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Legality of deliberate incipient spin demo if AFM prohibits spinning

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Legality of deliberate incipient spin demo if AFM prohibits spinning

Old 18th Nov 2019, 12:27
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Legality of deliberate incipient spin demo if AFM prohibits spinning

//www.atsb.gov.au/publications/investigation_reports/2017/aair/ao-2017-096/

The aircraft (Diamond) entered a developed spin during manoeuvres consistent with advanced stall recovery training which likely included intentional incipient spins. The spin continued until the aircraft collided with terrain. The instructor and student were fatally injured and the aircraft was destroyed.

What the ATSB found. The ATSB found that the aircraft limitation prohibiting intentional spins was intended to include incipient spins. However, the manoeuvre was not defined and some operators considered that the manoeuvre was not an intentional spin. In addition, the aircraft was not certified for developed spin recovery, and the capability of the aircraft to recover from a developed spin had not been established nor was it required to be.

While competency at recovery from an incipient spin is still a requirement for the PPL has CASA addressed the situation if spinning is prohibited in the aircraft type (Cessna 172 et al) See ATSB comments above..
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Old 18th Nov 2019, 14:01
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Most 172's I've flown aren't spin prohibited. They just don't spin very well (1/2 - 1 turns before you're into a spiral).

I know the diamonds da40's are spin prohibited, including any 'wing drop'. Students would need to demonstrate incipient spin recovery competency in another aircraft type...
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Old 18th Nov 2019, 18:09
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I think it’s fair to say now..unless anyone has a different experience to volunteer..that Diamonds can’t be recovered from a spin and anyone attempting deep stalls in one is asking for trouble
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Old 18th Nov 2019, 19:25
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Diamond issues aside, there is no clear definition of incipient spin, yet we are required to teach it.

One person's incipient spin is a minor yaw at stall, another's is up to 2 turns (in some aircraft) before the spin stabilises - others are somewhere in between - it is in the MOS without a definition - what exactly supposed to be taught?
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Old 18th Nov 2019, 21:24
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Part of the initial stalling lesson we used to do in the 150/152's involved teaching wing drop recovery which would happen more often than not when setting up with 20deg flap and power at 1500-1700rpm. Then later on in the advanced stalling lesson from climbing & descending turns. That was back in the day when 150/152's were still approved for spinning (even though spinning had been removed from the syllabus as a requirement).

How are you supposed to confidently teach stalling in an aircraft that may not be able to be recovered, from what should be a relatively simple manoeuvre like a wing drop..? Demonstrated recovery from an incipient spin is still a requirement for a PPL I'm assuming..? Does this not then render this Diamond aircraft obsolete for PPL training/testing..?

I guess you can avoid the possibility of an incipient spin by keeping the stalling lesson very 'tame' but what about when the inevitable student 'mishandled recovery' induced incipient spin occurs..? They need to be shown what it looks like and how to safely recover from it. To not do so because it is too unsafe is doing them a disservice and making them less safe in my opinion. Aren't heaps of flying schools using these Diamond aircraft for their training now..? It's pretty concerning.
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Old 18th Nov 2019, 21:34
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IFEZ, to put your concerns another way, I don't believe aircraft endorsements cover spinning behaviour. Then we get "modern " aircraft like the DA40 and others that have benign stalling characteristics, for example a gentle break with almost full aileron authority in the stall? So we train in these delightful aircraft....

....So now our new PPL goes and buys/flys something that can bite. She does not have the skills or experience to deal with that.
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Old 18th Nov 2019, 22:37
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Contrary to the above I think the 150 (and probably the 152) is still approved for intentional spinning ?
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Old 18th Nov 2019, 22:39
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Sunfish - yup. And there's plenty of pilots out there, who are genuinely shocked and scared when the aircraft does something unexpected - wing drop or turbulence. These people NEED substantial exposure to the usual, to be safe pilots - because you can be sure that, one day, the unexpected will happen.
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Old 19th Nov 2019, 02:08
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Originally Posted by IFEZ View Post
Part of the initial stalling lesson we used to do in the 150/152's involved teaching wing drop recovery which would happen more often than not when setting up with 20deg flap and power at 1500-1700rpm. Then later on in the advanced stalling lesson from climbing & descending turns. That was back in the day when 150/152's were still approved for spinning (even though spinning had been removed from the syllabus as a requirement).

