Complex sentence: This arrangement was used to avoid the structural weight penalties of rear mounted engines and the potential ingestion problems of engines mounted under the wings, and allowed a short and sturdy undercarriage, specially suited for operations from poorly prepared runways.
Split into simpler sentences: This arrangement was used to avoid the structural weight penalties of rear mounted engines and the potential ingestion problems of engines mounted under the wings. This allowed a short and sturdy undercarriage, specially suited for operations from poorly prepared runways.