Safety Publications/Articles

Gear Sheared

Time To Be A Skeptic

While the power of positive thinking is generally good in life, it is far better to be skeptical of any aircraft that you intend to fly. Expect and look for problems. Be suspicious, and take your time. Encourage your students to do the same. A rushed preflight does not give you every opportunity to prevent difficulty. While that may not be the situation in this mishap, I know from my own experience that a calm and thorough preflight can turn up more discrepancies than a quickie.

The following narrative from the NASA Aviation Safety Reporting System (ASRS) shows how important it is to look. It also shows that even if you do look carefully, a problem may not be identified at that time. The landing gear of training aircraft is a special emphasis item because it receives a lot of abuse.

The pilot and CFI carefully checked the Piper Seminole's gear, according to the report, and noticed no deficiencies. They proceeded to conduct high-altitude airwork and returned to the traffic pattern for landing practice. The gear was extended on the downwind leg, and three green lights were confirmed. Several landings were conducted uneventfully.

On the last landing, the instructor reported, "The gear indicators were checked three times, and the nose gear was visually verified as down by way of the mirror on the left engine. An exceptionally soft landing was made on the main wheels and the nosewheel touched the runway a second later. It held for a second and then collapsed back into the wheel well."

The Seminole slid about 500 feet while the pilot and CFI cut the mixtures and shut off the magnetos. Upon inspection by a mechanic, it was discovered that a bolt had sheared, allowing the gear to collapse. The instructor had been flying Seminoles for five years and stated that he had never had a problem before. The middle nose-gear drag link bolt had failed, which, according to ASRS, is a very rare occurrence.

This is one of those "wrong place, wrong time" type of mishaps that could happen to any of us. It is instructional, however, to understand what can happen. For your continuing education and that of your students, it wouldn't hurt to stop by the shop on a poor flying day. Spend some time with the technicians asking questions and learn some of the vulnerable spots on the aircraft that you fly.

Bruce Landsberg is executive director of the AOPA Air Safety Foundation.

By Bruce Landsberg

Back to the Index of Instructor Reports