How are you supposed to confidently teach stalling in an aircraft that may not be able to be recovered, from what should be a relatively simple manoeuvre like a wing drop..? Demonstrated recovery from an incipient spin is still a requirement for a PPL I'm assuming..? Does this not then render this Diamond aircraft obsolete for PPL training/testing..?

I guess you can avoid the possibility of an incipient spin by keeping the stalling lesson very 'tame' but what about when the inevitable student 'mishandled recovery' induced incipient spin occurs..? They need to be shown what it looks like and how to safely recover from it. To not do so because it is too unsafe is doing them a disservice and making them less safe in my opinion. Aren't heaps of flying schools using these Diamond aircraft for their training now..? It's pretty concerning.
I instruct in the DA40NG first off to even get a wing drop is difficult you have to hold the aircraft stalled for quite some time, I demonstrate it and remind my students that it is past the point they would be expected to recover. However it does recover from a simple wing drop. I believe the reason for the low crash and fatality record is partly down to its stall characteristics, you really have to hold the stall for it to do anything. The worst I’ve had is the start of a spiral dive from a stall where the student put power in after a wing drop. But again spiral dive recovery is also taught. The DA40 is a brilliant trainer aircraft for modern operations.
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Old 19th Nov 2019, 05:19
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The accident record clearly shows that most inadvertent spins occur at such a low altitude that recovery would be unlikely even if proper spin recovery inputs are completed. Modern flight training has moved to stall recognition and recovery because if the airplane doesn't stall it can't spin. If it does stall and proper stall recovery techniques will ensure yaw is prevented and again a spin can't occur.

Bottom line for the spin to develop you have to be stupid times 3

1) The aircraft got into slow flight and you did nothing
2) The airplane stalled and you did not recover
3) With the airplane stalled not only did you not recover but you let uncontrolled yaw develop resulting in a spin entry

If you are that clueless do you really think spin training is going to save the day for you ?
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Old 19th Nov 2019, 06:17
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Modern flight training has moved to stall recognition and recovery because if the airplane doesn't stall it can't spin. If it does stall and proper stall recovery techniques will ensure yaw is prevented and again a spin can't occur.
Sanctimonious claptrap!

Stupid 3 times? No. Just stupid once.

It is exceeding the critical angle of attack that stalls the aerofoil, or part of it. That can happen at any speed.

Attempting a manoeuvre that stalls part of a wing causes an upset that may develop into a spin if incorrect control inputs are then applied or maintained.

Your proposed logic does not cover the full range of the flight envelope because after the pilot has tried "unstall" and "correct yaw" they have nothing else left in the tool box.
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Old 19th Nov 2019, 07:09
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Just do it in a Foxbat or Bristell, Bob's ya mother's brother, she'll be right.
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Old 19th Nov 2019, 07:36
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Originally Posted by Judd View Post
While competency at recovery from an incipient spin is still a requirement for the PPL has CASA addressed the situation if spinning is prohibited in the aircraft type (Cessna 172 et al)
The day after the ATSB alert CASA came out with their own:
Safety update: spin recovery training

The recent ATSB investigation into a fatal accident involving a Diamond DA-40 found the conduct of advanced stall training was a contributing factor to the cause of the accident. 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.

The release of the findings and the safety advisory notice are a timely reminder of the hazards of conducting an activity in an aircraft for which it is not certified.

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.

Incipient spins and training requirements

The conduct of an incipient spin in an aeroplane that is not approved for spinning places the aeroplane outside the normal operating envelope into the safety margins provided by the aeroplane certification standards for airframe structural integrity and demonstrated ability to recover from the manoeuvre.

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.

