Asiana B777 supporting statement B - final 8-5-13

SUPPORTING STATEMENT B
National Transportation Safety Board
Asiana Flight 214 Passenger Questionnaire
NTSB Investigation No. DCA13MA120
B. STATISTICAL METHODS
1. Sampling Universe, Sampling Methods, and Expected Response Rate.
As explained below, the NTSB intends to send the passenger questionnaire to all passengers
who survived (totaling 291) the Asiana 214 aircraft accident. In order to maximize the number
of responses, the NTSB plans to send the questionnaire to all passengers for whom the NTSB has
electronic mail addresses (totaling 87). The electronic version of the questionnaire will consist of
a fillable document in portable document format (PDF). For all other passengers, the NTSB will
send the questionnaire via postal mail or express mail service. For passengers residing in the
United States, the NTSB will include a postage-paid return envelope.
The NTSB expects to receive approximately 30 percent of the questionnaires completed and
returned. The NTSB does not plan to contact passengers to request completion of the
questionnaire if the NTSB does not receive a completed questionnaire in response to its original
request. The NTSB will consider all completed questionnaires it has received by the time it
creates a survival factors group factual report, and include the questionnaires in the public docket
for the accident investigation. If the NTSB receives questionnaires following its release of the
group factual report, it may also include those questionnaires in the public docket, even though
the description of the total data received in the factual report will not reflect the receipt of a
questionnaire provided after the report’s release.
2. Procedures for Collection of Information.
The NTSB has obtained contact information on passengers from several sources, including
the passenger manifest the NTSB obtained from Asiana Airlines, information the NTSB obtained
from the Federal Bureau of Investigation, information from local hospitals or other medical
facilities, and information from family members. Some sources of information contain
electronic mail addresses for 87 of the passengers. For each of these passengers, the NTSB will
send questionnaires via electronic mail. For passengers for whom the NTSB does not have an
electronic mail address, the NTSB will then send the questionnaire via postal mail or express
mail transportation service, with instructions for returning the questionnaire to the NTSB in the
form of a scanned document electronic mail, or a paper copy of the document via facsimile,
postal mail, or express mail transportation service. The NTSB will include postage-paid,
addressed envelopes to all passengers for whom the NTSB has a United States mailing address.
3. Methods to maximize response rates and deal with issues of non-response.
The NTSB will request responses to the passenger questionnaire on a voluntary basis. If the
NTSB becomes aware of an intentionally inaccurate response to question(s) on the questionnaire,
the NTSB may choose to exclude the erroneous questionnaire. Such an assessment will be based

on whether the NTSB hasreason to believe the information provided completed questionnaire is
purposefully misleading or untruthful. If the NTSB receives any response that the NTSB believes
may warrant further investigation, the NTSB may contact the respondent and request additional
information, via a telephone call. The NTSB anticipates witnesses’ ability to recollect crashrelated events may have diminished by the time they complete the questionnaire; therefore, the
NTSB may receive some questionnaires that contain inadvertently incorrect information. The
NTSB may note this source of potential imprecision in its report. For purposes of describing
witnesses’ memories of the safety briefing prior to takeoff and the evacuation of the aircraft
immediately following the accident, the NTSB’s report will benefit from a general overview and
understanding of witnesses’ conduct at the commencement and conclusion of the flight. The
NTSB will describe in its survival factors report the degree to which it believes the data provided
in the questionnaires was useful. The NTSB survival factors group will use multiple techniques
for assessing the data provided in the questionnaires. These validation techniques include
comparing the feedback on the questionnaires with other data the NTSB has obtained, such as
hospital records, reports from other passengers or crew, feedback from first responders, and the
like.
4. Tests of procedures or methods.
The circumstances of this information collection do not lend themselves to tests of
procedures or methods by which the NTSB will obtain information in this collection. The NTSB
does not plan to test formally the procedures or methods it will use in obtaining the information,
but will compare the feedback it receives on the questionnaires to other sources of data, as
described above.
5. Name and telephone number of individual(s) consulted; Name of person who will
collect and/or analyze information collected.
The NTSB has not consulted with anyone concerning distribution of the questionnaire. The
NTSB investigator who is overseeing the survival factors group is Jason Fedok. Mr. Fedok will
review and analyze the information collected on the questionnaire, with the assistance of the
other members of the survival factors group for NTSB Investigation No. DCA13MA120.