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Radical has all the wrong implications. It's a "major alteration" in a regulatory sense, done from an approved kit of parts, with a very well documented install
by dramm 2y ago
Radical has all the wrong implications. It's a "major alteration" in a regulatory sense, done from an approved kit of parts, with a very well documented installation and post-installation operation and maintenance procedures.
The aircraft was modified with a Robertson STOL kit. A common type of modification to make to a "bush aircraft". In the USA the modification is covered by an STC (Supplemental Type Certificate), the installation needs to be supervised and approved by an A&P technician with IA (Inspection Authority). The STC will modify the airspeed indicator markings, including the stall speed markings (bottom of green and white arcs), and modify the approved flight manual/pilot operating handbook and maintenance documentation for the aircraft. Since this is a major alteration (in a 14CFR regulatory sense) that modifies the flight characteristics of the aircraft it needs to be test flown after the work, and the STC will also separately requires this. I expect/hope the STC includes instructions for checking stall characteristics including airspeed. In European countries a similar level of regulation/documentation is followed based on the USA STC.
Give the description of the pilot's sad lack of understanding of basic operation of the aircraft I am doubting they even read the pilot operating handbook.
- avianlyric 2y agoAs noted in the article, the plane had been modified with far more than just the STOL kit. > A further issue was that his Cessna 185 had been extensively modified. The addition of floats, cargo pack, short take-off and landing kit and a three-blade propeller had never had their combined effect documented. That’s a lot of things that modify the flight characteristics of a plane, all interacting together in what seems to be a previously untested configuration. I can completely see how each individual modification might modify the planes flight characteristics in a well know manner. But I struggle to see how anyone could realistically predict the result of all the modifications without some basic empirical testing.
- dramm 2y agoA three bladed prop modification along with floats is very common. Wipaire, the leading float manufacturer has its own STC for that. In combination with STOL kits is not uncommon either. I expect the Robinson STOL STC explicitly accommodates floats (Wipaire’ STOL STC sure do) but not sure since I don’t have the paperwork in front of me. You are over inflating issues here. Are you a pilot? The issue here is straight up incompetent operation of an aircraft. Operating a floatplane and separately operating with a STOL kits can increase complexity and risks especially when aircraft are mishandled/abused like here with an incompetent pilot who does not know what they are doing. You don’t need to dream up issues from combination of stuff here, the simple linear addition of issues was more than enough for an incompetent pilot to get into trouble, and seems they are lucky they did not get into more trouble before, and lucky they were not killed. The C185 is a beautiful well behaved workhorse used extensively in bush and floatplane flying, often with multiple STCs to upgrade these aircraft.
- michaelt 2y agoI get what you're saying, and I agree this sounds like operator negligence to me. But the article does say that investigators had to get another aircraft set up with the same modifications and fly it around with bits of wool all over it in order to understand the stall characteristics. So I assume this plane setup isn't so widespread that its stall behaviour is common knowledge.