Incipient spin instruction legalities
Thread Starter
I suggest that the OWT about aileron's being a killer in the stall dates back aeons to the rather early rag bag aeroplanes with yaw and local stall problems associated with the use of aileron.
It is interesting to compare the two vastly different incipient spin recovery techniques and the techniques for stall recovery with and without a wing drop in CASA’s Flight Instructor Manual with the FAA’s revised Airplane Flying Handbook.
I wonder whether CASA will go back to the old Day VFR Syllabus with just a wing drop as an incipient spin or go with EASA’s new definition of the incipient spin required for training.
In my airplane that results in a neat transition to an inverted spin.
In my airplane that results in a neat transition to an inverted spin
The recovery may be discussed in three parts, but the ultimate objective is to coordinate all three actions.
To unstall
Keep the ailerons neutral.
At the same time
Simultaneously decrease the back pressure/check forward and apply sufficient appropriate rudder to prevent further yaw.
Excessive rudder should not be applied (to level the wings through the secondary effect of rudder) as this may cause a stall and flick manoeuvre in the opposite direction to the initial roll (wing drop).
To unstall
Keep the ailerons neutral.
At the same time
Simultaneously decrease the back pressure/check forward and apply sufficient appropriate rudder to prevent further yaw.
Excessive rudder should not be applied (to level the wings through the secondary effect of rudder) as this may cause a stall and flick manoeuvre in the opposite direction to the initial roll (wing drop).
John T and I generally only discuss certified airplanes. We now have AC 23-15 for small, simple low performance airplanes which still requires testing for abnormal control usage in that first turn of a spin. Worth noting that the spin testing required for LSAs is much less stringent than for FAR 23 normal category. Then there are homebuilts.
Stall recovery per the manual for my certified airplane is lower nose and add full power simultaneously. Use the rudder to maintain lateral control. Pretty much what CASA states in the stall chapter of the Flight Instructor Manual. Get it not quite right and it will spin doing that per https://www.facebook.com/watch/?v=455183408172041 (near the start of the video).
The placard summarising the emergency spin recovery procedure for FAR 23 normal category types is relevant. Normal category certification flight tests start that spin recovery procedure at one turn (or 3 seconds). The emergency spin recovery procedure is to be used when stall recovery is delayed or messed up and it is progressing towards a spin. Still in the incipient stage by that one turn. Do people assume that the emergency spin recovery procedure in the placard and in the AFM is only to be used once you are in a fully developed spin with a normal category airplane?
I suggest that the OWT about aileron's being a killer in the stall dates back aeons to the rather early rag bag aeroplanes with yaw and local stall problems associated with the use of aileron. The basic story is, read the POH/AFM guidance and limitations and stick with that information.
The FAA's new guidance is fairly straightforward - you get a stall recovery template and a spin recovery template (subject to what's in the AFM). Fairly clear as to when each is applicable. AFMs are the same - they talk about stall then they talk about spin. Nothing in between.
By comparison, CASA's Flight Instructor Manual has a method for stall recovery with an additional action for an uncommanded roll at the stall. Then it has two different incipient spin recovery methods in the spin chapter. Then it goes on to the recovery from the fully developed spin.
CASA on 23rd May: "CASA is developing further guidance material in relation to the conduct of incipient spins and advanced stalls and how to meet the flight training and testing standards in the Part 61 manual of standards. We expect to finalise these over the coming weeks." "Further guidance"?? - has there been any so far?
"It also highlighted that there can be varying interpretations of an ‘incipient spin’, and this has led to aircraft not approved for intentional spins being used for incipient spin training and assessment." Naturally, as CASA has never defined an incipient spin.
"Flight training operators, their Heads of Operations and Flight Examiners are obliged to ensure that aircraft used for training, flight reviews and testing purposes are certified for the manoeuvres being performed." I wonder why CASA didn't offer this advice upon reviewing Ops Manuals or non-conformances at audits when they know that types not approved for intentional spins are being used for incipient spin training.
Further good information from the FAA in their AC 61-67 https://www.faa.gov/documentLibrary/.../AC_61-67C.pdf
Interesting that for my FAR 23 certified airplane the manual states not to use the aileron as large aileron deflections will aggravate a near-stalled condition - it does indeed. I can demonstrate that a small aileron deflection near the stall will cause the opposite wing to drop, just like simple pilot theory. I'm not an old wife but feel free to call me a dinosaur.
His summary (as I read it) was out of roll aileron was generally found to be pro spin for most of them - hence NASAs recommendation about neutral aileron as a general rule although timing was important - it could be used to prevent spin entry in some at an early entry stage but then became pro-spin soon after.
In Stowell's book there is a list of published spin recovery techniques from many manufacturers and many quote neutral aileron.
I think one problem is instructors are aware of the neutral aileron idea and know rudder is used but I believe many think it is the roll that must be immediately stopped and the aircraft must be brought wings level immediately.
Knowing they are not supposed to use aileron they use rudder "to pick up the wing".
