### APP E NDIXA METHODOLOGY FOR THE 200 5 GENERAL AVIATION AND AI R TAXI ACTIVITY AND AVIONICS (GAATAA) SURVE Y

Purpose of Surve y The purpose of the GAATAA Surve yis to provide the Fede ral Aviation Administration (FAA) with information on general a v iation and on-demand Part 135 aircraft activity. The information obtained fro m the surve yenables the FAA to mo nitor the gen eral aviation fleet so thatit can, among other activities, a n ticipate an d meet demand for National Airspace System (NAS) facilit ies and services, assess the impact of regul atory changes on the fle e t, and implement measures to assure the safe operation of all ai r c raft in NAS. The data collected are also used by other government agencies, the ge neral aviation industry, trade associa t ions, and pr ivate businesse s t o pinpoint safety problems and to form the basis for critica l re search and analysis of general aviation issu es.

Backgroun d and History Prior to the first implementation of th e annual GAATAA Surve yin 1978, the FAA used the Aircraft Registration Eligi b ility, Identifi c ation, and Activity Rep o rt (AC Form 8050-73) to collect data on gen eral aviation activity. The form was sentannually to all owners of civil air c raft in the United States and served two purposes: (1) Part1 was the mandatory a i rcraft registra tion revalidation form, and (2) Part 2 was voluntary a nd applied t o general aviation aircraf tonly, asking que stions on the owner-discr etionary characteristics of the aircraf tsuch as f lig ht hours, avionics equ ipment, base location, a nd use. The FAA used this informatio n to estimate aircraft activity. In 1978, the FAA replaced AC Form 8050-73 with a new system: Part 1 was replace d by a triennial registration prog ram. In January 1978, the FAA implemented a new procedure, known as triennial revalidation, for maintaining its maste r file. Instea d of requirin g all aircraft owners to revalidate and update th eir aircraft registration a nnually, the FAA only re quired revalidation for those aircraf towners who had not co ntacted the FAA Registry for three years. This le ss frequent updating of the master file affected its accuracy an d represent ativeness:
1. The accuracy of current owners and their addresses deteriora ted.
2. The master file combine d a residue of aircraft, w h ich under t he old revalidation system woul d have been reregistere d and purged from the file, but now remain under the new system. Part 2 of AC Form 8050-73 was replaced by t he General Avi a tion Activit y(GAA) Survey. Conducted annually, the survey is based on a statis tically selected sa mple of aircraft, and it requests the same type of information as Part 2 of AC Form 8050-73. The first GAA Surve ytook place in 197 8, collecting data on the 1977 general aviation fleet.

A-1Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey In 1993, the name of the GAA Surve ywas chang ed to the General Aviation and Air Taxi Activity (GAATA) Su rvey to refle c t that the survey includes air taxi (t hat is, on-de mand Part 1 35) aircraft. Starting in 1 999, the avionics se ctio n, which wa s previously included on ly every othe r year, was asked every year. As a result, the su rvey’s name was chang ed to the General Aviation and Air Taxi Activity and Avionics (GAATAA) Surve y

. This is the nam e under which the 2005 survey was conduct ed. The GAATAA Surve yha s undergone periodic revisions to con t ent, implementation, an d definition of the GA population in order to remain current wit h regulation s , activity patterns, and general aviation commu nity. The table below su mmarizes changes in survey conte n t.
Year Description of change to surve yc ontent 1993 Added sight seeing and external load to use cat egories 1996 Added publi cuse (i.e., f l ights for the purpose of f u lfilli ng a go vernment fu nction) to use categories 1999 Significant re -design of t he entire sur v ey form to reduce item non-response, add new content, and be compatible with optical scan n ing Added air medical services to use ca tegories Discontinue d the use of a catch-all ‘other’ categ o ry as used in previous years Began colle cting avionics data every y ear, rather than every other year 2000 Public use a sked as a separate question, indep endent of ot her use cate gories (e.g., personal/recreation, business transp o rtation) , be cause it was not mutually exclusive with respectto other flig ht activity 2002 Use categor ies refined t o be mutually exclusive and exhaustive and mat c h definit ion s used by NTSB for accid ent reportin g 2004 Air medical services was divided int o two separate types to capture air medical fligh t s under Part 135 and air medical flights not covered by Part 135 A more clearly defined ‘other’ categ o ry was reintroduced 2005 Fractional o w nership question was changed from yes/no to a percentag e Reduced the number of fuel type response cate gories by removing obsolete option s Added question asking f o r average fuel consum ption (in gallons per hou r) Revised avi onics page by adding and rearranging items