In the meantime, please contact [email protected] if you have any questions or require clarification.
CASA knew that they had expanded the scope of flight training with these incipient spins per Part 61, they knew how they described an incipient spin in their Flight Instructor Manual (see the chapters on stalls and spins), they knew what aircraft types everyone was using, they knew that many were not approved for intentional spins, they knew that manufacturers considered an incipient spin as a spin wrt what is written in the AFM. So, CASA knew what it was doing with Part 61!

Incidentally, many C172s are unable to be loaded in utility category without removing the rear seats so not approved for spinning as configured. NASA did some spin tests on a C172 near the aft limit in normal category and found unrecoverable spins.

Originally Posted by Judd View Post
The ATSB found that the aircraft limitation prohibiting intentional spins was intended to include incipient spins. However, the manoeuvre was not defined and some operators considered that the manoeuvre was not an intentional spin.
As jonkster stated
here is no clear definition of incipient spin, yet we are required to teach it. One person's incipient spin is a minor yaw at stall, another's is up to 2 turns (in some aircraft) before the spin stabilises - others are somewhere in between - it is in the MOS without a definition - what exactly supposed to be taught?
I guess that you get to choose how much of an incipient spin to do if you have a type approved for spinning, if not then don't intentionally enter an incipient spin. CASA should have provided appropriate guidance when they started to implement Part 61 - I wonder what they will offer in "coming weeks"?

Originally Posted by Judd View Post
The aircraft (Diamond) entered a developed spin during manoeuvres consistent with advanced stall recovery training which likely included intentional incipient spins. The spin continued until the aircraft collided with terrain.
I look forward to reports on the Bristell spin accidents.
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Old 24th Nov 2019, 18:13
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US FAR 23.221 covers the spin requirements for normal category aircraft ( ie not approved for spins)Sec. 23.221 — Spinning.

(a) Normal category airplanes. A single-engine, normal category airplane must be able to recover from a one-turn spin or a three-second spin, whichever takes longer, in not more than one additional turn after initiation of the first control action for recovery, or demonstrate compliance with the optional spin resistant requirements of this section.

(1) The following apply to one turn or three second spins:

(i) For both the flaps-retracted and flaps-extended conditions, the applicable airspeed limit and positive limit maneuvering load factor must not be exceeded;

(ii) No control forces or characteristic encountered during the spin or recovery may adversely affect prompt recovery;

(iii) It must be impossible to obtain unrecoverable spins with any use of the flight or engine power controls either at the entry into or during the spin; and

(iv) For the flaps-extended condition, the flaps may be retracted during the recovery but not before rotation has ceased.

(2) At the applicant's option, the airplane may be demonstrated to be spin resistant by the following:

(i) During the stall maneuver contained in §23.201, the pitch control must be pulled back and held against the stop. Then, using ailerons and rudders in the proper direction, it must be possible to maintain wings-level flight within 15 degrees of bank and to roll the airplane from a 30 degree bank in one direction to a 30 degree bank in the other direction;

(ii) Reduce the airplane speed using pitch control at a rate of approximately one knot per second until the pitch control reaches the stop; then, with the pitch control pulled back and held against the stop, apply full rudder control in a manner to promote spin entry for a period of seven seconds or through a 360 degree heading change, whichever occurs first. If the 360 degree heading change is reached first, it must have taken no fewer than four seconds. This maneuver must be performed first with the ailerons in the neutral position, and then with the ailerons deflected opposite the direction of turn in the most adverse manner. Power and airplane configuration must be set in accordance with §23.201(e) without change during the maneuver. At the end of seven seconds or a 360 degree heading change, the airplane must respond immediately and normally to primary flight controls applied to regain coordinated, unstalled flight without reversal of control effect and without exceeding the temporary control forces specified by §23.143(c); and

(iii) Compliance with §§23.201 and 23.203 must be demonstrated with the airplane in uncoordinated flight, corresponding to one ball width displacement on a slip-skid indicator, unless one ball width displacement cannot be obtained with full rudder, in which case the demonstration must be with full rudder applied.

So although the aircraft will not be approved for spinning it still must be able to demonstrate recovery from a one turn spin. Note the requirement is for the recovery to be possible after 360 degrees of rotation.

