FIELD APPROVAL FOR PA28-235 HEATED PITOT

[akoprivnik]

Please open attachment containing the 337 and data reference used to modify my aircraft back in 1971. You can use the 337 and letter from piper along with the paperwork from kit 757-004 and piper drawing 69046 to modify your aircraft.

 

[philiplane]

None of what is on that 337 is considered a major alteration. Back in the day, people did 337's for everything, thinking it somehow made things "legal".

Approvals are required when altering the way an electrical system functions, not when you add or subtract loads.

All of that could have been done with a logbook entry, but most mechanics aren't good at understanding what is major or minor.

 

[Dravnx]

Years ago, almost any alteration was considered a major alterration. When I opened my repair station in 1994, I had a discussion with one of my maintenance inspectors about what constituded a major alteration and he said that anything that is not original is a major alteration. Of course, he was wrong but that was a common interpretation.

 

[akoprivnik]

Any time you change the original certification of the aircraft, it is a major modification. As the letter from Piper and the 337 notes: If the original alternator is a 35 amp unit, by installing this system it will exceed the 80% load requiring you to shed other systems to prevent an overload. Now that is based on my aircraft and if I still had a 35 amp alternator or generator. (Early versions had generators) With that said, I am only providing information as requested by this owner. It's between him and his tech. I've been an active A&P for 46 years and an IA for 43. I've seen how it was done in the "old" days and how it is done today. I agree, determining Major versus Minor can be subjective. Even the FAA has trouble making that call.

 

[NorthernAviation]

Years ago when getting regulatory information required a paid subscription and a microfiche reader, or a trip to the FSDO, confusion to what the regs actually said was understandable. Now where the answer is no further than the smartphone in your pocket taking literally a minute or two, what is the excuse for continuing to cite "regs" that don't exist? The definition of a major alteration isn't complicated, and it even states that alterations or repairs the don't meet the definition of major, are thereby minor. Pretty simple, yet some claiming to be card carrying AMT's for decades still struggle to figure it out.

A good example of this is the repeated claim that any change is major because it changed the original type certificate. Have these folks never actually read a type certificate for something like a cherokee? Apparently not, if they had they would have noticed stuff like switches, door stewards, battery cables, or in this case pitot heat, are not even mentioned. How are you changing something that didn't exist in the first place?

I remember a conversation years ago long before I was a card carrying AMT, when one of the old mechanics told me that basically any modification required a 337. I had to ask the obvious, if this is true why is the form clearly titled "MAJOR REPAIR AND ALTERATION". if it was for any alteration or repair, why does it say "Major" right there in the title? No answer...

Then there is repeated claim without any factual basis to back it up that in the event of an accident your insurance will be null and void when they discover your illicit led dome light bulb, or Napa alternator belt... Funny enough that this is entirely made up, but more puzzling, at least to me, is why some people care? Navigating the minefield of regulations and the exorbitant costs associated with airplane ownership is bad enough, without making stuff up to make it even more burdensome than it already is.

Jeff

 

[Phoenix86]

Yours is a later s/n . This is the 72nd one built, and pitot heat was not an option for this s/n . The IPC and piper tech rep both confirm this.

Mine is s/n 28-10333 so it was the 33rd off the line. It appears to have the original heated pitot and Aircraft Logbook confirms.

 

[philiplane]

One of Piper's problems was that they made a lot of changes on the fly, and the paperwork did not catch up for some time later. The parts catalogs are great examples of that. You'll find planes with factory installed equipment, which was installed before the parts book shows eligibility. Or the plane left the factory without it, and the selling dealer installed it before customer delivery. In the 1960's Piper cranked out lots of basic planes and sent them to dealers. Where the final features would be installed, like radios, autopilots, heated pitot's, wheel fairings, etc. That's why you see that extensive list of Optional Equipment Kits in the back of the parts manuals. And nothing shows in the weight and balance & equipment lists because the dealer forgot to revise them. This is why you see so many crazy high useful loads in older weight and balances. They left the factory pretty bare, then the dealer installed 40 to 60 pounds, or more, of options into the plane. In an Aztec for example, the Lear L2B autopilot alone weighed 52 pounds, and the radio package another 40 to 70 pounds.

This is very common on any Piper built from 1960 through 1970, and even more so in the Cherokee line. In later years they did better.

 

[akoprivnik]

Bottom line is ,the FAA burdens the installing technician with determining major versus minor and the owner makes the ultimate decision of airworthy. The modification may never cause an issue and in the case of the heated pitot tube, would enhance the safety of the aircraft. The installing technician needs to make him/her self aware of any data that can be acquired to safely install the modification and is done with at least acceptable and/or approved methods.

 

[philiplane]

Bottom line is ,the FAA burdens the installing technician with determining major versus minor and the owner makes the ultimate decision of airworthy. The modification may never cause an issue and in the case of the heated pitot tube, would enhance the safety of the aircraft. The installing technician needs to make him/her self aware of any data that can be acquired to safely install the modification and is done with at least acceptable and/or approved methods.

https://www.faa.gov/documentLibrary/media/Order/Order_8300.16A.pdf

 

[tonispins]

well, I own a cherokee 1964 pa-28-140 s.n. 20109 . bought it in 2000. equiped it for I.F.R. , ILS,DME,ADF, s-tec 30 2 axis autopilot AND A VENERABLE Garmin GNS-300XL. HAD A HEATED PITOT INSTALLED. but the static line did not go to the wing, had 2 static ports either side of rear fuselage, and that is the way it stayed. aircraft was certified that way and thats the way it is going to stay. words of my installing mechanic. so when having my pitot static system calibrated and certified I have a little story to tell the techs , otherwise they tell me that there is a massive leak in the tubing