Performance Profiles


#1

I just got the announcement email, so I decided to play around a little.

Tried to enter a Piper Arrow. Put in P28R/G as the type. No go. Tried P28, which seemed to make the programmer happier.

Added enough data to make the programmer completely happy, created the airplane record.

Went to add performance, but no pre-stored performance was shown.

Did more or less the same thing with a 172, called it a C172, and got a match on performance data.

There is apparently no way to know, when performance data is not offered, whether it is not offered because it is not there or because I have not correctly guessed the syntax of a type designation that will match. PA-28R-200? PA-28R? P28? PA28? P28R? I don’t have the patience to engage in a guessing game with the programmers.

Ideally, there should be a pick list that contains only designations that will make the programmer happy.


#2

Good point, mitty. The type is probably “P28R” like you’d file IFR with. P28R/G is the type AND FAA equipment code.


#3

… probably …

You make my point for me very nicely. We shouldn’t have to guess.

From your comment, the program is apparently looking for the FAA flight plan designation. That list is not so long that it couldn’t be provided as a pick list, automatically narrowed as I type successive characters.

You’ve probably already thought about it, but the FAA designator/performance profile relationship is a one-to-many mapping. There are several different Arrows that use P28R, for example. 180hp, 200 hershey bar wing, 200 taper wing, and Turbo 200 that I can think of offhand. Lots of flavors of Cxyz performance too, of course. So you need a designator syntax that works for that.


#4

The list is about 2200 aircraft that we know of, so it’s a little difficult to provide. However, we definitely will be improving the interface. As far as different performance profiles for an aircraft code, that is handled already; you select the climb, cruise, and descent profile for the aircraft code that you want copied into your profile.


#5

The list is about 2200 aircraft that we know of

I was thinking of aopa.org/whatsnew/acdesig.html, which now that I look carefully, is around 600 type designations. But I’ll bet the 90/10-type rule applies. Maybe you can cover 90% of users with a 50-100 item pick list. From your database, you can test that idea in two minutes I’d guess.


#6

There’s a list of aircraft types that we have performance data available for in the FAQ.


#7

If this is the a/c you fly, I would think you wouldn’t have to guess at the type code needed for a flight plan.


#8

In some ways, while the “other type” information is useful, there should be a “subtype” field for the performance profiles.

For instance, the 182 entered in the system already is a (I’m guessing) “Q” Model 182. I fly a “T” model. The performance data is not the same, on the other hand, other than the fact that the weights are 2950 for the posted one and 3100 for mine, this would be very hard to distinguish.

Furthermore, not all aircraft have the “neat” 55, 65, 75 percent boxes in the performance. As there is no way to enter more advanced information, I’d need to do a fair amount of manual math to calculate the numbers for the 182T (sorry I don’t have a digital copy, my scanner is on the fritz).

In addition, some aircraft (DA40 for instance) separate power and speed into disperate sections, again, manual calculation would be required to derive the requested information.

Finally, I believe that performace id 1029 and 1030 illustrate a problem with the climb tables. 1029 is the proper time, distance, fuel used chart. 1030 is fuel burn, rate of climb speed chart. Obviously, a 182 does not burn 0.3 GPH at sea level in a climb (I promise, it doesn’t even idle on that little). At the same time, most books don’t provide fuel flow on the latter graph, and so this information would need to be manually synthesized from the former (see 182T POH 5-18 and 5-19).

~ Christopher

P.S. I Faxed you DA40 and C182T POHs. I’ll post them here for the board once the scanner is fixed.


#9

I cant get my profiles to stick for P46T meridian?


#10

If this is the a/c you fly, I would think you wouldn’t have to guess at the type code needed for a flight plan.

Possibly if you read the thread more carefully you would understand the issue.

jwriteclub, I have the same feeling about profiles. They are potentially quite a swamp. I have at least seven POHs here for airplanes that I fly and will scan and send them if I get serious about using this tool. DIY profiles look like far too much work. There are also QC issues if you cannot get a complete printed version of the online data to review and check off against the POH. Too many parameters, scattered too many places, for me to be confident about doing it on-screen. YMMV.

mduell, thanks for the point-out. The list is much smaller than I expected. No wonder I was having trouble getting a match. For no reason, probably, I assumed that you had data on a large number of common aircraft. I guess that will come.


#11

We’re using the aircraft description to describe the specific subtype.

We’ve distinguished between the two by displaying the description and we’ve also entered your 182T data.

We enter performance profiles as RPM/Manifold Pressure when we can, but when the POHs only have % Power we’ll enter that instead.

We deleted the erroneous profile 1030.

Thanks for sending those in, they’re both available online now.