The NTSB has released its factual report on a 2018 incident that ended with the pilot of a Cessna 172 coaxing the aircraft ten miles to a safe landing missing four feet of the left wing and most of the trailing edge. The pilot was uninjured. The aircraft was on a pipeline patrol south of Abilene, Texas, on Dec. 21, 2018, when it hit a tower guy wire. The pilot was able to maintain control of the plane and land at Abilene.
The aircraft was on an inspection flight from Temple, Texas, to Snyder, Texas, and had been in the air almost two hours when the pilot, who did not have an observer with him, felt the plane “pull to the left,” according to the NTSB report. He later said he was looking down at the time, writing observation notes, when the incident occurred. He said he never saw the wire. The impact took off the section of wing just outboard of the left aileron and the trailing edge peeled inboard almost to the fuselage. The pilot later reported that in the absence of a second crew member to note observations, he could have waited to make his notes.
If EVER there was a commercial for strut braced Cessna’s … this’d be it. I think I’ll keep my 172 forever, now.
As a CFI, For many years I have used a pocket-sized digital recorder hung on a lanyard around my neck. I record all kinds of notes that can later be used for de-briefing a student or for transcription when on the ground. This keeps my head and eyes “out of the cockpit” looking for traffic (or obstructions).
It’s a Timex!
I’m no expert, and I’m full of curiosity.
The spar held which makes some sense (and kept drag more even?). Why did the rear of the wing peel off? I suppose it’s not engineered for this sort of thing, and perhaps the design is best to carry the more likely forces, but you’d think the ribs would have held better to the spar.
Seems what “should” happen is to lose the tip and then maybe the aileron, isn’t it? Is it because of surface area? Simply more rivets between the skin and ribs overcome the small contact area and attachments between rib and spar? I don’t even know how the ribs are joined to the spar.
The NTSB docket has a higher-resolution picture of the plane. It’s hard to tell from the angle, but it appears the guy wire struck the wing about 3-4 feet in from the left wingtip and sheared through the wing like a cheese slicer. Most of the aileron was cut off, but the remainder peeled back. Again, guessing from the photograph, it appears the aileron pushrod is still intact and barely visible in the center of the mayhem. A 172 aileron is almost 9-feet wide with the pushrod about in the center, so that fits the dimensions of the damage. It also matches the pilot’s description as he had to fly for an additional 5 minutes to make the airport and still had “aileron and rudder control” despite the damage.
The NTSB factual report is surprisingly sparse on facts. It says a “4-foot section of the left wing was torn off the airplane, just outboard of the left aileron,” but the only thing ‘outboard’ of the aileron is the wingtip, and that isn’t 4-feet wide. And I’m not sure where the statement that the “trailing edge peeled inboard almost to the fuselage” comes from, because I can’t find it in the NTSB report. Looking at the photo, the flap (and trailing edge) from the strut attach point inboard appears intact. Maybe it was bent but certainly not ‘peeled’ back.
About 9 miles from my home airport there is a cluster of tall broadcast towers, six of which are over 2,000 feet tall. They sit under a section of class B airspace with a floor of 2,000 feet, so there is a considerable amount of traffic flying past these towers well within range of their guy wires. Fortunately, there has never been an incident of a plane striking either the towers or the wires, but I have often wondered what an encounter with a wire would do to a plane. This pretty well illustrates that scenario. If you have never seen these types of wires up close, they are pretty stout. Unlike electrical wires strung between transmission towers, which are relatively thin and light aluminum, these guys (no pun intended) are thick, high strength steel designed to support the tower in category 4 hurricane winds. Definitely not something you would want to mess with, struts or not. 😉
Hope that guy went out and bought a lottery ticket after that incident because he sure is one lucky person. Flying four feet or so to the left and this would have been a very different story.