AA2016-6
AIRCRAFT ACCIDENT
INVESTIGATION REPORT
JAPAN COAST GUARD
JA727B
July 28, 2016
The objective of the investigation conducted by the Japan Transport Safety Board in
accordance with the Act for Establishment of the Japan Transport Safety Board and with
Annex 13 to the Convention on International Civil Aviation is to determine the causes of
an accident and damage incidental to such an accident, thereby preventing future
accidents and reducing damage. It is not the purpose of the investigation to apportion
blame or liability.
Kazuhiro Nakahashi
Chairman,
Japan Transport Safety Board
Note:
This report is a translation of the Japanese original investigation report. The text in Japanese shall
prevail in the interpretation of the report.
AIRCRAFT ACCIDENT INVESTIGATION REPORT
DAMAGE TO THE AIRFRAME DURING LANDING
JAPAN COAST GUARD, BOMBARDIER DHC-8-315, JA727B
SENDAI AIRPORT
AT ABOUT 15:58 JST, MAY 30, 2015
June 24, 2016
Adopted by the Japan Transport Safety Board
Chairman Kazuhiro Nakahashi
Member Toru Miyashita
Member Toshiyuki Ishikawa
Member Sadao Tamura
Member Keiji Tanaka
Member Miwa Nakanishi
1 PROCESS AND PROGRESS OF THE ACCIDENT INVESTIGATION
On June 4, 2015, the Japan Transport Safety Board received the report of the accident and
designated an investigator-in-charge and an investigator to investigate this accident. An
accredited representative of Canada as the State of design and manufacture of the aircraft
involved in this accident, participated in the investigation.
Comments were invited from parties relevant to the cause of the accident and the relevant State.
2 FACTUAL INFORMATION
2.1 History of the On Saturday, May 30, 2015, a Bombardier DHC-8-315, registered
Flight JA727B, operated by Japan Coast Guard, touched down on the runway
with strong impact against the nose landing gear, causing the damage of
the airframe, in landing on Sendai Airport (hereinafter referred to as "the
Airport"). Although the captain, the trainee, and crew members (the total
of eight people) were on board, there were no dead or injured.
According to the statements of the captain and the trainee, and the
records of the flight data recorder (hereinafter referred to as "FDR") and
the cockpit voice recorder (hereinafter referred to as "CVR"), the history of
the flight is summarized as follows.
At 13:58, the aircraft took off from Hanamaki Airport, operated by the
trainee, with the captain who is a instructor on the right seat and the
trainee on the left seat for training flight for obtaining the type rating
related to First Officer certification in the Japan Coast Guard. After the
aircraft conducted touch-and-goes training repeatedly at Hanamaki
Airport, the aircraft conducted emergency procedure training in the high
altitude training / testing area for Japan Self-Defense Force aircraft (D-1)
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located southeast of Hanamaki Airport, and went towards the Airport in
order to conduct flap up landing (landing with flap of 0°) which was the last
training subject on that day.
The captain and the trainee completed the flap up landing checklist
just before the arrival of Yuriage (a visual reporting point of the Airport),
and the captain told the trainee that if the pitch angle (nose-up angle)
exceeded 6°, corrective control would have to be performed by pushing the
control column forward. Vref (reference speed for landing) was decided to
126 kt. The aircraft entered the traffic pattern of runway 09 of the Airport
and made landing with landing clearance at around 15:58.
Although the trainee made the main landing gear touch on the ground
near the aiming point marking for the runway 09 in landing, he felt it took
a great deal of time to lower the nose. This time the captain on the right
seat felt that the nose would up higher than the attitude with which the
main landing gear touched the ground, and pushed the control column
forward considering worry of tail contact (the contact of the after lower part
of the fuselage against the surface of the runway), then the nose landing
gear touched the ground with stronger impact than usual. Both of the
captain and the trainee were not aware of irregularity of the aircraft in
landing roll, therefore they continued taxi and the aircraft arrived at apron
at around 16:05.
After the engines were shutdown, the nose landing gear was found to
be damaged in post-flight inspection by on-board mechanic. Afterward,
detailed inspection was conducted, which revealed abrasion marks on the
lower part of the nose landing gear, damage on components of the nose
landing gear, and deformation of the forward fuselage skins of the
airframe. It is considered possible from the abrasion marks of the
components of the lower part of nose landing gear that the aircraft might
come in contact with the runway, therefore the runway inspection was
conducted by Japan Civil Aviation Bureau and abrasion marks were found,
which seem to be caused by the contact of the aircraft part.
