NAR C Altitude, E impulse?

[JordanT]

I was browsing the records on NAR and the E altitude record is "only" 1128m for the adults. Is there something special about the E impulse - it seems like an anomaly, being lower than the D record. I ask primarily because just a slight modification of a current model I have in OR easily makes that altitude, and a preliminary test using a B engine actually went slightly higher than predicted.

 

[RoyAtl]

I would say it is because 1) some altitude events are rarely held, therefore the opportunity for record flights are fewer, 2) clubs don't schedule record trials that much, and those that do, may not have the equipment, field size, or expertise to track that high. 3) It may be that attempts have been made but didn't get a good track. That E record is probably just the highest that got a good track.

 

[Peter Olivola]

There's also the issue of Ed LaCroix's six seconds of terror D3's. There was nothing comparable in an E.

 

[Rocketjunkie]

There's also the issue of Ed LaCroix's six seconds of terror D3's. There was nothing comparable in an E.

E6's are still available. I still have a D3...

 

[JordanT]

Yeah, the E6 is what does it. Though my test rocket Don't Blink lifts off at 12Gs under E6 power. It's designed to be stable with both an E75 and an F240 so aside from a potential long walk there's no stability issues with something like an E6. Boy howdy those plugged casings certainly are precious to Aerotech, though!

 

[bobkrech]

The E Alt team record is 1387 meters = 4550'.

A very low drag (Cd=0.5) 24 mm rocket on an E6-8 with a 80 gram or less lift-off weight should hit >4700' or >1430 m.

Note it is very difficult to get the Cd that low and lightweight, and there can't be any wind or the rocket will weathercock and loose altitude.

Bob

 

[kjohnson]

Yeah, the E6 is what does it. Boy howdy those plugged casings certainly are precious to Aerotech, though!

Almost as precious as the SU E6 you can get from Apogee.

kj