Walt
Well Known Member
This SAIB has been out for a while but has come up again so I thought it was worth re-posting to the RV crowd.
Potential propeller failures, aircraft damage, and potential loss of aircraft control for certain untested propellers installed on experimental aircraft.
http://www.avweb.com/news/features/Propeller-Care-224607-1.html
http://hartzellprop.com//wp-content/uploads/2012/12/NE-08-19.pdf
FAA Aircraft Certification Service
SPECIAL AIRWORTHINESS INFORMATION BULLETIN
SUBJ: Propeller Installations on Experimental Aircraft
SAIB: NE-08-19 Date: May 14, 2008
This is information only. Recommendations aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) alerts you, owners, operators, pilots,
mechanics, and certificated repair stations of concerns for potential propeller failures, aircraft
damage, and potential loss of aircraft control for certain untested propellers installed on
experimental aircraft.
The FAA is concerned that builders of experimental aircraft and experimental propeller installations
do not always consider the consequences of using an untested/ uncertificated propeller and engine
combination. One example of an inappropriate propeller installation application is the use of Hartzell
( )8468( )* series blades installed on Lycoming ( )( )-360 series engines. There may be other
inappropriate propeller installations. Consult the appropriate propeller manufacturer for installation
data to help ensure continued airworthiness.
The FAA acknowledges that the aircraft builder has the ultimate responsibility for the parts/
components used on their experimental aircraft. The builder of the propeller assembly is often a
propeller repair station who might be unaware of the consequences of using untested/ uncertified
propeller assemblies on a specific engine. To the extent that the propeller shop may be
knowledgeable of such matters, they also share some responsibility in notifying the experimental
aircraft builder of the potential consequences of using untested/ uncertified propeller installations.
Background
There were two accidents resulting from propeller blade failures on experimental aircraft using
Hartzell ( )8468( )* series blades installed on Lycoming ( )( )-360 series engines. This blade design
uses a thinner airfoil than that used on other Lycoming 360 applications. Also, the accident-related
blades incorporated a modification that reduced the blade diameter to less than other approved
designs. These differences result in exposure to high vibratory stress loadings that exceed the
structural levels allowed for safe operation. In both accidents, the high propeller blade vibratory
stress loading is considered a contributing factor in the failures. These accidents show that specific
engine and propeller combinations are an important design consideration that requires careful
research regardless of the propeller manufacturer.
Builders of experimental aircraft are permitted to use experimental propellers. However, certain
propellers, even those with type certificates, might not be suitable for use on certain engines. If
combined, there is the potential for an unsafe condition to exist.
Propeller Repair Stations have, on occasion, been reported to assemble an experimental propeller
using propeller blades retired from use on certificated aircraft for being undersize in width, thickness,
or diameter. Such a propeller enables the builder of an experimental aircraft to reduce costs, but could
result in an unsafe application that does not meet any approved or tested engine and propeller
combination.
2
* There are numerous variations in Hartzell ( )8468( ) series propeller blades such as: F8468A-6R,
F8468-2, FC8468-6R, etc.
Recommendations
Propeller Repair Stations –
• If asked to build an experimental propeller, confirm the specific engine model being used and
only select a propeller that is known to be vibrationally/ structurally compatible with that
engine. As necessary, contact the appropriate propeller manufacturer for assistance in making
this selection.
• Advise the customer of the experimental, untested nature of the propeller installation and its
potential airworthiness consequences.
• Do not install Hartzell 8468 series blades on a propeller for use on a Lycoming 360 series
engine.
Experimental Aircraft Builders –
• Wherever possible, always use an FAA-approved or propeller manufacturer-recommended
engine and propeller combination.
• If either an engine or propeller does not meet FAA type design, seek a recommendation from
the kit provider (if applicable), the propeller manufacturer, or the engine manufacturer, to
obtain the most suitable application possible to avoid an unsafe condition. Builders should
make informed decisions concerning their engine and propeller installation combinations.
• Do not use a Hartzell 8468 series blade on a propeller for use on a Lycoming 360 series
engine.
• There may be other engine and propeller combinations that result in unsafe installations.
Contact the appropriate propeller manufacturer for additional guidance.
Experimental Aircraft Owners –
• If you are unfamiliar with the propeller on your aircraft, perform the research necessary to
ensure the propeller/ engine combination meets an approved design. If you do not do the
research, consider changing the propeller, or at least become aware of the increased risk and
the consequences of a propeller failure.
• If you have an aircraft with a Lycoming 360 series engine, check the propeller to determine if
Hartzell 8468 series blades are installed. If they are installed, replace them before further
flight.
