Earlier this year, I attended some launches of a local group that has high power flights. They have two sites that allow HPR with flight ceilings of over 10,000 feet! They have large rockets that fly with L size motors and above. I was able to build an Apogee Rocketry Zephyr rocket and fly to get my Level 1 High Power Rocketry Certificate.
Here is a shot of me and the Zephyr before my certification flight:
Following the Level 1 flight, I upgraded the Zephyr by adding an instrument/electronics bay (ebay). Here is the rocket taking off with the extended electronics bay using an I500 rocket motor. This is about the most powerful motor that I can fly with a Level 1 cert, and needed because the rocket is a lot heavier with the added electronics bay.
For this flight I flew my Adafruit M4 based instrument package. Unfortunately, the recovery system did not deploy properly and the rocket ended up in a tree. The trees are visible in the background here. The Zephyr ended up spending 2.5 months in a tree before a club funded (and personally reimbursed) recovery guy got it down for me. There was some damage to the rocket which is being repaired. The instrument package survived ok, and I was able to get the data off the micro SD card. Below is the altitude chart:
I have taken the written test for the Level 2 Certification and passed. I am hoping and planning to fly the Zephyr again with upgraded recovery system and get my Level 2 Certification before the end of the year. Once I have the Level 2, I can fly J and K sized motors and will be able to test more advanced avionics similar to what will be needed for the balloon flights.