On December 20, 1995, at 11:36 a.m. Tower
Air flight 41, a Boeing 747, veered off the left side of runway
4L during an attempted takeoff at John F. Kennedy International
Airport (JFK), Jamaica, New York. The flight was a regularly
scheduled passenger/cargo. Of the 468 persons aboard (451 passengers,
12 cabin crewmembers, 3 flightcrew members, and 2 cockpit jumpseat
occupants), 24 passengers sustained minor injuries, and a flight
attendant received serious injuries. The airplane sustained substantial
damage. The weather at the time of the accident was partially
obscured, with a 700-foot broken cloud ceiling, 1½ mile visibility,
light snow, and fog.
The safety issues discussed in this report
include the adequacy of Boeing and air carrier procedures for
Boeing 747 operations on slippery runways; adequacy of flight
simulators for training Boeing 747 pilots in slippery runway operations;
security of galley equipment installed on transport category aircraft;
role of communications among flight attendants and between the
cabin crew and the flightcrew; adequacy of Tower Air galley security
training; compliance of Tower Air's maintenance department with
its established procedures; failure of the flight data recorder
system to function during the accident; adequacy of the Tower
Air operational management structure; adequacy of FAA surveillance
and workload imposed on principal operations inspectors; adequacy
of runway friction measurement requirements, including correlation
of runway friction measurements with aircraft braking and ground
handling performance.
2. The air traffic control personnel involved
with the flight were all properly certificated and qualified.
3. The airplane was properly certificated,
equipped, and maintained (with the exception of the flight data
recorder system) in accordance with approved regulations. The
weight and balance were within allowable limits.
4. The captain's decision to attempt the
takeoff on runway 4L was appropriate.
5. Asymmetric thrust was not a factor in
the loss of directional control.
6. The captain's failure to correct the airplane's
deviation from the centerline resulted from his overcontrolling
the nosewheel steering through the tiller.
7. The captain of flight 41 first relied
on right tiller inputs as the airplane continued to veer left,
then applied insufficient or untimely right rudder inputs to effect
a recovery.
8. Current Boeing 747 operating procedures
provide inadequate guidance to flightcrews regarding the potential
for loss of directional control at low speeds on slippery runways
with the use of the tiller.
9. The procedural change by Tower Air to
reevaluate and eliminate its standard procedure of guarding the
tiller during the takeoff roll through 80 knots will make overcontrol
of the tiller less likely for its own operations; however, other
air carrier operators of the Boeing 747 may need to make similar
changes to their procedures.
10. Current Boeing 747 flight manual guidance
is inadequate about when a pilot should reject a takeoff following
some indication of a lack of directional control response.
11. Improvements in the slippery runway handling
fidelity of flight simulators used for Boeing 747 pilot training
are both needed and feasible.
12. The captain's failure to reject the takeoff
in a timely manner was causal to the accident.
13. The inadequate Boeing 747 slippery runway
operating procedures developed by Tower Air and the Boeing Commercial
Airplane Group, and the inadequate fidelity of Boeing 747 flight
training simulators for slippery runway operations, contributed
to the cause of this accident.
14. The captain abandoned his attempt to
reject the takeoff, at least temporarily, by restoring forward
thrust before the airplane departed the left side of the runway;
this contributed to the severity of the runway excursion and damage
to the airplane.
15. The material or installation of secondary
latches in the galleys of N605FF was inadequate.
16. Despite some ambiguity about the situation,
there were ample indications in most parts of the passenger cabin
to have caused a greater number of flight attendants to shout
brace commands before the airplane came to a stop.
17. The existing Tower Air flight attendant
procedures provided inadequate guidance to flight attendants on
how to communicate with each other, passengers and flightcrew
and how to coordinate their actions during and after the impact
sequence.
18. Tower Air flight attendant galley security
training was inadequate because flight attendants had not received
"hands on" training with all the galley equipment that
they were required to operate.
19. Based on the limited amount of time between
the rental of the test equipment and the movements of the airplane,
Tower Air did not perform the flight data recorder (FDR) functional
test; this resulted in the loss of FDR data related to the accident
flight that were of critical importance to the Safety Board's
investigation.
20. The Tower Air maintenance program deviated
in significant ways from the procedures established in the company's
general maintenance manual.
21. The continuing airworthiness surveillance
and reliability programs in the maintenance department of Tower
Air were performing inadequately at the time of the accident.
22. Tower Air was operating with an inadequate
management structure at the time of the accident.
23. The principal operations inspector (POI)
and assistant POI assigned to Tower Air were overburdened, and
the Federal Aviation Administration program for routine surveillance
of the operational functions of Tower Air was inadequate.
24. The failure of the Port Authority of
NY & NJ or Federal Aviation Administration air traffic control
tower personnel to provide friction measurement data to the pilots
of flight 41 did not contribute to this accident.
