Non-Fatal Accidents, 1996

April, 1996

Where:Kentucky, United States
When: April 26, 1996
What:TEAM MiniMax
How: Stall/spin at low altitude
Injuries: Minor, bruises and scrapes. Plane destroyed
Training & Experience of Pilot: Several years in a Cessna 150 Aerobat, aerobatic training. No ultralight-specific training.

Discussion and Commentary

Date: Wed, 01 May 1996 00:38:39 -0400 From: Sam Buchanan <sbuc@companet.net> To: ultralight-flight@inslab.uky.edu Subject: MiniMax; past tense (long)

Many of you will recall that I recently posted an ad listing my beloved Minimax for sale due to a lack of hanger space. The hanger space problem was resolved this past Friday evening, but in a manner that I regret.

The Max was lost in a stall-spin accident that fortunately did not result in serious injury. I will relate the details and draw some conclusions for your study, consideration, and comment.

The pilot is the owner of the 1800' grass strip that serves as the base of my home built activity. The pilot has several years experience flying his Cessna 150 Aerobat out of the strip and has some aerobatic time. He has no formal UL training. He had flown my Max on several occasions after I had given him some ground school. We discussed in detail the importance of careful airspeed management in very light aircraft due to their low mass and high drag. His landings and takeoffs were superb and he pronounced the Minimax to be "a blast to fly!".

Friday evening was a beautiful time to fly with very light wind. After shooting a couple of touch-and-goes on runway 36, the pilot came around for his third landing (and the Minimax's last) on 18. The strip is located in a rural area, and as the pilot turned to final he noticed two men struggling to subdue a large bull with ropes just north of the runway. Concerned that overflying the bull would aggravate the situation, he decided on short final (about 100' altitude) to turn to the right and make a go-around to give the men some time to get the bull under control.

The pilot related to me (I was not at the field at the time of the accident) that he had just checked airspeed (55 mph, OK) and the engine gauges. As he applied full power and began the turn to the right, the right wing dropped and the Max began a steep spiral to the right. The aircraft impacted the ground after spiraling 270 degrees, and was totally destroyed. The right wing impacted first, followed by the gear, then the nose. The right wing literally exploded on impact, blowing all wooden structure except spars out of the fabric. The gear collapsed and the pilot went through the bottom of the plane. As the nose impacted, the engine (at full throttle) ripped from the mounts and landed several feet from the plane. The pilot ended up sitting on the ground in the middle of a pile of what used to be a really nice airplane. The fuse from the rear of the cockpit forward was absolutely demolished. Miraculously, the pilot was only bruised and scraped and jumped up immediately and stepped out of the mess because he was concerned about a fire. The fuel tank was not ruptured, however, and the pilot was able to show me the entire incredible sight the next day.

Some thoughts:

The pilot was extremely fortunate. Most stall-spins from low altitude have tragic consequences (Yes, the plane HAD a chute....however, I had sold and removed it two weeks before.....the pilot said he didn't have time to even think about the chute). He took full responsibility for pilot error and wrote me a check for the airplane. Can I pick classy friends or what!!

The pilot and I agreed on the probable cause of the accident:

1) He was distracted by events outside the cockpit. He should have FLOWN THE PLANE, and let the bull run wild (He could have apologized to the neighbors later).

2) I suspect that more time transpired between his last check of the airspeed and his abort than he realized. All during the decision phase of the go-around, airspeed was probably decaying, and when the nose lifted slightly with application of full power, and the bank was initiated, the stall fully developed.

Both of us were tremendously impressed with the way the Minimax absorbed an awesome lick. Many people consider wood aircraft to be unsafe due to crash protection, but I believe the opposite to be true. All of the crushing and crumpling represented gobs of energy being transferred away from the pilot. I must admit that I was concerned about my friend being impaled by some of the sharper pieces, but I guess that was his lucky day. NONE of the AN bolts and 2024 fittings broke. I now have more respect for the strength of AN hardware; DO NOT, I repeat, DO NOT ever replace AN bolts with hardware store fittings.

Some of you are going to comment on the lack of formal UL training. I will not argue with anyone that says the pilot could have had more training. I will, however, disagree with you if you state that the accident would not have happened it he had received UL specific training. The moral of this story is:

ALL PILOTS, EVEN GOOD PILOTS, CAN/DO MAKE MISTAKES! Fortunately, most mistakes don't result in a crash. If you think you can "train away" all accidents, you are living in a dream world!

I hope all of us will show the same class my friend did if we do screw up. We need to 'fess up, and if we damage somebody else's machinery, we need to make sure the owner is compensated.

There are some salvageable parts from Minimax Sierra Bravo, and I will post a list of available parts so anyone with a Minimax project can get a good buy. The wood airframe, however, is headed for the bonfire.

Hope this post is food for thought.... Sam Buchanan
To: ultralight-flight@inslab.uky.edu Date: Wed, 01 May 1996 09:18:58 Subject: Re: MiniMax; past tense (long), stall/spin From: mike@mcfly.win.net (McFly)

For the benefit of the new UL pilots on the list, I wanted to make some observations about stall/spin accidents.