YURIAGE
Sendai Airport
Digital Basic Map, Geospatial Information Authority of
Japan (Map Information)
Figure 1 Estimated approach route
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According to the records of FDR and CVR, the pitch angle started to be
moved upward at around 15:58:21 and the elevator angle was changed to
the nose-down direction from the time when the pitch angle exceeded 6°. At
around 15:58:23, the pitch angle started to be moved downward and
continued moving downward after the main landing gear touched the
ground at around 15:58:24, then at around 15:58:25, the nose landing gear
touched the ground once. The elevator angle was changed to the nose-up
direction again soon before the nose landing gear touched the ground, and
the pitch angle was moved upward after the nose landing gear touched the
ground once. At around 15:58:27 when the pitch angle exceeded 3.5°, the
elevator angle was largely changed to the nose-down direction and at
around 15:58:28, the nose landing gear touched the ground again. The
recorded value of vertical acceleration (G) of this time was +1.47. In
addition, impact sounds were recorded in CVR.
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Touch on
the ground Touch on Touch on the
of Main the ground ground again
Landing of Nose of Nose
Gears Landing Landing Gear
Gear
(Elevator angle)
*1
(Japan Standard Time)
Figure 2 FDR records during the time of the accident
2.2 Injuries to None
Persons
2.3 Damage Extent of damage of the aircraft : Substantially damaged
・Nose landing gear The bottom of strut was partly attrition, components
of shock strut were broken and deformed marks of
both tires.
・Fuselage Left and right fuselage skins of the airframe were
deformed in the rear of the nose landing gear
mounting areas.
*1 "WOW: Weight On Wheel" refers to the data recorded in FDR by signals from a sensors which works if loads are
put on each landing gear. In the case of the aircraft, "GND" is recorded in FDR if loads are put on all of the nose
landing gear and main landing gears, and "AIR" is recorded if loads are not put on one of landing gears, even
if a remaining landing gear touches down and enough load is put.
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Photo 1 The aircraft
From the forward From the rear of
lower part of the the nose landing
nose landing gear gear
Abrasion status of the lower Damage condition of
part of strut for the nose components of shock strut
landing gear for the nose landing gear
Right tire of nose
wheel
Right forward
airframe
Deformed marks on tire The deformation to the airframe
2.4 Personnel (1) Captain (instructor) Male, Age 45
Information Commercial pilot certificate (airplane) January 27, 1994
Type rating for Bombardier DHC-8 November 11, 2010
Class 1 aviation medical certificate
Validity June 3, 2015
Total flight time 4,659 hr 57 min
Flight time for the last 30 days 34 hr 35min
Total flight time on the type of aircraft 1,617 hr 00 min
Flight time for the last 30 days 14 hr 15 min
Flight instructor certificate
The captain had an instructor certificate (a certificate which is valid
only in Sendai air base).
The flight on the day of the accident was the first training flight for
the captain after he was certified to be an instructor in Sendai air base.
Total flight time as instructor in other air bases 20 hr 50 min
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(2) Trainee Male, Age 32
Commercial pilot certificate (airplane) December 24, 2010
Type rating for multi-engine (land) December 28, 2009
Class 1 aviation medical certificate
Validity January 13, 2016
Total flight time 530 hr 04 min
Flight time for the last 30 days 4 hr 00 min
Total flight time on the type of aircraft 15 hr 50 min
Flight time for the last 30 days 4 hr 00 min
2.5 Aircraft (1) Type of aircraft: Bombardier DHC-8-315
Information Serial number: 586, Date of manufacture: June 9, 2002
Certificate of Airworthiness No. TO-26-564, Validity: March 4, 2016
Category of airworthiness Airplane transport T
Total flight time 16,204 hr 15 min
(2) When the accident occurred, the weight of aircraft was estimated to
have been 36,015.9 lb and the position of the center of gravity is
estimated to have been 21.8 % mean aerodynamic chord (MAC*2 ). Both
of them were estimated to have been within the allowable ranges.
