Rears to toggle transition

[clustermagnet 0]

Hi All!

  Lets say equally loaded crossfire and jfx are landing… Would one expect to transition from rears to toggles sooner on a crossbraced canopy, or are canopies like crossfires fly longer on rears due to flat trim?

thank u!   And of course, practice up high!!!!

[BMAC615 209]

7 hours ago, clustermagnet said:

Hi All!

  Lets say equally loaded crossfire and jfx are landing… Would one expect to transition from rears to toggles sooner on a crossbraced canopy, or are canopies like crossfires fly longer on rears due to flat trim?

thank u!   And of course, practice up high!!!!

This is a question for your canopy pilot coach/mentor. If you don’t have one, pay the best one you can find as much as you can afford - your life depends on it.

[Deimian 43]

On 7/3/2022 at 5:06 AM, BMAC615 said:

This is a question for your canopy pilot coach/mentor. If you don’t have one, pay the best one you can find as much as you can afford - your life depends on it.

This is solid advice. But this particular question can be at least partly answered without a coach IMO, of course taking into account that communication in person can be more accurate than in a forum, since the chance for miscommunication is lower in person.

To answer the original question:

There are many many things that influence how long you can keep in rears. It is not simply a matter of "Crossfire vs JFX". Let me go over some of them.

The fact that a canopy is trimmed flatter than another one, does not mean that it holds longer in rears. It is almost the opposite. When you pull on your rears you are effectively altering the trim of the canopy. If the trim is already flat, you have less giggle room to produce changes in the canopy behaviour without stalling it.

Cross-braced canopies are more efficient due to the way the top skin holds its shape (21-27 "compartments" instead of 7-9 cells). That means that all other things being equal, they create more lift, which means that the same input on rears have a greater effect in producing lift at a given airspeed.

Another thing that greatly affects how long you can hold in rears without sinking is airspeed. The higher the airspeed, the more lift the canopy produces, so the longer you can keep on rears. So you might hold longer on a Crossfire going at a certain speed, than in a JFX going at half of that speed. But JFX is a more steep canopy, so at the same wingload you are probably going to be faster on a JFX than on a Crossfire.

Yet another thing is parasitic drag in the trailing edge. So a canopy with miniribs will have less parasitic drag, and is therefore more efficient, and can hold longer on rears than one without. On that sense, a JFX 2 is better than a JFX 1 for instance.

So, to summarize, the *chances* that you can hold longer on rears on a JFX than on a Crossfire are very high, but you can't say that in all circumstances you can hold longer on rears on a JFX.

[BMAC615 209]

@Deimian, this one screams, “I’m teaching myself to fly a canopy outside my ability and don’t have a coach.”

[Deimian 43]

11 hours ago, BMAC615 said:

@Deimian, this one screams, “I’m teaching myself to fly a canopy outside my ability and don’t have a coach.”

Sure, and that's not good. But I think it is not the same asking "which kind of canopy hold longer in rears", which is valuable knowledge, and "I have 200 jumps, I am ready for a VC90, where can I get one without too much supervision?".

OP has been in the forum since 2008, so I would also hope he is not a dumb hot shot. But maybe I am too naïve 

[BMAC615 209]

18 hours ago, Deimian said:

Sure, and that's not good. But I think it is not the same asking "which kind of canopy hold longer in rears", which is valuable knowledge, and "I have 200 jumps, I am ready for a VC90, where can I get one without too much supervision?".

OP has been in the forum since 2008, so I would also hope he is not a dumb hot shot. But maybe I am too naïve 

That’s fair :)