he right landing gear of a New York
Airways, Inc., Sikorsky
failed while the aircraft was parked, with
The aircraft rolled over on its right side and was substantially damaged.
At
the
rotors turning, on the rooftop heliport of the Pan Am Building in New York, New York
time of the accident four passengers had boarded the aircraft and other passengers
were in the process of boarding. The passengers and the three
onboard
received either minor
o r
no
injuries; however, four passengers who were still
the aircraft and were waiting to board were killed and one was seriously injured.
was seriously injured when they were struck by a separated portion of one of the mai
One pedestrian on the corner of Medison Avenue and 43rd Street was killed and anothe
rotor blades of the aircraft.
the accident was the fatigue failure of the upper right forward fitting of the right
main landing gear tube assembly. Fatigue originated from a small surface pit of
undetermined source. All fatalities were caused by the operating rotor blades as
a result of the collapse of the landing gear.
The National Transportation Safety Board determined that the probable cause of
17.
Key Words
Fatigue
landing gear; fracture of right hand
main landing gear forward fitting; fracture initiation
P/N
surface pit.
and propagation; stress corrosion cracking; fitting
Classification
Classification
(of this report)
(of this page)
UNCLASSIFIED
UNCLASSIFIED
NTSB
1765.2 (Rev. 9/74)
Statement
This document is available
National Technical
to the public through the
Virginia 22151
Service, Springfield
of Pages
I TABLE OF CONTENTS
!
Page
Synopsis
1
Investigation
. . . . . . . . . . . . . . . . . . .
2
History of the Flight
2
Injuries to Persons
. . . . . . . . . . . . . . . .
4
Damage to Aircraft
4
Other Damage
. . . . . . . . . . . . . . . . . . . .
4
Personnel Information
4
Aircraft Information
. . . . . . . . . . . . . . . .
4
Meteorological Information
5
Aids to Navigation
5
Communications
. . . . . . . . . . . . . . . . . . .
5
Aerodrome Information
. . . . . . . . . . . . . . .
5
Flight Recorders
. . . . . . . . . . . . . . . . . .
5
Wreckage and Impact Information
. . . . . . . . . .
6
General Examination
. . . . . . . . . . . . . . . .
6
Landing Gear Examination
. . . . . . . . . . . . . .
6
Medical and Pathological Information
7
Fire
. . . . . . . . . . . . . . . . . . . . . . . .
7
Survival Aspects
. . . . . . . . . . . . . . . . . .
8
Tests and Research
. . . . . . . . . . . . . . . . .
9
Additional Information
10
History of Heliport Operation
. . . . . . . . . . .
10
History of
Forward Lower Landing Gear to
Fuselage Attachment Fitting Failures
. . . . . . .
11
Normal Helicopter Operations
. . . . . . . . . . . .
12
New Investigation Techniques
12
Analysis
. . . . . . . . . . . . . . . . . . . . . .
13
Conclusions
16
Findings
16
Probable Cause
17
Safety Recommendations
. . . . . . . . . . . . . . .
17
Appendixes
1
.
1.1
1.2
1.3
1.4
1.5
1.6
1.8
1.7
1.9
1.10
1.12
1.11
1.12.2
1.12.1
1.13
1.14
1.15
1.16
1.17
1.17.1
1.17.2
1.17.3
1.18
2
.
3
.
3.2
3.1
4
.
5
.
Appendix A
.
Investigation and Hearing
19
Appendix
B
.
Personnel Information
. . . . . . . .
20
Appendix C
.
Aircraft Information
. . . . . . . .
22
Appendix D
.
Wreckage Distribution Chart
. . . . .
23
Appendix E
.
Right Main Landing Gear Area
(Photograph and diagram)
. . . . .
25
Appendix F
.
Laboratory Photographs
V
(Figures
1 through 10)
27
ii 2
2
4
4
4
4
5
5
5
6
6
6
7
9
8
10
10
11
12
12
13
16
16
17
17
19
20
22
23
25
NATIONAL TRANSPORTATION SAFETY BOARD
WASHINGTON, D.C. 20594
AIRCRAFT ACCIDENT REPORT
Adopted: October
1 3 ,
1977
NEW YORK AIRWAYS, INC.
SIKORSKY
PAN AM BUILDING HELIPORT
NEW YORK, NEW YORK
MAY
16, 1977
SYNOPSIS
New York Airways, Inc., Sikorsky Model S-61L helicopter,
failed
while the aircraft was parked, with rotors turning,
on
the rooftop
heliport of the Pan
Am
Building in New York, New York. The aircraft
rolled over
on
its right side and was substantially damaged. Four
process of boarding. The passengers and the three crewmembers onboard
passengers had boarded the aircraft and other passengers were in the
received either minor or
no
injuries; however, four passengers who were
was seriously injured. One pedestrian
on
the corner of Madison Avenue
still outside the aircraft and were waiting to board were killed and one
and 43rd Street was killed and another was seriously injured when they
were struck by a separated portion of one
of
the main rotor blades of
the aircraft.
