Loss of control in flight (LOC-I)

N.B: For most up-to-date information on LOC-I events, change language selection to Finnish. 

Loss of Control in Flight 2024

In 2024, 14 incidents of loss of control of an aircraft during flight were reported. This was well below the 2014–2023 average (18.8) and was also lower than the previous year. The majority of incidents were related to drone operations, as in previous years.

In manned aviation, four losses of control were reported, which was below the long-term average (7.4). One of these occurred in recreational aviation and three in general aviation. Two resulted in an accident and two in a serious incident. Loss of control situations often lead to serious consequences, but the number of both accidents and incidents remained below the average last year.

No loss of control was reported in commercial air transport, which is typical, as such situations are rare in commercial operations.

Loss of control incidents are more common in general and recreational aviation, but last year four incidents were reported, which was slightly below the long-term average. 
One incident was reported in recreational aviation, which was lower than the average number in previous years (2–3 incidents per year). This incident was classified as a serious incident, as the glider entered an unexpected spin but the pilot managed to regain control of the aircraft before an accident occurred. 

Three incidents were reported in general aviation, which was in line with the long-term average. Two of these resulted in an accident and one resulted in a serious incident.

In the first accident, a general aviation aircraft crashed after takeoff at Räyskälä aerodrome, killing both occupants. OTKES has launched an investigation into the incident  (External link), and the causes will be determined once the investigation is complete. Based on preliminary information, it is estimated that the engine malfunction during takeoff led to loss of control. 
In the second accident, a general aviation aircraft lost oil pressure in the engine during the flight, as a result of which the pilot made an emergency landing in a field. During the landing, the aircraft overturned on its roof through the nose and was severely damaged.

In the serious incident, a general aviation aircraft stalled during landing and suffered structural damage in the subsequent hard landing.

In terms of number of LOC-I incidents in general and recreational aviation, year 2024 was better than average. However, in loss of control type accidents, the impact energies are usually high, which easily leads to loss of life. This was unfortunately also the case last year.

Drone operations accounted for the majority of last year's reported losses of control, but the number remained below average and was approximately the same as the previous year. Typical causes were technical failures, such as propellers or batteries detaching during flight. Reporting practices in drone operations continue to vary, and clarifications on reporting criteria are expected from the European Aviation Safety Agency. Awareness of reporting requirements is currently variable among pilots, which contributes to the number of reported incidents.

Types of incidents that contribute to LOC-I events

In addition to the laser interference, bird strikes and fire & smoke observations incidents described in more detail below, other types of incidents that may contribute to the loss of aircraft control and that are monitored include, for example, aircraft speed limits being exceeded or exceeded, incidents caused by wake turbulence, deficiencies in de-icing and anti-icing, flight control system failures and different deviations related to aircraft loading, such as load placement contrary to loading instructions or errors in securing the load or in weight calculations.

Flight control system failures were reported at a higher than average rate, and the number of such incidents has been increasing slightly for several years. Such failures include, for example, flap and aileron malfunctions and speed or attitude sensor failures. The majority of incidents are reported in commercial air transport, with the most typical incident involving a flap system failure. Although these failures can affect aircraft controllability, they did not result in any significant incidents last year.

De-icing and anti-icing deficiencies were reported at an average rate. Ice accumulating on aircraft surfaces can significantly impair the aircraft's flight characteristics and, in the worst case, lead to loss of control. Last year, the reports mainly related to inadequate de-icing on commercial air transport aircraft. These did not result in any significant incidents. Traficom updated the 2024 winter operational bulletins, which comprehensively address icing prevention. The bulletins are available on Traficom's website in versions aimed at airlines (External link)and at general and recreational pilots  (External link).

Various loading- related deviations were reported somewhat more than average. These often involved cases where the cargo was placed in the hold contrary to what was specified in the loading instructions, or the cargo was not secured properly, for example, the cargo container was not properly locked, or the nets holding the cargo in place were not properly secured. These cases were observed particularly at Helsinki Airport when flights arrived in Finland. The actual error had therefore occurred abroad when the aircraft departing for Finland was loaded. 
Loading errors did not cause significant hazards, but can increase the risk of loss of control if the cargo shifts or the weight distribution changes.

There were also more reports than average of various high speed and low speed events. Exceeding aircraft's speed limits can cause strain on the aircraft's structures and affect, for example, the execution of an approach. Similarly, too low a speed can lead to the aircraft stalling. Underspeed is most often a more dangerous condition than overspeed. Almost all of last year's incidents concerned overspeeding situations. Most often, the aircraft involved were commercial air transport aircraft. The incidents did not cause any serious consequences. Typically, the specified speeds were exceeded either during the e route phase (most often weather phenomena contributed to the unexpected change in speed) or during the approach phase (weather phenomena also as one influencing factor, but also, for example, too early extension of the flaps by the crew).