A-2Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey
The table be low summarizes cha nge s in survey implementati on.
Year Description of change to surve yi m plementation 1999 Non-respondent telepho ne survey conducted to adjust act i ve aircraft and hours flown estimates 1 Sample design revised to stratify by aircraft type (19 categories) and FAA region (9 categories) 2 2000 Discontinue d non-respo ndent teleph one survey because of t he variability of telephon e non-respon dent factors Added Internet response option 2003 Added a reminder/thank-you postcard between the first and second mailings 2004 Introduced “ m ultiple aircraft” summa ry form to allow owners/operators of multiple aircraft to re port aggregate data for their entire fleet on a sin g le form Phone calls placed by PA and aviation associat ions to enco u rage participation by large fleet operato rs

The table be low summarizes cha nge s to the definition of the general aviation population and sample design.
Year Description of change to definition of the GA population and sample design 1993 Number of a i rcraft types classified by the sample was expanded from 13 to 19 2003 Aircraft with known incor r ect addresses and ident ified as “Postmaster Return” status o n the Registry were retained in the def inition of the survey pop ulation and were eligible for selecti o n into the sur v eysam p le 2004 Aircraft repo rted as “registration pen ding” or sold (if sold stat us less than 5 years) on the Registry were retained in the def inition of the survey pop ulation and were eligible for selecti o n into the sur v eysam p le Sample design revised to stratify by aircraft type (19 categories), FAA region (9 categories), and whether or not the aircraft is own ed by an entity certified t o fly Part 135 (2 categorie s) Introduced 1 00% sample of the follo wing groups: turbine aircraft, rotorcra ft, on-demand Part 135 aircraft, and Alaska-based aircraft 2005 Sample design and reporting revised by introducing Light-spo rt aircraft as a 20th aircraft type sampled at 100%

The 2005 st atistics in th is report were derived from the twent y-eighth GAATAA Surve y , which was implemented in 200 6.

1 Telephone surv e y s of non -respo ndents also w e re conducted in 1977, 1978, 19 79, 1997, and 19 98. Please refer to th e 1999 GAATAA Surve yreport fo r a full d i scussion of the telephone surve y of non-r e sponde nts. 2 Before 199 9, the sample w a s stra tified by aircraft t y pe ( 19 categori e s) and state/ter r i tory (5 4 categori e s).

A-3Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey Improvements to the 2005 Surve y As part of o ngoing effort s to improve the survey data, four ke y changes were made to the 2005 surv ey : 1. The field per iod opened on March 29, 2006, the e a rliest date since the large-scale survey re-de s ign in 1999

. 2. To gather more accurate fuel consu m ption data, a question was added asking for average fuel consumptio n (in gallons per hour).
3. In order to remain current with tech nological a d v ances, the avionics section was revised by adding and re arranging ite m s. 4. Light-sport a i rcraft were added as a 20th aircraft type, and are reported as a separate cat egory Each of these improve m ent is discussed in fu rthe r detail in su bsequent se ctions of th is Appendix.

Surve y Pop u lation and Surve y Sa mple The survey population f o r the 2005 General Avi a ti on and Air Taxi Activityand Avioni cs Survey includes a ll civil aircraft registered with the FAA that are base d in the U.S. or U.S. territories and that were in existence a nd potentially active between January 1 and De cember 31, 2005. 3 This includes a i rcraft operatin g under:

• Part 91: General operating and flightrules.

• Part 125: Certification a nd operation s : Airplanes having a seating capacity of 20 or more passengers or a maxi mum p a yload capacity of 6,000 pounds or more (but not for hire).

• Part 133: Rotorcraft external load o perations.

• Part 135: On-demand (air taxi) and commuter o perations no t covered by Part 121.

• Part 137: Agricultural a i r c raft operations. Aircraft operating under Part 121 as defined in P a rt 1 1 9 a r e e x c l u d e d from the surve y population. Foreign air carriers, which operate under Part 129, are also n o t part of th e survey population. Civil aircraft that are kno w n not to be potentially active durin g the survey year are also exclude d from the population—i. e., aircraft displayed in museums, aircraft destro y ed prior to January 1, 2005.