I think some instructors have progressively been underdone on stalling over the years and are wary of it, having been poorly taught themselves and that passes on to students who then become instructors and so it continues.
Spot on I reckon. It must be taught but they don't define it.
It also highlighted that there can be varying interpretations of an ‘incipient spin’, and this has led to aircraft not approved for intentional spins being used for incipient spin training and assessment." Naturally, as CASA has never defined an incipient spin
The incipient phase occurs from the time the airplane stalls and starts rotating until the spin has fully developed. This phase may take two to four turns for most airplanes. In this phase, the aerodynamic and inertial forces have not achieved a balance.
An incipient spin is that portion of a spin from the time the airplane stalls and rotation starts, until the spin becomes fully developed.
Full forward stick??
So do I, and I have flown quite a few aircraft that had mean stall/spin characteristics ---- including virtually any taper wing DH product.
The Hornet Moth was so bad that many were retro-modded with DH-82 wings. Ground loops in a Hornet Moth were not really ground loops at all --- they were incipient spins interrupted by mother earth.
Some will remember the Lockheed Hudson --- in Australia, civil versions had the final stage of landing flap locked out.
Tootle pip!!
The Hornet Moth was so bad that many were retro-modded with DH-82 wings. Ground loops in a Hornet Moth were not really ground loops at all --- they were incipient spins interrupted by mother earth.
Some will remember the Lockheed Hudson --- in Australia, civil versions had the final stage of landing flap locked out.
Tootle pip!!
About the best definition is that of the FAA in some documents.
https://www.faa.gov/regulations_poli...06_afh_ch4.pdf
https://www.faa.gov/regulations_poli...06_afh_ch4.pdf
Those FAA documents and your AFM only mention stall recovery and spin recovery - nothing in between. My simple view is that if you intentionally put the aeroplane in a situation which requires the spin recovery procedure then you have intentionally entered a spin. i.e. a spin is a spin.
EASA is working on their UPRT requirements and they have defined an incipient spin in that context:
"Incipient spin’
refers to a transient flight condition in the post-stall regime where an initial, uncommanded roll in excess of 45° has resulted from yaw asymmetry during a stall and which, if recovery action is not taken, will lead rapidly to a developing spin. Prompt recovery during this incipient spin stage will normally result in an overall heading change, from pre-stall conditions, of not more than 180°.
‘Developing spin’
refers to a flight condition in the post-stall regime where the aeroplane exhibits abnormal, but varying, rates of yaw and roll, together with changing pitch attitude, following an incipient spin but before the establishment of a developed spin. A developing spin follows an unrecovered incipient spin and will usually persist, in the absence of any recovery action, until a developed spin ensues.
‘Developed spin’
refers to a flight condition in the post-stall regime where the aeroplane has achieved approximately constant pitch attitude, yaw rate and roll rate on a descending flight path. In transition from a stall with significant, persistent yaw, with no recovery action, to attaining a developed spin,the aeroplane is likely to have rolled through at least 540°."
Sorry, could only get you this link https://www.scribd.com/document/4014...ote-UPRT-Items
I look forward to CASA's further advice on incipient spin training. Further to what current advice?
Last edited by djpil; 26th May 2019 at 00:03. Reason: Typo plus a sarcastic comment at the end.
djpil, perhaps you or JT know the answer. Casting the memory back (always a dangerous thing to do) I seem to recall the Victa 100 had a three turn limit on spinning. Why? Because it got nasty?
As for the word "incipient" I'm happy with the dictionary definition - In an initial or early stage; just beginning to exist or appear.
The AOPA in one paper quotes 10% of all accidents and 13.7% of all fatalities in GA are a result of stall/spin. In my day spinning was part of the syllabus, I gather not so now. The only time an incipient spin would be recognised would be by a well trained pilot, the average Joe has never seen a spin, by the time s/he got their wits about them it would be fully developed I suspect.
Note aileron a 172N, might call it incipient.
As for the word "incipient" I'm happy with the dictionary definition - In an initial or early stage; just beginning to exist or appear.
A good starting point for any investigation of "incipient" is the Latin verb incipere, which means "to begin." "Incipient" first emerged in English in a 1669 scientific text that referred to "incipient putrefaction." Later came the genesis of two related nouns, "incipiency" and "incipience," both of which are synonymous with "beginning." "Incipere" also stands at the beginning of the words "inception" ("an act, process, or instance of beginning") and "incipit," a term that literally means "it begins" and which was used for the opening words of a medieval text. "Incipere" itself derives from another Latin verb, capere, which means "to take" or "to seize."
Note aileron a 172N, might call it incipient.
Moderator
I seem to recall the Victa 100 had a three turn limit on spinning.
I don't recall the Victa limitation - too long ago, now, and my copy of the original AFM is somewhere in the archives ... Dave and I did our initial aeros with Aub Coote on Dave's 100 back in the early 70s so he probably will have the information to hand.
