Incident Summary
On a local instructional flight from St. John's International Airport, Newfoundland and Labrador, a Piper PA-28-140 (registration C-FYKS, serial number 28 25719) departed at 1338 Newfoundland standard time with an instructor pilot and a student pilot on board. The aircraft climbed on a southwesterly heading to 2000 feet above sea level (asl). At 1343, the pilot reported leaving the control zone, which was the last radio communication.
Air traffic control radar data showed the aircraft descending gradually while executing a series of 90° turns. Ground speed during descent was between 50 and 70 knots. After the fourth turn, ground speed increased to 100 knots. The aircraft disappeared from radar at about 600 feet asl (200 feet agl), reappearing 37 seconds later at 700 feet asl (250 feet agl). It entered a tight left turn and finally disappeared from radar at 1352:10, on a westerly heading at 70 knots ground speed. The last radar position coincided with the accident site. The student pilot died in the crash. The instructor received serious injuries, including head injuries with post-trauma amnesia, and could not provide investigators with information about the accident. No known witnesses saw the accident. Occupants of a passing vehicle noticed the wreckage and called 911 at 1359:51.
Flight Purpose and Maneuvers
The purpose of the flight was to instruct the student on engine-out, forced-landing glide techniques. The normal method begins at 3000 feet, but the aircraft encountered a lowering ceiling that restricted maximum altitude to approximately 2000 feet asl. The normal recovery altitude is 500 feet agl; however, instructors may descend lower. It appears the glide sequence was initiated. It was not possible to determine if the cold-weather glide technique was used.
Weather Conditions
At departure, the airport reported wind from 215° Magnetic at 10 knots, visibility 12 statute miles, few clouds at 3000 feet agl, overcast ceiling at 5500 feet agl, temperature 2°C, dew point -3°C, and altimeter setting 29.88. While transiting out of the control zone, the aircraft would have encountered a lowering ceiling that restricted altitude to approximately 2000 feet asl. Snow squalls moved through the area after the accident, but personnel near the site reported no snow prior.
Pilot Information
The instructor held a valid commercial pilot licence with a Class Three Instructor Rating, about 1000 hours of instructional time, and 1300 hours total flight time. The student had 21.3 hours of flight time, had made steady progress, and had completed three solo flights totaling 2.3 hours. The instructor had not flown with this student before. The chief flying instructor spoke with both before the flight to outline its purpose and limitations and assess readiness. Pre-flight briefings, checks, and calculations were completed.
Aircraft Information
The aircraft was registered for commercial operation with a valid certificate of airworthiness and was maintained in accordance with approved procedures. It was not equipped with flight data or voice recorders. It carried a DEFT 1 emergency locator transmitter (ELT), activated by impact. Weight and center of gravity were within limits at take-off.
Investigation Findings
The TSB investigation found the aircraft was flying in conditions conducive to serious carburetor icing at any engine power setting, according to A.I.P. Canada. The temperature and dew point were conducive to icing. It could not be determined if carburetor heat was applied during the practice glide or subsequent maneuvers. Carburetor ice likely formed during the glide descent if heat was not used or if the engine was not cycled as recommended. If ice had already formed, applying carburetor heat at low altitude could have reduced rpm further, preventing level flight. The lack of propeller bending, low engine rpm, and cool exhaust stacks supported low engine power at impact. The 20° nose-down attitude and stall warning light indicated the wings were stalled at impact.
The lower ceiling meant the glide entry was 1000 feet lower than normal, restricting glide time. This might have delayed climb initiation below 500 feet, but does not account for the failure to climb or prolonged low-level flight. If normal power was available, it is unlikely the instructor would have intentionally flown at low airspeed and altitude.
Probable Cause
The most likely reason for the failure to climb after the forced landing exercise was insufficient engine power available. Fuel was available and no pre-existing mechanical fault was found. The most probable reason for reduced power was carburetor icing. The aircraft subsequently struck the ground, perhaps as a result of a stall.
Related Reports
The TSB Engineering Laboratory completed reports: LP 169/04 – Instrument Analysis, LP 170/2004 – Exhaust Temperature Analysis, and LP 171/04 – Flap Extension Rod. These are available upon request. The Board authorized release of this report on 06 July 2005.