Mike,
“…the single cause of divorce, worldwide. Marriage.”
That was good.
Salil
9 percent of general aviation accidents are stall/spin accidents. Or that 29 percent of these accidents are fatal. Stall/spin accidents kill almost 13 percent of all people lost in GA aircraft.
and
Stall Spin accidents
1.60% of stall/spin accidents take place during the takeoff/ landing phases of flight
2. 66% of general aviation accidents have as major factors failure to maintain climb/approach speeds.
3. Low wing aircraft increase rate of spin just prior to recovery.
4. Fewer than 5% of all spin accidents occur high enough above the surface to allow normal recovery.
5. About 8% of general aviation accidents are spin related and account for nearly 25% of the fatalities.
If one assumes takeoff stall/spinn accident rate to be equal to landing stall/spinn accident rate (big assumption) then perhaps less than 2.7% of the GA accidents could be attributed to the “Base to Final type of stall/spinn situation”. I would imagine that most if not all would be fatal (except for the lucky few).
Salil
Mike, I tried to cull some data from the NTSB files but it’s such a pain to find accidents by cause and using keywords like “stall”, “spin” “landing” etc. results in such a large number of records that I gave up.
I would expect that the stall/spin on base to final is usually with an inexperienced pilot. An exception might be a spin resulting from disturbed airflow over an iced up airplane during a circling approach, or a very tight circle on any non precision approach where the turn is tightened up too much in an attempt to keep the airport in sight. I also would intuitively think that certain airplanes (specifically those without aileron/rudder interconnects) might be more prone to this type of accident. In fact I believe that this accident type was much more common in the past when many pilots were flying Cubs, Stinsons, Swifts etc.
Ironically the only accident I’ve ever personally witnessed was precisely this type. It was at DPA 10+ years ago. There was a student pilot in a 150 in the pattern. She was on downwind when an FAA King Air reported a 5 mile final. The tower cleared the Cessna to land and asked the pilot to tighten the pattern and keep it in close. The student complied and tightened it so much that she spun right in. I was taxing out at the time and since tower and ground were combined I heard and saw the whole thing. It was horrible.
they’ve discovered the single cause of divorce, worldwide. Marriage. <
Big chuckles-I can’t wait until the next wedding I go to. I can pull the groom aside and tell him, “Congratulations, you are halfway to a divorce!”
Salil,
Thanks; interesting stats.
They include an apparent discrepancy, although perhaps I’m missing something. You said “Stall/spin accidents kill almost 13 percent of all people lost in GA aircraft.”. Then, point number 5 says “About 8% of general aviation accidents are spin related and account for nearly 25% of the fatalities.”. So I’m confused about whether the 13% and the 25% refer to different things.
The thing I’m really interested in, though, is how often (what %) of pilots with (say) > 1,000 hours total time and (say) > 200 hours TIT get into a stall-spin? Intuition says that it’s a pretty small percentage, but I’d love to find hard data.
Thanks for getting this info.
Mike.
Jerry,
Just reading your account of that crash made me cringe.
Ever since Gordon’s comment earlier today, I’ve been thinking about what it would take to get me into that situation. Ice, and distraction during the approach/landing, come out near the top.
By the way, I saw a crash happen in South Africa in 1977 or so - but it was at an airshow , and so there was a higher acceptance of risk. It was a Britten-Norman Trislander (no “Pilatus” in the name back then), that hit the ground at the bottom of an inside loop. The pilot had acheived a level attitude perhaps 50 feet higher, but the airplane was still mushing down. It hit hard enough to drive both main gear struts up through the wing… the left and right engine mounts broke and both engines pivoted so that the props were pointing straight down. The point of impact was less than 50 feet from where I was standing. The middle engine kept going, and the airplane “bounced” airborne; the pilot somehow managed to control the airplane to a semblance of a controlled crash. There was no fire, and the two-man crew survived, both with back injuries.
Being that close gives a real, sickening sense of the speed, violence and power of impact with the ground that can’t be forgotten. Also the thought that there, but for 50 feet…
Mike.
Mike,
The two sets of data are from two separate sources. The top data is from the AOPA Safety and the bottom data is from the website you had pointed to me in the past regarding “cam shaft crack related accidents” (I must say it was very informative). 9% vs 8% is nothing to make a fuss over. I do agree that there IS a great discrepancy between the proportion causing fatality (13 vs 29). That is the reason I ignored that data. I simply looked at the 60% of stall/spin caused in takeoff and departure phase, split it in half (my assumption) arriving at “perhaps less than 2.7% of the GA accidents could be attributed to the 'Base to Final type of stall/spinn situation”. The last remark that perhaps most of these are fatal was based on my sense of the matter (weather you believe in 13% being fatal or 29% being fatal it is irrelevant in this situation since neither applies strictly to the base/final type) and not on these numbers.
Salil
PS I will see if I can find the data you are looking for.
Who would be crazy enough to loop a Trislander in the first place??
Still, since life is a terminal condition…
that hit the ground at the bottom of an inside loop. The pilot had acheived a level attitude perhaps 50 feet higher, but the airplane was still mushing down.
Mike,
What a wonderful description of the cause of any stall: ANGLE OF ATTACK!!!
Salil
I have recently heard that approximately 50% of all marriages in the U.S, end in divorce. Given that the other 50% end in death, what’s the point?
Marty
In reply to:
approximately 50% of all marriages in the U.S, end in divorce. Given that the other 50% end in death, what’s the point?
