Slip With Flaps

[Charles K]

Would you want to fly in a plane where the airframe cannot take the stress of a slip? I would hardly believe there is an authoritative source stating the airframe could not take that stress. Our DA40s are TOUGH!

[dant]

During training I had plenty of less than ideal approaches that required some... extensive... slips to land, and I never had a hint of engine hiccup. I guess it's possible that I coincidentally always had the right tank selected... but I doubt it.

[Rich]

Some comments:

"Stress" of slips is a problem? Give me a break. I could start a rant about "mistakes by CFIs". But I won't.

As David posted, the fuel issue is not mentioned with the DA40-180. I've slipped plenty without a hiccup. In reality, the forward slip is only maintained for a matter of maybe 10 seconds. During which the engine consumes less than an ounce of fuel (assuming at idle).

At a 5 degree angle of bank in a slip, the "lower" fuel chambers are basically level due to wing dihedral.

[dant]

At a 5 degree angle of bank in a slip

Working off of memory as I rarely need to slip these days but I feel like when I'm slipping things are wayyy more tilted than that.

I think the last time I did was in Crescent City where I did a short approach power off 180 to make sure I was clear before an incoming instrument approach fedex plane and my passenger commented "I didn't know you could land these like a helicopter"

[Rich]

At a 5 degree angle of bank in a slip

Working off of memory as I rarely need to slip these days but I feel like when I'm slipping things are wayyy more tilted than that.

Likely true. I was referencing the notation in the NG manual. In principal I could see unporting of fuel from the lower wing if it's low on fuel. Like you I haven't paid attention but I suspect while it can be slipped beyond 5 degree bank it may be less than one thinks.

For a really steep descent try a C-150 in a full slip with full (40 degrees) flaps. The flaps are flapping and the rear fuselage oil-canning

Then there is the ercoupe-no flaps and no rudder pedals. (Even those that have had them added have very little rudder authority.)

To use the behind-the-curve technique one must be comfortable flying considerably below the speeds recommended in the DA40 POH. In reasonably calm air it is my normal practice to be a bit below those speeds and still wind up with unnecessary float. So there is more margin available.

[DaveS1900]

I teach primary students in the DA40. We side-slip and forward-slip. Both are required maneuvers for the Private Pilot student. I have done numerous side-slips on final due to wind.
Dave S.
Woodstock OH

[Colin]

There's a TBM accident where the pilot was unaware that the plane was flying along in a slip for hours. It ran a tank dry and he crashed. I think it was an improper setting of rudder trim or something like that which caused the autopilot to compensate so he was flying with a wing a little up.

[erchegyia]

couldn't a slip with full flaps negatively affect the airflow over the control surfaces resulting in the risk of unintended spin?

[dant]

I think it was an improper setting of rudder trim or something like that

The T182T I have a handful of hours in flies with the right wing slightly high and runs that tank down faster. The rudder trim did not perform as expected (and indeed I stopped flying it once I noted the discrepancy).

[Soareyes]

"couldn't a slip with full flaps negatively affect the airflow over the control surfaces resulting in the risk of unintended spin?"

In some Cessnas there is a caution about slipping with full flaps, not because of spinning but because of problems with pitch control. There is no similar worry in the DA40.

Slips are safe, useful and fun. You are slipping every time you land with a crosswind which, to some degree, is almost every landing. They should be part of every pilot's repertoire.

Spins result from a combination of stall and skid. It's hard (but not impossible) to stall with the nose pointed down and a slip is not a skid.