About 1735
on
May
16, 1977, the right landing gear of a
The National Transportation Safety Board determines that the
probable cause of the accident was the fatigue failure of the upper
right forward fitting of the right main landing gear tube assembly.
Fatigue originated from a small surface pit of undetermined source.
All fatalities were caused by the operating rotor blades as a result
of the collapse of the landing gear.
27 1. INVESTIGATION
1.1
History of
the
F l i g h t
On
May
16,
1 9 7 7 ,
New
York
Inc.
F l i g h t 972, a
passenger f l i g h t from t h e rooftop h e l i p o r t (JPB)
of
the
Pan
Sikorsky
was
being operated
as
a r e g u l a r l y
Building a t 200 Park Avenue, Manhattan,
New
York, t o John
I n t e r n a t i o n a l A i r p o r t
New
York,
New
York.
landed a t t h e h e l i p o r t a t about
1732.
There
were
20 passengers and a
crew of 3 aboard.
The f l i g h t o r i g i n a t e d as F l i h t 971 from JFK A i r p o r t and
A f t e r approaching from t h e n o r t h e a s t and landing, t h e a i r c r a f t
was
t a x i e d t o t h e boarding g a t e , which required a
180'
t u r n t o t h e l e f t
and a s h o r t t a x i
of
10
t o
20
f e e t t o p o s i t i o n t h e a i r c r a f t p r o p e r l y .
The c a p t a i n s t a t e d t h a t he used t h e t a i l r o t o r i n s t e a d of h i s b r a k e s t o
which was
a
normal procedure.
The a i r c r a f t
was
chocked and passengers
a s s i s t i n t a x i i n g . He set h i s brakes and l e f t t h e t a i l wheel unlocked,
began t o deplane. According t o witnesses and passengers, t h e landing
had been smooth and g e n t l e .
The c o l l e c t i v e
was
bottomed ( n e g a t i v e p i t c h ) and torque
was
about
18
percent
on
each engine. The engine speed c o n t r o l s
were p o s i t i o n e d
t o maintain
100
percent r o t o r speed
and t h e automatic f l i g h t c o n t r o l
The f i r s t o f f i c e r s t a t e d t h a t a s he f i l l e d out t h e f l i g h t l o g , he had h i s
s y s t e m
was
on
with
a l l
c o n t r o l s centered--a normal operating procedure.
knee a g a i n s t t h e c o l l e c t i v e t o i n s u r e t h a t it
was
bottomed.
The
c a p t a i n remained i n h i s s e a t with h i s hands on t h e c o n t r o l s .
The c a p t a i n estimated t h a t they had been s i t t i n g
on
the
h e l i p o r t
were boarding. He heard a " f a i n t noise," which he believed t o have come
f o r 1 t o 2 minutes. Passengers had deplaned and t h e outbound passengers
noise" and a buckling sound. The crumpling sound w a s accompanied by a
from t h e r o t o r system, followed immediately by a "crumpling, crunching
s e t t l i n g and yawing motion, followed by a r o l l of t h e a i r c r a f t t o t h e
r i g h t .
A s
he
heard t h e
first
" f a i n t n o i s e , " t h e c a p t a i n reached f o r
t h e
t o s h u t t h e engines down. He p u l l e d them back immediately t o
t h e a i r c r a f t r o l l e d beyond i t s
p o s i t i o n .
t h e
ESC's
are
i n
t h e
t h e ground i d l e d e t e n t and then i n t o t h e engine shutoff p o s i t i o n b e f o r e
s h u t o f f
f u e l i s s h u t off
in
the
engine f u e l c o n t r o l u n i t s .
The c a p t a i n s t a t e d t h a t when t h e blades s t r u c k t h e concrete they were
n o t being powered by t h e engines.
A l l
times h e r e i n a r e e a s t e r n d a y l i g h t , based
on
the
24-hour clock.
s l i g h
r i g h t
w i t h
cap t a
h e l p
from
them
t h e
The
f i r s .
t u r n
r o t o
r a p i
and
one
f
hear
f
was
the
who
s
on
:
i n s
so
:
of
he
of
f
tow
whi
i t
t o I
,
972,
a
erican
and
and a
-
s l i g h t l y t o t h e r i g h t and heard a crunching n o i s e , followed immediately
by a " g e n t l e smooth r o l l " t o t h e r i g h t .
The f i r s t o f f i c e r s t a t e d t h a t he f e l t
the
a i r c r a f t
s e t t l e
r i g h t a t t h e c a p t a i n who was i n t h e r i g h t cockpit
seat
and
saw
t h e
w i t h t h e a i r c r a f t . The r e l a t i o n s h i p of t h i s t i p p a t h remained c o n s t a n t ,
c a p t a i n reach f o r t h e
ESC's.
He a l s o s a w
t h e
b l a d e t i p p a t h plane r o t a t i n g
from t h e u p r i g h t p o s i t i o n , throughout t h e e n t i r e r o l l . He reached up t o
h e l p t h e c a p t a i n p u l l t h e
ESC's
b u t