Before Jerry points it out, I’ll say it: EVERY activity by living humans that isn’t otherwise ended is ended by death. So, what’s the point of ANYTHING?
It’s the journey, my friend… and I say, if I’m going to have a journey, I’d like it to be in a Cirrus! [:)]
Mike.
In reply to:
Who would be crazy enough to loop a Trislander in the first place??
Clyde,
Nobody, apparently.
I’ve been wondering about that one ever since you asked. The Internet provided few clues - if you search for “Lanseria” in these sites http://www.baaa-acro.com/archives/accident_1977.htmYahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos, you can find sketchy references to the crash, which happened on August 10th, 1977.
Finally I emailed my friend Ernie Brown, who was there with me. His recollection of it was a little different than mine; I’m sure his is the more accurate.
Ernie replied: “The Trilander accident was at the air show at Lanseria (can’t remember the year), and he tried to do a stall turn and did not take into account the high altitude so was still nose down when the ground rose up and smote him mightily. The starboard engine dropped off, the port engine was pointing at the ground, leaving only the tail engine. They bounce up to a 1000 feet and then descended into the ground by the threshhold of 06 and broke in two. The pilot was the Trilanders chief pilot and the only passenger was Mike Wrigley (he who had brought a BE23 to Umtata on demo) also he was a cousin of Annette Sparg who was a member of the Umtata Flying Club.”
So it seems that even though the pilot wasn’t crazy enough to loop a Trislander, he did think that a stall-turn in one at Lanseria (elevation: 4,517’) was reasonable!
- Mike.
Its true that you can be near the stall speed on this turn:
I was trained in Duluth to be at 85KIAS on base, with 50% flaps. Then turn to final,
putting in 100% flaps at this point, to help slow to 80KIAS.
According to the POH (using 3400 LBS, w/worst case CG), the stall speed with
50% flaps is 80KIAS when in a 45 degree bank…stall speed goes up to 95KIAS
in a 60 degree bank.
So slowing to 80KIAS in this turn, if its steep (e.g. 45 degrees) , before having all
the flaps in, puts you right at the stall speed. So if this turn is done at more than 30
degrees, speed needs to be high (e.g >=100KIAS) and carefully controlled.
Michael
In the mountain flying seminar I took this spring in Idaho (in my 182, pre-Cirrus), they taught a “canyon turn” for course reversal that was quite remarkable and could turn the airplane around 180 degrees in an astoundingly short radius, at a reasonable airspeed, without pulling “Gs”. (The turn also involves briefly applying full power and full flaps.)
The relevant aspect of it (to this topic) is to avoid loading the wing in a steep turn by pushing the nose down, resulting in a 1-G 45 degree bank turn. If you don’t load up the wing, the stall speed does not increase. The textbook stall-vs-bank angle calculations assume you are maintaining level flight which increases the G-factor.
On a base-to-final turn you are descending anyway, so if you sacrafice a little altitude by pushing forward a bit to avoid any additional Gs you can avoid getting any closer to the stall.
At least this is how it was explained to me, and it makes sense. I hadn’t heard of this previously. I’d love to hear if anyone thinks there’s a flaw in the logic.
Regards,
Tim
In reply to:
Where you ditch (close to where you can be found and rescued quickly) seems to be much more important for survival than how you ditch.
Thanks for your interesting post and observations. As you stated, ditching is almost always a survivable event, and it’s what occurs after you ditch that determines survival. The one-mile threshold you mentioned largely goes away if you have appropriate equipment on board and are prepared to use it. I’m talking about life vests (which should be worn in-flight), a raft, and a GPIRB. That GPIRB will broadcast your exact position to SAR and you’ll likely not even have had time to barf in the raft before they’ll be there.
Without appropriate post-ditching equipment, if you ditch in deep water away from vessels or shore you might as well save everyone the misery and just dive the airplane straight into the water for a quicker demise.
Jeeze Gordon, there is always hope. People do get lucky, even with poor planning.
In reply to:
Jeeze Gordon, there is always hope. People do get lucky, even with poor planning.
Ok, Ok. Grant me a little morbid hyperbole now and then! [:)] (Just wanted to see if anyone was listening!)
Heck, in the Cirrus, with all those sealed plastic wing compartments, maybe the dang thing will float indefinitely. Calling Lionel Morrison - let’s test the theory!
Don’t underestimate the potential for floating. An acquaintance of mine recently ditched a Pitts in a river. Contrary to the POH, he elected to leave the canopy on and locked. It hit at 80 mph+ and nosed down into the water, hit the bottom of the river (14 feet down), then popped right back up like a cork. They had plenty of time to scramble out and call for help on the cellphone (which was still dry) while it floated. The plane was structurally undamaged (except for water corrosion) and some fool bought with intent to fly it again (The water damage would disincline me from ever getting in the thing…it is, after all, made of wood and glue!).
I suspect the wings on the Cirrus are equal in strength and that it would probably float. The $10 million question is: Do I open those door before impact, or not???
In reply to:
Do I open those door before impact, or not???
Dave,
Personally, I would not.
- Mike.
In reply to:
The $10 million question is: Do I open those door before impact, or not???
I agree with the others. In this particular aircraft, I’d keep the doors closed.
Please send the $10 million c/o PO Box 4031, Santa Barbara, CA. Thanks for this kind offer! Goes a long way toward paying my wife’s hairstyling bills. [;)]