2.6 Meteorological (Observation records at the Airport and the statements of crews in the
Information aircraft)
Aerodrome routine meteorological report (15:00)
Wind direction 140°, Wind velocity 8 kt, Prevailing visibility 35 km
Cloud Amount FEW 1,000 ft (Stratus), Temperature 22℃,
Dew-point 16℃, Altimeter setting (QNH) 29.51 inHg
While the aircraft was flying in the traffic pattern, wind direction/wind
velocity reported from the tower to the aircraft were 150°/08 kt.
2.7 Additional (1) Information on flight recorder
Information The aircraft was equipped with U.S. Honeywell's FDR which can retain
about 25 hours data and U.S. Honeywell's CVR which can retain about 2
hours data, both of which retained the records when the accident occurred.
The time calibration for the flight recorder was performed by making
time signals recorded in the air traffic control communication records
correspond to VHF wireless transmission signals and air traffic control
communication recorded in the flight recorder.
(2) Information of accident site
The runway 09 in the Airport where the accident occurred is 3,000 m
in length and 45 m in width and had scratched marks of about 2.2 m in
length at about 743 m from the runway 09 threshold and about 5 m right
side (south) of the runway center line in the approach direction.
*2 "MAC" refers to the abbreviation Mean Aerodynamic Chord. It is a wing chord that represents the aerodynamic
characteristic of the wing, and indicate the average of when the wing chord such as the rear wing chord is
variable. 21.8 % MAC indicates a 21.8 % position from the front of the mean aerodynamic chord.
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about 743 m
Approach
direction
Wind information reported
from the tower
Wind direction 150°
Wind velocity 8 kt
Figure 3 The approach direction of the aircraft and the abrasion marks on the runway
(3) Information on flap up landing
The aircraft operation manual of the Japan Coast Guard had the
following description. (Excerpts)
FLAP UP LANDING
(Omitted)
CAUTION : Pitch Attitude in landing must not exceed ６° , which
could cause tail contact.
NOTE : The nose wheel should be promptly brought into contact
with the ground following main wheel contact.
3 ANALYSIS
3.1 Involvement of No
Weather
3.2 Involvement of Yes
Pilots
3.3 Involvement of No
Airplane
3.4 Analysis of (1) Analysis of weather
Findings When the accident occurred, 8 kt steady wind blew from the direction
of 150° in the Airport. The direction of the landing runway is 09 of the
Airport; therefore, it is probable that the aircraft was exposed to the wind
from the right direction of about 60°. The crosswind component is about 7
kt this time and there is no information such as gusts in the report and
statements; therefore, it is highly probable that the weather at the time of
the accident did not affect landing control of the aircraft.
(2) Situation from main landing gear touch on the ground up to nose landing
gear touch on the ground
Based on FDR records and the statements of the captain and the
trainee, after the main landing gear of the aircraft touched the ground the
nose landing gear touched the ground once; however, the elevator angle was
changed to the nose-up direction by supporting the control column (the
control for moving the nose downward gently) just before the nose landing
gear touched the ground. Afterward, the nose started to up again due to the
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delay of control to loosen the support for the control column and the reaction
from touch on the ground of the nose landing gear, and it is probable that
the control for moving the nose downward was performed at the time when
the pitch angle exceeded about 3.5°.
(3) Control of the aircraft in nose landing gear touch on the ground again
Based on FDR records and the statements of the captain and the
trainee, the nose landing gear touched the ground once and the nose has
begun to nose up again, thereafter, the control column was pushed for about
one second until the nose landing gear retouched the ground and the
elevator angle was largely changed from +7° through －15° in the one
second. It is probable that this was because the captain who considered
worry of tail contact pushed the control column forward. It is probable that
this sudden and large control for moving the nose downward made the nose
landing gear strongly retouch on the ground and causing the damages of the
nose landing gear and the forward fuselage skins of the fuselage. The value
of maximum G (vertical acceleration) at this time was recorded to be +1.47.
4 PROBABLE CAUSES
In this accident, it is probable that the nose of the aircraft suddenly downed and the nose
landing gear strongly touched down on the ground after the main landing gear touched the ground
in the landing, therefore the components of the nose landing gear were damaged and the fuselage
skins of the airframe was deformed.
Regarding the fact that the nose landing gear of the aircraft strongly touched the ground on
the ground, it is probable that it was because that the captain who considered worry of tail contact
performed the sudden and large control for moving the nose downward, when the nose-up attitude
tended to be too excessive after the nose landing gear touched the ground once and the nose upped
again.
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