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Hi all

Is this feasible and if so what's do you think the cost would be to convert a standard range DA40 to a long range?

I'm considering buying a Pre-G1000 DA40 to avoid the non-WAAS headaches of the earlier G1000 birds and I also like the lighter weight of the earlier DA40's. Early DA40's I've seen on the market have 40 gallon tanks. This may be sufficient, but I would like the option to convert to 50 gallon tanks in the future if the 40 gal capacity ends up being too short of range for my missions. I may put a lot of goodies on this bird so don't want to put the time and $$ into to a DA40 that can't accept larger tanks if the standard range tanks end up being too small for my needs.

I understand DA40's with LR tanks required a larger rudder, so assuming this would be fairly involved
1) New or serviceable LR vertical stab
2) New or serviceable LR rudder
3) New or serviceable LR tanks which I believe involves removing the wings.

Cheers,

SnowFlyer

When we bought our '02 we had ordered the long-range tanks. But the option had not yet been certified when the plane was available for delivery. We accepted it with the contractual provision of having the stuff retrofitted at the factory for the original option price ($3,900 IIRC). This was good for a limited time, something like 1 year after the option was certified.

We never exercised that option and I don't regret it a bit. Over the last 18 years I have had only something like 3 legs total where it would have been helpful. On the other hand I have had numerous flights where I have had a CG that was beyond the limit the 50-gallon option imposes.

FWIW, I recall hearing that the cost of the retrofit of this is now more like $12,000. I haven't noticed an OSB for this, but it might be lurking out there. To my knowledge a new vertical stabilizer is not required. The larger rudder can be (and has been) retrofitted onto pre-existing airframes. But some additional obvious details:

Remove the current outer cells.
Add something into the wing to support the new cells?
Install new center and outer cells.
New fuel sensors in the outer cells.
Wiring and plumbing additions/changes, includes new switch to manage fuel gauges.
Some work on the wing skins for relocation of fuel filler caps and vents.
Reprogramming VM1000 (if that's what is still in the plane).

Mine has larger rudder standard with standard tanks. 04. Changing rudder is super easy so finding one is the hard part.

My wing skin has area already to go for new fuel filler cap and plugged so that is likely not a biggie either.

I have never really felt the need for the 50 gallons.

Smart to buy a non G1000 DA40. Wish I had done that.

Are there any Diamond repair centers in the south west US who could do this kind of work with quality comparable to the factory? Thanks for the feedback.

Just a matter curiosity: Where do the panels with the fuel vents wind up with 50-gallon tanks? In the 40-gallon case, they have their own panels just outboard of the outer cells. The likely locations for the 50-gallon tank vents are occupied by the pitot-static blade on the left wing and the magnetometer on the right for the 40-gallon planes.

SnowFlyer wrote:Are there any Diamond repair centers in the south west US who could do this kind of work with quality comparable to the factory? Thanks for the feedback.

Woodland Aviation at KDWA.

Rich wrote: ↑Sat May 02, 2020 8:40 pm Just a matter curiosity: Where do the panels with the fuel vents wind up with 50-gallon tanks? In the 40-gallon case, they have their own panels just outboard of the outer cells. The likely locations for the 50-gallon tank vents are occupied by the pitot-static blade on the left wing and the magnetometer on the right for the 40-gallon planes.

Rich: The vent panel appears to be in the same place in both variants:
The vent panel is between the outboard and middle tanks on the 50 gallon variant, rather than at the outboard end of the outboard tank as in ours.

Steve

I've had both the 40 and 50 gallon variants and find that I prefer the long-range ones without question. Not for every flight, of course, but in general it makes life easier. Fewer fuel compromises, ability to have longer legs, as well as ability to round-trip from further away places without having to worry on fuel.

I wouldn't pay $12K for it, but a few thousand ... absolutely.

I would much rather have 50 gallons but also want to be able to carry a big load at times. What’s your empty C.G. and MTOW with the 50 gallon tanks and do you notice an issue with a more aft C.G.?

This is a sample loading hypothesizing 50 gallon tanks in my plane and assuming an additional 10 lb. for the modification itself. Bear in mind mine is one of the lightest we know of (Steve owns the distinction of the lightest right now). Generally, the pre-G1000 planes are lighter AND have a more forward CG, so that mitigates the CG problem. Note that this particular load is hypothetical and does not represent the most rearward CG I have ever had. Note that this load is bumping up against the MTOW of 2646 and 100.4 in. The earlier DA40s had a lower MTOW and need the mod to handle it, which my plane has, others may not.