Forward Slips Part Two

[TwinTails]

That buffeting your feeling is as has been stated is a disruption of airflow over the horozontal stab. From what I've been told this can turn into a tail stall in the right situation. Although I've never experienced this personally. I've slipped many a cessna with full flaps and if I feel it start to buffet I usually just ease off a little.

I deffenitly don't think a slip is an "emergency manuver" I grew up around, and learned in, tailwheel and no flap airplanes though and was tought the slip from day one. Heck if one knows what he's doing you can put any airplane in an uncoordinated path to lose a little altitude or airspeed.

 

[tothelineplz]

The whole reason a pilot uses wing flaps is to "increase the angle of descent without a resulting increase in airspeed" and I maintain that the forward slip accomplishes the same objective. Why, then, would a pilot resort to a forward slip if he still has additional flaps to available? To me, that's foolish. I don't disagree that this maneuver should be introduced prior to solo, rather, what I contend is that IP's should teach airmanship along with it, therefore teaching a student that they should never have to use it if their planning is correct. A 172 fueled halfway provides enough endurance for quite a few go arounds after a 1.0 to 1.5 solo practice mission. Using the Forward Slip to "make up" for lack of planning in the pattern or on approach to landing is bad technique and should not be used as a crutch nearly as often as it is.

Regarding Bluestreak's statement that some of us need to read Mr. Schiff's "The Proficient Pilot" is right on target. Couldn't agree more. But, then again, the proficient pilot would never place himself in a position of having to utilize this maneuver in the first place.

How many instructors out there teach their students to "carry a little extra airspeed during a forward slip? How silly is that? Go faster so you can slow down? Come on folks. The ASI is subject to errors during this maneuver.

Finally (for this post)...If a pilot makes an aeronautical decision to fly an airplane at the limit of the performance envelope (full forward slip) to make that large of a correction to the glide path on final, it's an admission that he screwed up and is hell bent for leather to salvage a bad approach and make a good landing. That makes absolutely no sense from an ADM standpoint. So far I've heard zero justification for use of this maneuver on any of these posts. Can someone please do this?

That is all...

 

[bigD]

totheline - I'm not sure that anyone here is advocating the use of forward slips as a justification for making a sloppy approach. One poster made a good point that if going into a small unfamiliar airport at night when you know there are obstacles at the end of the runway, it might be prudent to intentionally fly a high approach and steeper decent. Or in an emergency situation when you have to get the plane down ASAP or dead stick it into a tight spot.

Speaking for myself - I just enjoy doing them. That's all there is to it. I love to fly, and I enjoy excercising all the tools available to me. To me, forward slips are some of the more enjoyable things to do. Why do I still enjoy practicing stalls or spins? Certainly I don't plan on flying the plane so sloppily that I'm ever going to inadvertantly stall? Or why did I get my taildragger endorsement? I doubt I'll ever have to fly one professionally, so why spend the time and money getting one if I can stick to trikes and reduce the possibility of ground looping? Simply - because I can. It makes my flying experience more enjoyable.

 

[Buffettpilot]

BigD has a good point. Practicing manuvers such as spins/stalls and slips are a good way of keeping airmanship skills. I do em to keep abreast (ha, ha, I found a way to put breast in this post) just in case.....god forbid..... I find I'm in a situation that I need to reach into that 'bag o'tricks to save my own A$$.

I try not to slip a cessna with full flaps (reason being from posts above) but flying pipers around, its always fun to have a forward slip to land.

I just did my CFI a few weeks ago and the DE loved it when I was high on the 180 power-off precision landing. I turned base early to make SURE I had the field, full flaps, no power, still high. Just slip it in and stick the landing. He just looked at me and said "got the slip out of the way".

 

[TXCAP4228]

Lack of planing?

from totheline:

Using the Forward Slip to "make up" for lack of planning in the pattern or on approach to landing is bad technique and should not be used as a crutch nearly as often as it is.

Its not a lack of planning, and I absolutely do not consider forward slips to be an emergency procedure.

Interesting to see this thread this morning. Yesterday, approach handed me off to tower and told me to maintain 3000 until midfield on downwind (elevation is 640). I think approach planned for me to be number 2 or 3. Tower, however, had different ideas. He asked if I could make a short approach (I was in a C172). Sure I could. Why not? Flaps and forward slip.

I'm profficient, it was vmc, I know the airplane well. Yes, I can do that. I'll add that there certainly was no lack of planning.

This is a proficiency maneuver that examiners look for. Why shouldn't I practice it? Why shouldn't I use it? Not all of us have the 10,000 foot runways available at military bases.

The whole reason a pilot uses wing flaps is to "increase the angle of descent without a resulting increase in airspeed" and I maintain that the forward slip accomplishes the same objective. Why, then, would a pilot resort to a forward slip if he still has additional flaps to available?

This is a legitimate question. With a forward slip I can descend 1500 or 2000 feet per minute - with flaps and no slip, maybe 700-800. When I have to get down, I use a forward slip.