Weather phenomena affected many reported incidents, and their share has been monitored for a long time. In 2024, the number of incidents related to weather phenomena increased again. From the beginning of 2024, special monitoring of incidents in which significant turbulence was observed during the flight began. One turbulence incident led to a serious incident on a small Finnish commercial aircraft, when a passenger was injured due to turbulence during the en route phase of the flight. 

In addition, in August, OTKES began an investigation  (External link)into a serious incident that occurred on a Norwegian airline flight from Rhodes to Helsinki on 11 August 2024, in which two cabin crew members were injured after the aircraft flew into turbulent airflow. 

Injuries caused by turbulence also occur in the cabin of Finnish aircraft every year, but they are typically not very serious. Turbulence usually causes problems during the enroute phase, when seat belts are not necessarily used in the cabin. Turbulence cannot always be detected in advance (for example, CAT or Clear Air Turbulence), so it is wise to always keep your seatbelt fastened when sitting in the cabin. 

During the approach and landing phase of the flight, everyone has their seatbelts on, and then unexpected changes in wind direction or speed can cause unstable approaches, for example. In some cases, the conditions can be so bad that the aircraft has to fly to an alternate airport. Last year, there were more such cases than average. It is safer to make such a decision than to try to land despite the conditions.

Technical failures in aircraft can lead to a variety of consequences, loss of control being one of them. One indicator to monitor is the number of technical failures that lead to flight cancellation or diversion. The number of such incidents has been on a slight decline since 2019. Last year, the number remained at the average for the years 2014-2023 (approx. 120). 
In commercial air transport in particular, there are precise criteria for the condition of aircraft systems. If these are not met, the flight must be cancelled or aborted. In commercial air transport, the number of such failures that led to flight cancellations was at the average level. 3 incidents were classified as serious incidents, and they involved smoke observations that were caused by a failure of the aircraft's technical system. 
The numbers in general and recreational aviation were also at the average level. 2 of them led to an accident and 5 to serious incidents. These figures were approximately at the level of longer-term averages.

Laser interference

A detailed review of laser interfence situation is available here (External link). 

Bird strikes

A detailed review of bird strikes and an interactive report of them is available here (External link). 

Fires and smoke detection on aircraft

One of the indicators of loss of control of aircraft monitored by Traficom is fires and smoke observations on aircraft. A fire on an aircraft is a serious situation that, if it occurs in the air, can quickly lead to loss of control of the aircraft and, in the worst case, its destruction.

A total of 18 smoke observations or fires on aircraft were reported in 2024. The majority of incidents occurred in commercial air transport, as has been typical in previous years. However, more incidents were reported in commercial air transport than the average for 2014–2023.

Three incidents were classified as serious incidents, slightly more than in previous years. In two cases, smoke was observed in the cabin during the flight, which resulted in the flight being aborted and the aircraft landing at the nearest suitable airport. In the third case, smoke began to form during the aircraft taxiing, leading to the evacuation of passengers. In all of these cases, the smoke was apparently caused by overheating of systems. No significant fires occurred in these cases.

In general and recreational aviation, six smoke observations and fires were reported, which was also above the long-term average. Of these, two resulted in accidents and two in serious incidents.

One of the accidents occurred in recreational aviation when smoke was observed in the cockpit of an ultralight aircraft, which made a forced landing and rolled over and was damaged. The other accident occurred in general aviation when an aircraft engine caught fire during start-up, severely damaging the aircraft. Such fire situations that result in accidents have been very rare.

Serious incidents occurred in general aviation. In one case, an engine caught fire during start-up, but the fire was extinguished. In another case, smoke entered the cockpit during take-off, and the plane had to return to land.

In addition, two smoke observations occurred in foreign commercial air transport in Finnish territory, one of which was classified as a serious incident. In that case, an airliner engine had leaked oil on the apron, and the hot engine ignited it. The crew started the engine, which caused the air flow to extinguish the fire.

Last year, passenger smoking on Finnish aircraft did not cause any serious incidents, but slightly more incidents were reported than average. These incidents also included the use of e-cigarettes. The year before last, one incident of smoking led to a fire in the aircraft's toilets, but fortunately the fire was quickly extinguished.

Traficom published a press release in October 2023 (External link) regarding unruly passengers. One form of such behavior is also smoking on the plane. More about disruptive passengers in the next section 9.5.

Tieto.traficom also has an overview of cases related to disruptive passengers (External link).