Safety Board Criticizes Another Case of Inadequate Oversight

Air Safety Week, Oct 18, 2004

Maintenance error strikes again, and a pilot and his passengers pay the price, according to the National Transportation Safety Board's (NTSB) Oct. 13 hearing of the July 13, 2003, ditching of a Cessna 402 into the Atlantic Ocean about seven miles short of Treasure Cay Airport in the Bahamas.

"This was an egregious and preventable accident that raises many safety issues that need to be addressed," declared NTSB Chairman Ellen Engleman-Connors.

Additional recommendations to the Federal Aviation Administration (FAA) seem sure to follow the one issued last week, urging the FAA to publish a flight standards information bulletin (FSIB) to the effect that pilots provide better pre-ditching briefings to their passengers.

This case goes far beyond that limited action, as the accident involves issues of aircraft certification (under decades-old standards), maintenance, pilot proficiency and FAA oversight.

The accident airplane, a twin-engine piston model, was engaged in a scheduled commuter flight by Air Sunshine, Inc. (doing business as Tropical Aviation Services) from the Bahamas to Ft. Lauderdale, Fla., with a single pilot and nine passengers aboard. The right engine failed during descent, pilot Hassan Moslemi, 45, was forced to ditch the airplane, and two passengers died after evacuating the airplane. The pilot and three passengers sustained minor injuries.

The case features similarities to the fatal May 31, 2000, crash into the water of a Whyalla Airlines piston-powered twin-engine airplane, a Piper Chieftain, after catastrophic engine failures. The crash occurred off the coast, about 35 miles from the flight's destination of Whyalla, South Australia. The pilot was lambasted until Australian investigators looked more closely at the engines. The second engine could not take (as in survive) the load after the first engine failed, and the 22-year old pilot did not survive the ditching (for more on the Whyalla tragedy, see www.airsafety.com.au/whyalla/whyalla.pdf).

The general similarities in the two cases aside, the NTSB has documented a litany of shortcomings in the Air Sunshine accident that paint a pretty sorry picture all around. Numerous safety defenses-in-depth were breached, culminating in this accident:

* The right engine failed while the airplane was descending through an altitude of about 3,500 feet. Two or more of the right engine No. 2 cylinder hold-down nuts became loose, which resulted in high-stress fatigue fractures and sudden separation of the cylinder from the engine.

* Air Sunshine personnel had applied insufficient torque to the nuts during maintenance that was "not documented."

* NTSB investigators concluded that Air Sunshine's maintenance and record-keeping practices were "not adequate."

* At least a portion of the engine work was performed by an assistant mechanic who had never done such repairs before - a repeat of improper elevator cable work done by an untrained mechanic on an Air Midwest Beech 1900D that later crashed due to, among other things, restricted elevator movement (see ASW, Aug. 11, 2003).

* The pilot had a history of below-average proficiency before the accident flight, including nine failed FAA flight tests. Moslemi's substandard airmanship skills, the NTSB concluded, "contributed to his inability to ... reach land when the right engine was lost."

* When the ditching was inevitable, the pilot failed to brief passengers on emergency procedures, including correct use of personal flotation devices. The failure to conduct this briefing contributed to the resulting fatalities. Only four of the inflatable life vests stowed under the seats were used. In the case of the Whyalla accident, the airplane was not even required to carry life rafts or vests. All quite legal under rules in effect at the time. But the Whyalla flight was at night, Spencer Gulf was wide, the options were few, the pilot ditched and they all drowned. Australian investigators concluded that two lives might have been saved had flotation devices been available. In November 2000, life jackets or flotation devices were made compulsory for all small commercial aircraft in Australia taking off or landing over water.

* Contrary to regulations, the Air Sunshine pilot did not have his shoulder harness fastened when the airplane hit the water. The head injury he sustained negated his ability to assist passengers after the ditching.

* Although in accordance with its standard guidelines, FAA oversight was "not sufficient to detect maintenance deficiencies at Air Sunshine." (ASW note: recall similar FAA oversight deficiencies at Alaska Airlines, Evergreen Worldwide Airlines and at Air Midwest, as documented in detail in previous editions of this publication. See ASW, Dec. 16, 2002; May 26, 2003; Aug. 11, 2003)

Another issue may be involved here - the reduced performance of many light and medium twin-engine piston aircraft, especially the safety margins, on one engine, particularly when laden. And, finally, one is left with this question regarding design and certification standards: whatever happened to graceful degradation? It's much preferable to sudden failure - and perhaps should be a design requirement.