3 According to the FAA Aircraft Re gistration Master File—the samp le frame for the surv ey (discussed below)-- over 99 p e rcent of t he aircraft in the 20 05 surve y po pulation w e re r egister ed to o w ne rs in the 50 states, the District of Columbia, Puerto Rico or oth er U.S. territories, such a s American Sam oa, Guam , and t he Virgin Islands.

A-4Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey
The Aircraft Registration Master File, maintained by the FAA’ s Mike Monroney Aeron autical Center in Oklahoma City, serves as the sample frame or list of cases fro m which a sample of civil aircraft is select ed. The Registration Master File (“Registry”) is the official re cord of registered civil aircraft in the United States. For t he purpose of defining t he 2005 sur v ey population, we used the Registry’s list of aircraft as of Dece mber 31, 2005. The Registry, like all sa mple frames , is an imper fe ct represe n tation of th e survey po pulation. While it may exclude a very small number of aircraft that ope rate under the FAA regulations governing the operation of general a v iation and on-demand Part 135 aircraft, it also includes aircraft that are not part of the survey population. Prior to sa mple selection, several steps are taken to remove ineligible aircraft fro m the sample frame. Sp ecifica lly, this include s re moving the following :

• Aircraft missing key iden tifiers that ar e necessaryfor classification or merging with other data sources (e.g., N-number, serial number, make/mo del information)

• Aircraft whose registration has been cancelled o r revoked

• Aircraft based in Europe or registered to a foreign company that have not returned flight hour re ports

• Aircraft that operate under Part 121

• Aircraft dest r oyed or mo ved to muse ums prior to January 1, 2005

• Aircraft repo rted sold bef ore 2000 (5 years prior to survey ye ar) 4

• Aircraft that are flagged Postmaster Return (known to have incorrect add ress information) since before 1995 (10 years prior to survey year)

• Aircraft that are missing information on the regist rant’s name (i.e., the field is blan k) (Aircraft for which the re gistrant is listed as “Pending” are ret a ined in the survey population 5 )

• Aircraft that lack informa t ion necessary to execu t e the sample design (i.e ., aircraft type, FAA re gion) The Registry included 3 59,516 aircra ft as of De cember 31, 2005. After excluding th e aircraft described a bove, the sample frame contained 2 98,901 reco rds used to define the g eneral aviation population. Sample Des i gn The 2005 GAATAA Survey Sa mple is stratif i ed by aircraft type (20), FAA region in which the aircraft is re gistered (9), and whether the aircraftoperates un der a Part 135 certificat e (2). Part 135 aircraft were identified using the FAA’s O perations Specifications Subsystem (OPSS)

4 Prior to 2004, air c raft w e re exclud ed if reporte d sold more than 1 ye ar prior t o the surv ey y e a r

. 5 Prior to 2004, air c raft w i th “Regist ration Pending” w e re e x cluded fr om the populatio n.

A-5Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey
database th at was merged with the Registry by N-number. The three st ratifying variables yield a matrix of 36 0 cells.
The 2005 su rvey sa mple included se veral types of aircraft th at were sampled at a rat e of 1.0 (i.e., 100 pe rcent sample). Because of the FAA’s interest in gaining a be tter underst anding of the operatio n of these aircraft, all su ch aircraft li sted in the Registry were included in the survey sample to ensure a sufficient number of surveycompletes to support analysis and pro v ide more precise estimates of fleet size and aircraft act i vity. These in clude:

• 100 percent sample of turbine aircraft(turboprops and tubojet s)

