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The FAA has granted a revised temporary
alternative means of compliance (AMOC) for the T-34 based on
completed and submitted engineering data obtained through a study
funded the T-34 Association. On December 10, 2004, FAA
grounded the entire T-34 fleet when pre-existing fatigue cracks were
found in the center section of an aircraft that had crashed three
days earlier. The T-34 Association managed to obtain a temporary
AMOC allowing the fleet to fly for 240 hours with certain flight
restrictions. This latest approved AMOC revises that original
directive.
The revised AMOC allows two options:
1. Complete a surface eddy current
inspection of the inner—31 channel of the lower forward carry
through structure around each of the 9 fasteners that
attach the wing attach fitting to the "-31" channel in all 4 corners
(36 fasteners in all). This option requires a repeat of the
inspection at 120 hours TIS. At the end of the second 120 hours
either #2 or the airplane must be modified with an FAA-approved mod
approved for AD2004-25-51 (see "Long Term AMOC's" below). This procedure has the following
flight limitations of; +2.5 G’s / -0 G’s, 152 Knots Never exceed
speed (Vne) and no aerobatics permitted. (This is basically the same
as the AMOC that we have been operating on)
2. Complete a surface eddy current
inspection of the 7 outboard fasteners as described
in #1 above and remove all 4 #8 & #9 fasteners (Total of 8) and
perform a rotating bolt hole eddy current inspection of all 8
fastener holes. The Bolt Hole inspection inspects both the -31inner
and -33 outer channels. Once this procedure is performed it allows
for an additional 600 hours TIS. Once the Bolt Hole inspection is
completed, the airspeed restrictions are removed and are returned to
the normal 219 Kts Vne. This inspection increase the acceleration
limits to +4.4 G’s / -2.5 G’s, and no aerobatic maneuvers are
approved.
The revised AMOC, which supercedes all
previous temporary AMOCs, expires on May 15, 2010. To operate a T-34
beyond this date, the airplane must be modified with an FAA-approved
Modification/Replacement program specifically approved for
AD2004-25-51.
Aircraft that have already been returned
to service by the T-34 Spar Corporation temporary AMOC to
AD2004-25-51 may continue to operate with those flight restrictions
until they reach the maximum allowable of 240 hours TIS and then
complete the Bolt Hole Inspection (#2 above) for an additional 600
hours TIS. Or, at the owner’s discretion, they can immediately
perform the Bolt Hole Inspection for 600 hours TIS.
For those that have not yet complied
with AD2004-25-51, at the owners discretion they can complete #1
above for a maximum of 240 hours TIS and then complete #2 for an
additional 600 hours TIS, or perform #2 only for a total of 600
hours TIS.
Long Term AMOC’s
Aviadesign has already been granted an
AMOC to AD2004-25-51 by installing an external Spar Strap. This AMOC
removes all flight restrictions. The airplane must be inspected in
accordance with Aviadesign’s Continued Airworthiness Instructions
specified within their AMOC to maintain compliance with
AD2004-25-51.
Parks Industries has submitted
engineering data to obtain an STC to remove the -31 Channel and
install a new part (H Beam) in its place. FAA approval is expected
shortly. This AMOC will also require the aircraft to be inspected in
accordance with Parks Industries Instructions for Continued
Airworthiness Instructions to maintain compliance with AD2004-25-51.
The T-34 Spar Corporation is developing
an Internal Cable (“ALEC”-Airframe Life Extension Cable). They
anticipate submitting the final data package to the FAA soon. This
AMOC will also incorporate Instructions for Continued Airworthiness
to maintain compliance with AD2004-25-51.
If you would like further information on
this AMOC or would like to use this AMOC please contact either:
Tim Roehl
T-34 Spar Corporation
(888)-359-6424
Jud Nogle
Nogle and Black Aviation, Inc.
(217) 253-4342 |
