Spins and other “aerobatics”

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Spins and other “aerobatics”

Postby GAHorn » Tue Nov 24, 2020 7:14 pm

As a young CFI applicant I was taught spin entry and recovery by my CFI as a FAA requirement for that certificate. The Cessna recommended entry and recovery is very basic and quite predictable for C-150 aircraft, which was my primary training aircraft.
For a few years afterward I demonstrated the maneuver to my clients who were at the appropriate point in their training to experience that maneuver. These demonstrations typically involved 3-turn spins which were predictable in recovery, and always entered above 5K AGL or greater. These 3-turn spins usually required 2-thousand feet in 150 aircraft and 2500’ in 172 aircraft. The attraction for me as a young CFI to perform these demonstrations was the exhilaration of the maneuver, as well as the reward-felt in teaching it.

I’ve also spun the Avions-Mudry CAP-10B left, right, and inverted, as well as numerous other aerobatic maneuvers in that airplane as a client at the Gene Soucy aerobatics school. That course was a part of what I considered necessary for pilot training and frankly, I would endorse any and every CFI to take such instruction.

I write this as a lead-in to discussion of performing spins... or avoiding them....in our 60-year-old Cessna 170’s.

I’ve occasionally heard of and read of 170 pilots who have spun their airplanes and, frankly, it gives me concern. Not only are these airframes 60+ years old, even the best of them, in fully-restored condition, are not the airplanes I feel good about spinning, for several reasons.
For one, they  are rarely found in their original condition as far as rigging, weight-and-balance, and structural integrity. Cables, pulleys, and tensions ...as well as attachment hardware and mountings... are no longer pristine...not even in “restored” aircraft. I own such an aircraft and despite it’s having been awarded the “Restoration Award” at AirVenture Oshkosh ‘97... I do not feel it should be spun. The actual weighing and subsequent calculations of it’s CG and accuracy of “utility category” status is not the same as when it left Wichita in Nov ‘52 as a ‘53 B-model.
For another, although many of these airplanes are still “earning a living” in some commercial services and for others they are reasonably-priced daily flyers.... I view our 170’s as “flying museum artifacts” worthy of extra care, not only for their preservation for future generations of pilots to enjoy, but also to avoid unnecessary risk and exposure to hazardous operations. Yes! I consider spins to be hazardous operations when conducted outside of advanced pilot-training and/or airframe certification-flights. Those type flights deserve extra care in the categories of maintenance, pre-planning, and exigency-planning.
What I am suggesting is: If anyone wishes to investigate spins then it is best to do so in an aircraft which is regularly used in that instruction and includes bail-out capabilities with parachutes.
I do not expect universal agreement from our fellow owners, but I hope this topic will be helpful and encouraging to a similar view.

If anyone is “fence-sitting” on this topic, I’d encourage them to consider the National Test Pilot School (NTPS) accident which occurred in 2014, wherein a meticulously-maintained aircraft which was specifically-designed for spin training was lost with a NTPS instructor and NTPS engineering student who were killed while demonstrating spins. The aircraft had been recently inspected for rigging, Wt/Bal and was dispatched for the specific purpose of demonstrating 3 and 6 turn spins. It was an aircraft which had very predictable spin characteristics and was equipped with a jettison-able canopy and the crew wore 5-point harnesses and parachutes. Despite extensive experience and the correct aircraft for the purpose, that airplane could not recover and entered a 34-turn spin into the ground and the mandatory bailout altitude of 6,000’ proved insufficient for survival. Both parties died, the instructor-pilot never able to get out of his seat and the student jumping from the right wing too late.
WHY? Why did an airplane that had been purposed for spin-training not been capable of recovery even by a spin-proficient instructor and a student who on previous flights also had demonstrated ability to recover a spin?
I believe there are times when aircraft don’t always do what the “book” says. I believe there are conditions which creep into familiar situations that may go unnoticed and may alter expected outcomes, and even the best preparations sometimes go awry.

Bottom line:I do not recommend spinning your 170.

