The International Cessna^® 170 Association

• Moderators note: This thread contains links to the final NTSB report for the fatal accident of N2865C owned and operated by Bruce and Kathy Rhymes. Here is the link to the thread created upon learning of their accident and deaths. http://www.cessna170.org/forums/viewtop ... =5&t=10589

The final reports are out on Bruce and Kathy's accident. I think of them often. The Probable Cause report says the reason for the stall could not be determined, but after reading all of the reports I highly suspect that it may have resulted from slipping with full flaps. I did discuss the issue of slipping with full flaps in 170B's with the investigator. From the Probable Cause report: "The last three GPS data points showed the airplane at a groundspeed of about 64 knots, which was well above the stall speed. The GPS data showed that the airplane was well above the 3-degree glidepath to both the runway threshold and the precision approach path indicator location. Wreckage and impact signatures were consistent with a stall and subsequent spin and a near-vertical impact with terrain. However, the reason for the stall could not be determined." The flaps were found set at 40 degrees in the wreckage.

Report: (broken link deleted by mod)

Docket: (all supporting information, photos, etc.): http://dms.ntsb.gov/pubdms/search/hitli ... N=16910254

Probable cause: (Broken link deleted by mod)

John, thanks for jogging my memory. The report was brought to my attention by the investigator and I did talk to him about the investigation conclusion. I started to study the report and then life got in the way and the report slipped my mind.

The GPS data they extracted from the remains of the GPS draws a pretty conclusive picture.

My conclusion from the data I read was like yours, a full flap, slip, elevator stall fits the data and eventual conclusion like a glove. The investigators just can not say it is so.

In memory of Bruce and Kathy we ALL need to do a much better job of getting the word out.

Reading and seeing that report breaks my heart all over again. We must bring this phenomena to the consciousness of all 170-B and similar models (early 172, etc.)

Bruce
Maybe the association could make a nice label something like "Slips Prohibited with Flaps" and send it to all the B drivers for them to place on their panels with a letter explaining the concern.
I would chip in some money.
Dan

One of the instructors in that flies my family's 170 loves to do slips with flaps because "Cessna didn't say you couldn't do it in that year". He and my father got into a heated discussion when my dad found out that he was doing that in our airplane when we owned it.

I am shocked at how utterly destroyed the airplane was. It's indeed a very sobering reminder and such a sad loss of life.

Honestly, a good YouTube video of this performed at altitude by a competent pilot would do wonders to spread the word. In cockpit and external views of the phenomenon with good graphics and explanations would be an engaging and educational experience. Just like that video of the L19 ground looping and ripping the gear out...most people have no idea until they see it.

John, thanks for posting the accident data. I had wondered when or if we would see it. Its difficult to read and see the photo and know its someone a lot of us had gotten to know and both were such good folks. Maybe our tribute to them is to learn from this accident and not have it repeated. Thanks again for posting it.

This is important enough that members should be warned of the hazards of slipping with 40% / full flaps. I like the idea of a decal being sent with a short warning or something in the eflyer or quarterly magazine. Maybe a note put in the welcome kit that is mailed to new members.

The reason I am passionate about mentioning my experience to any 170B people I meet is because once it has happened you become convinced you do not want anyone else to experience it.

For 40 years I slipped with full flaps in any light Cessna I flew. The book said something like “Slips with full flaps not recommended”. I took that to mean they were not prohibited only not recommended.

On a close in base and a bit high I put in full flaps in my 170B and during the turn to final added a slight left slip. The nose instantly dropped straight down and I was standing straight up on the rudder pedals with dirt and junk sliding forward. Pushed and pulled on the yoke and it moved very easily with no resistance at all. About a second later I began to feel a little pressure in the yoke and shortly it was fully functional again. The plane started a smooth recovery and I found myself about 100 feet above ground level on short final. It is quick, you have no control, and the straight down view is very disconcerting.

I now think prohibited would have been a better recommendation on full flap slips.

The GPS data should remove any doubt that this could have been a simple base to final stall/spin.
This is a true tragedy. Not just an unfortunate chain of events but a tragedy due to a poorly documented or misunderstood nasty behavior in an otherwise gentile aircraft. To think, these lives might have been saved if Cessna would have used stronger wording in an owners manual that was written over 60 years ago makes me feel sick.

I would support a statement made by TIC170A that it is the associations official position that forward slipping with flaps fully extended is to be considered a dangerous maneuver and should be prohibited. Of course, that won't prevent anyone from doing it but it goes a long way when a type club takes a stance on a subject like this.

I'm adding a new placard to 81D: "Forward Slips with Flaps Extended Prohibited in This Aircraft"
As the owner, I can at least do that.

My personal rule is slips with 10 or 20 degrees are permitted, go around if I am tempted to slip with 30 or 40 degrees. I feel that it is a good balance. I find that with 40 degrees the descent is steep enough that if I am still too high I need to admit that I really have failed to set up the approach, and a go around is the only sensible thing. I am NOT a brave pilot.

Accidents like this one just confirm how careful we all need to be in life, one small judgement error can have tragic consequences. Very sad in this case.

Both of my planes 1955 170B and 1964 Skyhawk, each have the flap handles placarded. AVOID SLIPS WITH FLAPS DOWN Factory Installed placard.

Arash,
Have you ever tried slipping with full flaps to see if having a leading edge cuff makes any difference in this stall spin characteristic?

johneeb wrote:Arash,
Have you ever tried slipping with full flaps to see if having a leading edge cuff makes any difference in this stall spin characteristic?

Unless the cuff is on the horizontal stabilizer, I don't see how it will make a difference. It's not the wing that stalls.

I understand why we shouldn't do a slip with 40 degrees of flap (maybe not even 30 degrees) but now I wonder if there could be an issue with 30-40 deg flap and a really aggressive turn to base or final. Especially if one overshot base to final and turned hard to correct the overshot. Much as Jack B---- did in his jet up at Oshkosh in 2010?

bagarre wrote:

johneeb wrote:Arash,
Have you ever tried slipping with full flaps to see if having a leading edge cuff makes any difference in this stall spin characteristic?

Unless the cuff is on the horizontal stabilizer, I don't see how it will make a difference. It's not the wing that stalls.

Is the Horizontal Stab stalled or is it blanked out by the wing?

Years ago I tried a slip with full flaps in my B model with a Horton STOL kit. I did it at altitude to be safe. There is a reason that this is not recommended. The nose dropped suddenly. Had I done this close to the ground like on final it might have been ugly.