by ViennaVA223 » Tue May 17, 2016 12:12 am
During the 1950s, I lived on a fahm (that's Downeast for "farm") in Maine. I attended Dedham Elementary School, a modest educational facility (I am being kind) that housed grades K-8 in three rooms. In Nellie Magoon's room (grades 3-5) reposed, on a shelf, the 1933 edition of Compton's Pictured Encyclopedia; it might be there still. In one volume of the encyclopedia was a lovely B&W photo, shot from below, of a pilot in an open-cockpit biplane descending under a huge, white (probably cotton twill) whole-airplane parachute canopy. I'd been airplane-crazy since I could walk, and I thought that photo was one of the coolest things I'd ever seen. I still do.
I don't recall any text that might have accompanied the photo, but today I suspect the photo was of Roscoe Turner, the famed air racer and showman, who flew test flights of a whole-airplane parachute system for the Russell Parachute Company in 1928. Today Roscoe reposes in Crown Hill Cemetery in Indianapolis, IN.
But I digress ...
As many know, decades went by with naught to show for these early, successful experiments. Flash forward to 1975, when Boris Popov survived a 400-foot descent after a structural failure in his hang glider, wishing he had a parachute to deploy. In 1980, Boris launched Ballistic Recovery Systems (BRS). Second Chantz and others entered the market later.
Today, BRS claims more than 30,000 units installed, and 350 lives saved. The BRS set-up is available today as an option on the SubSonex for $3,830, but is not available on any of the four Sonex piston models. Some people continue to ask if/when BRS will become available on the prop jobs. In fact, during the EAA webinar featuring John Monnett on the Sonex Model B and other things Sonex, just a few weeks ago, a webinar listener asked the question.
John reiterated that the design of the SubSonex, which has the jet engine aft of the cockpit and thus balances that weight with the pilot forward of the wing spars, can have the BRS harness well aft of the pilot and thus not risk decapitating the pilot as would happen with a BRS installed in one of the piston models.
Unfortunately, John also claimed that the Sonex "stalls at 35, and you come down at 30" under a BRS canopy, implying that a BRS on a Sonex wouldn't confer much survival advantage to a Sonex pilot and passenger. I have seen no effort to correct him on this misleading statement, so I'll do it: Because John said the Sonex "stalls at 35," that suggests he was thinking in knots. The 30 knots of vertical descent rate he assigned to an airplane under a BRS canopy translates to 34.5 mph, or about 52 feet per second (fps). That doesn't begin to square with the statement in the FAQ section of the BRS website that the descent rate will be 15-28 fps at 5,000 feet density altitude with the rated weight of the canopy. I believe the BRS folks have lots of FAA certification data to back up their numbers.
Then there's the other little nit: Yes, the Sonex will stall at 35 knots in a full-flap, 1g, level, unaccelerated stall with the airplane under control, and it should stall at a slightly lower speed under the same conditions at less than gross weight. All of which is excellent, but not the conditions guaranteed for your future inflight crisis.
Anyway, let's start with the BRS data for vertical descent rate and work backwards from there. I'm not an engineer, nor have I stayed in a Holiday Inn Express any time recently, but I can't believe that engineering some modifications to the Sonex, Waiex, Xenos, and Onex to permit safely installing and using a BRS system in those aircraft would be that huge a challenge. Sonex hired a young engineer/pilot/Sonex builder some months ago; she has eye-popping credentials. Perhaps she will find a solution. It would mean a WHOLE lot more to me than the extra five gallons of fuel the B model will carry. In fact, here's a tradeoff: if I were flying solo, I could gas up with a full 20 gallons; with a passenger, I could forego the extra 5 gallons (30 pounds) to "pay" for the BRS. Yes, it would add cost, complexity, weight, etc. It still would be the single most important change to the design my friends at Sonex could make.
Oh, one more thing: The competition. At Sun 'n' Fun last month, I stumbled upon the SPA display area right next to the Sonex area. Three SPA Panthers (two built by customers and flying extensively) were on display: Several engine options, beautiful engineering, folding wings, LSA, aerobatic--and designed to be fitted with a whole-aircraft parachute system. The two-seat (tandem seating) Cougar reputedly is in the works. Lookin' GOOD .... So perhaps competitive pressure will change some thinking at Sonex on this one.
Finally, I and many others respectfully await publication of the NTSB report of its investigation into the Sonex accident at Oshkosh last June. I know that the field investigator sent from HQ has an engines background; however, a thorough investigation and report should cover many different aspects of the accident, including survival factors. I suspect that intelligent and honest people may find reason to discuss this BRS issue again after the report is finalized and released to the public.
But Bryan Cotton and son Adam are building a legacy Waiex, not a SubSonex, so I should return to what I have claimed since the beginning of of my entry into this thread: There is SO MUCH to say about emergency parachutes for sport pilots--i.e., the kind one straps onto one's mortal bod, not the airplane.
To be continued ....
Keep your rivets in tight formation,
ViennaVA223