Propeller Blade
In-Flight Fires
Omission in Pilot Training
January 12, 2002, a Hamilton Sundstrand 568E propeller blade
separated adjacent to the propeller hub on the right engine of an
Anions de Transport Regional airplane. Shortly after takeoff the
pilots felt high vibrations in the airplane as the right engine’s
low oil pressure warning light illuminated. The fuel lever jammed
when the pilots tried to show down the engine and they had to emergency
land, leaving minor damage to the airplane.
Require Hamilton Sundstrand to perform additional analytical examinations
and testing, including removal of the compression wrap so that the
tulip can be fully examined, of a sample of high service-time 568F
propeller blades with serial numbers 1,699 or greater to determine
if rust and corrosion pitting are occurring in the fillet radius,
and, on the basis of the results of those examinations, require
additional inspections, modifications, or repairs as appropriate.
For all Hamilton Sundstrand 568F propeller blades with serial numbers
1 through 1,698:
- Require the immediate inspection and repair (including removal
of the compression wrap and any existing corrosion, a nondestructive
inspection for cracks, shot peening of the radius, and installation
of an appropriate corrosion protection system) of all blades that
have been in service more than 6 years or 11,700 hours
- Immediately determine a conservative threshold for the inspection
and repair of the remaining blades that is appropriately less
than 6 years or 11,700 hours in service, taking into account the
uncertainties in the failure mechanism (including the initiation
and growth rate for the pitting and fatigue cracking)
- Require the immediate inspection and repair of those
propeller blades that have already reached or exceeded the threshold
determined as a result of (2), above; and (4) For those propeller
blades that are not immediately inspected and repaired in accordance
with (1) and (3), above, require that they be inspected and repaired
as soon as possible, but no later than the threshold determined
as a result of (2), above. (Urgent)
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Due to investigations on in-flight fires there were various
aviation safety recommendations made.
November 29, 2000, an American Airlines operated DC-9-82
was struck by lightning and had an in-flight fire that forced an
emergency landing and evacuation, leaving minor damages. August
8, 2000, an Air Tran Airways operated DC-9-32 had to emergency land
after an in-flight fire started, resulting in minor injuries and
smoke inhalation. September 17, 1999, a Delta Air Lines operated
McDonnell Douglas MD-88 made an emergency landing and evacuation
after an in-flight fire started, leading to minor damage. June 2,
1983, an Air Canada operated DC-9 made an emergency landing and
evacuation due to an in-flight fire, detected by a passenger. The
fire caused 23 passengers to become trapped in the aircraft to their
deaths, and the airplane was completely destroyed.
- Issue an advisory circular (AC) that describes the need for
crewmembers to take immediate and aggressive action in response
to signs of an in-flight fire. The AC should stress that fires
often are hidden behind interior panels and therefore may require
a crewmember to remove or otherwise gain access to the area behind
interior panels in order to effectively apply extinguishing agents
to the source of the fire.
- Develop and require implementation of procedures or airplane
modifications that will provide the most effective means for crewmembers
to gain access to areas behind interior panels for the purpose
of applying extinguishing agent to hidden fires. As part of this
effort, the FAA should evaluate the feasibility of equipping interior
panels of new and existing airplanes with ports, access panels,
or some other means to apply extinguishing agent behind interior
panels.
- Require principal operations inspectors to ensure that the contents
of the advisory circular (recommended in A-01-83) are incorporated
into crewmember training programs.
- Issue a flight standards handbook bulletin to principal operations
inspectors to ensure that air carrier training programs explain
the properties of Halon and emphasize that the potential harmful
effects on passengers and crew are negligible compared to the
safety benefits achieved by fighting in-flight fires aggressively.
- Amend 14 Code of Federal Regulations 121.417 to require participation
in firefighting drills that involve actual or simulated fires
during crewmember recurrent training and to require that those
drills include realistic scenarios on recognizing potential signs
of, locating, and fighting hidden fires.
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There are a couple recommendations made in response to industry-wide
safety issues that involved the omission in pilot training on transport-category
airplanes. The NTSB has found that many pilot training programs
do not include information about structural certification requirements
for the rudder and vertical stabilizer on transport-category airplanes.
Even at speed below the design maneuvering speed, the NTSB found
that sequential full opposite rudder inputs may result in structural
loads exceeding what is addressed in the requirements. Some airplane
pilots may think that the rudder limiter systems installed on most
transport-category airplanes that limit rudder input from overloading
the structure prevent sequential full opposite rudder deflections
from damaging the structure. Structural certification requirements
for transport-category airplanes do not take maneuvers into account
and the sequential opposite rudder inputs can produce loads higher
than required for certification and exceed structural capabilities
of the airplane.
November 12, 2001, an American Airlines flight was destroyed
after crashing into a residential area following takeoff. Prior
to the impact, the vertical stabilizer and rudder separated from
the fuselage, leaving the 2 pilots, 7 flight attendants, 251 passengers,
and 5 people on the ground dead.
- Carefully review all existing and proposed guidance and training
provided to pilots of transport-category airplanes concerning
special maneuvers intended to address unusual or emergency situations
and, if necessary, require modifications to ensure that flight
crews are not trained to use the rudder in a way that could result
in dangerous combinations of sideslip angle and rudder position
or other flight parameters.
- Require the manufacturers and operators of transport-category
airplanes to establish and implement pilot training programs that:
(1) explain the structural certification requirements for the
rudder and vertical stabilizer on transport-category airplanes;
(2) explain that a full or nearly full rudder deflection in one
direction followed by a full or nearly full rudder deflection
in the opposite direction, or certain combinations of sideslip
angle and opposite rudder deflection can result in potentially
dangerous loads on the vertical stabilizer, even at speeds below
the design maneuvering speed; and (3) explain that, on some aircraft,
as speed increases, the maximum available rudder deflection can
be obtained with comparatively light pedal forces and small pedal
deflections. The FAA should also require revisions to airplane
and pilot operating manuals that reflect and reinforce this information.
In addition, the FAA should ensure that this training does not
compromise the substance or effectiveness of existing training
regarding proper rudder use, such as during engine failure shortly
after takeoff or during strong or gusty crosswind takeoffs or
landings.
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