Aviation Safety Letter 3/2004

Recently Released TSB reports

The following summaries are extracted from Final Reports issued by the Transportation Safety Board of Canada (TSB). They have been de-identified and include only the TSB's synopsis and selected findings. For more information contact the TSB or visit their Web site at www.tsb.gc.ca/ — Ed.

TSB Final Report A02P0136 — Aircraft Stalls on Takeoff

Aircraft Stalls on TakeoffOn July 1, 2002, a rented Cessna 172N was taking off from Boundary Bay Airport, British Columbia, at 12:14 Pacific Daylight Time (PDT), with the pilot and three passengers on board, for a local pleasure flight. The takeoff on Runway 25 appeared to be normal until the main wheels left the ground, whereupon the nose rose to a very steep attitude. The aircraft climbed to an estimated height of 100 to 150 ft, the right wing dropped, then the left wing, then the right wing again, and the aircraft struck the runway nose down and right wing low. A fire broke out in the area of the left cowling, fed by a broken fuel line from the left fuel tank, but was quickly extinguished by bystanders with portable fire extinguishers. Two passengers were fatally injured, the pilot sustained serious injuries, and the third passenger died in hospital the next day. The aircraft was destroyed.

Findings as to causes and contributing factors

1.  The elevator trim tab was set halfway between the neutral (take off) position and full nose up on the cockpit indicator, which resulted in a very strong nose up pitching moment at lift off, causing the aircraft to stall aerodynamically at a height from which recovery was not possible.

2.  The checklist used by the pilot contained no challenge to verify the position of the elevator trim tab before takeoff.

3.  The flaps were set inappropriately for the attempted takeoff, adding to the instability.

4.  The aircraft was overweight at takeoff; it is unlikely a weight and balance calculation was completed prior to flight.

5.  The aural stall warning mechanism was defective and probably did not activate when the aircraft stalled during the accident sequence.

6.  The wrong flap selector plate for the particular Cessna 172 model was installed around the cockpit flap lever, which limited flap extension to a maximum of 30°.

TSB Final Report A02C0072 — Runway Excursion

Runway ExcursionOn April 16, 2002, a Swearingen SA226 TC Metro II was on a scheduled flight, under instrument flight rules (IFR), from St. Theresa Point to Winnipeg, Manitoba, with two pilots and 13 passengers on board. The crew was anticipating a visual approach to Runway 36 at Winnipeg International Airport but, because of conflicting traffic, accepted vectors for the instrument landing system (ILS) approach to Runway 13. At approximately 19:08 Central Daylight Time (CDT), the aircraft landed to the right of the runway centreline, then drifted further right and departed the runway surface, damaging a runway edge light, a taxiway edge light, and a runway identification sign. It then travelled 1 150 ft through the infield and came to rest near the intersection of Runways 13/31 and 18/36. There were no reported injuries. The aircraft's left engine (Garrett TPE 33) sustained damage from ingested mud and vegetation. The right wing, left wing, and fuselage were damaged when the aircraft struck the edge lights and the runway identification sign. After the aircraft stopped, the crew shut down the engines and advised the Winnipeg Airport air traffic controller of their position. The airport crash alarm was activated and emergency response personnel responded.

Findings as to causes and contributing factors

1.  The aircraft landed during heavy precipitation on a wet runway, and it likely hydroplaned, resulting in a loss of directional control and runway excursion.

2.  The aircraft was cleared, on short notice, for an approach to a runway with a tailwind that exceeded MANOPS guidelines for operations on a wet runway, and was cleared to land with a crosswind that approached the limit in those guidelines.

3.  The crew continued with an instrument approach in rapidly deteriorating weather conditions characterized by heavy rain, low visibility, wind shear, turbulence, and tailwind and crosswind components.

Safety action — After the occurrence, the operator added a crew resource management (CRM) segment to its training program for Metro pilots.

TSB Final Report A02C0145 — Collision with Water

Collision with WaterOn June 29, 2002, at approximately 14:10 Central Standard Time (CST), a Cessna A185F seaplane was taking off from Engemann Lake, Saskatchewan, on a visual flight rules (VFR) flight to Thomson Lake, with a pilot and two passengers on board. The aircraft was about 10 to 15 ft above the water, established in a wings-level, nose up climb attitude, when the pilot glanced to the left. Before the pilot was able to look back to the front, the aircraft struck the water, overturned, and began to sink. The pilot and front seat passenger escaped from the sinking aircraft and survived. The second passenger, who was in the left rear seat directly behind the pilot, sustained serious injuries to the legs, chest, and head during the impact, did not escape from the aircraft, and drowned. The aircraft was substantially damaged. The accident occurred during daytime visual meteorological conditions (VMC).

Findings as to causes and contributing factors

1.  The horizontal stabilizer trim was set to a nose down setting, resulting in a need for the pilot to maintain back pressure on the control column to hold a nose up climb attitude.

2.  The pilot most likely unintentionally relaxed the control column back pressure after takeoff, causing the aircraft to pitch nose down and strike the water.

Findings as to risk

1.  The eye bolt from the upper left forward float strut attachment had a pre impact fatigue crack greater than 75% of the cross section of the eye bolt.

2.  Injuries sustained by the rear seat passenger likely prevented his escape from the sinking aircraft. The risk of injury was increased because the seat was not equipped with a shoulder harness.

3.  The pilot's rest period the night before the accident was less than the minimum required by either the Canadian Aviation Regulations (CARs) or the company operations manual.

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