Homebuilt Aircraft Fleet Sizes

[rwanttaja]

Per my usual practice, I downloaded the FAA Aircraft Registration database on 31 December. Here are the sizes of the number of aircraft that are registered as Experimental Amateur-Built. Note this does not include examples that are registered as Light Sport, or have a blank in the column where the type of registration is normally listed.

For each year, the fleet size shown is on the last day OF that year. Final row is the total number of EAB aircraft in the registry for that year.


Type

2012

2013

2014

2015

2016

2017

2018

2019

2020


Air Command

54

36

35

31

31

25

19

18

18


Aventura

77

71

68

63

65

57

50

49

50


Avid

453

359

359

343

352

342

296

289

280


Baby/Junior Ace

275

230

228

228

230

225

204

201

199


Bede BD-4

134

98

91

93

92

90

78

82

78


Bede BD-5

70

49

43

40

41

38

34

35

32


Benson Gyro

518

271

218

200

198

158

105

79

64


Bowers Fly Baby

244

183

168

167

167

160

140

139

135


Carbon Cub (EAB)

21

29

46

64

90

119

177

244

308


Challenger

657

584

594

586

593

578

491

480

476


Christen Eagle

238

214

207

206

205

204

194

192

192


Cozy

164

158

160

164

165

163

151

151

156


Glasair

651

601

606

596

603

599

571

571

563


GlaStar/Sportsman

358

374

386

396

407

424

410

424

438


Harmon Rocket

84

88

85

87

85

85

80

77

75


Hatz

109

105

107

110

111

110

112

111

110


Kitfox

1027

905

918

936

950

946

875

871

889


Kolb (Ex-AB)

296

248

241

236

235

227

205

198

186


Lancair (All Models)

850

835

847

855

875

866

824

826

834


Lancair IV

246

246

244

259

260

249

236

240

243


Midget Mustang

282

241

240

236

238

233

207

205

204


Murphy

182

173

171

171

176

174

156

161

159


Pietenpol

351

307

313

311

321

319

296

297

289


Pitts (EX-AB)

743

639

613

617

625

608

548

543

534


Pulsar/KIS

150

130

126

124

125

122

107

108

105


Quickie/Q2/Q200

277

168

148

140

143

130

109

103

100


Quicksilver EX-AB

296

170

163

156

162

154

134

127

129


RAF-2000 Gyro

124

113

114

110

111

90

69

69

69


Rand KR-2

314

194

175

167

167

154

132

132

124


RANS

684

627

638

659

677

673

636

651

652


RANS S-12

161

130

129

128

128

121

107

106

109


RANS S-6

216

200

201

208

213

211

204

205

200


RANS S-7

178

180

189

202

206

209

202

210

208


Rotorway

495

404

392

374

380

350

296

296

287


Rutan Long-EZ

482

428

418

416

417

406

379

380

378


Rutan Varieze

423

323

297

286

286

272

243

238

231


SeaRey

237

231

242

242

249

255

241

238

235


Sonerai

287

215

199

194

194

184

156

156

158


Sonex

346

383

420

451

484

497

486

510

527


Steen Skybolt

284

250

246

247

248

235

215

215

215


Stolp

458

404

396

399

402

385

358

349

354


Stolp Starduster

404

357

349

351

352

337

310

302

308


Thorp T-18

290

261

259

259

262

257

239

238

236


Vans

5674

5745

5956

6110

6293

6414

6447

6634

6779


Vans RV-3

172

155

154

158

160

152

149

149

149


Vans RV-4

987

952

956

955

965

958

921

921

921


Vans RV-6

1786

1763

1783

1775

1795

1796

1731

1742

1737


Vans RV-7

946

1000

1066

1118

1170

1220

1244

1285

1322


Vans RV-8

1012

1038

1082

1123

1161

1198

1215

1252

1278


Vans RV-9

484

522

552

588

611

630

638

658

677


Vans RV-10

281

304

340

366

394

419

434

459

492


Vans RV-12 (EX-AB)

28

36

49

53

63

68

74

75

74


Vans RV-14

0

0

0

0

14

38

66

98

134


Velocity

245

232

237

235

240

236

222

224

228


Volksplane

176

104

95

85

86

76

48

47

48


Zenair

841

862

920

965

1013

1028

992

1013

1028


Zenair CH-601

344

340

348

353

367

367

339

332

325


Zenair CH-701

316

323

326

341

344

340

310

328

333


Zenair CH-750

57

86

127

145

171

187

209

229

247


Overall

32041

27946

27909

28078

28830

28451

26572

26842

26941


I added the Carbon Cub to my standard list this year. It includes all variations of CCs... the 1865, the 2000, the CCX, and the CCK.

