What happened
On October 31, 2000, at Kuopio Airport, a Finnish Air Force F-18C Hornet, registration HN-401, was conducting a training flight in instrument meteorological conditions (IMC). The flight involved a series of VOR/DME and precision approach radar (PAR) approaches to runway 15. During the final stages of a PAR approach, the aircraft descended to an altitude of approximately 10 meters above the runway threshold.
At the time of the low approach, several maintenance vehicles were operating on the runway. As the pilot reached the threshold, they observed the flashing lights of the vehicles and initiated a go-around. Simultaneously, the PAR controller observed the potential hazard and instructed the pilot in Finnish to execute the go-around. The pilot confirmed the maneuver and noted the presence of traffic on the runway.
The investigation
The investigation examined radio communications between the pilot, the precision approach radar (PAR) controller, and the tower (TWR) controller. Investigators also reviewed the aircraft's Head-Up Display (HUD) video footage, which captured both the cockpit information and the external landscape.
Technical inspections focused on the communication equipment used between the PAR and TWR controllers. The investigation found that the light-based signaling device used to coordinate landing clearances between the two controllers was not approved by the Finnish Civil Aviation Authority. Additionally, it was noted that a precision approach simulator installed at Kuopio was not operational for use.
Findings
- The pilot experienced a strong desire or perceived need to execute a go-around from a very low altitude at the runway threshold.
- This impulse may have been influenced by the cloud base dropping below predicted levels, reaching the minimums for a Class 1 approach.
- Inconsistent use of standard phraseology in radio communications contributed to the situation, as some approach-related clearances were not provided by air traffic control.
- The pilot did not receive specific instructions regarding a low approach or associated altitude restrictions during the final approach.
- The signaling device used for coordination between the PAR and TWR controllers lacked a specific indicator for low approaches and was not an approved piece of equipment.