In Canada the incipient spin is typically presented as a climbing tun stall in a scenario of what happens with a short field takeoff that goes bad. So full power and 15 to 20 degrees of bank starting at the Vx nose up attiude and thenroll and pull to "avoid the obstacle". When the airplane breaks the most dangerous scenario is when it rolls into the turn ( i usually make sure this happens by sneaking in a bit of inside rudder ). If the wheel/stick is immediately moved forward and yaw controlled then any aircraft will not enter a spin. This should be practiced until the correct automatic actions are applied.

I am firmly convinced if the incipient spin is taught that way the intent of the exercise is achieved and it it is perfectly safe in any aircraft. Unfortunately there are still instructors who insist in colouring outside the lines. They get bored or let their ego get the better of them and try to make an exercise more sporty like instead of recovering as soon as the aircraft stalls in an incipient spin, letting it wind up a bit. With respect to the Australian Diamond accident I find it hard to believe that a positive recovery was initiated immediately.....


Incidentally Cessna produced a pamphlet on spin characteristic for their aircraft

a link to it is here

https://www.kevincfi.com/files/pdf/m...%20Cessnas.pdf
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Old 25th Nov 2019, 06:06
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US FAR 23.221 covers the spin requirements for normal category aircraft ( ie not approved for spins)Sec. 23.221 — Spinning.(a) Normal category airplanes. A single-engine, normal category airplane must be able to recover from a one-turn spin or a three-second spin, whichever takes longer, in not more than one additional turn after initiation of the first control action for recovery, or demonstrate compliance with the optional spin resistant requirements of this section.
My understanding is the above instructions are compliance for certification. It does not mean an aircraft is approved for spinning.
For example, the Cessna 172 Model 172N Skyhawk Information Manual published by the manufacturer I July 1979, states the following in the chapter on Limitations under the heading MANEUVER LIMITS - Normal Category.
This airplane is certificated in both normal and utility category. The normal category is applicable to aircraft intended for non-aerobatic operations.
These include any maneuvers incidental to normal flying, stalls (except whip stalls), lazy eights, chandelles, and turns in which the angle of bank is not more than 60 degrees. Aerobatic maneuvers,
including spins, are not approved
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Old 25th Nov 2019, 06:25
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Originally Posted by djpil View Post
I look forward to reports on the Bristell spin accidents.
I believe GL at LTV did a fair bit of testing on the Bristell characteristics at the request of CASA, however the word on the street was that nothing significant was found. Would love to hear more on it if anyone knows...
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Old 25th Nov 2019, 07:48
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I believe GL at LTV did a fair bit of testing on the Bristell characteristics at the request of CASA
Uh-huh

however the word on the street was that nothing significant was found.
Not what I heard.

Would love to hear more on it if anyone knows...
I wouldn't touch one of them with a barge pole.
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Old 25th Nov 2019, 08:13
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Originally Posted by The name is Porter View Post

Not what I heard
I had been thinking that if the results were too bad, they may have taken action. Aka Jabiru style.
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Old 25th Nov 2019, 10:45
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Have a chat to GL about them.
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Old 25th Nov 2019, 11:59
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May I suggest that the problem we are talking about is known as risk shifting. That is when the safety features built in to a machine encourage more risky behaviours.

This has allegedly been seen with the introduction of ABS in cars, encouraging people to drive closer than is safe.

In aviation, i’ve seen this first hand with a grade 3 instructor doing my Evector Sportstar endorsement. “It’s a kitten, it just mushes down, watch this”. He said. We mushed from 3000 ft to 500ft. Yes, there’s was aileron authority. It was a kitten, right up until it bites - which it did for another “student” (80 years old) who was experienced on WWII machines, who knew how to provoke it.

I treat claims about safe characteristics with with a large grain of salt because you don’t get something for nothing.

My contention is that the DA40 is most probably spin resistant and very safe, with huge margins for error and mishandling — but that comes with the existence of a point of no return.

To put that another way, perhaps we have traded spin resistance for easy spin recovery.
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