• 100 percent sample of rotorcraft

• 100 percent sample of aircraft operat ing on-demand Part 135

• 100 percent sample of aircraft based in Alaska Altogether, these aircraftcontributed 42,543 obse r vations to the 2005 sur v ey sa mple.
In addition t o the four groups list ed above, the 2005 GAATAA Surve ytra cked Light- s port aircraft as a 20th air c raft type for the first tim e . Because t he survey u n iverse cont ained only 193 Lightsport aircraft , these aircra ft were also sampled at 100 percen t. Other aircraft that are no t part of a 1 00 percent sample are subject to se lection base d on sampling fractions def in ed for each cell in th e sa mple design matrix. Ave r age annual flight hours is the primary measure n eeded by the FAA to addr ess survey goals. Sample fractions for each sample strat a are define d to optimize sample size to obtain a desired lev e l of precision for an estimate of flight activity. Data from the prev ious survey year on average hours flown, variability in hours flo w n by region and aircraf ttype, and response rat e s are used to set precision levels and identify the optimal sample size for each stra ta. Aircraft a r e randomly selected fro m each cell in th e matrix, subject to the desired sample size. Strata t hat yield a very small sample size are examine d and adjust ed to includ e all observ a tions in the strata if necessary. In 2005, an additional 3 4 ,667 aircraf twere sampled at a rate of less than 1.0, yielding a total survey sample of 77,403. T able A.1 sho w s the number of aircra ft selected into the survey sample, by aircraft type, as well as the prop ortion of the population r epresented by the samp le.

A-6Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey
TABLE A.1: SURV EY S A MPL E AN D POP U LA TION FIGU RES BY AI RCRAFT T YPE

Aircraft T ype Population Sample Size Sample as Percent of Population Fixed Wing - Piston 1 engine, 1

- 3 seats 64,841 15,618 24.1 1 engine, 4 + seats 128,059 14,531 11.3 2 engines, 1-6 seats 16,181 4,772 29.5 2 engines, 7+ seats 7,475 2,127 28.5 Piston: Other 227 227 100.0 Fixed Wing - Turbopro p 1 engine 2,809 2,809 100.0 2 engines, 1-12 seats 4,806 4,806 100.0 2 engines, 13+ seats 977 977 100.0 Turboprop: Other 78 78 100.0 Fixed Wing - Turbojet 2 engines 9,750 9,750 100.0 Turbojet: Other 1,027 1,027 100.0 Rotorcraft Piston 4,452 4,452 100.0 Turbine: 1 engine 5,891 5,891 100.0 Turbine: Multi-engine 1,322 1,322 100.0 Other Ai rcraft Glider 3,201 1,448 45.2 Lighter-tha n-air 7,160 1,823 25.5 Experimental Amateur 34,907 2,936 8.4 Exhibition 3,180 1,049 33.0 Experimen tal: Other 2,365 1,567 66.3 Light-sport 193 193 100.0 Total 298,901 77,403 25.9

Weighting th e Survey Da ta Data from completed surveys are weighted to re flect populat ion characte ristics. The weights reflect the proportion of a i rcraft sampled from the population in each sample strata an d differential re sponse as well as a small adjustme n t for aircraf tthat are no t part of the survey population. Initially, each aircraft for which we receive a comp leted survey is given a weight that reflects sampling fraction and dif ferential response. That is:

A-7Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey WEIGHT = (Population N ijk/Sample N ijk ) * (N Re spondents ij k/ S ample N ijk ) where i, j, a nd k represe n t the three sample strat a of aircraft t y pe, FAA re gion, and Part 135 status. The weight is subseque ntly adjuste d to reflect n e w information about no n-general aviation aircraft. Tha t is, survey responses th at identify an aircraft as not being pa rt of the survey population

— destroyed prior to Jan uary 1, 2005; displayed in a museum; operated p r imarily as an air carrie r under Part 121 or 129; or a military aircraft—are used to remove aircraft proportionally from the s a mple and from the population. This adjustment is done at th e level of the 20 aircra ft types. The procedure assumes th at non-GA a i rcraft occur in the same proportion among survey respondents and non- respondents. To the extent that non- GA aircraft are less likely to rece ive and complete a survey, this approach will un derestimate the adjustment for aircraft that are not part of the general aviation p opulation. Errors in Survey Data
Errors asso ciated with survey data c an be classif i ed into two types—sampling and no nsampling errors. Sampling errors occur because t he estimates are based on a sample of aircraft rather than the entire po pulation, an d we can expect, by chance alone, t hat some aircraft selected int o the sample differ from aircraft that were not selected. Non-sampling errors ca n be further subdivided into a) errors that arise from difficultie s in the execution of the sample (e.g., failing to obtain co mpleted interviews with all sample u n its) and b) errors cause d by other factors, su ch as misinterp r etation of q uestions, in ability or un willingness to provide accurate answers, or mistakes in re cording or co ding data. Sampling Er ror The true sa mpling error is never kn own, but in a designed survey we c an estimate the potential magnitude of error due to sampling. This estimat e i s t h e s t a n dard error . The standard error measures the variation that would occur among the estimates from all po ssible samples of the same desig n from the same population. This publica t ion reports a standard e rror for each estimate based on survey sample data. An estimate and its standard error can be used to construct an interval estimate (“confidence interval”) with a prescrib ed level of confidence th at the interval contain s t he true population figure. In ge neral, as sta ndard errors decrease in size we saythe estimate has greate r precision (the confide n ce interval is narrower), while as sta ndard errors increase in size the e s timate is less precise (the confide n ce interval is wider). Ta ble A.2 sho w s selected interval widths and their corresp onding confidence.
TABLE A.2: CONFI D ENCE OF INT E RVAL E S T I MATES