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http://www.kathrynsreport.com/2017/05/s ... fr_14.html
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Re: Spins and other “aerobatics”

Postby ghostflyer » Tue Nov 24, 2020 11:16 pm

I have seen it written some where that [type certificate] the 170 isn’t to be spun or not approved for aerobatics. . I un -intentionally spun a 172 and it ended up on its back flat. Motor cut out , recovery was at about 500ft . I was trying to hold altitude [5000ft] initially without airspeed indicated . I noticed the horizon slowly turning and gently touched the rudder . The aircraft flipped over on its back and I was in a flat spin .[some times known as a dead leaf spin] .popped a heap of rivets on the main spar on recovery . VNE was exceeded well and truely . I was lucky , but wasn’t intentionally setting out to exceed the aircraft flight parameters. So these days it’s “group captains “ weather flying and treat the old aircraft[170A] if she was my grandmother. So I have learnt that treat the aircraft very carefully as per the book and think before acting.
Last edited by ghostflyer on Tue Nov 24, 2020 11:43 pm, edited 1 time in total.
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Re: Spins and other “aerobatics”

Postby GAHorn » Tue Nov 24, 2020 11:41 pm

David, according to the AFM the 170 may engage in certain mild aerobatics if operated in the “utility” category. This is described in the Owner’s Manuals under “Operating Limitations”. According to those documents, Stalls (except “whip stalls”) and Spins are to be entered under “slow deceleration”, while “Lazy Eights, Chandelles, and Steep Turns are to be entered at 115 mph. Flight load factors are not to exceed 3.8 G’s positive and 1.52 G’s negative Flaps Up, and 3.5+ and Zero Neg. flaps down. Obviously, this was addressing a pristine new aircraft. I don’t know of too many 170’s with G-meters.

The AFM is also specific about “inverted flight” : It is NOT approved. The 172 is also so-restricted. Your story has been reported to the authorities. :mrgreen:
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Re: Spins and other “aerobatics”

Postby ghostflyer » Wed Nov 25, 2020 12:01 am

Thank you for the numbers and now trying to find my AFM. Due to the virus all books and paperwork came home .I had a placard in the cockpit stating no spins or aerobatics [previous owner put it there] allowed and thought it was printed else where. I will still continue to treat it like a grandmother and give it presents [new instruments ,etc] every now and then. I know that a actual spin the aircraft is in a stalled condition but it’s the recovery that’s the most stressful to all. This is the second time that I have found placards in the aircraft wrong . My baggage placard was wrong as the kilos to lbs calculation was incorrect . For years I have only been 1/2 capacity loading my baggage area.

My story about the 172 mishap was reported to the authorities and I was patted on the back . The previous day that aircraft was being flown along a beach very low and struck the beach at high speed and was videoed [by phone ] by some one on the beach . The pilot didn’t report it to the aero club about the hard landing but it was on the “currant affairs” program on the TV that night about cowboy pilots . After I landed I reported it to the CFI that I had found all these popped rivets on the main spar. The CFI of the aero club had just received a phone call from the press asking for a comment about the hard landing and low flying on the beach on the previous day , while I was out flying .
The CFI just exploded , I went and made him a coffee. He then thanked me for my “”effort”” and then asked me would I write out a damage report as an engineer .
“ I problem ,only too happy to help “
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Re: Spins and other “aerobatics”

Postby Richgj3 » Wed Nov 25, 2020 12:42 am

In 1967 my instructor demonstrated a 7 turn spin in a 150. It really wound up. The heading indicator bit the dust. I’ll spin a Cub. I used to spin my T-Craft. Three turns max. I won’t spin my 170 B. We are both too old. When I got my CFI I owned a Great Lakes and a parachute so that was easy.

I knew a woman who flew aerobatics in an S1 Pitts. She must have spun it hundreds of times until the last time when it didn’t recover. Too many stories like that.
Rich Giannotti CFI-A. CFI-I SE.
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Re: Spins and other “aerobatics”

Postby GAHorn » Wed Nov 25, 2020 12:59 am

Yes, Rich... Even experienced Engineering Test pilots sometimes get surprised by airplanes which supposedly are “approved” for spins. WD Thompson, one of Cessna’s old-time test pilots wrote of several instances in which airplanes already approved for spins.... refused to recover and he nearly lost his life over it. An extremely minor difference of the leading edge on the horizontal stab nearly cost him as it spun down from 10K feet in an almost unrecoverable event. Pure luck and happenchance saved him and his FAA observer as the airplane entered more dense air nearer the surface.