Potential propeller failures, aircraft damage, and potential loss of aircraft control for certain untested propellers installed on experimental aircraft.
http://www.avweb.com/news/features/Propeller-Care-224607-1.html
http://hartzellprop.com//wp-content/uploads/2012/12/NE-08-19.pdf
FAA Aircraft Certification Service
SPECIAL AIRWORTHINESS INFORMATION BULLETIN
SUBJ: Propeller Installations on Experimental Aircraft
SAIB: NE-08-19 Date: May 14, 2008
This is information only. Recommendations aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) alerts you, owners, operators, pilots,
mechanics, and certificated repair stations of concerns for potential propeller failures, aircraft
damage, and potential loss of aircraft control for certain untested propellers installed on
experimental aircraft.
The FAA is concerned that builders of experimental aircraft and experimental propeller installations
do not always consider the consequences of using an untested/ uncertificated propeller and engine
combination. One example of an inappropriate propeller installation application is the use of Hartzell
( )8468( )* series blades installed on Lycoming ( )( )-360 series engines. There may be other
inappropriate propeller installations. Consult the appropriate propeller manufacturer for installation
data to help ensure continued airworthiness.
The FAA acknowledges that the aircraft builder has the ultimate responsibility for the parts/
components used on their experimental aircraft. The builder of the propeller assembly is often a
propeller repair station who might be unaware of the consequences of using untested/ uncertified
propeller assemblies on a specific engine. To the extent that the propeller shop may be
knowledgeable of such matters, they also share some responsibility in notifying the experimental
aircraft builder of the potential consequences of using untested/ uncertified propeller installations.
Background
There were two accidents resulting from propeller blade failures on experimental aircraft using
Hartzell ( )8468( )* series blades installed on Lycoming ( )( )-360 series engines. This blade design
uses a thinner airfoil than that used on other Lycoming 360 applications. Also, the accident-related
blades incorporated a modification that reduced the blade diameter to less than other approved
designs. These differences result in exposure to high vibratory stress loadings that exceed the
structural levels allowed for safe operation. In both accidents, the high propeller blade vibratory
stress loading is considered a contributing factor in the failures. These accidents show that specific
engine and propeller combinations are an important design consideration that requires careful
research regardless of the propeller manufacturer.
Builders of experimental aircraft are permitted to use experimental propellers. However, certain
propellers, even those with type certificates, might not be suitable for use on certain engines. If
combined, there is the potential for an unsafe condition to exist.
Propeller Repair Stations have, on occasion, been reported to assemble an experimental propeller
using propeller blades retired from use on certificated aircraft for being undersize in width, thickness,
or diameter. Such a propeller enables the builder of an experimental aircraft to reduce costs, but could
result in an unsafe application that does not meet any approved or tested engine and propeller
combination.
2
* There are numerous variations in Hartzell ( )8468( ) series propeller blades such as: F8468A-6R,
F8468-2, FC8468-6R, etc.
Recommendations
Propeller Repair Stations –
• If asked to build an experimental propeller, confirm the specific engine model being used and
only select a propeller that is known to be vibrationally/ structurally compatible with that
engine. As necessary, contact the appropriate propeller manufacturer for assistance in making
this selection.
• Advise the customer of the experimental, untested nature of the propeller installation and its
potential airworthiness consequences.
• Do not install Hartzell 8468 series blades on a propeller for use on a Lycoming 360 series
engine.
Experimental Aircraft Builders –
• Wherever possible, always use an FAA-approved or propeller manufacturer-recommended
engine and propeller combination.
• If either an engine or propeller does not meet FAA type design, seek a recommendation from
the kit provider (if applicable), the propeller manufacturer, or the engine manufacturer, to
obtain the most suitable application possible to avoid an unsafe condition. Builders should
make informed decisions concerning their engine and propeller installation combinations.
• Do not use a Hartzell 8468 series blade on a propeller for use on a Lycoming 360 series
engine.
• There may be other engine and propeller combinations that result in unsafe installations.
Contact the appropriate propeller manufacturer for additional guidance.
Experimental Aircraft Owners –
• If you are unfamiliar with the propeller on your aircraft, perform the research necessary to
ensure the propeller/ engine combination meets an approved design. If you do not do the
research, consider changing the propeller, or at least become aware of the increased risk and
the consequences of a propeller failure.
• If you have an aircraft with a Lycoming 360 series engine, check the propeller to determine if
Hartzell 8468 series blades are installed. If they are installed, replace them before further
flight.