WIDTH OF I N TERVAL APPROX I M ATE CONFI D ENCE THAT INTE RVAL INCL UDES TRUE POPULATION VALUE 1 Standard error 68% 2 Standard error 95% 3 Standard error 99%

A-8Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey This report presents a “ percent stan dard error” for each estimate, which is the stand ard error relative to the mean. The percent st andard error is simply the ratio of the standard er ror to its estimate multiplied by 10 0. For example, if the estimate is 4,3 76 and the standard error is 30.632, then the percent standard erro r is (30.632 /4,376) * 100 = 0.7. Reporting perce nt standard erro rs makes itpossible to compare the precision of estimates a c ross ca teg o ries. Estimates and percent standard errors reported in Table 2.1 provide an example of h o w to compute and interpret confidence in tervals. To obtain, for example, a 95 percent conf idence interval for the estimated number of total hours f l own for turbojets in 200 5, where the total hours flown is estimated to be 3,767,327 a nd the perce nt standard error of the estimate is 0.8, the following co mputation applies: Lower confidence limit: 3,767,327 – 2(0.8/100)(3,767,327) = 3,707,050 Upper confidence limit: 3,767,327 + 2(0.8/100)(3,767,327) = 3,827,604 In other words, if we dre wrepeated samples of t he same design, 95 per cent of the e s timates of the total hou rs flown by turbojets wo uld fall betw een 3,707,0 50 and 3,82 7,604. Non-sampling Error Sampling error is estima ble and can be reduced t h rough survey design (e.g., by increasing sample size ), but it is d i f f icult, if not impossible, t o quantify the amount of non-sampling error. Although extensive efforts are undert a ken to minimize non-sampling error, the succe ss of these measures cannot be qu antified. Steps taken to reduce no n-sampling error fall into two classe s—strategies to reduce n onresponse an d efforts to minimize measurement and coding errors. To th is end, implementation and design of the 2005 GAATAA Su rvey incorpo r ated the following steps to maxi mize cooperation among sample members:

• Two modes of administration to facilitate access to the survey—a postcard invitation to complete the survey o n the Intern et followed by a mail survey to be c o mpleted by pen or pencil

• Three mailings of the sur v ey to indivi duals who h ad not yet responded, as well as a reminder/thank-you postcard

• Cover letters accompan ying each survey mailing clearly explained the purpose of t he survey as well as the en dorsement (organization al logos) of several aviation associat ions 6

• Cover letters assured o w ners of the confidentia lity of their responses an d informed them: “Na m es of individ uals are never associa t e d with respo n ses. There is an identifica t ion number on your surve yonly so [sur vey contractor] knows who should receive the survey.”

6 The follo w i ng associations’ logos appeared on the 2005 cover lette r : Aircraft Owners and Pilots Association (AOPA), E x periment al Aircraft Associati on (EAA), Gene ral Aviation Manufacturers Associ ation (GAMA), Helicopter Associat io n International (H AI), Nati onal Agricultural Aviat i on Associat ion (NAAA), National Air Transportatio n A ssociation (NATA), National B u siness Aviation Associatio n (NBAA), Small Aircraft Manufactu rers Association (SAMA).

