SkyDemon Forums

Feature request: Extended Performance Profiles (Temp, RPM, MP)

http://forums.skydemon.aero/Topic28463.aspx

By FlorianK - 5/7/2019 11:36:31 PM

Hi, 

after having used Skydemon since quite a while, I've invested quite some time to build very detailed performance profiles based on the figures from my three relevant POHs, generating the whole XML-Data of the profile via a makro from a very detailed spreadsheet. While the current possibilities with multiple performance values per profile for different altitudes is great, this could easily be extended to offer even better flexibility without much effort:

Suggestion 1:
Add an (ISA based) temperature field to the performance data, allowing us to enter multiple values for the same altitude (e.g. ISA, ISA+20°C and ISA-20°C). Then either let us select the correct temperature level (e.g. ISA+20°C) in the "route"-tab in addition to the performance profile [basic implementation] or alternatively calculate it based on the weather data for the planned route (maybe even even interpolating the performance figures, e.g. for a leg in ISA -7.4°C) [advanced implementation]. 
Currently I have performance profiles for 55%, 65%, 75% and MCP for five different temperature levels (ISA-20°C, ISA-10°C, ISA, ISA+10°C, ISA+20°C), resulting in 20 performance profiles per plane which makes things quite "crowded".

Suggetion 2:
Add fields for RPM and (optionally) MP to the performance entries and (optionally) display the appropriate values for the current altitude during navigation. 
When I started building performance profiles, I build the profiles based on fixed RPM values (e.g. a "2400rpm" profile). While this means that setting the correct power during flight was very straightforward even when flying routes with permanently changing levels due to airspace restrictions ("always set 2400rpm") this wasn't a good solution compared to building profiles base on power percentages (e.g. 65%), as 2400rpm might be a fast, high power setting MSL but a slow, low power setting on high altitudes. 
But when using power percentage profiles, one always need to keep a copy of the power charts at hand, especially when flying permanently changing altitudes (starting at 2500 ft, then 4500 to fly over a CTR, then 5500 when turning NE, then 2500 while turning NW and flying below an C airspace....). It would be great if SD could just show the appropriate values for the selected profile during navigation so I can see my target RPM (and MP, if applicable) value for the current altitude.

Best regards
Florian
By ArnaudC - 5/28/2019 5:31:13 PM

 
Tim Dawson - 5/14/2019 10:05:49 AM
How would having separate data fields for RPM or MP be better than the free-text Name field we have at the moment? SkyDemon wouldn't actually use the values internally as part of the performance modelling.

For in-flight reference.
You can group all the 65% power TAS/FF like today (which is very neat), and upon click somewhere it would show the MAP/rpm for the current (or nearest) altitude.
Using the current free-text Name field means un-grouping like it was before, which is much less readable, more cumbersome in planning, and not practical for in-flight re-planning (where ATC might issue something else than you had planned).