Kolibri;n1138383 said:
fara, how many ADs and SBs do Mooney, Cessna, Piper, Beech, etc. blame on the pilots improperly storing or flying the aircraft?
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Probably none. But how many ADs and SBs from us, AutoGyro or ELA have you seen that blame the pilots in the documents?
I honestly haven't seen all the ones from AutoGyro or ELA etc. but I know we have not blamed any pilot for the couple of mandatory ADs we have released and the ones I have seen from others have not to the best of my knowledge.
Kolibri: I do not think you are all wrong on all your points. You talk about problems with RAF. I have no comment because I don't know or have not looked at RAF closely enough to be qualified to counter your points. I know RAF does not have a HS and I would stay clear of that but that's my opinion. You may be completely right about their issues. I am not knowledgeable enough about that design to comment on construction methods they used. Same for Dofin Fritts. I don't know.
You talk about points about ELA that Mike Goodrich brought up. I have no problem with those specific points. Mike G presented specific examples, specific problems with technical details usually much beyond a normal end user envelope because he has obvious background in engineering. His points were specific with examples and made in such a way that its hard to argue at least for me. I have not much to add than what Mike G has already pointed out. The data is there for anyone to see.
Its when you take a welding and composite issue that is specific to ELA and only after a certain date of production and start to generalize it to all Stainless Steel masts or take an issue which happened to AirCopter rotors that MTO used and start to generalize it is where I have issue with your approach. Those problems are happening due to specific reasons. I don't want to go into details of why those specific problems happened because each is a full discussion on its own but your conclusion that oh its because its made from Stainless Steel for example is completely wrong. If your conclusion was correct why ELA masts did not fail and only the tail booms are cracking. Per your analysis the masts are critical and have more vibration and should have cracked first then, right? Why did ELA's made in early days do not have this issue so far? Obviously its more than your simplistic approach and thinking. That is what I am trying to object to.
In terms of do SD and ADs blame the pilot. Like I said I am not aware of any that do but sometimes honestly the pilots are to blame. Just recently in ASTM Design and Specification standard for airplanes, there has been a work item for vapor lock prevention. The background for it is as follows
"Rationale
During a recent F37 LSA task group meeting at EAA AirVenture 2018, a discussion was led by members of the FAA Small Airplane Standards Branch. This discussion centered around two recent SLSA incidents in March 2018 due to loss of engine power, both of which were attributed to vapor lock. One of them resulted in an accident where both the pilot and passenger sustained serious injuries. It was further discovered that both aircraft were unknowingly fueled with a winter automotive gasoline (autogas, or mogas) blend when the Outside Air Temperature (OAT) was approximately 80° Fahrenheit. Upon review of the details surrounding the incidents, it was revealed that F2245 has no requirement for consideration of operating environment related to fuel, or more specifically maximum fuel vapor pressure that can be experienced in the field, to ensure that the engine functions properly when installed on an SLSA in all likely operating conditions. It was the consensus of this task group to add a requirement to section 7.3 Fuel System of F2245 to better define the requirement to prevent vapor lock and define a fuel on which to show worst-case scenario compliance, rather than having to test a myriad of various fuel blends."
These users used 3 or 4 month old auto fuel from winter formulation in the summer and because of hot weather had vapor lock happen. Most POH and specifically these aircraft POH specify to not use fuel more than 3 weeks old so whose fault is it? Even so, in the standard now the manufacturers have to do specific testing to the following proposal
"7.3.1 The fuel system must be free from vapor lock when using an aircraft manufacturer-approved fuel at its critical temperature,6 with respect to vapor formation, when operating the aircraft in all approved operating conditions.
NOTE 10—If the airplane is intended to be approved for use with automotive gasoline (autogas, or mogas), either containing ethanol or ethanol-free, compliance with this section must be demonstrated on the highest vapor pressure autogas likely to be experienced in the field. Autogas is governed by ASTM D4814 in the US and by EN228 throughout Europe and other parts of the world. Compliance with this section, with respect to autogas, is then shown when the aircraft fuel system can demonstrate successful operation free from vapor lock while using a Class E-6 blend autogas according to D4814 with a vapor pressure minimum of 103 kPa (15.0 psi); or a Class F blend according to EN228, with a minimum vapour pressure of 100 kPa (14.5 psi).7 These are the high limits for vapor pressure of each of their respective standards. Autogas shall not be listed as approved on the airplane unless demonstration according to this section can be achieved on either of the above prescribed fuels. if successful compliance is shown with autogas using either of the above blends, avgas (either leaded as defined in D910 and/or unleaded as defined in D7547) may be added to the aircraft’s approved fuels without further demonstration.
NOTE 11—If the airplane is intended to be approved solely for use with an ASTM-approved avgas specification, either leaded (e.g. ASTM D910) or unleaded (e.g. ASTM D7547), compliance with this section, with respect to avgas, is then shown when the aircraft fuel system can demonstrate successful operation free from vapor lock while using a blend with a vapor pressure minimum of 49.0 kPa (7.1 psi). If successful compliance is shown with the 49.0 kPa avgas blend, avgas, either leaded or unleaded, may be added to the aircraft’s approved fuels; this compliance showing does not, however, allow for autogas to be added to the aircraft’s approved fuels without further testing, as outlined in Note 10."
Increasing compliance burden and cost when the simple prevention was don't fly with auto gas stored for multiple months. Its going to cost every new airplane buyer more because someone has to pay for all that testing manufacturers will have to do.
I also don't buy the comments that simply using A&Ps is the answer for perfect maintenance. There are plenty of A&Ps who can't think one step ahead of themselves. There are plenty of lawsuits against maintenance shops at fault. Yes likely that the chances of mistakes are less than if an amateur is doing it I guess but by no means perfect. In the end when you go buy a used aircraft you better know what you need to be doing or have someone who knows and not rely on the other party. Otherwise stick with new aircraft purchase. You as pilot in command are responsible for declaring the aircraft airworthy and that is eventually the bottom line.