A-9Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey

• Use of additional source s to obtain u pdated cont act information and help ensure the mail survey reaches the sample me mber (e.g., National Change of Address, update s from aviatio n associatio ns)

• Use of a toll-free 800 telephone number and email address t o respond to questions

• Collaboratio n with aviation organizat i ons and ind u stry groups to encourag e cooperation of owners or operators o f multiple air c raft The survey also reflects efforts to minimize m easurement error by increasing the likelihood that respondents share a co mmon unde rstanding of survey questions and re ducing errors in data coding. The se include :

• Close collab o ration with the FAA, other federal a gencies and aviation groups to refine and clarify questio n wording as well as def initions t o q uestions. Th e questionnair e is re-examined each year to identif y ambiguities or revision s necessary to remain consistent with aviation regulations and definition s

.

• Significant re views and re-designs o f the questio nnaire have been undertaken periodically (see “Backg round” section of this re port). Each re-design is t horoughly pre-tested with a sample of aircraft o w ners or operators and, if necessar y , modified on the basis of the pre-t e st result s.

• Comprehen sive editing and verificat i on procedur es to ensure the accuracy of data transcription to machine-readable for m as well as internal con s istency of re sponses.

Surve yCon t ent The 2005 GAATAA Survey questionnaire, sho w n in figure B.1 of Appendix B, requests the aircraft owner or operator to provide the followin g information on the sa mpled aircraft’s characterist ics and use s : 1. Number of t o tal hours flown in 2005, and hours f l own by use
2. Airframe ho ur reading a nd the aircra ft’s base location as of December 3 1 , 2005 3. IFR hours, percentage of hours flown in Instrument Meteorological Conditions (IMC) and Visual Meteorological Conditio n s (VMC) d u ring the da y and eveni ng 4. Number of l andings in 2 005
5. Fuel type and average fuel consumpt ion
6. Whether the aircraft was part of a fra c tional owne rship progra m in 2005
7. Avionics eq uipage The survey questionnaire was largely unchanged from the 2004 survey t o the 2005 survey, with the following exceptions:

A-10Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey

• The fraction al ownership question ( Q 6) was changed from yes/no to a percentage. This allows hours flown by aircraft that operate o n ly part of the tim e under a fractional o w nership program to be reported proportionally rather than an “all or nothing” manner. Also, t h is item was moved to p age 2 of the questionnair e

.

• Based on recommendati ons by the FAA and industry experts, the followin g fuel types were remo ved from Q15 : propane, a v iation fuel - 80 Octane, and 82 UL.

• To gather more accurate fuel consu m ption data, a question was added asking for average fuel consumptio n (in gallons per hou r). Prior to the 2 005 survey, fuel burn rates were hard coded b a sed on the 19 aircraft types. This procedure was adopted from earlier years, and the origin of t he hard cod ed values is uncertain. T he estimates presented in t he 2005 GAATAA reportare based o n a new question (Q16), which asks re sp ondents to report their a v erage fuel consumptio n rate. This figure is multiplied by th e total hours reported to calculate tot a l fuel con s umed. Fuel consumptio n estimates in 2005 sho u ld reflect d i fferences by aircraft makes-models, use patterns, etc. more accurately.

• In order to reflect techn o logical adv ances, the a v ionics sect ion was revised by adding and r earranging it ems. Items which were added to the 2005 survey include:

- Integrated All-glass Cockpit

- Electronic Flight Bag (EFB) - Installe d

- IFR LPV Ap proach (WAAS)

- ADS-B ( M o de S) - ADS-B ( U A T ) - Altitude Preselect

- Attitude & Heading Reference System (AHRS)

Surve yMethod Appendix B presents the materials used to cond uc t the 2005 survey. The standard su rvey form is shown in Figure B.1. The postcard invitation t o the Intern et component and the re minder/ thank-you postcard are shown in Fi gure B.2. Each of the three mailings for the stand ard survey was accompanied by a cover letter, shown respectively in Figures B.3, B.4, and B.5. The protocol used for the 2005 survey is similar t o that used since the 20 00 survey. T he survey data were collected fro m owners a nd operators of the sampled aircraft through two venues – the Internet and mailings of the question naire. The I n ternet component was implemente d before the mailing portion to capture as many respondents el ectronica lly as possible. Sampled aircraft were first se nt a postcard inviting th em to participate in the I n ternet version of the sur v ey. The postcard wa s sent out o n March 29, 2006, and th e Internet co mponent continued thro ugh August 14, 2006. There were three mailings of the sta ndard questi onnaire, and a reminder/thank-you postcard sent between the first an d second mailings. Th e first quest i o nnaire maili ng, sent out on April 26, 2006, covered 52,330 aircraft in the sample that had not completed a sur v ey via the Internet or had not rece ived a final disposit ion d ue to a returned postcard (refused, re spondent d e ceased, undeliverable with no new address, etc.). The re minder/thank-you postcard was sen ton