  1. A Stall occurs when the wing's Critical Angle of Attack is exceeded..PERIOD! The Angle of Attack is the angle formed by the chord line of the wing and the relative wind (opposite and parallel to the airplane's flight path). Stalling can occur at ANY airspeed and therefore understanding the factors that effect "stall speed" will help avoid a stall.
  2. The "Stall Speed" published by the aircraft manufacturer is only good for 1 G flight! We all know that as you increase bank angle during a level or climbing turn (like in this accident), the load factor or number of G's increase. In a 60 degree bank, level turn you will be pulling 2 G's. As the G force on an aircraft increases, so does the stall speed. In a 60 degree bank level turn (2 G's), the stall speed increases 41%. At 3 G's, stall speed increases 73%, and at 4 G's stall speed DOUBLES. If your aircraft has a published stall speed of 40 mph and you do a go-around with a 60 degree turn, the aircraft will now stall at 57 mph and therefore a normally safe speed of 55 on final is now below the stall speed!!! It is my opinion that this COULD have been what caused this accident.
  3. While I agree with Sam that not all accidents will ever be prevented, this accident was certainly preventable. Flying is more than being able to takeoff and land; a thorough understanding of aerodynamics and proper training SHOULD prevent accidents like this from happening. I certainly agree with Sam that lack of specific UL training was not the cause in this accident. If this person was a licensed GA pilot, he certainly should have known better and he should have received extensive training in stalls previously. A stall is a stall in any aircraft, and having the basic knowledge and training is the only defense for this type of accident


McFly
Date: Wed, 01 May 96 09:41:52 EST Encoding: 14 Text To: ultralight-flight@inslab.uky.edu Subject: re: MiniMax; past tense

I am certainly very glad to hear the pilot is OK and some form of luck was with him last Friday.

I'm sorry to hear about the Minimax.

And I'm particularly relieved that the story didn't unfold differently. That the missing BRS chute would have "saved the day" since I'm the one who purchased it from Sam and it's now mounted to my MX.

Best regards, Dave
Date: Wed, 01 May 1996 10:26:01 -0400 From: Sam Buchanan <sbuc@companet.net> To: ultralight-flight@inslab.uky.edu Subject: Re: MiniMax; past tense (long), stall/spin References: <413@mcfly.win.net>

McFly wrote:

3. While I agree with Sam that not all accidents will ever be prevented, this accident was certainly preventable. Flying is more than being able to takeoff and land; a thorough understanding of aerodynamics and proper training SHOULD prevent accidents like this from happening. I certainly agree with Sam that lack of specific UL training was not the cause in this accident. If this person was a licensed GA pilot, he certainly should have known better and he should have received extensive training in stalls previously. A stall is a stall in any aircraft, and having the basic knowledge and training is the only defense for this type of accident.



Mike,

This is why the pilot was really hacked with himself....HE KNEW BETTER than to exceed critical angle of attack. I think we need to realize the danger of getting preoccupied with events outside the plane and forgetting that we have to fly the plane at all times.

Sam
Date: 01 May 96 11:50:18 EDT From: Kurt Mastopietro <72652.505@CompuServe.COM> To: "(unknown)" <ULTRALIGHT-FLIGHT@inslab.uky.edu> Subject: mini max accident

From what I have read it sounds like the person forgot the basic

ALWAYS FLY THE PLANE

Bull or no bull

October, 1996

Where:Nome, Alaska, United States
When: October 18, 1996
What: Unspecified
How: A microburst sheared the tail off the plane about 10 feet off the ground
Injuries: 3 broken ribs, 1 broken arm
Training & Experience of Pilot: 1 year of recreational flying

November, 1996

Where:Hillsboro, Oregon, United States
When: November 10, 1996
What: TEAM aircraft, exact type unspecified
How: While in flight the engine began to alternate between idle and high rpm, and eventually quit. The pilot made a deadstick landing without further incident.
Injuries: None
Training & Experience of Pilot: 1,000+ hours in ultralights including Weedhopper, Phantom, and TEAM. 50 hours in general aviation, but no pilot's license.

Pilot Commentary:

Flew into Olinger field from my 800' home strip to practice landings and takeoffs on the 1800 ft strip at Olingers. On first flight out, took off into mild breeze to the West, turned South and was still climbing out and about 800 ft and about about 1/2 mile from the field when the 447 Rotax engine lost rpm, going to idle, then immediately again going to full throttle, then idle, oscillating between these 2 extremes. Did immediate left turn, nose steeply down and headed back to field. Informed field via radio I was making an emergency landing. Engine continued to go from idle to full throttle with a period of about 1-second. Lined up on runway and when I felt I could make it even if the engine stopped completely I closed the throttle. The engine immediately stopped. Made a dead stick landing safely. Could not restart engine (electric start), would not even turn over. Next day I found the problem, MY problem. I had connected the electrical ground wire from the electrical box to the starter ground ON THE ENGINE. This single multiple strand wire had either worn (or my foot had hit it, since the wire was PREVIOUSLY low enough to have been caught with my left foot) When this wire seperated it cut the ignition to my engine. Without the ignition on, the engine stopped but as it started to slow down the lack of torque allowed the engine to rotate counter-clockwise on its rubber mount just enough to make contact with the broken lead which again connected the spark. The engine would then start to run but the torque would pull the starter/wire connection loose once again. This process continued until I pulled the throttle back, at which time the engine simply stopped.

My errors: I should have used a redundant lead on a connection this important. I also connected that single lead I did have to a point on the engine that moved with respect to the connecting wire and therefore would mechanically move that wire each time the engine rpm was changed, subjecting the wire to flexure. What I SHOULD have done (and will do prior to flying this aircraft again) is to connect two seperate wires from the electrical box to the engine and I will connect to a more physically stable point on the engine.


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