To the best of my recollection, the Victa wouldn't really spin - more or less a spiral dive sort of thing. Prior to my first solo - on the Victa at RACNSW some years earlier - I was a bit concerned that I hadn't looked at spinning. Cec (Randall) had me put the aircraft into a steep turn and then, totally unannounced, suddenly put in full top size 14, whereupon I had my first exposure to whatever it was that the Victa did. Certainly got my attention ... as I recall, I may have said a naughty word at the time whilst recovering.
My first exposure to a real spin was with John S-J in the RVAC Chippy a little later ... whence I acquired the long-lasting nickname, "Chuck". The three of us were on the Nomad program at GAF at the time.
I don't recall the Victa limitation - too long ago, now, and my copy of the original AFM is somewhere in the archives ... Dave and I did our initial aeros with Aub Coote on Dave's 100 back in the early 70s so he probably will have the information to hand.
To the best of my recollection, the Victa wouldn't really spin - more or less a spiral dive sort of thing. Prior to my first solo - on the Victa at RACNSW some years earlier - I was a bit concerned that I hadn't looked at spinning. Cec (Randall) had me put the aircraft into a steep turn and then, totally unannounced, suddenly put in full top size 14, whereupon I had my first exposure to whatever it was that the Victa did. Certainly got my attention ... as I recall, I may have said a naughty word at the time whilst recovering.
My first exposure to a real spin was with John S-J in the RVAC Chippy a little later ... whence I acquired the long-lasting nickname, "Chuck". The three of us were on the Nomad program at GAF at the time.
It is worth repeating that "Inflight loss of control is the leading cause of fatalities in aviation." While we wait for further guidance.
Folks,
I agree with djpil and JT about the Victa, it did n't develop a stable spin ----- and I did enough instructing on both the 100HP and the 115hp models for my students to have plenty of opportunity to get into the situation --- stall and recovery training "back in the day" was far different to now.
As an aside, the "good old " C-172 ( and many similar aircraft) was a very different animal at max weight and aft C.of G limit, compared to "utility" weight and C.of G, something I made certain all my students experienced and understood.
Re. many of the twins, not required to demonstrate spin recovery for certification, at the approach to the stall, a PA-23 (Apache/Aztec) had a degree of rudder blanketing such that you could waggle the rudder almost full deflection with little or no result.
Tootle pip!!
I agree with djpil and JT about the Victa, it did n't develop a stable spin ----- and I did enough instructing on both the 100HP and the 115hp models for my students to have plenty of opportunity to get into the situation --- stall and recovery training "back in the day" was far different to now.
As an aside, the "good old " C-172 ( and many similar aircraft) was a very different animal at max weight and aft C.of G limit, compared to "utility" weight and C.of G, something I made certain all my students experienced and understood.
Re. many of the twins, not required to demonstrate spin recovery for certification, at the approach to the stall, a PA-23 (Apache/Aztec) had a degree of rudder blanketing such that you could waggle the rudder almost full deflection with little or no result.
Tootle pip!!
Avoid imitations
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I instructed on the RAF Bulldog for a few years. The propensity for "funny" spin modes was well publicised, well before my time in the job. As QFIs we had to practice entry and recovery form a high rotational spin on a regular basis (once a month). We had to carry this out on a mutual basis with another QFI. During the climb we briefed how we intended to enter the spin, how we intended to recover from it (and what minimum aircraft abandonment altitude was) and monitored each other. Always good fun but some QFIs hated doing it. Some QFIs preferred method of getting the spin rate to go high rotational was to enter with and hold some aileron. My technique was to enter normally with neutral aileron then allow the stick to come off the back stop by about one inch - that always worked nicely!
Not long before I left for another job I obtained more aircraft detail regarding weight and balance after the "Navaids upgrade" involved having the aircraft re-weighed (it hadn't been readily available in the past). I did some calculations on our squadron aircraft (I was practicing for my civvie exams). I discovered that it was likely that some were inadvertently being spun outside their C of G limits. If our squadron fleet was typical, it might explain why some pilots found the Bulldog more exciting than it should have been.
Not long before I left for another job I obtained more aircraft detail regarding weight and balance after the "Navaids upgrade" involved having the aircraft re-weighed (it hadn't been readily available in the past). I did some calculations on our squadron aircraft (I was practicing for my civvie exams). I discovered that it was likely that some were inadvertently being spun outside their C of G limits. If our squadron fleet was typical, it might explain why some pilots found the Bulldog more exciting than it should have been.
I'm worried that 3/4 of the Spin Recoveries mentioned here, does not include the very important first step of POWER - IDLE.
Remember that a spinning propellor will provide exciting and adverse gyroscopic effects.
Remember that a spinning propellor will provide exciting and adverse gyroscopic effects.
CASA on 23rd May: "CASA is developing further guidance material in relation to the conduct of incipient spins and advanced stalls and how to meet the flight training and testing standards in the Part 61 manual of standards. We expect to finalise these over the coming weeks." "Further guidance"?? - has there been any so far?