A-11Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey May 17, 200 6, and inclu ded only those aircraft in the sample that had not yet responded to the survey and were not part of the non- active sample. The seco nd survey mailing was sent on June 1, 200 6, and inclu ded only those aircraft in the sample that had not yet responded to the survey and were not part of the non- active sample. The third mailing was sent on July6, 2006, to owners and operators of the sampled aircraft who had not responded t o the first or second mailings. Alternative Surve yfor Reporting on Multiple Aircraft The 2005 GAATAA Survey continued the effortin itiated wit h the 2004 GAATAA Su rvey to increase co operation a m ong respondents who own or operate multiple aircraft. To achieve this objective, th e 2005 survey emplo y ed the data collection tools and methods introduce d in 2004. The responses of multiple-aircraft owners/operat ors are extremely important for accu rately estimating g eneral aviation activity. Because of t he increase d burden of reporting for multiple aircraft, ther e was a con c ern that the s e high-end, high-use op erators were less likely t o respond to the survey. Therefore, after the sa mple was selected, the F AA’s Operations Specif ications Subsystem ( O PSS) was used to group aircraft bel onging to the same operator’s fleet. Operators with three or more aircraft were classified as “multiple owners/operators” f o r survey pu rposes, regardless o f the number of their aircraft present in the survey sample. To avoid confusion among responde nts, aircraft were assign ed to a single data colle ction track. The 11,093 aircraft in th e “multiple owner/operator” track followed an independent protocol developed last year. The remaining 66,310 aircra ft followed the same protocol used in previous years and is described a bove. In order to minimize the reporting burden on operators of multiple aircraft, a summary surve y was developed with the cooperation of several aircraft operat ors and aviation asso ciat ions to enable an o perator to report activity for an entire fleet on a single conden sed form, instead of completing t he longer qu estionnaire f o r each individual aircra ft. This surv ey form (Ap pendix B, Figure B.6) allows operators to rep o rt on key variables for major classes of aircraft , including hours flown, how flown, fuel consum ption, and n u mber of landings. The f o rm did not collect d a ta on flying co nditions, fue l type, fractional ownership, or avionics. Data collection for multiple-aircraft o w ners/operators followe d the same timing as the standard data colle ction track. Like the standa rd survey pr otocol, an In ternet survey that match ed the mail questionnair e was programmed to al low online r eporting.
To maxi mize the survey response ra te, follow-up phone calls were place d to all multiple-aircraft owners/operators. These calls fo cuse d not only on encouraging survey p a rticipation , but also on ensuring sur v ey mailings were reaching the appropriate person in the op erator’s org anization. In many cases, aviation association s with whic h op erators had an existing re lationship made these telephone calls. Benefits resulting from the new systems of data collect ion implemented since 2000 in clude quicker processing of th e results, improved data quality, and considerable savings of time and money to bo th the public and the fed e ral government.

A-12Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey Response Rate
As shown in Table A.3, t he overall response rate for the 2005 survey was 44.5 percent 7 . The response rat e for the Int e rnet portio n of the survey was 18.9 percent and accounted f o r 41.9 percent of th e total respo n ses to the survey. The first mailing had a respo n se rate of 1 7 .2 percent and accounted f o r 30.5 percent of the tot a l response s to the survey. The second mailing had a respo n se rate of 9

. 6 percent, which accou n ted for 20. 5 percent of the total responses to the survey. The third mailing produ ced a respo n se rate of 7

. 3 percent, a pproximatel y 7.1 percent of th e total respo n ses to the survey. TABLE A.3: SUMMA RY OF RES P ONSE INF O RMATI O N

P h a s e V a l i d Sample 8 C o m p l e t e s 9 R e s p o n s e R a t e % T o t a l Response Internet 77,199 14,555 18.9% 42.5% 1 stMailing 66,203 11,395 17.2% 33.3% 2 nd Mailing 52,426 5,037 9.6% 14.7% 3 rd Mailing 44,337 3,238 7.3% 9.5% Overall 76,902 34,248 44.5% 100.0%

Table A.4 illustrates the steady incre a se in the In ternet respo n se as a per centage of a ll returned surveys from 2000 to 2005 (16.4 percent for 2 000 compared with 42.5 percent for 2005). This increase in response il lu strates an in creasing eff e ctiveness o f utilizing the Internet for data collect ion, th ereby impro v ing the efficiency and cost savings of the data collection pro c ess.

