Forward Slips with Flaps on a Practical Test

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Revtach

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Revtach
Hello,

I am going to be signing off a couple students for their private pilot practical tests. One area of concern I have is that I've taught them that slipping with full flaps extended in our C172 is perfectly fine even though our POH has the "Should be Avoided" disclaimer. On their practical test, I worry that the examiner may see it differently and I don't want to set them up for a disapproval.

I wanted to ask, in your experiences, did you all perform your forward slip with flaps extended on your practical test? Are examiners generally ok with it despite the advisory in the POH?

Just to be safe, I'm thinking of instructing them to perform the forward slip maneuver with the flaps up on their checkride but not sure if I'm overthinking it.

Thank you.
 
why not just clarify that while you have thought them that it's not an unforgiveable demon, and something they can keep in their back pocket bag of tricks
that they should follow the regs and the POH when practical..... in other words, follow the POH unless they can't. On the test, follow the guidance of the POH.

In my ancient experience which is very fuzzy in my memory now, generically speaking this is the sort of thing that might come up in the oral. As long as the student understands the POH guidance and can explain why it's there and also explain when and why they might need to ignore that guidance, then isn't that just going to present to the examer as mastery of the topic?
 
Brad W said:
As long as the student understands the POH guidance and can explain why it's there and also explain when and why they might need to ignore that guidance, then isn't that just going to present to the examer as mastery of the topic?
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:yeahthat:
Two keys for me:

1. When you send your student to an Examiner, part of your job is to learn that's Examiner's personal preferences. If new, that may mean speaking with other instructors and pilots who have done checkrides with them. It might also mean calling the DPE yourself. They are people, not monsters. If I were afraid to do that, I wouldn't use the DPE.

2. Exactly what @Brad W said.
 
The reason that is in the POH is that slips with 30 or 40 degrees of flaps can blanket the horizontal stabilizer with turbulent air, causing an uncontrolled nose drop. Most of my hours are in Cessna's, 182 and smaller.

On short final, that has killed pilots, many years ago, according to my instructor, in 1971.

Sufficiently high, the slip is just terminated, the attitude recovers, you are fine, even if this now requires a go around due to too high to land.

I have experienced this event, at much altitude, transitioning from an IFR flight to VFR below a cloud layer with a suitable hole and ATC separation . Full deflection slip, 40 degrees of flap, and the nose oscillating up and down.

Your students should know this risk, and be ready for the results.
 
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I did a forward slip on my PVT checkride with full flaps in a C172. The DPE did freak out...but it's bananas. So many CFI's have approved of me doing it. They do it. We all do it. If we need to lose altitude what's the big freaking deal? On my Comm checkride I did it, and a different DPE said good job. I think people get nervous about it, but as long as you are doing it right what's the problem?
 
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Princesspilot206 said:
I did a forward slip on my PVT checkride with full flaps in a C172. The DPE did freak out...but it's bananas. So many CFI's have approved of me doing it. They do it. We all do it. If we need to loose altitude what's the big freaking deal? On my Comm checkride I did it, and a different DPE said good job. I think people get nervous about it, but as long as you are doing it right what's the problem?
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Certain models of 172s would go into an oscillation while slipping with full flaps. But some CFI's and DPE's then think that means ALL 172s shouldn't be slipped with full flaps.
 
Revtach said:
Hello,

I am going to be signing off a couple students for their private pilot practical tests. One area of concern I have is that I've taught them that slipping with full flaps extended in our C172 is perfectly fine even though our POH has the "Should be Avoided" disclaimer. On their practical test, I worry that the examiner may see it differently and I don't want to set them up for a disapproval.

I wanted to ask, in your experiences, did you all perform your forward slip with flaps extended on your practical test? Are examiners generally ok with it despite the advisory in the POH?

Just to be safe, I'm thinking of instructing them to perform the forward slip maneuver with the flaps up on their checkride but not sure if I'm overthinking it.