Simply-put... despite the certifications...it is not an “ordinary” maneuver like stalls and chandelles. MInor differences in atmospherics and minor repairs can make the difference between recovery and no. It has killed experts.

David, you can download a copy of your Owner’s Manual and also your AFM (Airplane Flight Manual....which by the way is REQUIRED to be on-board during flight).... at the Members Only page of this website.
'53 B-model N146YS SN:25713
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Re: Spins and other “aerobatics”

Postby cessna170bdriver » Wed Nov 25, 2020 8:29 pm

I’m not at all into aerobatics but I did do a couple of 1-turn spins in 98C (with an instructor during a BFR) back in the early 90s without any issues whatsoever. A fully developed multiple-turn spin such as the one in the NTPS accident might be a different story.

Even though I don’t do spins, and I certainly wouldn’t recommend anyone spin their 170 or perform any maneuver they weren’t comfortable with, I wouldn’t fly an airplane at all that I thought was no longer capable of performing the maneuvers it was approved for when new. It doesn’t take much aggravation to get a departure stall to roll off on a wing; it’s not difficult to botch a lazy eight and approach Vne; and you never can tell when you might encounter turbulence where you’d want the full designed strength of the airplane. Also, I personally don’t consider an airplane a “museum piece” unless/until it has some actual historical significance, or is no longer maintainable in an airworthy condition.
Miles
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Re: Spins and other “aerobatics”

Postby Jr.CubBuilder » Wed Nov 25, 2020 10:54 pm

Lots of good food for thought.

My first "flight lesson" was with a jackass instructor who put me through spins in the C152. I didn't know any better at the time, I thought I was learning when in reality he was just having a lark and trying to make me sick.

My 170 has a bit of character and led an exciting life prior to me, I wish that it could talk, I bet the tails would be epic. There is a repair from its glory days on one wing that has been deemed non-structural through many inspections, but the end result is that the tail end of the wingtip sits about 3/4" higher than the aileron at neutral. Previous owners had compensated for this by putting the wing concentrics at opposite adjustments, added trim tab on the opposite side aileron, and at some point someone rigged it to slightly drag the flap on the same side as the damaged wing. The opposite side wing always breaks first during a stall.

I bought the plane after a PrePurchase inspection that cost me several hundred dollars and was worth exactly nothing. Knowing nothing about the wing issues (or many other things I've since learned) I was blissfully unaware till I switched mechanics. After the first inspection and prior to fixing a couple items my new IA said he'd like to show me some things he had found before fixing a few that he felt were of immediate concern. The wing tip was one he pointed out but didn't need to be addressed unless I wanted. I recall it was the long rivets for one of the seat rails that had been folded over like bent nails that was one of the more pressing areas of concern. The absence of any shim adjusters underneath the gear were another, and I noticed that after installation a lot of the rattle sound I had heard landing on my favorite grass strip was no longer present.

Wonder what those wings would do to the spin characteristics? I don't plan on finding out.
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Re: Spins and other “aerobatics”

Postby ron74887 » Thu Nov 26, 2020 3:28 pm

Guys, let me tell you a good one. years ago when i was learning to fly. another student was flying a 150 practicing. during one of his stalls the plane went into a spin. he did not know how to recover and just started throwing his weight around and and actually stepped on the correct rudder pedal! landed and was scared to death. went back up with the instructor so he could show his what he did wrong! stalled the plane and it went into a spin-did it a few times and every time went into a spin. Called Cessna and they sent engineers and all down every time it would go into a spin with them also. FLAGGED THE PLANE "NO STALLS". Cessna could not determine what was the problem and they tested rigging and everything they knew that would cause it. Never fixed the problem. Ron


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Re: Spins and other “aerobatics”

