gahorn wrote:Highly opinonated comments follow:
We all have strong opinions!
gahorn wrote:Slips were used on flap-less airplanes to lose altitude quickly during an approach which required a steep angle that did not accommodate flap-less aircraft. Once it's advantages were discovered ..even on ordinary arrivals to adequate runways which approaches the pilot had not properly executed ...those pilots employed slips to "save" their poor approach planning.
Flaps were developed as a significant improvement to airframes/flight capabilities. Slips were added to flap-equipped airplanes by those pilots who still couldn't plan/execute an approach.
Either use flaps. Or use a slip. Don't combine the two.
My 'highly opinionated' opinion is you're confusing tactics with capabilities...the tactic is rapidly losing altitude and flap-equipped aircraft, like the C170B have two ways (capabilities) to do it.
Slips are an aerodynamic capability of almost all aircraft, regardless of whether or not they are equipped with flaps. Flaps are simply a way to change the chord and camber, and thus the lift profile, of a wing...regardless of how an aircraft behaves when slipped.
Consequently, there is both a capability on the design side and the simple aerodynamic side. Aircraft behavior during specific maneuvers is independent of capability and really only goes to best practices...or unwise practices. To illustrate my point, for example, just because a Mooney is placarded against intentional spins doesn't invalidate the aerodynamic principles that govern spins. The spin is an aerodynamic principle/phenomenon that occurs under specific conditions - the Mooney will spin (and recover), but the recovery requires multiple turns and due to the 'clean' airframe, results in excessive speed during recovery and the potential to over-G the aircraft or exceed Vne. Consequently, it is placarded against such maneuvers because of behavior due to specific design characteristics based on compromises elsewhere.
While I have no placard, my '53 Owners Manual says, "Slips with full flaps are to be avoided..." - that doesn't seem to be much of a warning. And I concede that prior to that, it states: "The flaps on the 170 allow steep, well controlled approaches making slips unnecessary." - which I assume weighs heavily on your reading based on your "highly opinionated" position.
But knowing one's plane is imperative. I would actually recommend practicing slips with full flaps AT ALTITUDE to understand how your aircraft behaves. I believe it is imperative to know where the corners of your envelope are and explore them in a safe environment, when possible. And this is not so you can max perform your aircraft on every maneuver, rather, for those (hopefully) rare times that circumstances, environment, or self-induced buffoonery conspire against you and put you in a corner you'd rather hope not to be in otherwise...but have the ability to recognize and operate safely out of.
There is much to be said for stabilized approaches. There is equally much to be said for knowing how to safely fly your aircraft steeper than normal, and equally, shallower than normal. You never want to find yourself in an unfamiliar position if you can avoid it...I avoid 'learning' when it 'counts' as much as I can.
gahorn wrote:I would not recommend slip/spin/flight-testing a 60 year old airplane in order to discover an elusive, unpredictable response to a stressful maneuver without a jettisonable-door and parachute...especially only for the purpose to re-discover or re-document what is already known by the factory.
While I can fully endorse your intention here, I respectfully disagree that we have enough data from the factory. A mild caution recommending against something without explaining the severity is not as black and white as we'd like. I think it's far more important to know your aircraft under all operating circumstances to the maximum practical possible level. I am not endorsing full-on flight testing, but equally I'd never suggest flying an aircraft I was afraid of, or thought would be damaged (or worse) doing normal maneuvers...if you're that scared of the structural integrity of your 60-year old aircraft, perhaps it should be parked...and while I am by no means a metallurgist, I fully understand fatigue and necessary vs unnecessary stresses on an aircraft (which isn't always as black and white as we'd like it to be either).
The engineers design an aircraft that will be structurally guaranteed so long as it stays within a certain envelope. The factory write manuals that create an ellipse that lives wholly inside the rectangular box the engineers designed. Normal limitations and other rules/practices create yet a smaller ellipse concentrically within that larger manual-derived ellipse...the challenge is you may find yourself outside of the comfort of that smallest ellipse, and perhaps out near a corner of the larger box...that's not the time to learn something new. Know it before you find yourself there and plan to avoid that by all means, but be prepared for the unexpected.
For me, that means flying 3-5 good solid predictable patterns to landings with well-stabilized approaches. I then go out and do different things - I pull power earlier and leave it there and try to ensure I know how to make it to my intended point of landing. Or, I stay high on purpose to ensure I know how best to put my plane exactly where I need it to be. If you can "fix" the "unfixable" nothing will every catch you out. If you only fly vanilla, there's no guarantee you can get yourself out of a jam when you back is against the wall.
I'm in no way suggesting everyone immediately go out and become test pilots, rather, to incrementally challenge themselves to become better by increasing their skill set and filling their 'bag of tricks' with more tools and options based on their experience and comfort level.
YMMV.
*//donning flame retardant suit//*