Knowing When To Quit
Listen To Your AirplanePersistence is said to be a virtue. In business, perseverance and enthusiasm will frequently overcome the lazy but intellectual approach. In aviation, however, when the aircraft hands you a problem, it¿s wise to listen and not press on until it¿s been resolved.
A Cessna 172K was destroyed when it struck the water during takeoff from a lakeside beach in mountainous terrain. The weather was not a factor.
While en route, the pilot had observed smoke coming from the cowling and some smoke in the cockpit. He elected to land on a beach alongside a reservoir. After landing, the pilot inspected the airplane but was unable to locate the smoke source. He allowed the fumes to dissipate and prepared for takeoff. According to his statement, ¿All engine instrument indications were normal and maximum engine power was developed.¿ The pilot made a short field takeoff, and the aircraft lifted off ¿prior to the go/no-go decision point.¿ As the Cessna crossed over the water, it began to lose altitude. The right wing dropped; the airplane struck the water and nosed over. The commercial pilot was the sole occupant aboard and was not injured.
The pilot noted that extensive maintenance on the airplane had been performed on two different occasions, and he had made prior off-airport precautionary landings because of smoke in the cockpit. In the first incident, wiring inside the transponder had burned. In the second incident, unsecured wires had chafed against a bus bar and short-circuited. He surmised that the smoke source during this latest incident was due to the ¿breaking in¿ of the newly installed muffler and exhaust stacks. (Important safety tip: There is nothing on an aircraft that routinely smokes during break-in.) The source of the smoke was not determined.
Density altitude was probably a factor in the poor climb performance and subsequent crash. However, there are several other messages in this incident that should be shared with students. There are enough opportunities for problem solving when difficulties arise without warning. In this case there was considerable warning. It appears that the maintenance practices on this particular aircraft left a lot to be desired.
Smoke in the cockpit should never be treated as a minor problem. Air carriers have learned the hard way that fires aloft, while rare, can rapidly escalate out of control. If you are not an A&P, it¿s not wise to second guess the good decision that you initially made to terminate the flight when an abnormal situation appeared. The pilot did the right thing when he landed immediately, including choosing an off-airport site to resolve the issue. The bad choice occurred when, after everything appeared to be normal, he attempted a takeoff. Without knowing whether the aircraft was operating normally or if it would be able to become safely airborne under the ambient conditions, the pilot¿s risk level went way up.
This pilot may have become desensitized to the recurring problems with the aircraft. When the aircraft complains, have a mechanic look at it and sign off the return to service. In this case, the third time was not a charm.
By Bruce Landsberg