25. The circumstances of this accident indicate
that the issue of correlating airplane stopping performance with
runway friction measurements should be revisited by the Government
and the air transportation industry.
The National Transportation Safety Board
determines that the probable cause of this accident was the captain's
failure to reject the takeoff in a timely manner when excessive
nosewheel steering tiller inputs resulted in a loss of directional
control on a slippery runway.
Inadequate Boeing 747 slippery runway operating
procedures developed by Tower Air, Inc., and the Boeing Commercial
Airplane Group and the inadequate fidelity of Boeing 747 flight
training simulators for slippery runway operations contributed
to the cause of this accident.
The captain's reapplication of forward thrust
before the airplane departed the left side of the runway contributed
to the severity of the runway excursion and damage to the airplane.
As a result of the investigation of this
accident, the National Transportation Safety Board makes the following
recommendations:
--to the Federal Aviation Administration:
[1] Require modification of applicable operating
procedures published by the Boeing to further caution flightcrews
against use of the tiller during slippery runway operations, including
low-speed operations (for airplanes equipped with rudder pedal
steering) and to provide appropriate limitations on tiller use
during these operations (for airplanes not equipped with rudder
pedal steering).
[2] Issue a flight standards information
bulletin to principal operations inspectors assigned to air carriers
operating the Boeing 747, informing them of the circumstances
of this accident and requesting a review and Commercial Airplane
Group and air carrier operators of the Boeing 747 modification,
as required, of each air carrier's takeoff procedure regarding
pilot hand position with respect to the tiller.
[3] Require the Boeing Commercial Airplane
Group to develop operationally useful criteria for making a rapid
and accurate decision to reject a takeoff under slippery runway
conditions; then require that Boeing 747 aircraft flight manuals,
operating manuals, and training manuals be revised accordingly.
[4] Evaluate Boeing 747 simulator ground
handling models and obtain additional ground handling data, as
required, to ensure that Boeing 747 flight simulators used for
air carrier flightcrew training accurately simulate the slippery
runway handling characteristics of the airplane.
[5] After completing this evaluation, issue
a flight standards information bulletin urging principal operations
inspectors assigned to air carrier operators of the Boeing 747
to enhance simulator training for slippery runway operations,
including limitations on tiller use and instructions for rudder
use during the takeoff roll.
[6] Develop certification standards for the
installation of secondary galley latches; then use those standards
to conduct an engineering review of secondary galley latches on
all transport-category aircraft. Require changes to existing
installations as necessary to ensure that the strength of secondary
latches and their installation are sufficient to adequately restrain
carts.
[7[ Issue a flight standards information
bulletin to principal operations inspectors of 14 CFR Part 121
air carriers to ensure that flight attendant training programs
stress the importance of shouting the appropriate protective instructions
at the first indication of a potential accident, even when flight
attendants are uncertain of the precise nature of the situation.
[8] Issue a flight standards information
bulletin requiring principal operations inspectors of 14 CFR Part
121 air carriers to ensure that their air carriers have adequate
procedures for flight attendant communications, including those
for coordinating emergency commands to passengers, transmitting
information to flightcrews and other flight attendants, and handling
postaccident environments in which normal communications systems
have been disrupted.
[9] Issue a flight standards information
bulletin that encourages the use of this accident as a case study
for crew resource management training.
[10] Review the structure and performance
of the continuing airworthiness surveillance and reliability programs
in the Tower Air maintenance department.
[11] Revise 14 CFR Part 119 to specify that
the chief pilot and all operational functions under that position
report through the director of operations.
[12] Immediately implement the plan to assign
the Tower Air certificate to a principal operations inspector
(POI) and assistant POI who do not have oversight responsibility
for any other carriers.
[13] Develop, by December 31, 1997, standards
for enhanced surveillance of air carriers based on rapid growth,
change, complexity, and accident/incident history; then revise
national flight standards surveillance methods, work programs,
staffing standards, and inspector staffing to accomplish the enhanced
surveillance that is identified by the new standards.
[14] Require the appropriate Aviation Rulemaking
and Advisory Committee to establish runway friction measurements
that are operationally meaningful to pilots and air carriers for
their slippery runway operations (including a table correlating
friction values measured by various types of industry equipment),
and minimum coefficient of friction levels for specific airplane
types below which airplane operations will be suspended. (To be
edited to include a request for definitions of slippery runway,
contaminated runway, etc.)
--to Tower Air, Inc.:
[15] Revise Tower Air's initial flight attendant
training program to include "hands-on" training for
securing each type of galley and cart included in its Boeing 747
fleet.
(The following recommendation to the FAA
was proposed by Member John Goglia. It will be revised by staff
and presented to the Board at a later date.): Reassess the approach
for the detection of potentially fraudulent or false maintenance
records with the intention of enhancing the ability of inspectors
to identify discrepancies in the analysis of records and work-site
inspections.