Thank you.
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Section 9 of the Airplane Flying Handbook
Page 9-13 says to consult the AFM on flap use.
Page 9-15 says the procedure in normally demonstrated flaps retracted.

Private Pilot ACS page 33. For a forward slip to landing under risk managememt, the applicant is required to identify, assess and mitigate risks to include fuel flowage, tail stalls with flaps, and airspeed control.

How is the applicant mitigating risk by performing a maneuver in a configuration the AFM says to avoid?
 
I’d consider the oral and practical just an extension of the written: there is only one correct answer on the test, particularly when it comes to POH guidance. Otherwise, you’re playing roulette with a lot of time and money wasted if the DPE has strong thoughts on the matter. If I were the student, I’d expect you to cough up cash if you guess wrong.

Stick to the facts. Answer the questions asked and don’t go embroidering around trying to be clever. Slips with full flaps are “not recommended, according to the POH.” If the DPE pursues the matter further or asks for a demonstration of full flaps in a slip, that’s different. But the pilot should always add the disclaimer, “that’s not recommended by the POH.”

The point here is the same as the written, pass the test by recognizing the correct answer.
 
geezer said:
The reason that is in the POH is that slips with 30 or 40 degrees of flaps can blanket the horizontal stabilizer with turbulent air, causing an uncontrolled nose drop. Most of my hours are in Cessna's, 182 and smaller.

On short final, that has killed pilots, many years ago, according to my instructor, in 1971.

Sufficiently high, the slip is just terminated, the attitude recovers, you are fine, even if this now requires a go around due to too high to land.

I have experienced this event, at much altitude, transitioning from an IFR flight to VFR below a cloud layer with a suitable hole and ATC separation . Full deflection slip, 40 degrees of flap, and the nose oscillating up and down.

Your students should know this risk, and be ready for the results.
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On Friday, my DPE set me up for an emergency landing where the best choice was to use a forward slip with flaps to drop to the only good landing site. This was in a Warrior.

Agree with the above, though - find out what this DPE likes.
 
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I've always forward slipped my Warrior with full flaps.

My Warrior's POH only mentions slips once:
Power off landings:
...When the field can easily be reached, slow to 63 KIAS for the shortest landing. Excess altitude may be lost by widening your pattern, using flaps or slipping, or a combination of these.
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Is blanketing the horizontal stabilizer with turbulent air, causing an uncontrolled nose drop not an issue in Cherokees?

The only admonition about forward slips in my POH is this:
Prolonged slips or skids which result in excess of 2000 ft. of altitude loss, or other radical or extreme maneuvers which could cause uncovering of the fuel outlet must be avoided as fuel flow interruption may occur when tank being used is not full.
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What fuel outlet is being referenced here? Is this a reference to the fuel tank pick up tube?
 
At pattern altitude, a sudden nose drop, and loss of 20 feet of altitude, is a non event, but on short final, 20 ft AGL, it is a crash. I never slipped with full flaps below 50 feet above all fixed objects between me and the runway.

Up higher, I probably have slipped full flaps an accumulated 2 miles or more. My two young sons liked the motion! The wife, not so much.
 
Domenick said:
I've always forward slipped my Warrior with full flaps.

My Warrior's POH only mentions slips once:


Is blanketing the horizontal stabilizer with turbulent air, causing an uncontrolled nose drop not an issue in Cherokees?

The only admonition about forward slips in my POH is this:

What fuel outlet is being referenced here? Is this a reference to the fuel tank pick up tube?
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Yea, sloshing fuel away from the fuel pickup tube. & we’re discussing a quirk of the 172 design.
 
Domenick, that is the fuel lines leaving the tanks. Since Pipers do not have a Both, that is easy to do. At altitude, my Commercial instructor had me demonstrate that, and the proper recovery.
 
Every plane is different.

Early Musketeers had a warning about prolonged slips because at low fuel levels the pickup could become unported in a slip. If you slipped long enough to run the carb float bowl dry the engine would quit, which can be a little disconcerting when you’re at 100’AGL slipping to a landing. Had nothing to do with flaps or blanking the tail. I seem to recall that some Mooneys have a similar issue.

