neema wrote: ↑Tue Jan 12, 2021 8:57 am
Does your plane have AC installed? We can end up forward of the CG limit too, but only with TKS 100% full and 400 lbs of people up front with zero bags. One 15 lb bag usually takes care of it. Or leaving out a few pounds of TKS.
No AC installed in N449TS... yet. We're thinking about having it installed between now and summertime. We need it rather infrequently in the Pacific Northwest, so I was thinking of doing something removable like the Arctic Air Real A/C.
TimS wrote: ↑Mon Jan 11, 2021 1:39 pm
Run a scenario where you take off for a long flight in winter with full TKS and aux tanks and end up using the fuel but not the TKS. If your takeoff CG was forward to start with it will move further forward, possibly ahead of the allowable range.
Consider the same flight but starting with a rearward CG. You run into icing early in the flight and use a lot of TKS before using much fuel. The CG may move too far to the rear.
Running the numbers for ours, it would be pretty difficult, though perhaps not impossible, to come up with a configuration that results in a too-rearward CG without violating the MTOW as well. Perhaps after the A/C is installed it could be an issue.
Chris wrote: ↑Tue Jan 12, 2021 4:25 pm
No AC installed in N449TS... yet. We're thinking about having it installed between now and summertime. We need it rather infrequently in the Pacific Northwest, so I was thinking of doing something removable like the Arctic Air Real A/C.
That seems like the best bet to keep space in the back. An easy to install/remove tail weight would be great for bringing things in check. Probably good for a couple knots too if you fly around with back seats empty a lot.
When I've needed ballast in my DA40,I use a 10 litre water container from the supermarket. Costs about $5 (including the water) and is easy to fill or empty away from home base if the mission changes half-way through a series of flights. And (not sure if this applies in the US) it caters for the requirement to carry emergency water in Designated Remote Areas, so it doesn't always chew up useful load.
I own a DA40 NG without A/C. With two 185 lbs guys in the front and full fuel I just put 20 lbs of ballast in the rear tube. Seems to fix the W&B issue and I don't have to worry about water leaking.
ScottOHare wrote: ↑Wed Jan 13, 2021 8:42 pm
I own a DA40 NG without A/C. With two 185 lbs guys in the front and full fuel I just put 20 lbs of ballast in the rear tube. Seems to fix the W&B issue and I don't have to worry about water leaking.
I had the same issue with myself (185) and a 230lb CFII. I bought two 20lb dumbbells and keep them in my hangar, but haven't needed them since.
For the GC, you can keep a case or two water water bottles in the back. Then you always have a drink if you need one but they're not so expensive to leave somewhere if you need to lose some weight.
I use weights like Russ but I really like Greg and Jon's idea about water. I fly Angel Flights with a co-pilot in my 2003 DA40 with the heavy aluminum prop and we're close to forward CG with full tanks on the trips to the passengers and the homeward flights from dropping them off. At the same time, I need to cut down on weight for my passengers on their flight so this is an elegant solution. Thanks.
Bernie Seward, IR, AGI
2003 DA40 N377DS
KCHO Charlottesville, VA
I would suggest instead collapsible camping bottles. No plastic wastage, easy to fill at a remote location if you need to, or empty if desired.
I used to use 1 gallon ones from REI; three of them gave me 18lbs of ballast, and weighed only a few ounces when empty.
Thanks for all of the suggestions! I like the ideas of using drinking water as ballast. I think a couple of smaller containers would be better than one large one, both for ease of loading as well as less risk of trouble if a container leaks.
My solution for this winter will probably be a 2.5 gallon jug of TKS fluid, weighing in at over 20 lbs, and the "bag of goodies" that came with the plane. Both of those in the back compartment makes the W&B work out nicely. In the summer it will probably either be water or an AC unit.
The copilot brakes are fully functional after bleeding the lines properly, so that's a relief.
Surprisingly, the weather was perfect for flying today so my instructor and I went up for more practice maneuvers and procedures. Steep turns went much more smoothly now that I know how to disable ESP. I'm really loving how the DA42 flies... nice and smooth like a small airliner. Of course, the weather was rather calm today anyway. I still need to get used to the wider turn radius in order to make pattern turns more precise, but I think I'm starting to get a feel for it.
TimS wrote: ↑Wed Jan 13, 2021 10:19 pm
I used to use 1 gallon ones from REI; three of them gave me 18lbs of ballast, and weighed only a few ounces when empty.
Tim
Hey Tim. If you filled them, you had 25 pounds of ballast - density of water is roughly 8.345 pounds/gallon.