TABLE A.4: PERCENTA G E OF ALL COMPLE TE D SURVEY S RESP ONDING BY INTERNET

2 0 0 0 2 0 0 1 2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 Total C o m p l e t e s 1 5 , 6 8 9 1 6 , 4 3 2 1 5 , 2 5 4 1 4 , 4 7 1 3 2 , 0 5 6 3 4 , 2 4 8 Internet Completes 5,144 5,954 5,304 6,059 13,441 14,555 Internet % of Total 32.8% 36.2% 34.8% 41.9% 41.9% 42.5%

7 Although the 20 05 response rat e of 44.5% repr esents a decrease f r om response rat e s prior to 2003 , this decrease is attributabl e to changes in survey method olog y th at have o ccurred over the past 6 years. The inclusi on of bad ad dres ses in the response rate calculation, adding more aircr a ft r egistered as “Sale Report ed” o r “ R egistration Pen d i ng” to the surv e y population, a n d other facto rs have resulted in the decrease to t he response rat e

. 8 Even though effo rts are mad e to remove non- GA aircraft from th e population befor e the sample is selected, a small number of surve y s are retur ned each y e ar in dicating t hat the aircraft should no t be part of t he s u rve y po pulation (e.g., the aircr a ft w a s used primaril y as a Pa rt 121 air car r ier, or w a s a museu m piece the ent ir e surve y year ). T he Total Valid Sample Size used to compute the overall survey re sponse ra te e x cludes such aircraft. 9 The total numb e r of completes is not an e x act sum of the separat e components due to a small number of aircraft th at d i d not receive a mailing but that w e re re ported b ya larg e fleet and there f o r e received a co mplete dispositio n.

A-13Appendix A: Methodology for the 2005 General Aviation and Air Taxi Activity and Avionics (GAATAA) Survey

A-14 Table A.5 shows responses by aircraft type. TABLE A.5: RESPONSE RATE BY AIRCRAFT TYPE
Aircraft Type Sample Invalid Sample 10 Responses Response Rate Fixed Wing - Piston

1 engine, 1-3 seats 15,618 112 7,557 48.7% 1 engine, 4+ seats 14,531 66 7,195 49.7% 2 engines, 1-6 seats 4,772 23 2,124 44.7% 2 engines, 7+ seats 2,127 7 820 38.7% Piston: Other 227 2 48 21.3% Fixed Wing - Turboprop

1 engine 2,809 19 1,337 47.9% 2 engines, 1-12 seats 4,806 33 1,903 39.9% 2 engines, 13+ seats 977 3 301 30.9% Turboprop: Other 78 1 18 23.4% Fixed Wing - Turbojet

2 engines 9,750 49 4,301 44.3% Turbojet: Other 1,027 9 280 27.5% Rotorcraft

Piston 4,452 31 1,449 32.8% Turbine: 1 engine 5,891 35 2,241 38.3% Turbine: Multi-engine 1,322 3 616 46.7% Other Aircraft

Glider 1,448 10 700 48.7% Lighter-than-air 1,823 22 652 36.2% Experimental

Amateur 2,936 36 1,509 52.0% Exhibition 1,049 29 464 45.5% Experimental: Other 1,567 10 611 39.2% Light-sport 193 1 122 63.5% Total 77,403 501 34,248 44.5%

10 Even though efforts are made to remove non-GA aircraft from th e population before the sample is selected, a small number of surveys are returned each year indicating t hat the aircraft should not be part of the survey population (e.g., the aircraft was used primarily as a Part 121 air carrier, or was a museum piece the entire survey year). The Invalid Sample represents such aircraft , which are excluded from re sponse rate calculations.