Flight Testing Ballast?
Posted: Tue Jun 09, 2020 5:43 pm
by Rynoth
What have folks used for ballast during Phase 1 flight testing to explore and prove the flight envelope? I need to perform some max gross weight testing as well as aft CG testing and am trying to figure out a safe/secure way to add weight to the plane.
Re: Flight Testing Ballast?
Posted: Tue Jun 09, 2020 6:59 pm
by lakespookie
I hear Cement bags and or sand bags work great if you have a canvas duffle bag to put said sand or concrete bags then secure that with a seatbelt.
Re: Flight Testing Ballast?
Posted: Tue Jun 09, 2020 7:14 pm
by Sonex1517
Large bags of sand worked for me in a canvas bag. That was secured in place by the shoulder and lap belts.
The obvious statement is make sure it’s going to stay there.
Re: Flight Testing Ballast?
Posted: Tue Jun 09, 2020 9:12 pm
by jaflint
I used a small carry-on suitcase to hold bags of mortar mix (…sand, cement mix, all the same). Buckle it in like a passenger, off you go!
Re: Flight Testing Ballast?
Posted: Tue Jun 09, 2020 9:18 pm
by mike.smith
I used my old Army duffel bag and put bags of pea stone inside (the duffel was in case any of the bags sprung a leak), and seat belted it in. The duffel has straps, so I put the seat belt through the straps “just in case.”
Re: Flight Testing Ballast?
Posted: Wed Jun 10, 2020 12:24 am
by wlarson861
I needed water softener salt at about the same time I needed to do my gross weight testing, Strapped in like a passenger in the right seat. 4 bags, 160 pounds. Close to the FAA standard person.
Re: Flight Testing Ballast?
Posted: Wed Jun 10, 2020 3:45 am
by rizzz
Borrowed these from my gym:
20kg (44lbs) weights.
They don’t take up much space and can be secured using the seatbelts.
In the end I had 4 in the passenger seat and 1 in the baggage compartment.
Re: Flight Testing Ballast?
Posted: Wed Jun 10, 2020 8:15 am
by DCASonex
I had a coal stove in my shop so my first “passenger” was Old King Coal. in 40 pound bags. Each bag in a large trash bag to help keep interior clean.
David A.
Re: Flight Testing Ballast?
Posted: Wed Jun 10, 2020 12:02 pm
by avee8r
Being close to automotive work, I borrowed a “water dummy”. I could work with any weight by filling or siphoning off water. Perfect for my center stick Sonex. If I’d had dual sticks, I would have had to remove the right one for these tests.
Happy Landings
John
N50NX
Re: Flight Testing Ballast?
Posted: Wed Jun 10, 2020 12:40 pm
by Fastcapy
I used 60lb bags of concrete mix. I wrapped them in additional heavy duty garbage bags as well to prevent any kind of mess.
I chose 60lb bags because it gave me a good weight range. I started with 2 at 120 lbs to make sure everything was good, then added another to get to 180 which is about the average FAA adult, and then 240 which put me right at gross. I strapped the bags together with ratchet straps and secured them tightly with the seat belt. Worked out well.
Re: Flight Testing Ballast?
Posted: Thu Jun 11, 2020 2:30 am
by NWade
If you use bags of anything, be EXTREMELY CAREFUL that they are secured in a way that will not allow them to shift!
I know a pilot who used sandbags as ballast in his tandem-seat aircraft and used the seatbelts to secure them, only to have turbulence cause a bag to shift and slide partly free of the belts. It prevented him from getting full stick-travel and being a tandem-seat arrangement he could not reach back to fix the bags… in the pattern he could only really turn one direction and then slowly level out - scary stuff!
Our side-by-side seating is a bit different, but trying to manhandle a heavy object (especially if it’s amorphous) while seated and controlling an aircraft that can’t really be flown “hands off” for very long is still challenging.
Be careful out there,
—Noel
Re: Flight Testing Ballast?
Posted: Sun Jun 14, 2020 3:38 pm
by Rynoth
Thanks for the tips! As it happened, I had several 40-lb bags of water softener salt in my basement. They did the trick!
They stayed in place very well, and actually kind of made the cockpit more comfortable. Nice to have the armrest. No issues with full control deflection.