This study examines the impact of vowel quality and syllabic position on the aerodynamic requirements for producing the French uvular trill. The findings suggest that using the vowel [a] when producing rhotics is more likely to result in trills, whether in word-initial or intervocalic positions. This is followed by [u], while rhotics produced with [i] tend to favor fricatives rather than trills. Trill production is more advantageous in word-initial positions compared to intervocalic positions. Furthermore, the results demonstrate that as the duration of sustained productions above a 2 hPa threshold increases, the conditions for trilling become more favorable in the [a] and [u] contexts. The recommended time limits for trilling in these contexts are 110 ms for [a] and 140 ms for [u]. Additionally, voiceless trills are significantly longer than other modes of articulation for French rhotics (i.e. approximants and fricatives), suggesting that duration can be employed as a distinguishing factor for voiceless trills.