Regarding the posts you made about accidents. The fact that the pilots were attempting a forward slip does not make slipping undesirable or inappropriate. I'll bet the real story in all of these cases was something more along the lines of a pilot who was behind the airplane anyway and was trying to salvage a bad situation. The accident resulted from lots of things and the slip is just one of them. Hell, lots of pilots have accidents on landing but that doesn't mean we should stop landing.

I think you're making a good case for pilots needing to be more proficient, but I would argue that being able to execute a good forward slip is part of being proficient.

Try flying a light airplane into a class B airport sometime without slipping to get out of altitude. Maybe you'll have a different perspective.

 

[tothelineplz]

Making a short approach does not mean it is necessary to use this maneuver. Try unloading the airplane (which happens to be 27 degrees in most light GA metal) and you will find you can increase your sink rate within reason. A sink rate of greater than 1000 feet per minute is ill-advised when below 500 feet AGL.

I will also add that "airmanship" is an entirely different, however interrelated, concept than "flying skills" (usually called stick and rudder). Just as "proficiency" is a different concept than "CRM".

I was amused by the comment by one poster who claimed the DE "loved it" when he slipped on the business end of a 180 power off approach...the sarcasm and dismay in the DE's voice must've been obvious. Wish I could've ridden along on that ride!

Dude...he/she cut you a break because you were fairly well prepared and did not "consistently exceed tolerances". Finding yourself in a position where you had to use the FS falls outside the tolerances for satisfactory completion of that task under the appropriate objective in the PTS. At least you did something to demonstrate positive command of the airplane instead of saying "what do I do now?" as I've heard from examinees before.

Congratulations on earning your CFI, now I challenge you to continue learning and someday consider yourself an expert.

That is all...

 

[ShawnC]

Toline,

If you never practice it because it's a emergency procedure how are you supposed to have it in your bag of tricks? Frankly slips should be practiced regularly you need to be as good slipping as you are on an engine out apporach. Heck the Air Canada incident (Gimili Glider) might have turned out diffrent if he wasn't good at slipping.

 

[tothelineplz]

I'm not advocating not practicing this maneuver. Proficiency in this is important, just not below 500 and preferably 1000 feet AGL. Just don't think it's a good idea to be fully cross controlled below a grand...but that's just my opinion. Airplanes were not meant to fly that way. Besides, it is very hard on the aircraft structurally.

That is all...

Oh...in my next post, I will provide the PT Standards for Normal Takeoffs and Landings.

 

[tothelineplz]

FAA-S-8081-14 1-14
G. TASK: FORWARD SLIP TO A LANDING
REFERENCES: AC 61-21; Pilot's Operating Handbook, FAAApproved
Airplane Flight Manual.
Objective. To determine that the applicant:
1. Exhibits knowledge of the elements related to a forward slip
to a landing.
2. Considers the wind conditions, landing surface and
obstructions, and selects the most suitable touchdown point.
3. Establishes the slipping attitude at the point from which a
landing can be made using the recommended approach and
landing configuration and airspeed; adjusts pitch attitude and
power as required.
4. Maintains a ground track aligned with the runway centerline
and an airspeed which results in minimum float during the
roundout.
5. Makes smooth, timely, and correct control application during
the recovery from the slip, the roundout, and the touchdown.
6. Touches down smoothly at the approximate stalling speed, at
or within 400 feet (120 meters) beyond a specified point, with
no side drift, and with the airplane's longitudinal axis aligned
with and over the runway centerline.
7. Maintains crosswind correction and directional control
throughout the approach and landing.
8. Completes the appropriate checklist.

I don't see a provision for holding on for 8 seconds, cowboys...

Number 3 is particularly perplexing.

Anyway...let's move on to another topic, as I think we've beat this horse to death.

Very interesting hearing from everyone on this.

One final comment...as far as forward slipping over trees at night goes...more power (no pun intended) to you. If I can't see the trees, I'm not going to descend at an excessive rate at a point where I "think" I will clear them. But that's just me. Feel free to fly your airplane as you see fit.

As far as that goes, Stall/Spin Awareness is under-emphasized during private pilot training and the combination of this fact and lack of understanding of the elements of the FS is bad juju. Teach it carefully and if you don't fully understand the dynamics of this maneuver, seek out someone who does because passing along misinformation to your students is reckless and negligent. Rarely in my years in this business have I found a pilot who even knows the difference between a side and forward slip. Now that's scary!

 

[ShawnC]

It may seem preplexing to you but to me reads:

The pilot must be able to demostrate the use of power, pitch and forward slip for altitude and speed managment in landing configuration for landing.

For DJS airport, he said you mantian your altitude until you get past the trees then drop out of the sky to you can land on the numbers.

To the line I have to be very frank with you, have you ever truely flown engine out? I haven't in a powerplane, but I have flown sailplanes, that truely teaches you energy managment that few power pilots know. Frankly I find that quite a few heavy iron pilots lose the abillity to truely manage power, kentic and potentiol, by saying increase the power, you seem to think that it will always be there. Times have shown that it is not always true, as such you should plan an apporach that you could lose your engine at anytime, you should be able to make the numbers if your engine went out from downwind to final, that means extra altitude.