The Effect of Re-Registration

[rwanttaja]

Good points, Wes. I'm curious now to download some other countries' databases and see if I can correlated aircraft S/Ns with the ones exported from the US.

Unfortunately, there are a bunch of factors at work with the deregistrations so like many "social science" type investigations, it may be almost impossible to identify the most important cause of the change.

An especially good point. The re-registration effort got started because the FAA had to go in front of Congress and admit they didn't really know how many airplanes were in the US, or where they were located. Getting rid of some of the deadwood is going to help, but there's still a bunch of things wrong that aren't being corrected by the current program. There are 20% more homebuilts in the FAA register than are officially recognized as such. I'm hoping that they'll finally recognize them as such, but there's no real incentive for them to do so.

For example, go to http://www.faa.gov/ and enter "16JA". This is an RV-6 a friend of mine built 20 years ago. If you scroll down to Airworthiness, you'll see it says "Unknown" under Classification. This means the FAA does NOT count it as a homebuilt! If you run that number through the NTSB accident records, you'll see two accidents with this airplane (after my friend sold it). In other words, it only counts as a homebuilt when it crashes.

I've attached a list of nearly 6000 aircraft registrations that come up as "Unknown". Yes, some certified airplanes are there. Some Warbirds. Some LSAs, too. But the vast majority are recognized homebuilt types.

These all have "passed" the FAA re-registration effort. But they don't contribute to the FAA's estimate of how many hours homebuilts flew last year. The only time they're counted as homebuilts is when they crash.

Arghhhh.

Ron Wanttaja

[rwanttaja]

Per the FAA Executive summary from the Federal Register (http://www.gpo.gov/fdsys/pkg/FR-2010...2010-17572.htm) the FAA estimated that approximately 1/3 of the 357,000 registered aircraft are inaccurate. If the actual number is a 15 percent reduction in the fleet vs a 33 percent reduction in the fleet it would seem GA got a whole bunch safer as the "per 100,000 flight hours" would be a larger denominator in the fraction accidents/100,000 flight hours.

Ron, do you know how per 100,000 flight hours was adjusted for fleet size?

Nope. I've never seen a write-up on how the FAA makes its estimation. Yet "everybody" uses it, especially the Nall Report.

It's one of the reasons I assess accident rates as a percentage of the fleet. Anyone can access the same basic data and re-create my analysis to verify the results.

Ron Wanttaja

[Jim Hann]

More interesting stuff. This is a plot of the number of homebuilts deregistered vs. the "year of manufacture" in the FAA records.
Attachment 3470
Note the big spike in 1983. This is comprised of a *lot* of ultralight-inspired homebuilts: Quicksilvers, Goldwings, Eippers, Rallys, Tierras, etc.

Ron Wanttaja

I know of at least one and probably two or three ultralights like this that were, um, "down-converted" some time in the past. In other words, they had built them as E-AB because of the uncertainties of 14CFR103 even existing at the time. Once the path was clearer, the markings and paperwork were removed and the airplanes became air vehicles.

I believe all of these craft have since been scrapped, the paperwork is just now catching up, 20 years later.

Jim

[rwanttaja]

Spent some time this weekend counting up how much the re-registration hurt the fleet size for various homebuilts. This plots what percentage of the fleet for a number of homebuilt types were de-registered since October 2010. As one might expect, the older homebuilt types were hit the hardest.


Ron Wanttaja

[steve]

Registration Round 2 is upon us. Hard to believe it's been 3 years already. There will probably be a few lengthened bars on your chart after this go around, Ron.