Know your airplane.
 
Not a flight instructor, but it seems to me that preparing your students to argue with the DPE on the accuracy of the POH is setting them up for a failure. I can't see a scenario when a DPE can fail a student for following the POH to the letter.
 
EdFred said:
Certain models of 172s would go into an oscillation while slipping with full flaps. But some CFI's and DPE's then think that means ALL 172s shouldn't be slipped with full flaps.
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If the POH says you should n0t, then you should not. Period.
My F model would bob uncomfortably if you slipped with the barn doors fully open; I only slipped to drop it in under windy conditions, when I didn't want flaps over the runway.
 
See what I mean? You still don’t know YOUR DPE’s thoughts on the subject after all replies.

The only way to know for sure is to ask.
 
rhkennerly said:
I’d consider the oral and practical just an extension of the written: there is only one correct answer on the test, particularly when it comes to POH guidance. Otherwise, you’re playing roulette with a lot of time and money wasted if the DPE has strong thoughts on the matter. If I were the student, I’d expect you to cough up cash if you guess wrong.

Stick to the facts. Answer the questions asked and don’t go embroidering around trying to be clever. Slips with full flaps are “not recommended, according to the POH.” If the DPE pursues the matter further or asks for a demonstration of full flaps in a slip, that’s different. But the pilot should always add the disclaimer, “that’s not recommended by the POH.”

The point here is the same as the written, pass the test by recognizing the correct answer.
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I disagree. Pass the test by operating as you would in real life within the scope of the ACS.
 
I'm 172s with 40* flaps, some POHs say slips with flaps fully extended are prohibited. That's different from "not recommended" in planes with 30* flaps.

But still, if I was going to do something on a check ride that is not recommended by the aircraft manufacturer, I'd be prepared with a good explanation for the examiner--and I wouldn't wait to give it after he calls me on it--and I'd also be prepared to explain why my "not reconnect" method was superior to a recommended method, like not extending full flaps of I'm planning to slip.... Demonstrate good ADM.

Since these are private candidates, I'd lean towards using an approved method, but I agree that calling the DPE and discussing it is your best strategy as an instructor.
 
Domenick said:
I've always forward slipped my Warrior with full flaps.

My Warrior's POH only mentions slips once:


Is blanketing the horizontal stabilizer with turbulent air, causing an uncontrolled nose drop not an issue in Cherokees?

The only admonition about forward slips in my POH is this:

What fuel outlet is being referenced here? Is this a reference to the fuel tank pick up tube?
Click to expand...
There are a number of aircraft which have cautions about slipping with flaps for different reasons. In some, like your Cherokee, it's about prolonged slips with flaps, often having to do with fuel. Cirrus, for example, cautions against uncoordinated flight when the tanks are less than 1/4 full. So do a lot of aircraft, including Cessnas.

The Cessna "special" one, as mentioned, is because of potential blanketing the horizontal stabilizer, not a concern for other aircraft unless mentioned in the manual.

1726422307132.png



Part of the Cessna "slips with flaps" mystique is that it actually was a prohibition at some point.

1726422537606.png

It keeps getting liberalized. Even the "to be avoided" and "not recommended" language went away in later models

1726423213084.png
 
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Revtach said:
Hello,

I am going to be signing off a couple students for their private pilot practical tests. One area of concern I have is that I've taught them that slipping with full flaps extended in our C172 is perfectly fine even though our POH has the "Should be Avoided" disclaimer. On their practical test, I worry that the examiner may see it differently and I don't want to set them up for a disapproval.

I wanted to ask, in your experiences, did you all perform your forward slip with flaps extended on your practical test? Are examiners generally ok with it despite the advisory in the POH?

Just to be safe, I'm thinking of instructing them to perform the forward slip maneuver with the flaps up on their checkride but not sure if I'm overthinking it.

Thank you.
Click to expand...
You've received lots of good responses. It appears that the informed consensus is that, under the circumstances, you would indeed be setting your students up for a disapproval.