Ron Wanttaja

[rwanttaja]

A bit of detailed information on the homebuilt fleet sizes. The previous posting will show the net change between years, but this shows how many EAB aircraft were actually added in a given year.


Year

New EAB

EABs Deregistered


2009

1136

464


2010

1077

309


2011

1022

666


2012

954

1951


2013

918

5013


2014

1047

1084


2015

950

781


2016

977

225


2017

917

1296


2018

888

2767


2019

1186

916


2020

959

860


The FAA re-registration process is really biting into the fleet sizes. The US registry is down about 85,000 airplanes from 2010 (the year the re-registration process started), and homebuilts are down about 5,700 aircraft.

Edit: It should be noted that the "New Homebuilts" include aircraft previously de-registered, but that have been added back to the fleet. So they aren't all new construction.

Ron Wanttaja

[planecrazzzy]

I don't register mine every year ...
They try to hit me with a late fee...
several notices ...and costing more .

Finally I have to call them to tell them I'm not flying it ...
When I do...I'll be sure that it has current registration .
They back off .
.
I do plan on flying the Kolb this year... Registering it is the cheap part...only $25 bucks
Being Current ...and insurance are the big palms that need to be greased .
.
Gotta Fly...
.

[Sam Buchanan]

I don't register mine every year ...
They try to hit me with a late fee...
several notices ...and costing more .

Finally I have to call them to tell them I'm not flying it ...
When I do...I'll be sure that it has current registration .
They back off .
.
I do plan on flying the Kolb this year... Registering it is the cheap part...only $25 bucks
Being Current ...and insurance are the big palms that need to be greased .
.
Gotta Fly...
.

Ron's excellent table of stats is referring to FAA registration, not registration with the state or locality in which you reside.

FAA registration renews every three years and is applicable once issued regardless of whether or not the aircraft is flying.

[Frank Giger]

I don't know why, but it cheers me to see 289 Pietenpols still active on the register.

[Bill Berson]

My aircraft is FAA registered. But it isn't active. In the past they sent an "activity" query each year but haven't seen that in years. So I don't think anyone knows the inactive number.

[rwanttaja]

I don't know why, but it cheers me to see 289 Pietenpols still active on the register.
Even better, SEVEN Piets were added to the rolls in 2020. Four were new builds, three were previously-deregistered airplanes returned to the registry.

Ron Wanttaja

[rwanttaja]

My aircraft is FAA registered. But it isn't active. In the past they sent an "activity" query each year but haven't seen that in years. So I don't think anyone knows the inactive number.

Sounds like you used to receive the annual FAA General Aviation Survey. They use the survey to estimate a variety of factors related to GA activity.

https://www.faa.gov/data_research/aviation_data_statistics/general_aviation/

Chapter 2.1 includes an estimate of how many aircraft are active. For instance, the 2019 Survey estimated that

66.1% of fixed-wing piston GA aircraft with fewer than four seats were active
84.3% of fixed-wing piston GA aircraft with four or more seats were active
66.2% of Experimental Amateur-Built aircraft were active.
88.6% of Special Light Sport aircraft were active.

They combine these percentages with the FAA registry to determine how many active aircraft there there are. The survey also estimates how many hours the average aircraft files every year, so they can generate an estimate of the total hours flown. This is used, for instance, by the Nall Report folks to provide estimates of the accident rate per 100,000 flight hours.

The FAA began the requirement for triannual aircraft re-registration in 2010, and it REALLY hosed up the Survey process. The analysis is based on surveys returned. However, people who DIDN'T respond to their re-registration notice had their planes removed from the registry.

So the survey's estimate of active aircraft hardly changed, but the overall FLEET SIZE dropped dramatically. This meant that the Survey's estimate of active aircraft ALSO dropped dramatically, even though, in truth, the same number of aircraft were active.

