Safety Issues
Safety Study of Piloting Skills, Abilities and Knowledge in Seaplane Operations
Seaplanes account for 19% of the Canadian aircraft fleet and 18% of the total number of accidents. However, in most parts of Canada, seaplanes operate only about six months of the year. Thus, the number of seaplane accidents would appear to be disproportionately high.
It is also observed that aeroplanes which are most frequently float equipped, such as Piper Cub "derivatives" (J3, PA11, PA12, PA14, PA18, PA20, PA22), Cessna 172, Cessna 180, Cessna 206, Beaver, and Otter, have more fatal accidents on floats than on wheels. When these aeroplanes are on wheels, 10% of the accidents are fatal, but when on floats, 17% are fatal.
As a result of these disturbing numbers, the TSB undertook an intensive investigation into the seaplane accident record, identifying safety deficiencies associated with the levels of skills, knowledge, and decision-making abilities of pilots engaged in seaplane operations.
The study first describes the characteristics of seaplane accidents which differentiate them from other aeroplane accidents. It then considers the factors which have contributed to these accidents and examines the training and background of the pilots involved. Finally, the report describes the safety deficiencies identified and proposes safety actions to correct them.
The Accidents
The study broke accidents down into two categories, with major injury or fatal accidents being designated as "Serious Accidents."
Phase of Flight
En route accidents account for a little less than a quarter of all accidents, but for more than a third of the serious accidents. However, this study focuses on those aspects of seaplane operations which differentiate them from other flying operations.
Standing & Taxiing
During the standing and taxiing phase, most accidents involved losses of control, propeller contacts, nose down/over, and collisions. As far as serious accidents are concerned, 15 resulted from propeller contact, 3 from nose down/over, and 2 from loss of control.
Take Off
The most frequent types of serious accidents during take-off were loss of control in flight (47 accidents), engine failure (31 accidents), and collision with objects (16 accidents). Loss of control on the water surface and dragged wing were also frequent on take-off, but seldom resulted in serious or fatal injuries.
Approach & Landing
Although hard landings were the most frequent types of accident, loss of control in flight resulted in the largest number of serious accidents (15). Collisions with objects resulted in 12 serious accidents and nose down/over on the surface resulted in 11 serious accidents.
Contributing Factors
Loss of Control on the Water During Take-off
The majority of factors are related to the wind, (improper wind compensation, unfavourable wind, sudden wind shift, rough water), and suggest a lack of proper technique in dealing with various wind conditions. A seaplane is affected much more by wind during landing and take-off on water than is a landplane as there are no brakes and no nose or tail-wheel steering.
Lakes are frequently surrounded by hills which can cause unpredictable shifts in wind speed and direction. On rough water, there is a natural tendency for pilots to pull the aircraft out of the waves as early as possible; however, rough water is often a consequence of strong gusty winds, and a longitudinal oscillation can quickly develop when the aircraft is on the step, causing the aircraft to nose-over.
Loss of Control in Flight During Take-off
Loss of control in flight is either a stall, or a situation in which an aircraft goes out of control and strikes the ground, water or objects.
Factors such as "Failure to maintain flying speed," "Premature lift-off," "Misused flaps," "Improper operation of primary controls," and "Improper wind compensation" are frequently related to poor technique or a lack of skill.
Factors such as "Unsuitable area," "Inadequate pre-flight preparation," and "Failed to follow approved procedures" might demonstrate a lack of knowledge.
Factors such as "Operation beyond ability" and "Failed to abort take-off" can result from poor judgement.
Engine Failure During Take-off
"Water in fuel" ties with "Engine failure for undetermined reason" for number one contributing factor.
On seaplanes, carburettor icing on take-off is a greater risk than on landplanes because of the high level of humidity, due in part to the water-spray on some models, during the take-off run.
Collision With Objects During Take-off
The most frequently indicated factor, "Pilot selected an unsuitable area for take-off," suggests that the pilot exercised poor judgement.
"Inadequate pre-flight preparation," "Failed to abort take-off," and "Operations beyond ability" also reveal behaviours in which poor judgement would have been a factor.
Loss of Control in Flight During Approach
These accidents were generally characterized by a stall, or a stall followed by a spin at low altitude, while turning from base leg to final. Many of the visual cues and approach aids that are available to land-based aircraft are not there for seaplanes about to land on the water, and mountainous or hilly terrain on the final approach may alter the pilot's perception of the correct approach angle.
In the absence of a clearly defined and visible landing area, the turn from base to final can be easily misjudged and result in excessive angles of bank during a critical manoeuvre for landing. The illusions created by the topography and drift at low altitude can also contribute to approach accidents.
Loss of Control on the Water During Landing
The majority of "loss of control accidents occurring during landing on water" happened in cross-wind or glassy-water conditions.
A balked glassy-water landing frequently entails a loss of control. If the flare is too high, the aircraft stalls and the nose or one wing drops. If there is no flare, and with the slightest yaw and/or pitch down, the front end of one float hits the water first and creates an immediate and violent unbalance. In a stalled, nose-down condition, the aircraft usually noses over.
Pilot Factors
While commercial and private pilots are spread fairly evenly in the case of collisions with objects and loss of control during take-off, it can be observed that, in accidents caused by loss of control during landing and engine failures during take-off, more private pilots were involved.
As expected, pilots in the zero to 100-hour category assume the largest share of accidents. However, this is more so in the case of seaplane accidents than landplane accidents.
The Operating and Regulatory Environment
This section takes an in-depth look at factors such as, Attitudes Towards Safety, Training and Certification Requirements, Trainers' Qualifications, Learning and Decision Making, Proficiency, and Periodic Flight Review.
Summary
The report concludes that Seaplane operations are carried out in an unforgiving environment that requires special skills, knowledge, and decision-making abilities. And as Seaplanes are usually operated in remote areas, a distinct culture about their operations has evolved largely unchecked over the years. Consequently, seaplane pilots tend to acquire skills and knowledge through trial and error, peer example, and hearsay - not the most appropriate way to develop the required abilities.
Conclusions
The incidence and severity of seaplane accidents is disproportionately high in comparison to landplanes. Loss of control during take-off, engine failure after take-off, collision with objects during take-off, and loss of control during approach and landing are the most frequent types of accident resulting in serious injuries or fatalities.
The most frequently cited contributing factors in these accidents strongly indicate serious shortcomings in pilot knowledge, skills or techniques, and/or judgement in decision-making.
In sum, the evidence calls into question the adequacy of current practices and requirements for initial and recurrent training from water.
Recommendations
The report ends with recommendations on a variety of topics such as, Training, Trainers' Qualifications, Evaluation and Certification, Flying Currency for Passenger Operations, Periodic Flight Review, and Seaplane Pilots' Seminars.
