Dual Deployment - chute locations

[Jwptrek]

I have a rocket with the PML CPR system, which ejects the main chute from the top of the rocket and the drogue from the bottom. I am currently working on another rocket with dual deployment. I am not using CPR in it due to size. I'm starting with a kit that has a long aft body tube with slots already installed. Additionally, I would like the option of motor ejection. Is there any reason I can't have the main chute in the lower section and the drogue in the top? Why is the main chute at the top of the rocket the de-facto standard?

 

[Wally Ferrer]

I have a rocket with the PML CPR system, which ejects the main chute from the top of the rocket and the drogue from the bottom. I am currently working on another rocket with dual deployment. I am not using CPR in it due to size. I'm starting with a kit that has a long aft body tube with slots already installed. Additionally, I would like the option of motor ejection. Is there any reason I can't have the main chute in the lower section and the drogue in the top? Why is the main chute at the top of the rocket the de-facto standard?

It is so you can use motor ejection as a backup to the electronics, in which case you want the drogue chute to deploy at apogee. If you eliminate the motor ejection then it doesn't matter, besides which part of the rocket might touch down first.

 

[Jwptrek]

Makes sense. I didn't think about using the motor ejection as a backup. Thanks.

 

[Handeman]

I think the other reason for the apogee being the drogue is so the drogue can control the inverted V most want to see with DD on the way down from apogee. It also seems like it keeps the main pointed away from everything and you get a cleaner deployment of the main.