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Old 15 December 2008, 07:09 PM   #35 (permalink)
Joe Perkel
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Join Date: Oct 2007
Location: Miami / Sebring, Florida
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Ballistic Recovery System

The question of viability of a BRS system with a full scale authentic WWI replica, is worthy of closer examination. For the purposes of this thread, and for planning my own project, I just composed an inquiry to BRS Systems Inc. to determine compatibility and, or possible modifications necessary. I will inform the members what I find out.

The idea behind this being it's a final actionable option in an otherwise hopeless scenario, from modestly low altitudes,..ie 300' up to pattern altitude.

The scenario being that a particular event was survived, ie... midair collision, catastrophic structural failure, loss of control...whereby the impending surface impact would most certainly not be survived. The alternative being having to sit there with nothing to do but ride it down.

I believe that Cirrus was the first production aircraft to introduce the system, the ultralight industry had been using this for years. Systems can now be retrofitted into most light G.A. aircraft and, utilize a solid rocket deployment of the main chute, with the apparent wind (not altitude), being the critical canopy filling element. A successful outcome requiring a successful deployment, which comes with it's own set of problems. Structural attachments as noted and, unimpeded deployment of the system. There have been documented cases of the rocket and or chute being impeded by deformed structures, rapid rotation, and poor installations.

BRS claims a descent rate of 15 - 28 fps under canopy with a properly matched system. Here is an interesting calculator to plug-in some numbers, (scroll down to the velocity calculator).......Unit Conversion Calculators :: Weight, Volume, Length, Pressure, Energy, Calorie, Velocity, Temperature


Quote:
What if the problem is a fire?
Fire,....bad news for any aircraft,...particulary catastrophic for a WWI replica. This one simply has to be prevented before takeoff. If not, you can consider yourself to be especially unlucky. The hazards of the BRS rocket deployment, also need to be dealt with and, to my knowledge can be successfully employed in fabric covered aircraft.

Deploying a BRS in this scenario, would likely only serve to increase the altitude from which you would end up leaping from.

Conclusion?

If compatible with authentic replica construction, then it seems to me that the questions of increased costs in weight, complexity, and dollars,... needs to be weighed against the probabilities of the types of accidents it is designed to mitigate. I have not looked at this close enough to come to any conclusions yet.
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