I should know better than to open this can of worms...
I believe the main point of the test period is "test". That is, have the flying or operating characteristics been vetted? Does it stall funny, did the ROC change, is there some new procedure required to operate the aircraft, etc. You are not going to get any useful "reliability" data from a 5 hour trip through Phase 1 - not any more than the typical and expected functional test flight that we all do (or should be doing) following maintenance.
Let the fireworks begin...
You are not going to get any useful "reliability" data from a 5 hour trip through Phase 1 - not any more than the typical and expected functional test flight that we all do (or should be doing) following maintenance.
I am looking to see how the FAA interprets "Major" modifications and how other have interpreted this definition.
I assume the intent of the requirement is to test only the unique aspects of the modification and hence the shorter test period . I was looking more to the obligation, not the necessity. I never look for logic or reason in anything regulatory. I am obligated to do Phase I testing for "Major" modifications. I am looking to see how the FAA interprets "Major" modifications and how other have interpreted this definition.
Larry
My guess is this is a major modification to the fuel system that is a major system to the aircraft.
Example: Changing from a magneto to EI - EAA says "no" to a major change (and I agree), yet if you call 20 different FSDO's you will get 25 different answers.
I guess my real question is, does my interpretation count for anything.
Larry
With respect to the wording of the regulation, installation of fuel injection will require the removal of a cockpit control (carb heat) and perhaps installation of new cockpit controls, plus introduction of new procedures for starting, running and re-starting the engine. One could easily and logically argue this modification materially changes the operational characteristics of the aircraft.
Very good post Mark. I agree wholeheartedly.
This raises an interesting point for me. I plan to fly this plane IFR someday and was considering leaving the carb heat setup after the conversion. My thought was that it could potentially eliminate or reduce water or even ice build up on the air filter when flying in rain. Is there a downside to this approach? I do have an alternate air door to overcome a clogged filter.
Thought I would follow up. I called FSDO this morning. As speculated by others, different FSDO's, different answers. They told me it was an Op's change and only maintenance type documentation is required; No Phase I. The gentleman indicated that it shouldn't change flight characteristics, therefore no Phase I. He followed the guideline from the certified side that states a 10 HP or greater change makes it a Major. Clearly, he recommended flight testing, but stated Phase I re-entry was not required, only logbook documentation.
I still plan to do testing and will do so in un-populated areas and without passengers.
Thanks again for the thoughtful advice here.
Larry
Would recommend asking nicely for an email stating this so you have a record for the future. Larry
Edit: As I was composing this and posting, I missed Larry's follow up. I'll leave the following for future reference in case anyone else does a search on the topic in the future...I just didn't know if I needed the rigor of the formal Phase I and the FSDO contacts. After all this, I may end up spending 5 hours getting comfortable with the performance and having given this more thought will likely just do the the Phase I testing and document it that way.
Larry
?..Some seem to think this is a real hassle, but for me it was not. You'll also have a chance to develope a relationship with your FSDO and make contacts that may benefit you in the future.
Just a data point, but it isn't a big deal and I'm glad I did it.
Joe