The FAA never released the 2011 survey; I believe it was because of the effect of the new re-registration process.

Ron Wanttaja

[Dana]

I don't know why, but it cheers me to see 289 Pietenpols still active on the register.

Glad to see Hatzes holding steady, too... Hatzes and Piets just seem to go together. The hotter planes (Pitts, Starduster, Skybolt, etc.) without current kit support are dwindling, I guess people are breaking them faster than new ones are being built.

[DonN]

I counted 312 Tailwinds in the registry, didn't look to see how many new, etc.

[rwanttaja]

I counted 312 Tailwinds in the registry, didn't look to see how many new, etc.

I get about 200. My filter designates it as a Wittman Tailwind if the aircraft model is a "Tailwind" or a "Tail Wind" or variations of W-8, W-9, or W-10 (with dash, or with a space, or no dash or space). There are still a number of false hits, so I don't include Tailwinds in my "standard" set.

[Edit: This erroneously said "get about 2000". The number was actually 200.]

Searching Tailwinds is difficult, since some of the designations (e.g., "W10") are used for other aircraft types as well (Augusta AW109SP or VIRUS SW 100, for instance) and you end up with false hits. The false hits are reduced if you don't use wild cards (e.g., "W-8" vs. "W-8*") but then you lose the examples where the builder reverses the order (N214SS, for instance, a "W-8 TAILWIND").

If there are more reliable search terms, I'd be glad to use them.

Ron Wanttaja

[Bill Berson]

"66.2% of Experimental Amateur-Built aircraft were active."

So the active number is about two thirds of the registration total from post one.

[rwanttaja]

I get about 2000 My filter designates it as a Wittman Tailwind....

Please note I had a typo in the above. The actual number of Wittman Tailwind hits I got was 200, not 2,000. Somehow I'd replaced the period with a zero.

Ron Wanttaja

[rwanttaja]

"66.2% of Experimental Amateur-Built aircraft were active."

So the active number is about two thirds of the registration total from post one.

I'd prefer to state that as, "The FAA estimates that the active number would be two thirds of the registration total from post one."

From 2010 to 2013, almost 8,000 homebuilts...about 24% of the entire homebuilt fleet in 2010... were removed from the registry. The FAA Survey active-fleet estimate for homebuilts actually DROPPED in this period (from 59.6% to 58.4%). One would assume that most of those 8,000 removed homebuilts were inactive, even no-longer-existing aircraft. But the upshot is, using the FAA Survey Data, over 3,000 active homebuilts had supposedly quit flying.

This is why the "official" homebuilt accident rate jumped so much in this time period. Not because accidents increased, but because of the official estimate of active aircraft dropped so much. This triggered a big FAA vs. EAA safety showdown, and a more-reasonable process for monitoring the homebuilt accident rate resulted (based on number of fatalities, not percentage of the estimated fleet).

The FAA Survey active fleet estimate for homebuilts jumped to 66.1% in 2014, which meant that the number of active homebuilts had decreased "merely" by 1,000 aircraft, from 2010 to 2014. I do not know how the FAA changed their processes to produce this jump. Note that in this same time period, 5,000 new homebuilts had been added to the registry.

I don't want to belittle the FAA Survey people...they're doing good work, and using good methodology. But the data they use for input has been messed about entirely, and it's not their fault.

For the 1.3 of you that might be interested on how this came about, I've attached a PDF file explaining what happened.

Ron Wanttaja

[Bill Berson]

Sorry, I can't make any sense from that PDF graphic.
I think using total fatals instead of percentage is dishonest.

[rwanttaja]

Sorry, I can't make any sense from that PDF graphic.

It works better in a Chapter meeting format where I can provide more background.

The upshot is:

Party "A" determines the number of active homebuilt aircraft based on responses from aircraft owners (surveys)
Party "B" determines the number of active homebuilt aircraft based on the LACK of response from aircraft owners (to the triannual re-registration notification)

But when Party B eliminates inactive aircraft, it has utterly no effect on the results from Party A. Yet the results from both Party A and Party B are combined as input to accident rate analyses.


I think using total fatals instead of percentage is dishonest.

Without a reliable estimate of active aircraft and average annual hours, basing one's assessment based on number of accidents eliminates most of the estimation process. I personally look at all accidents, not just fatals, but if you're looking for a metric, the number of fatal accidents every year is a pretty good one.

