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Charlie,
I have installed Valin Thorn's Starflight Condensor
package that I purchased through Flightline AC. It requires that two
8" holes be cut in the belly of the baggage compartment. The holes are
reinforced with 10 bid carbon fiber interlocking rings. I decided to make
mine a permanent installation and bonded the fiberglass condensor shell to the
floor for additional support. I'm still building but would be very interested
in any testing that would validate this modification to the airframe.
Stan Fields
L2K-RG #201
Austin
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf Of Charlie Kohler
Sent: Tuesday, May 01, 2012 8:56 AM
To: lml@lancaironline.net
Subject: [LML] Re: Harry League & Pat Franzen fatal IVPT accident
4/23/2012
I have raised the issue regarding the holes cut in the aft
fuselage for the air-conditioning for several years. Several years ago I sat at
a table with Martin Hollman, and Tim Ong and we talked in
general about gross weight increases over the years, modifications to the
fuselage, etc. etc. Martin agreed at that time that the only solution was
to have a new stress and flutter analysis performed.
He raised a red flag regarding the AC holes.
I would suggest Lancair together with Lancair IV owners initiated
a stress and flutter analysis of the current state of the fleet. Turbines/IVP's
with winglets etc. etc. considering newly recommended the gross weights and
airframe modifications.
Brent very ably addresses the issue when you are
facing weather and you know you have a fragile airframe that you have cut
two large holes in.
Here is his letter regarding another accident in which all the
blame goes to the weather. I can think of several others that faced---
something---- and did not fly out the other side. I wonder, if they had a
sound airframe going in. The latest accident has me questioning---just how
bad was this weather that caused airframe to come apart? Was airframe capable
of handling 3G-5G ??
Reread Brent Reagan's post from the Lancair list.
Late last
month I was contacted by the NTSB in Atlanta regarding the crash of
N29ME. It seems that there was an CFS EFIS-2000 system installed in the
airplane and they had recovered the IDUs from the
wreckage. They had learned from Kirk that the IDUs contained logs of the last
few flights and asked if I could recover the data for them.
I received the IDUs late last week and although the units had been severely
damaged I was able to remove the flash data card from the MFD and, after some
repair work, extract the log files.
The investigation into this accident is ongoing and detailed public discussions
of the data and conclusions should be reserved until the NTSB final report is
issued. However, this report is some months away
and there are two generic safety issues that that I would like to discuss in
the hope of improving flight safety during this thunder storm season.
From the Preliminary report:
The last flight left Portland Indiana at 15:45 eastern daylight time and proceeded
normally for just under two hours when, at 17:30 the pilot requested a left
deviation for weather. The deviation was not granted
until approximately 8 minutes later when the pilot then turned right 70 degrees
and remained on that course for 11 minutes while he descended from 17,000 to
13,000 feet. The plane then turned left, back on course.
Clearance was given to 11,000 feet and the last communication was at 17:49. The
last radar contact was at 17:55 at 11,700 feet. Level 5 thunderstorms were reported
in the area.
The data log records the conditions of flight once every 5 seconds. A new data
log is created when the system starts in flight mode and continues recording
until power is interrupted or the system resets. The
last 8 data points of the flight (35 seconds) show that while cruising at 187
KIAS the the nose pitched up 20 degrees and the plane climbed to 12,436 at a
peak of 5,328 fpm and banked left 50 degrees (imagine a wing
over). At 113 KIAS the nose pitched down 29 degrees below horizontal with a
left bank angle of 80 degrees. The G meter never goes negative but a large drop
in oil pressure indicates that it may have been
negative between data points.
The plane is in a steep left spiral dive with the peak rate of decent reaching
12,685 fpm. OAT is falling from 35 degrees F to 27 degrees F. Engine power
remains unchanged from the cruise setting of 70% and 2,400
rpm. G forces are rising as the nose starts to come up.
The last data point is at 9,146 feet with the plane pitched down 35 degrees
(decreasing) and banked left 71 degrees (also decreasing).
Decent rate is 10,208 fpm and airspeed is 253 KIAS. The airspeed is increasing
at 7.1 knots per second and at this rate Vne will be reached in less than 3
seconds. The G load is 3.75 Gs positive (it had climbed
from 0.68 Gs in the last 10 seconds). Within 5 seconds an event occurs that an
observer on the ground hears and describes as an explosion...
I can not say what actually happened in this case. We can consider a
hypothetical scenario as a way to better understand the dynamics of flight.
Imagine that the plane flew through an updraft / downdraft wind
shear. A sudden drop in OAT can indicate a downdraft. While in the downdraft,
the ground track shows the plane reversed course with the final data point
being just before re-penatrating the downdraft /
updraft interface. It is easy to imagine that the wind shear could apply the
additional loads needed to fail the wings.
Besides the sorrow of loosing four souls, members of the Lancair community,
there are two things that are, in my view, most apparent. The pilot requested a
deviation for weather that the controller did not
grant due to traffic. "Weather" in this case was level 5 thunder
storm cells. I cannot say what the pilot should have done but he did have the
option of saying "unable" or "I am declaring an emergency and
turning
left". Controllers are sitting safe and snug on the ground. The pilot is
responsible for the safety of the flight regardless of what the controller
says. If you are in an unsafe situation, do whatever you need to do to change
problems that must be solved in the air to problems that can be solved on the
ground. The worst administrative action is far better than the best funeral.
The second apparent thing is that if you know you are about to get, or are
being, knocked around, get your speed down under Va and keep the wings level.
Pitch for speed and power for altitude. Never dive for an
assigned altitude. We all know these things but it can't hurt to review them in
your mind to reinforce the understanding of your responsibilities as PIC.
My deepest sympathies and heartfelt condolences go to the families and friends
of the victims.
To everyone else, fly safe, please.
Regards
Brent Regan
----------------------------------------------------------------------------------
My
inspections over the years have brought several areas of weakness to light. I
would suggest all owners check their airplanes for a debonding of the skin
between the very aft end of the main landing gear doors.
Also
check for structural security and construction of the box that surrounds the
elevator push tube.
With
someone's help, go to the tail tiedown area and push up with
your back. You will see movement of the skin if there is a debond.
Quite often when I have discovered this I asked the owner if he was a
self-taught pilot? And did he have any hard landings? Most admitted it. I
recall one case (pre-Buy) in Northern California where the owner refused to
consider fixing this situation to effect the sale. He didn't think it
was a big issue at all.
From: Lynn
Farnsworth <farnsworth@charter.net>
To: lml@lancaironline.net
Sent: Wednesday, April 25, 2012 4:24 PM
Subject: [LML] Re: Harry League & Pat Franzen fatal IVPT accident
4/23/2012
Subject: Harry League & Pat Franzen fatal IVPT accident 4/23/2012
It is my
sad duty to report Mr. Harry League and Mr. Pat Franzen were killed yesterday
when the IVPT, N66HL,
[Lynn
Farnsworth] It appears to me that the aircraft disintegrated in-flight. What
kind of flight profile would include doing training that would lead to an
in-flight breakup?
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