Postby ron74887 » Thu Nov 26, 2020 3:29 pm

Guys, let me tell you a good one. years ago when i was learning to fly. another student was flying a 150 practicing. during one of his stalls the plane went into a spin. he did not know how to recover and just started throwing his weight around and and actually stepped on the correct rudder pedal! landed and was scared to death. went back up with the instructor so he could show his what he did wrong! stalled the plane and it went into a spin-did it a few times and every time went into a spin. Called Cessna and they sent engineers and all down every time it would go into a spin with them also. FLAGGED THE PLANE "NO STALLS". Cessna could not determine what was the problem and they tested rigging and everything they knew that would cause it. Never fixed the problem. Ron


Ron 74887
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46 7BCM champ N2843E Rebuilding stage
Cajun Connection way down south, most of you are yankees to me!
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Re: Spins and other “aerobatics”

Postby Richgj3 » Thu Nov 26, 2020 4:57 pm

When I was learning the instructor demonstrated three stalls. They all broke right. He talked through the recovery, left rudder, forward stick. Then he gave it to me. I stalled it, it broke left so I did what he told me, LEFT rudder. He saved it. After that he always said OPPOSITE rudder.
:D
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Re: Spins and other “aerobatics”

Postby daedaluscan » Thu Nov 26, 2020 7:27 pm

I don't spin my 170, but I don't think I would fly it if I thought it would not survive it. A spin is a low G maneuver isn't it?
Charlie

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Re: Spins and other “aerobatics”

Postby GAHorn » Fri Nov 27, 2020 1:16 am

I get what Miles was saying... and I don’t consider the 170 a “museum piece” not to be touched or operated. I thought “FLYING museum piece” would modify the phrase sufficiently to explain my view that the airplane should be flown with a view to preserving it ...as intended by our Assoc’n motto.

Daedaluscan, I agree with your statement completely...as well as agree with Miles’s .... in the sense that I only operate airplanes that meet their Type Design and are completely airworthy. My airplane and engine can be shut off in-flight and dead-sticked to a landing and I believe my airplane can spin and recover just fine. I just don’t think it’s a good idea to do either if I wish to preserve it, (and myself. As a young man I was also a long-distance runner. Now I’m 72 and I no longer attempt marathons.) :lol:

Ron: So what you are saying is... There are some things (such as those C-150 spins...and your posts.... which are unintentionally repetitive? :twisted: (You posted twice. LOL)

Here’s another “real life” reason to think twice before undertaking unnecessary risks: In 2018 I was assisting on an annual inspection of a ‘62 C-150 and discovered that it had been signed off on annual inspections by FOUR different inspectors. That airplane was used for many student pilots and likely with adventuresome instructors. (Read that to mean “instructors too inexperienced to resist showing how good they are to their students.) Despite a decade of training flights and Four different inspectors approving that airplane for return to flight.... that airplane was subject to an Unaccomplished AD Note prohibiting Spins until a modification was made! *

Rhetorical question: How many of us thought as I once did that all Cessna 150’s could be safely spun?

I’m not suggesting a similar AD note applies to 170’s. I’m only saying.... well,... I’ve said it. YMMV

* From the AD: “ Investigations of two spin accidents involving Cessna Model 152 airplanes revealed the rudder was found in the over-travel position with the stop plate hooked over the stop bolt heads. After examining the accident airplanes and other Cessna Models 150 and 152 airplanes, accident investigators determined that, under certain conditions, it is possible to jam the rudder past its normal travel limit. The jam occurs when the stop plate is forced aft of the stop bolt head. The forward edge of the stop plate can then become lodged under the head of the stop bolt causing the rudder to jam in this over-travel position. Recovery from a spin may not be possible with the rudder jammed beyond the normal rudder travel stop limits. “
As a matter of interest, my own “Restoration Award Winner” 170 had a condition (discovered/corrected at Del Lehmann’s shop ) where the rudder horn only marginally contacted the rudder-stop bolts. Perhaps in a hard application it may have been possible to force the rudder beyond it’s stops and jam it on that little AN3 bolt. Who knows what might have happened during a spin.
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