Here's my results for 1998-2019.
8784
Ron Wanttaja

[DonN]

I didn't use a search, just scanned through the list and counted what I thought were Tailwinds. I know this is not something that you can do for your report. There are SO many ways that people describe their airplanes, and many typo's. Even the variations in spelling wittman, witman, whitman, etc.

[Bill Berson]

"but if you're looking for a metric, the number of fatal accidents every year is a pretty good one."

Only if if the active number doesn't change over time. If the active number declines by half and fatals stays the same then the accident rate doubled by percentage. I can see why that was distressing for EAA when the list was suddenly culled.
But if the active EA-B flight hour numbers should double in ten years and they still measure by total fatals then the fatal rate has improved 100% by percentage but wouldn't know it.
The only way to compare with other aircraft types is with percentage, I think.

[rwanttaja]

but if you're looking for a metric, the number of fatal accidents every year is a pretty good one"but if you're looking for a metric, the number of fatal accidents every year is a pretty good one."

Only if if the active number doesn't change over time. If the active number declines by half and fatals stays the same then the accident rate doubled by percentage. I can see why that was distressing for EAA when the list was suddenly culled.
But if the active EA-B flight hour numbers should double in ten years and they still measure by total fatals then the fatal rate has improved 100% by percentage but wouldn't know it.

The only way to compare with other aircraft types is with percentage, I think.

Don't disagree with you; after all, that's how I run my comparisons. All it really needs is a consistent process. You don't need to know the percentage of active aircraft; you just compute the percentages and compare the values year-to-year. The FAA re-registration process is trimming out many of the inactive aircraft. In fact, the homebuilt fleet size hasn't changed much since the completion of the first re-registration cycle.
8786

The problem is, folks want to see a "accidents per 100,000 flight hours" comparison. Do do THAT, they need the FAA Survey estimate of number of hours flown. And that's where homebuilts take it in the keister; the 2019 survey said that fixed wing GA fleet flew an average of 102.1 hours per year, while the average EAB aircraft flew 46.6 hours. Yet 93% of those homebuilt hours are for "Pleasure," while only 35% of the overall GA hours fall into the same category. It's not a fair comparison.

My own metric for comparisons is weird. I take the average number of accidents per year over a long time span, and divide it by the number of aircraft on the registry in the last year of the time span. It's stinks when someone wants a black-and-white number as to a given airplane's accident rate, but it's great for comparing multiple aircraft...because the process is usually identical for each aircraft type.
8787
Ron Wanttaja

[Bill Berson]

What about comparing aircraft by total airframe hours logged at time of crash?
Does the NTSB list aircraft hours on the reports?

[rwanttaja]

What about comparing aircraft by total airframe hours logged at time of crash?
Does the NTSB list aircraft hours on the reports?
The NTSB lists the airframe hours on about 75% of the homebuilt accidents. My Cessna 172 accident database shows about 82% of the accidents had aircraft hours.

Otherwise, the average GA aircraft is older and has a *lot* more time. The average time on the 172s was over 5,000 hours, while the homebuilts had an average of about 350. Wouldn't really be a fair comparison.

Here's a plot of aircraft time vs. number of homebuilt accidents over a 22-year period.
8788
Ron Wanttaja

[Marc Zeitlin]

The NTSB lists the airframe hours on about 75% of the homebuilt accidents. My Cessna 172 accident database shows about 82% of the accidents had aircraft hours.

Otherwise, the average GA aircraft is older and has a *lot* more time. The average time on the 172s was over 5,000 hours, while the homebuilts had an average of about 350. Wouldn't really be a fair comparison.

Here's a plot of aircraft time vs. number of homebuilt accidents over a 22-year period.
Ron WanttajaIt would be interesting to see the data normalized against the number of aircraft that have reached a particular "Aircraft Time" level. IOW, if only five planes have reached 900 hours, and 4 of them crashed at 900 hours, that's a lot worse than 1000 planes reaching 100 hours and 75 of them crashing.

Does the data exist to do this analysis?

