23rd of March 2021, Chocks Away, Blog #739

In the morning of 23 March 2021, a routine operation over the Baltic Sea set the stage for an incident that highlights how small oversights can quickly escalate.

A pilot had just completed a photogrammetric flight north of Jastarnia in a Vulcanair P68. The next step was straightforward: return to the home base at Rzeszów–Jasionka Airport. After landing at Gdańsk Lech Wałęsa Airport, the aircraft was parked on apron 1, stand No 1. and prepared for the next leg.

The damaged cockpit section of the Vulcanair P68 [source: PKBWL]

While waiting for confirmation from the operations office, the pilot carried out a standard inspection. Fuel and oil levels were checked, and a walkaround was completed—including verifying that wheel chocks were in place. Everything appeared normal. The pilot then returned to the cockpit to wait.

About 40 minutes later, the go-ahead came: he would fly the return flight alone.

The pilot resumed preparations, completed the preflight procedures, started the engines, and received taxi clearance. But when power was applied to innitiate taxiing to the runway, something wasn’t right—the aircraft didn’t move.

The pilot suddenly realized that he had not removed the chokes, he then exited the cockpit with the engines still running to remove the chocks. It’s unclear whether the parking brake was set before doing so.

As the chocks were removed from the nose landing gear, the aircraft began to roll forward.

What followed unfolded in a few seconds. As the pilot attempted to stop the aircraft he tripped over the removed chocks and fell. Unable to regain control, least of all enter the aircraft. The pilot tried to catch up with the moving airplane, but failed to do so he then watched as the aircraft continued moving on its own.

The unmanned aircraft crossed a taxiway and struck a parked Saab 340. The impact caused substantial damage to both aircraft.

The rear fuselage damage of the Saab-340 [source: Gdańsk Airport]

The Vulcanair P68 sustained a substantial damage, mainly to its nose part, propellers and engines, i.e. the areas that collided with the other aircraft. The cockpit was severely damaged in its upper part from the nose of the aircraft to the center wing section. The glazing of the cabin on both sides cracked and its elements were pushed inside. On the right side, elements of the wing and the powerplant were damaged. On the left side, there was less damage to the powerplant and the wing was damaged.

The Saab 340 was substantially damaged, mainly the left rear part of the fuselage, the left wing flap and the rear part of the left engine nacelle along with the exhaust pipe. The damage was deep and involved both the skin and the structure of the airframe. was substantially damaged, mainly the left rear part of the fuselage, the left wing flap and the rear part of the left engine nacelle along with the exhaust pipe. The damage was deep and involved both the skin and the structure of the airframe.Most of the damage was caused by the rotating propeller of the Vulcanair P68 airplane. The following parts of the airplane were damaged:

• AFT shroud nacelle section;

• LH engine exhaust pipe;

• LH wing flap;

• tail cone skin, frames and stringers;

• tail cone electrical route;

• tail cone elevator control pushrods;

• LH ventral fin and both installation angles;

• tail cone detachable;

• fitting tail stand;

• air conditioning service tail cone doors;

• rear fuselage skin (FWD), bottom panel, stringers, frames;

• Cabin skin, rear bottom panel bonded assy, frames, stringers

• LH electrical power service door

damaged RH engine cowling (left photo) and damaged LH wing (right photo) [source: PKBWL]

An investigation was innitiated by the Państwowa Komisja Badania Wypadków Lotniczych (PKBWL). PKBWL is analyzing the airport's operational documentation, especially with regard to departing aircraft and is awaiting for the report on tests of the SP-FPM braking system, particularly the parking brake system.

The (preliminary) report of this accident, which served as the source for this blog, is available by clicking on the .pdf file below:

2021_0572_RW_ENG.pdf

Download PDF • 771KB

L/H engine and L/H wing flap damages (photo at left) and lower fuselage part (photo at right) of the Saab-340 [source: Gdańsk Airport]