X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 02 May 2012 09:00:15 -0400 Message-ID: X-Original-Return-Path: Received: from mail.tsnci.com ([216.12.62.56] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5517935 for lml@lancaironline.net; Tue, 01 May 2012 14:51:25 -0400 Received-SPF: none receiver=logan.com; client-ip=216.12.62.56; envelope-from=weinsweigd@tsnci.com Received: from TSNC_DOM-MTA by mail.tsnci.com with Novell_GroupWise; Tue, 01 May 2012 14:58:25 -0400 X-Original-Message-Id: X-Mailer: Novell GroupWise Internet Agent 6.5.7 X-Original-Date: Tue, 01 May 2012 14:57:54 -0400 From: "Dr. Weinsweig" X-Original-To: , Subject: [LML] Re: Harry League & Pat Franzen fatal IVPT accident 4/23/2012 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Although I did not know these 2 apparently good, fine gentlemen, my heart = goes out to their families. It is easy to explain away and discount crashes that occur in bad = thunderstorms or when people do stupid things or commit obvious errors. = However, when 2 competent pilots apprently fall out of the sky in vfr = conditions, answers must be sought. I trust in due time we will learn the = truth. I appreciate the input of those much more knowledgable than I-thanks = Charlie, Brent, Jeff, etc. Charlie, I agree that it must seem obvious to anyone who has been involved = in building a IV that the area of the fuselage behind the gear doors where = the A/C holes that you reference are made has to be the weakest area of = the fuselage. We installed Mike Custard's vertical fin extension to give = better yaw stability(in addition to the strakes) on my propjet and = unscientifically to my eye, this seems to beef up this area though from = the top rather than the underside. If any structural testing takes place = I think that this modification should also be tested to see if it helps. = Thoughts? I hate to render unsubstantiated opinions but Lynn, I wonder if a practice = emergency descent could cause the plane to have unexpectedly surpassed = Vne. Just a thought as on fast descents at "lower" altitudes Vne can come = quickly in a propjet. Fly Safe, David Weinsweig weinsweigd@gmail.com=20 N750DW Propjet >>> charliekohler@yahoo.com 5/1/2012 9:56:12 AM >>> Lynn=20 =20 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.=20 =20 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.=20 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 ?? =20 Reread Brent Reagan's post from the Lancair list. =20 To all Lancair Pilots; =20 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=20 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=20 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=20 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.=20 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=20 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=20 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=20 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=20 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).=20 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=20 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=20 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 /=20 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=20 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=20 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=20 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 ---------------------------------------------------------------------------= ------- =20 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.=20 =20 Also check for structural security and construction of the box that = surrounds the elevator push tube.=20 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. =20 =20 Additionally I suggest you read http://www.vansaircraft.com/pdf/hp_limts.p= df=20 =20 =20 Charlie K. See me on the web at=20 www.Lancair-IV.com=20 ________________________________ From: Lynn Farnsworth To: lml@lancaironline.net=20 Sent: Wednesday, April 25, 2012 4:24 PM Subject: [LML] Re: Harry League & Pat Franzen fatal IVPT accident = 4/23/2012 =20 =20 =20 =20 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,=20 =20 [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?