A3-4T Engine Flight Pack

The Estes A3-4T Flight Pack delivers a balanced combination of performance and control, making it an excellent option for lightweight model rockets. With a total impulse of 2.50 N-sec and a 4-second delay, the A3-4T is ideal for small, streamlined rockets needing a gentle but reliable boost. Its short thrust duration of 0.6 seconds provides a quick lift-off while leaving plenty of time for a safe recovery sequence.

This engine can lift rockets weighing up to 2.0 oz (57 g), making it best suited for mini engine-powered models with 13mm engine mounts. It reaches impressive speeds and altitudes with a max thrust of 6.8 newtons, delivering a strong initial push before handing off to recovery deployment. The 4-second time delay offers sufficient coasting time for many light rockets before the ejection charge fires.

The compact design—just 1.8 inches in length and weighing only 0.28 oz—ensures a perfect fit in small model rockets where space and mass efficiency are critical. Despite its small size, the A3-4T engine packs a dependable performance punch, thanks to Estes’ precise engineering and safety-tested reliability.

Each A3-4T Flight Pack comes complete with four A3-4T engines, four starters, four starter plugs, and twelve sheets of recovery wadding. It’s everything you need to keep your low-weight rockets flying smoothly and safely time after time.

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