Floats Sink Flight

Overweight utility plane cant match the challenges of the high terrain


Just as how we dress and what we drive help define who we are, so, too, does what we fly.

The practical ones drive sedans and fly Skyhawks; the rowdy ones lean toward sports cars and stunt planes. Somewhere in the mix is the large group of people whose wheels of choice are sport utility vehicles and pick-up trucks.

These load-haulers may be working, they may be playing, but theyre doing it hard. For them, a utility airplane is a natural.

The Cessna U206 has, over the years, gained a well-deserved reputation for its load-hauling ability. With its big rear doors and spacious cabin, it has found work as a cargo hauler, bush plane and jump plane. As an airplane for campers, hunters and big families, the U206 has made its mark.

The pilot of one U206 loaded his wife and a couple of friends into his plane for a trip from the Carson City, Nev., area to the San Andreas area of California – less than 70 nm as the crow flies, but this is the Rocky Mountains, and crows dont always fly in straight lines here. Birds arent the only things that dont always go straight, but more on that in a moment.

Investigators were not able to determine when the group launched into the clear fall mountain air.

The pilot didnt call for a weather briefing, nor were any calls made between the aircraft and the ground after takeoff. Shortly after the flight began. It came to a very premature end.

Mysterious Beginnings
At 4 pm Pacific time, the flight was reported overdue at Maury Rasmussen Field in Calaveras County, Calif. Rescuers searched the proposed route for days, scouring the wilderness areas that blanket the valleys between mountain peaks that soar over 12,000 feet. Finally, on the 10th day of searching, the wreckage was found. The flight had made it less than 30 miles.

The Cessna went down in a shallow canyon about two miles from a lake. The plane apparently had not deviated much from its on-course heading when it struck a series of 80- to 90-foot-tall pine trees.

It came to rest inverted, with all major components found within 10 feet of the fuselage. The engine and propeller were under the fuselage in a hole about 3 feet deep.

A post-crash fire had incinerated the wreckage, ending any chance the occupants may have had of surviving the accident. But even after the fire and the 10-day delay, investigators estimated the airplane contained about 30 gallons of fuel at the time of the accident.

The investigation disclosed several troubling aspects. The airplane was a 1966 U206B, equipped with a 285 hp Continental IO-520-F engine. The six-seat airplane had been modified with floats and a three-blade propeller – and therein was part of the problem.

Investigators determined that the maintenance records of the airplane were incomplete. The float and prop modifications had been made by the pilot himself less than four months before the accident, the logbooks showed.

No mechanic had signed off on the work or authorized the airplanes return to service. The mechanic who had conducted the last annual inspection – 11 months before the accident, said the owner generally performed his own preventive maintenance.

The NTSB report contains conflicting information on the ownership of the airplane. Some of the investigators documents show the pilot as the owner while others show the pilots father, who had the same name, was the owner.

At the time of the annual, the airplane had 8,623 hours on it and the engine had 576. Although it could not be determined specifically, the airplane may have had as many as 9,291 hours on the airframe and 1,244 hours on the engine.

The last weight and balance entry that could be found was dated more than two years before the accident and did not reflect the floats and the new prop.

Utility Runs Short
The Cessna Pilots Operating Handbook for the U206B gives a maximum takeoff weight for a float-equipped airplane as 3,500 pounds. Using the available information on the weight of the passengers and assuming full fuel and no baggage, the airplane would have weighed more than 3,900 pounds and would not have been within its center of gravity limits, a Cessna expert determined during the investigation.

There was no evidence of any pre-crash mechanical trouble.

We may never know just why the pilot was trying to fly an aircraft that was 400 pounds overweight over the Sierra Nevada mountains. The crash site was about 7,800 feet msl and likely had a density altitude of about 8,400 feet at the time of the accident. At that altitude, the aircraft would have been able to generate about 200 hp – not much to haul nearly 4,000 pounds of airplane.

If there had been any indication that the airplane wasnt working properly, the pilot had several emergency landing sites nearby – that is, if the pilot knew how to land on water.

Why Bother?
The aircraft flew within a few miles of Hellhole Lake and the crash site was about two miles away from Lower Sunset Lake. The accident report lists the pilot as having a private license with no ratings other than single-engine land. That brings up the question of why a pilot with such ratings would bother modifying his airplane with floats.

It is certainly possible he was working on his seaplane rating. His father, afterall, is a CFI and holds a seaplane rating. It is also possible that the father was, in fact, the owner and drove the modification. Its also possible that the 1,100-hour pilot disdained the federal bureaucracy and operated the airplane the way he wanted.

Investigators didnt pursue this angle because, frankly, it didnt really matter to them. What mattered was that an overloaded airplane crashed and burned in high terrain. The NTSB cited the pilots improper planning, which resulted in flight into terrain. Contributing factors were the overweight condition and the mountainous terrain.

Ignoring the operating limitations of an airplane is any pilots prerogative.

Common sense would dictate, however, that you should try not to take anyone else with you. If this pilot didnt know the airplane was overweight, he was careless to the extreme. If he knew it, and still subjected his wife and companions to the risk of a mountain flight, then his irresponsibility was inexcusable.

Many pilots make flights that arent strictly legal. Maybe your instrument currency is a few weeks out of date. Maybe you go ahead and bring your passengers home at night even though you havent flown after dark in a while. Depending on the circumstances and the pilots, those illegal flights may be perfectly safe.

But pilots who knowingly put unsuspecting passengers in harms way commit the worst kind of crime – the one against human nature.

-by Ken Ibold


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