Were I the DPE and our applicant attempted to operate the aircraft in a manner specifically prohibited or (in this case) cautioned against in the AFM or POH, and if our applicant explained that his CFI had taught him that it was "perfectly fine" to do so, then, in the words of Ricky Ricardo, "Revtach, you got some 'splaining to dooo." In that conversation, I would ask you to explain just how a procedure that the POH specifically states "should be avoided" somehow became, in your opinion, "perfectly fine," and why you think it is apporpriate to teach a student that it's okay to just ignore the POH/AFM whenever they think that they somehow know better than the people who designed, tested, and manufactured the plane, and who were directly involved in numerous investigations of accidents and incidents involving their product.

But I'm no DPE, I'm just some guy on the Internet and if you can enlighten me, I would be grateful.
 
Kenny Phillips said:
If the POH says you should n0t, then you should not. Period.
My F model would bob uncomfortably if you slipped with the barn doors fully open; I only slipped to drop it in under windy conditions, when I didn't want flaps over the runway.
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Where did I say any of what you think I said.

A D model POH doesn't have the exact same verbiage as an S. But someonr, somewhere read about something in a D and think it applies to D models as well. Which was my point. No clue why you went off the rails with the response.
 
It's been an awful long time since I had my private pilot checkride but I honestly don't remember needing to or being asked to do a slip since the aircraft was equipped with 40 degree flaps. In my old age I've become very comfortable doing very short approaches using full flaps and an aggressive slip for short, obstructed fields, but I would be very cautious encouraging a new pilot to max perform an airplane on landing without some experience behind him. As for what a DPE would do on today's private pilot checkride, since it's not a required maneuver to demonstrate, if it was my checkride, I'd say I avoid uncoordinated flight on final.
 
Kenny Phillips said:
If the POH says you should n0t, then you should not. Period.
My F model would bob uncomfortably if you slipped with the barn doors fully open; I only slipped to drop it in under windy conditions, when I didn't want flaps over the runway.
Click to expand...

Eh, I dunno. If the situation was an emergency landing, even a demonstration of one on a checkride, then I’d slip with full flaps if that’s what it takes for a successful outcome. Shouldn’t doesn’t mean don’t.

After missing the intended landing spot, “Sorry Mr Applicant, gonna have to disapprove. You should have slipped and you would have made it”

The OP clearly stated the airplane in question says, “should be avoided”, so most of you are telling him something he already knows.

He needs to call and ask.
 
MauleSkinner said:
I disagree. Pass the test by operating as you would in real life within the scope of the ACS.
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The point is to pass the checkride. Adherence to the POH is just another mental checkbox for the DPE. you’ll not be failed for sticking to the poh. You might be failed for deviating from the poh. It is an expensive & time consuming gamble if you are wrong.
 
Weigh it all against the cost of the checkride & the fact that your student might not get back on the DPEs schedule for months. Play it safe & down the middle with these kinds of questions. Also keep in mind that if the DPE takes strong exception to something like this, it will color his view of ever other student you send him. It might even earn you a proficiency checkride with the FSDO on his recommendation. A candidate can never go wrong with, “the POH recommends…”
 
rhkennerly said:
The point is to pass the checkride. Adherence to the POH is just another mental checkbox for the DPE. you’ll not be failed for sticking to the poh. You might be failed for deviating from the poh. It is an expensive & time consuming gamble if you are wrong.
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Again, I disagree. The point is to gain flying privileges, and the best way to do that is to learn to fly, not learn the test.
 
MauleSkinner said:
I disagree. Pass the test by operating as you would in real life within the scope of the ACS.
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I agree there can be more than one correct answer on a practical test, but the test isn’t as you would operate in the real life.
 
MauleSkinner said:
Again, I disagree. The point is to gain flying privileges, and the best way to do that is to learn to fly, not learn the test.
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In reality, a large majority of schools and CFIs are training students just to pass the checkride.
 
I was going to say using a slip is not on the private checkride but then I might have used the slip on mine, I don’t remember right now.

