Need Pro's/Con's of 'Flapped' landings

[poadeleted20]

OTOH, the common refrain I hear when people talk about checklists is that the manufacturer checklists are all "written by lawyers" whose =only= concern is liability. Given that, the Cessna advice to use flaps appropriate to the runway =must= be the safest way to go, right?

I think a review of my post above will show that I didn't stress the Cessna POH, which, especially for the 172, is written primarily to prevent stalls on final, not to make good landings. Y'all know that I have a particular issue with that one. However, that does not change my support of the FAA's contention that a stabilized approach at 1.3 Vs0 with all the flaps you've got is the best "standard" approach configuration (and one supported by nearly all other manufacturers), even if Cessna's lawyers would have you fly down final at nearly 1.5 Vs and are afraid to give you any clear guidance on the best flap setting for normal use.

 

[Pilawt]

[...] FAA guidelines such as the "Landings" pamphlets (which recommend stabilized approaches and as much flap as you've got for landings unless there's a real good reason to do it another way).

The actual language in FAA pamphlet P 8740-48 ("On Landings, Part I") is:

"One final point: full flaps should be used for all normal landings unless the manufacturer suggests otherwise."
​

WRT the C-150 and C-172, among others, Cessna says,

"Normal landings are made power off with any flap setting."

--and--

"When landing in a strong crosswind, use the minimum flap setting required for the field length."
​

(emphases added)

So I am compliant with the published FAA guideline if I land a C-150 with 20 degrees of flap down. Would the same be said of a pilot who prangs a 150 in a strong crosswind with full flap on a mile-long runway?

(No, those aren't lawyer-written recommendations in the manuals. The manufacturers didn't care much about product liability in the '50s when those recommendations were first made. It's a mighty slippery slope to start red-penciling manufacturer's recommendations based on presumed ulterior motives. If that were just a "CYA" recommendation, you'd think some knowledgeable inside aerodynamicist or test pilot would have copped to the conspiracy by now.)

I agree with the general principle that consistency is a good thing. In a perfectly consistent world we would always fly at the same weights, at the same temperatures, with the same winds, etc., etc. Some day a student may fly a high-performance airplane that requires partial flap for takeoff. Does that mean he must use partial flap for every takeoff in his trainer (within the allowable range), for consistency's sake?

Ron, I understand and appreciate your point. I just maintain that with lightweight, underpowered airplanes with oversized flaps (i.e., larger than those for which the airframes were originally intended) like C-150 and C-172, and where the manufacturer expressly approves multiple configuration options, there is another side to the issue, and merit to the idea of the student becoming familiar with all allowable configurations.

 

[midlifeflyer]

(No, those aren't lawyer-written recommendations in the manuals. The manufacturers didn't care much about product liability in the '50s when those recommendations were first made. It's a mighty slippery slope to start red-penciling manufacturer's recommendations based on presumed ulterior motives. If that were just a "CYA" recommendation, you'd think some knowledgeable inside aerodynamicist or test pilot would have copped to the conspiracy by now.)

Hear hear. Of course they weren't.

But it's not really red-penciling. It's more like accepting a statement to support what you believen anyway and rejecting the same statement when it doesn't.

If arguments were only as stable as final approaches well-flown.

 

[poadeleted20]

The actual language in FAA pamphlet P 8740-48 ("On Landings, Part I") is:

"One final point: full flaps should be used for all normal landings unless the manufacturer suggests otherwise."​

WRT the C-150 and C-172, among others, Cessna says,

"Normal landings are made power off with any flap setting."​

Saying you may land with any flap setting is a far cry from suggesting that you make landings with less than full flaps. Also, that "power off" recommendation dates from the old days when the FAA recommended all power-off landings, a recommendation that was replaced in the 1970's with one for partial-power stabilized approaches. I'll stick with my recommendation for full-flap, partial-power stabilized approaches as the "standard" way to land light planes, with deviations only as necessary (which ain't often).

 

[JimNtexas]

Now, I've done hundreds of slips in C-172's with flaps fully extended (including the older 40-flap models), and I've never run into that oscillation, but I know that if I do, all I need do is center the rudder and it will stop. And I've landed C-172's in some very short and obstructed fields by doing it -- fields I'd never have gotten into safely without a full-flap slip to a landing.

My experience is identical to Ron's. I've done full slip landings in Cessna's many times. When you learn to fly on a 1600 foot grass strip you learn to slip.

I'm pretty sure the Cutlass has a placard about full flap slips. When I took my commercial checkride the DE gave me a practice forced landing. "I'd use slip with full flaps if this were real" I told her. "Of course you would, so would I" she said.

When I took my BFR in my Cardinal the CFI did the same thing. When I transitioned to a full slip on final he says "you know that's dangerous". The Cardinal has no limitations on slips with flaps. After the flight I asked him about that. He admitted there is no limitation, but quoted the OWT. Very disappointing, and scary to think that his students will not have this important tool in their bag when they have a real power off landing.

This issue is right up there with downwind turns.