(CNN)An aerial display team using old-fashioned map navigation mistakenly performed over the wrong festival in Switzerland last weekend.
Swiss aerial display team performs over wrong festival after losing its way
The Patrouille Suisse -- part of the Swiss Air Force -- had been due to put on a demonstration honoring the centenary of the Swiss aviation pioneer Oskar Bider, but instead treated visitors at a nearby yodeling festival to the high-flying display.
The website of the country's armed forces describes the Patrouille Suisse as showcasing the "performance capacity, precision and operational readiness of the Swiss Air Force."
But it was a lack of GPS and outdated instruments left that left the forces red-faced on Saturday.
The fleet -- the Swiss equivalent of Britain's Red Arrows and the USA's Blue Angels -- were expected in Langenbruck, a municipality in north-western Switzerland that was the birthplace of Bider, the first aviator to cross the Alps in both directions.
According to the Patrouille Suisse's official Twitter account, the planes were due to perform for 15 minutes from 11 a.m. The demonstration would have accompanied a memorial service and musical entertainment, Langenbruck's official website said.
But it was attendees at the 31st Northwest Yodeling festival in nearby Mümliswil that instead watched the aerial acrobatics -- about four miles away from the intended location.
According to military spokesman Daniel Reist, the F-5E Tiger II aircraft are not equipped with GPS technology.
He told CNN: ''Unfortunate circumstances led to this incident. Between Mümliswil-Ramiswil in the canton of Solothurn and Langenbruck are only a few kilometers.
"Preparations were carried out by looking at a map, the measurement of 1cm on the map equates to 1km - and this equates to five seconds flight time."