diamondaviators.net

Hello, first post but I have been a lurker for a while.

I fly a 2003 DA40 XLT (one of our club’s birds) and am a Garmin Pilot user. I love both BUT I noticed that Pilot’s climb and cruise charts are seriously off compared to the POH in the plane. Does anyone know why this is? Has anyone played around with Pilot’s settings to fix this?

Does ForeFlight have a similar issue?

In FF I took there are a number of performance profiles for the DA40. I took one and used it as the basis for a customized profile based on my actual observed performance. This is to adjust for the fact the POH numbers don't reflect reality anyway, given the mods to my plane.

BTW a 2003 wouldn't be an XLT. But it may have been modified in ways that would be make similar in performance to an XLT.

Sorry, it is an XL. But regardless, the GP and the POH are vastly different.

Does GP allow customization of performance profiles? Do you have a Powerflow exhaust? The POH does not reflect improvements in climb and cruise that obtained from that feature and since it has been standard for a number of years GP may somehow reflect those numbers.

... Or they're totally off base.

For Lycoming DA40s produced since 2007, the AFM/POH has always understated the aircraft's true performance -- mostly due to the addition of Powerflow exhaust that reduces back-pressure and improves climb rate, cruise speed, and fuel consumption. Since Powerflow was added by the Diamond Canada factory via a Supplemental Type Certificate (even on new aircraft), there was no requirement for the airframe manufacturer to re-certify the aircraft's performance and revise the AFM/POH.

Does GP allow editing/creating performance profiles? That's the critical thing. If so the most straightforward thing is to create/edit to reflect what's in the POH. If the plane is still all original '03 then it'll be pretty accurate. I found this to be so way back when. If various mods have been done (notably PF) then you might tweak cruise speed(s) and climb airspeeds. This is mostly what I have done for mine. The remaining numbers I left alone, just leaving stuff like runway length and climb rate as published. Conservative numbers are fine by me.

I would be interesting to know in what ways the GP numbers disagree with the POH. They must have gotten them from somewhere.

Yes, You can edit and or create aircraft performance data. You have to go online to Flygarmin.com and log into your account to edit the aircraft data which then shows up on your phone. You can do the basic set-up which is just TAS and GPH at a given altitude, or you can go into advanced settings which gives you additional entry options for temp, weight, power settings, etc.

I have used a number of online and phone apps for flight planning, and I have always input the data for the aircraft I am flying.

Dave S.
Ohio