Vne is?IAS - not TAS.????? John
-----Original Message----- From: heavensounds <[email protected]> To: [email protected]; Ed Burkhead <[email protected]> Sent: Sat, 27 Dec 2008 11:54 am Subject: Re: [ercoupe-tech] Sebring crash, NTSB preliminary report Ed High altitude and a few mph short of Vne? Probably you were exceeding Vne! Remember that?altitude will make TAS?higher than IAS. Perhaps you could recall altitude and temperature that day and estimate what was your TAS? Eliacim ? ----- Original Message ----- From: Ed Burkhead To: [email protected] Sent: Saturday, December 27, 2008 10:42 AM Subject: RE: [ercoupe-tech] Sebring crash, NTSB preliminary report > NTSB Identification: ERA09FA087 > 14 CFR Part 91: General Aviation > Accident occurred Saturday, December 13, 2008 in Sebring, FL > Aircraft: ERCOUPE 415-D, registration: N99154 > Injuries: 2 Fatal. > . . . Another witness, who was also a certificated airline transport > pilot, stated that while outside working on his house he > observed the accident airplane flying overhead. . . . He > additionally noted that while the airplane was banking, > both ailerons were "fluttering" at a high frequency. . . . The mention of aileron flutter in the accident report brings me to recount my encounter with aileron flutter in a Coupe. At high altitude, in perfectly smooth cool air, I needed to descend to go under clouds far ahead. Rather than do a cruise descent, I decided to do a gentle dive to touch the Vne of the Coupe. I was still a few mph short of Vne when I felt a vibration very much like hitting the washboarding on a gravel road. For some strange reason, I deduced the cause in a very short time - between 1-3 seconds - and correctly figured out I needed to load the aileron to dampen the flutter. A sudden turn of the yoke instantly dampened the flutter and I slowed the plane gently, doing S-turns to keep the aileron loaded till I was down to normal cruise speed. The plane checked out, there in the air, so I continued on to home base. Testing on the ground showed that the aileron system had excess play. It's already part of the Coupe instructions how to check the aileron control system play. My recommendation to everyone is to DO IT! Check that aileron system play. Soon! Please! I'd also recommend a thorough inspection of the components of the control system. Perform the integrity test on the aileron push rods (is the ice pick actually the correct method?) and make sure all the parts of the control system are corrosion free and in good condition. And, consider that it's not necessarily a good idea to approach Vne in a 60+ year old airplane. Ed Ed Burkhead http://edburkhead.com/Ercoupe/index.htm ed -at- edbur???khead.XXX change -at- to @, remove ??? and change XXX to com
