportunity to gain clarification.
 
Another hint. Tell the examiner what your going to do. It shows you know the maneuvers and are making the airplane do what you want it to do.

This weekend I flew with a Student and asked him to demonstrate a Turn around a point at which point he starts describing the maneuver to me. For example..We will use that intersection over there we will line up going down wind about this distance from the point and stabilize at 3500ft Msl +/- 100ft. When we are abeam the point we will start are turn....

At this point I realized I didn’t need to see the turn around the point, he had already demonstrated to me during his setup and description that he knew the maneuver exceptionally well and by the time we completed a 1/4 turn of the turn around the point I could tell the rest was just a formality.

Brian
CFIIG/ASEL
 
Clip4 said:
YOU decide your weather minimums for the practical test. If YOU decide to take the flight portion of the test with winds or turbulence shame on you.
Click to expand...

I was unaware that the candidate picks the minimums. This solves a lot of problems.


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brcase said:
Another hint. Tell the examiner what your going to do.
Click to expand...
I too advise my students to do a running narrative of what they are doing.

Helps them to slow down the nervous and anxious brain, and bring in the ears when something is said and the "fact checking" part of their brain goes, "hold on, that's not correct."

@AndyMac ... And if a mistake happens, such as an error in altitude or heading, speak up to acknowledge it happened, possibly why it happened, and what you're doing to fix it.
 
deltaindia said:
Per the ACS, for slow flight you need to demonstrate control of the airplane at speeds that would result in a stall warning (horn, buffeting, etc.) if you make any increase in angle of attack, reduction of power or increased load factor. You need to be within 100 feet of assigned altitude and 10 degrees of assigned heading. So, can you get the Cessna down to a speed 5-10 knots above stall warning and safely demonstrate control of the aircraft to the ACS?

The main purpose of the slow flight exercise is to simulate proper control of the aircraft at landing speeds when you are low, slow and at greater risk of stalling than in normal cruise. Since you usually have full flaps for landing, this is usually part of the maneuver. But it's not etched in stone as long as you can meet the requirements of the ACS for this maneuver. Sometimes in gusty winds, I don't deploy full flaps.

https://www.aopa.org/news-and-media...light-training-magazine/checkride-slow-flight

https://www.faa.gov/training_testing/testing/acs/media/private_airplane_acs_change_1.pdf (page 41)
Click to expand...

Slow flight is more of a skill building exercise than emulating the landing configuration. While there are some similarities, they don't really translate to landing proficiency. Its probably closer to a go-around than a landing.
 
sarangan said:
Slow flight is more of a skill building exercise than emulating the landing configuration. While there are some similarities, they don't really translate to landing proficiency. Its probably closer to a go-around than a landing.
Click to expand...

Skill building for when the plane is slow, like during landing. I don't see anything wrong with what delta said.
 
I know there are a handful of threads around about this stuff (several of which I started) but I wanted to thank you all for your help. Passed my PPL checkride yesterday.


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Thanks everyone!


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