If you need to land and you are too high, a slip is needed to get where you need to go. So it is something to learn, but follow the POH and verbalize any limitations during your checkride. I don’t think DPE’s know the POH inside out either but it depends on the particular person and POH.

The other day I did a slip to land while in the pattern for fun. But the airplane did have some flutter? or bumps that caused my attention. I thought is that LLWS or did the engine cough at me. I was also wearing a different pair of headsets (sounds different). I think part of learning you should learn to fly with and without headset, with and without noise cancelling on your headset, both day and night and landing without a landing light. The different scenarios will really hit you especially when you have a lot of experience, it will say hey something is different and it might cause you to overthink nothing.
 
Never argue with a policeman, or a DPE. Those are ways to have a bad day.

Even if you are sure that you are right, and the POH is wrong.

I documented that I had burned enough gas before landing to get us 5 pounds under max gross.

I could have explained that by rotating a few knots faster, we would have plenty of lift, and the excess would burn of in the first hour of the check ride.

He might have agreed.
He might have sent me out to fly solo until we were POH legal.
He also might have sent me home, with an invitation to schedule another check ride when I understood that the POH numbers are important, with a new fee for the new ride.

If your instructor wants to make a point that he knows more than Cessna, he should go to the DPE and establish the point, with suitable documented flights, forward CG, aft CG, fully loaded, and near empty. Sea level, and 5,000 feet.

That is what Cessna did, and the POH describes the outcome.
 
TommyG said:
In reality, a large majority of schools and CFIs are training students just to pass the checkride.
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With the conversion to the ACS private pilot in 2016, the failure rate has increased to 25.5% over the last 6 years,

The NTSB considers CFIs with less than a 80% pass rate as ineffective and wants the FAA to take action against these CFIs.
 
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mandm said:
I was going to say using a slip is not on the private checkride but then I might have used the slip on mine, I don’t remember right now.
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Witmo said:
. As for what a DPE would do on today's private pilot checkride, since it's not a required maneuver to demonstrate, if it was my checkride, I'd say I avoid uncoordinated flight on final.
Click to expand...

It is part of the ACS for PPL: PA.IV.M.S7
 
Witmo said:
It's been an awful long time since I had my private pilot checkride but I honestly don't remember needing to or being asked to do a slip since the aircraft was equipped with 40 degree flaps. In my old age I've become very comfortable doing very short approaches using full flaps and an aggressive slip for short, obstructed fields, but I would be very cautious encouraging a new pilot to max perform an airplane on landing without some experience behind him. As for what a DPE would do on today's private pilot checkride, since it's not a required maneuver to demonstrate, if it was my checkride, I'd say I avoid uncoordinated flight on final.
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So I guess you’d intentionally fail if there were a crosswind landing involved?

And refuse to perform one of the tasks while demonstrating you didn’t read the ACS?

1726482829498.png
 
Clip4 said:
The NTSB considers CFIs with less than a 80% pass rate as ineffective and wants the FAA to take action against these CFIs.
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Is this documented publicly? This would seem to indicate that they want the pass/fail criteria to be altered to a statistical curve, rather than being firm performance standards.

Put another way, it would mean that the DPEs have to apply an altered set of criteria to force a specific pass/fail distribution, and that criteria set must almost certainly deviate from the requirements in the ACS. How does this make sense?
 
Clip4 said:
I agree there can be more than one correct answer on a practical test, but the test isn’t as you would operate in the real life.
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True, but while a safe and proficient pilot can pass a checkride, passing a checkride doesn’t make one a safe and proficient pilot.
 
StraightnLevel said:
Is this documented publicly? This would seem to indicate that they want the pass/fail criteria to be altered to a statistical curve, rather than being firm performance standards.

Put another way, it would mean that the DPEs have to apply an altered set of criteria to force a specific pass/fail distribution, and that criteria set must almost certainly deviate from the requirements in the ACS. How does this make sense?
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The NTSB has no recommendation concerning DPE failure rates.

 
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