Collaborators Team Negative G formation
 

I saw something this week at Oshkosh that I've never seen before - negative g (non-lead) formation flying. I'm not saying it hasn't happened before, I've just never seen it.

The Collaborators did a maneuver with all four members pushing hard negative g's while in formation. While it is common for the lead to be negative, I've never seen wingman negative (I might have seen a Blue Angel two ship with wingman negative, but not too close and directly behind lead). This would seem to be more difficult than it appears , since the wingman has to bank "toward" lead to move away. In other words, if aileron is used, the stick would be moved towards lead in order to move away. I'm wondering if the wings are simply kept level, and perhaps rudder is used to move closer/further from lead.

Anyone know how they do this? BTW, I have no interest in doing this...

Deven, if you are flying off someone, and you are positive g, you will move the stick away from the lead plane if you want to move away. This will reverse if you are negative g. Use your hands and imagine what needs to happen.

Some other formation display teams have done formation with the wingman inverted. The Snowbirds have a manoeuvre they call the Mirror Roll where two aircraft do a pass down the runway, one aircraft upright, and the other inverted, with a half roll in the middle. The half roll in the middle switches which aircraft is subjected to negative g, which allows them to respect the fuel system limitation of 15s max duration for negative g, while the total duration of the pass is longer than 15s.

More Snowbirds video here. The video from the middle of 9 plane diamond during approach and landing is especially impressive.

How they do it? I've never done inverted formation, but there is a Pitts formation team based at my airport who do it once in a while. I've talked to Andrew, the wing man about inverted formation in the past - you simply need to understand how the relationship between bank angle and movements to and away have changed, and do lots of practice.

Kevin, thanks. The mirror roll video is unfortunately not a continuous video all the way through the maneuver. I do not see in that video that the wingman is ever negative g. Only way to tell is through the curvature of the smoke. I believe you that they do it, but the video doesn't tell the story...

My bet is still that they use rudder... with your connections I'll bet you can find out from the source!

One thing to keep in mind is that the Snowbirds don't use the ailerons for station changes in formation... They use rudder. So the foot movements are the same upright and inverted. You can see this during the show, watch for changes to/from the 9-diamond pattern... the wingmen furthest out do a lot of hard yawing to change positions.

Rob - thanks, I suspected that this would be the only reasonable method when the wingman is negative g.

Air show formation trivia for ya. Anyone know why this is?

Wings level with lead at all times! My rudder feet are feeling the burn at this very moment.

That's not trivia
 

That's not trivia, that's FUNDAMENTAL