I like to think I have great attention to detail — that’s a cornerstone of what makes me a good pilot.
My wife thinks otherwise. She can enumerate countless times when my attention to detail was lacking enough I forgot to buy a food item clearly written on the grocery list, left my damp laundry overnight in the washing machine, or returned home minutes after leaving to retrieve my phone by the door.
Missing an item happens to the best of us. But when a rudder fails due to somebody’s inattention to detail, it’s important to analyze what happened in that moment and how it can be avoided in the future.
A maintenance technician submitted a report to NASA’s Aviation Safety Reporting System after incorrectly reassembled rudder control cables on a Cessna 172 went unnoticed and failed during a flight.
It all started when the Cessna was brought into the shop following a landing incident. A maintenance tech trainee was tasked with repair and replacement of the rudder cables.
The reporting A&P wrote, “Myself, along with several other technicians, failed to find that the rudder cable clevis was not safetied.”
During final inspection, even their chief inspector failed to notice that the cable was not secured. The aircraft was returned to service in that condition.
The aircraft flew several times without any problems. However, on this flight, the rudder failed during flight. The pilot landed safely and returned the C-172 to the shop. Upon inspection, the disconnected rudder cable clevis was discovered.
While reinstalling and rigging the cable, a technician also noticed that the rudder cables weren’t properly routed near the front pedals. The technician replaced the damaged cables and reinspected all other control cables before returning the airplane to service.
A Cessna 182 pilot who also performed parts of his own annual had to submit a NASA report after the rudder pedal separated from the rudder control post during taxi.
“In finishing the annual,” he wrote, “I had removed the bolt that connects the pilot’s left rudder pedal to the control shaft to more easily reposition the metal cover plate that surrounds the pedals.”
After he successfully returned the 182 to its tiedown spot, he performed a thorough inspection of the rudder pedal assembly. He found he had not completely reseated the pedal tube onto the control shaft. That’s why the securing bolt had passed above, instead of through, that shaft.
He had apparently tightened the nut on the bolt firmly enough that a test pull upward made him think he’d reinstalled everything properly.
“Of course, I have learned to verify bolt positioning and will likely never allow anything similar in the future,” he wrote in his conclusion.
Once the pilot fixed the problem, he took the opportunity to do another, more thorough aircraft inspection. It was then he discovered the tail cone had been slightly bent up and was contacting the rudder, which he subsequently fixed and logged.
Two pilots rented a Cessna 172 to get some time-building in. That time-building exercise turned into report-writing after an A&P’s inattention to detail caused rudder control and brake failure during taxi operations.
“I tested my brakes and they worked fine,” wrote the left seat, flying pilot. The right seat, non-flying pilot, however, did not test his brakes, according to the pilots’ NASA reports. During taxi out, the flying pilot depressed the left rudder to turn from one taxiway to another, and the plane failed to turn left.
He tried to correct by adding left brake to help the turn, but to no avail. Not only was the plane unresponsive, but there was zero pressure in the brake. The pilot pressed the brake full play. He then cut the power and stomped on both brakes. Nothing happened.
“I tried steering the plane off to Taxiway November because I knew we were going to crash. Our right tire dipped into the ditch and took our plane into the main part of the grass,” he wrote.
Once the plane stopped, the pilots contacted Ground Control, cut off fuel, master and magnetos, and exited the airplane.
Damage to the airplane included the right part of the horizontal stabilizer and right main. Both were bent upon impact. The 172 also suffered a dent in the right wing leading edge.
After the plane was towed back to the FBO, the pilots reported the problem and chose to inspect the maintenance logs. The logs revealed previous complaints about right seat low brake pressure. The logs also indicated the problem wasn’t fixed before the plane was put back into service and that the plane flew several hours between the complaint and the failure.
One of the pilots concluded: “To stop recurrence, pilots should be aware of reported issues and [maintain] their skepticism, even though it’s a small thing such as ‘just the left brake on the other seat feeling a little loose.’ Even though it was checked and flown just one-half hour before, things can go wrong in seconds.”
The pilots correctly pointed out that only one hydraulic system serves the brake controls on both left and right seat rudder pedals in a Cessna 172. A complaint about the right side should trigger alarm bells.
There are occasions when the inattention to detail is in the original design. What had been thought to be a feature sometimes turns out to be a bug, like in the case of an ASH-25 Glider’s aft cockpit left rudder cable assembly.
The glider is a two-seater. Front and aft cockpit rudder cables are mechanically attached to two primary cables from the rudder running straight to the front seat pedals. The rear seat pedals are “sistered” to the primary cables.
“I was flying in the rear seat when the left rudder pedal connection to the rudder cable lost tension while applying corrective pressure in a right turn,” the pilot wrote.
The pilot in the front seat did not notice due to the design of the cables from the rudder to the front seat. As such, the glider remained fully controllable. The rear seat pilot immediately slowed the aircraft and rolled wings level. Then he transferred rudder control to the front seat pilot.
The pair landed their glider safely. Upon inspection, they found that the rear seat connector cable winds through an S-shaped metal tube with an inner plastic sleeve designed to improve movement. The tube part closest to the pedal had worn through, chafing the cable and causing it to fail.
Sometimes the committee that reviews NASA reports will reach out to those who submit reports. That happened in this case. The glider pilot reported he had discovered that Schleicher, the manufacturer of the ASH-25, had been made aware of the S-tube/inner plastic sleeve design as a potential hazard from several reports of similar incidents. Schleicher’s newer glider models have been redesigned to prevent such failure.
A similar situation occurred with a Zivko Edge 540T pilot, who reported loss of rudder control after the rudder cable failed in flight. She was practicing maneuvers when “I initiated snap roll in the active aerobatic box at 3,000 AGL, and the left rudder cable failed, resulting in a loss of rudder control.”
The Zivko Edge is a highly aerobatic aircraft capable of a 420°-per-second roll rate and a 3,700 foot-per-minute climb rate. Flight control failure during a critical maneuver like a snap roll is potentially catastrophic. For her, it wasn’t. The pilot proceeded directly to enter left traffic to land. Upon landing, her plane yawed left. She used her left brake for directional control, but it eventually locked up, resulting in a prop strike. Other than the propeller, no substantial damage occurred and no one was injured.
She reported she had performed a thorough preflight before departure, a preflight that included checking rudder cables and attachment points. She had not noticed any fraying or damage to the rudder cable.
Post incident, she found that the area where the cable had snapped was enclosed in an S-shaped tube. It was constructed so the cable had to be removed from the tube to inspect it. As such, that part of the cable is normally only inspected by a mechanic during an annual.
A C-170 pilot submitted his NASA report after a hard tailwheel landing. He landed on an up-sloping runway tail first. He then allowed his main landing gear to thunk onto the pavement.
“The consequence of this was a tailwheel shimmy resulting in the tailwheel rudder control chain disconnecting from the tension spring,” he wrote.
He lost rudder pedal control of the tailwheel, which began to castor freely. He then applied incorrect crosswind correction, which put the plane into a ground loop.
Although there were no injuries or property damage, the hard landing did damage the aircraft’s sheet metal.
The pilot also did damage to his license.
“The FAA has required me to take commercial test and check flight over for competency,” he concluded.