[DaleB]

It would be interesting to see the data normalized against the number of aircraft that have reached a particular "Aircraft Time" level. IOW, if only five planes have reached 900 hours, and 4 of them crashed at 900 hours, that's a lot worse than 1000 planes reaching 100 hours and 75 of them crashing.

Does the data exist to do this analysis?
I can pretty much guarantee it doesn't. Just as there is no requirement to report the number of hours per year flown by pilots, there is no requirement to regularly report airframe time flown on Experimentals - or most GA airplanes, for that matter. No requirement, and to the best of my knowledge no process or place to report it even if you wanted to.

The FAA has a record that my plane exists, and that it has current registration, but no idea of the current hours. I suppose if someone were to crash it AND enough of the Dynon survived to tell the tale they might recover that information, or they could see the hours recorded during the most recent condition inspection. That's about it.

This is why I am somewhat suspect of any statistics on the number of hours flown per year by the GA or Exp fleet. I don't know how big a sample size is used, or what percentage of owners respond to the survey, but it's a statistical guess.

[Bill Berson]

The average time on the 172s was over 5,000 hours, while the homebuilts had an average of about 350. Wouldn't really be a fair comparison.

Here's a plot of aircraft time vs. number of homebuilt accidents over a 22-year period.
Ron Wanttaja

It isn't fair that homebuilts have more fatals, but is reality. My mother-in-law told me life isn't fair.
I think the data needs to list the fatal rate for each homebuilt type from zero to 200 hours aircraft time.

[rwanttaja]

It isn't fair that homebuilts have more fatals, but is reality. My mother-in-law told me life isn't fair.
I think the data needs to list the fatal rate for each homebuilt type from zero to 200 hours aircraft time.

Interesting suggestion. Here's a cut at it, for aircraft types with 50 or more accidents from 1998 through 2019.

Fatal Rate: Percentage of ALL accidents of that type that resulted in at least one fatality.

Fatal Rate for A/C with <200 Hours: Percentage of fatal accidents of that type that HAD an entry for aircraft time, and the aircraft time was less than 200 hours.

Percentage of Accidents with <200 Hours: Percentage of all accidents that HAD an entry for aircraft time, and the aircraft time was less than 200 hours.

Last line of the table gives the overall for the homebuilt fleet.


Kennel Name

Fatal Rate

Fatal Rate for A/C with <200 Hours

Percentage of Accidents with < 200 Hours


Avid*

7.9%

3.8%

49.4%


Challenger II*

34.6%

12.0%

64.0%


Glasair*

31.3%

3.0%

28.4%


Glastar*

10.8%

6.5%

52.2%


Kitfox*

14.1%

2.4%

45.6%


Lancair 4*

52.2%

20.4%

46.9%


Lancair Two Seat*

40.5%

11.7%

33.8%


Pitts*

20.8%

5.0%

26.7%


Rand KR-2*

24.0%

5.6%

55.6%


ROTORWAY*

6.5%

5.2%

78.1%


Rutan Long-EZ*

17.6%

5.6%

25.0%


SeaRey*

19.7%

8.7%

60.9%


Sonex*

28.0%

13.9%

72.2%


Starduster*

13.1%

0.0%

19.1%


Vans RV-4*

28.4%

3.0%

22.4%


Vans RV-6*

26.5%

4.9%

27.6%


Vans RV-7*

33.3%

6.3%

45.8%


Vans RV-8*

27.4%

7.9%

47.6%


Velocity*

19.7%

13.0%

58.7%


Zenair CH-601*

20.5%

10.6%

74.2%


Zenair CH-701*

11.8%

1.8%

70.9%


Overall

24.1%

9.0%

51.7%



Interesting how lower-time homebuilts have a lower fatality rate. I thought at first it was might be because of an increased rate of early-life engine issues, but the <200 hour's power-failure rate isn't that much higher than the overall fleet.

Ron Wanttaja

[Dana]

If you crash, the FAA or NTSB will ask to see the aircraft logbooks... they did when I had my accident.

[Bill Berson]

The danger zone is probably the less than 100 hours in type. That's why insurance companies want 100 hours in type.

[rwanttaja]

The danger zone is probably the less than 100 hours in type. That's why insurance companies want 100 hours in type.
Yep, makes sense.

8789
You'll notice how the NTSB guys like to round up... spikes at 100, 150, 200, etc.

Ron Wanttaja