US investigators believe a Cuban-registered Antonov An-2 crashed while attempting to land on a levee, after a pilot with limited understanding of the aircraft failed to activate oil-cooling shutters, causing the engine to overheat.
The aircraft had been flown, three weeks earlier, from Cuba’s Sancti Spiritus airport to Miami’s Dade-Collier airport by a pilot seeking asylum in the USA.
US Customs and Border Protection personnel took custody of the 40-year old An-2 before transferring it to a subcontractor, for ferrying to Fort Lauderdale on 14 November 2022.
But the Soviet-designed aircraft’s cockpit had instruments labelled in Cyrillic, and the pilot only had “partial excerpts” of a flight manual for the An-2 in Spanish, obtained from a friend in Argentina, says the US National Transportation Safety Board.
“The pilot did not know if it was an official flight manual,” it adds, pointing out that the manual had airspeed listed in imperial units while the An-2’s instruments were marked in metric.
Although the pilot recruited a co-pilot to help translate the instruments into Spanish, neither had accrued any flight experience in the An-2.
The aircraft was fitted with an engine oil-cooling system mounted under its fuselage which featured shutters that could be opened using cockpit switches in order to control airflow through the cooler. It was also equipped with cowl flaps for engine cooling.
While the pilot had, on three occasions, conducted inspections and engine run-ups, he had not used a checklist. He also noticed that the cylinder head temperature gauge, which would warn of engine overheat, was inoperative.
“When asked if he had the cowl flaps in the open position for the accident flight, [the pilot] advised that he might have had them closed,” says the inquiry.
“When asked how they were operated, he could not remember. When asked about the oil cooler and where the switch was located to open and close the shutters, he did not remember anything about an oil cooler.”
After taking off from Dade-Collier in temperatures of 28°C, the pilot noticed the An-2 was smoking abnormally and, some 20min into the flight, its engine began losing power. The aircraft descended and the pilot attempted to land on a narrow levee west of Miami Opa Locka airport.
As it touched down, the An-2 rolled down a bank, nosed over and came to rest inverted in the water and vegetation. The aircraft was substantially damaged but neither occupant was injured.
Analysis of the wreckage showed the cooling shutters closed, while video of the take-off also revealed that it departed with its cowl flaps shut, causing the engine to overheat and lose power.
Investigators state that the pilot failed to “adequately familiarise himself” with the An-2’s systems, while the decision to fly with an inoperative cylinder head gauge meant he could not monitor the engine’s rising temperature.
