X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Mon, 07 Dec 2009 11:51:38 -0500 Message-ID: X-Original-Return-Path: Received: from vms173015pub.verizon.net ([206.46.173.15] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTP id 4006078 for lml@lancaironline.net; Mon, 07 Dec 2009 11:46:42 -0500 Received-SPF: pass receiver=logan.com; client-ip=206.46.173.15; envelope-from=skipslater@verizon.net Received: from SkipPC ([173.58.203.163]) by vms173015.mailsrvcs.net (Sun Java(tm) System Messaging Server 6.3-7.04 (built Sep 26 2008; 32bit)) with ESMTPA id <0KUA0015ZJWM2KW9@vms173015.mailsrvcs.net> for lml@lancaironline.net; Mon, 07 Dec 2009 10:45:59 -0600 (CST) X-Original-Message-id: <1E500A3B450C41C994A7C050A604A351@SkipPC> From: "Skip Slater" X-Original-To: "Lancair Mailing List" References: In-reply-to: Subject: Re: [LML] Re: Vne is NOT a meaningless number X-Original-Date: Mon, 07 Dec 2009 08:45:58 -0800 MIME-version: 1.0 Content-type: multipart/alternative; boundary="----=_NextPart_000_0030_01CA7719.B22B4B70" X-Priority: 3 X-MSMail-priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MIMEOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_0030_01CA7719.B22B4B70 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mark, I beg to differ on the TAS vs IAS effect on Vne. A good example is = the ES. It has a Vne of 220 KIAS. However many turbocharged ES's (as = well as the Columbia 400) can fly up in the mid 20's at a TAS of around = 225 all day. I'm guessing that at that speed, the IAS is somewhere in = the vicinity of 150-160. Until you reach a critical mach number (I = don't even know what that is for my ES), IAS is the number you need to = worry about with regard to flutter. As for the military guys punching out at high speed, you're mistaken. = I have a few thousand hours in ejection seats and TAS has nothing to do = with opening shock - it's IAS we worried about. In the Navy jets I = flew, our chutes had a limiting IAS beyond which you could rip out the = parachute panels if you deployed them. The other issue was flailing = injuries to your body from wind blast at high speeds. I know of at = least two Viet Nam ERA POW's who had serious knee damage when they = punched=20 out of their A-4's at high speed (=E2=80=BA400 KIAS) after being hit by = SAM's (John McCain was one of them). I seem to recall max speed to punch out in my plane was 450 knots IAS. = Most seats employ a small drogue chute that deploys after ejection to = stabilize and slow you down a bit before pulling out the main chute. In = the McDonnell Douglas Escapac seats I flew, the seat had an altitude = sensor that wouldn't release you from the seat until you descended below = a preset altitude. My memory is a bit scratchy here, but I believe it = was somewhere around 20,000'. You could always manually release = yourself too. At low altitudes, you separated immediately. Martin = Baker seats worked differently, but still had a max IAS for ejection. = In F-14's you wore leg restraints that held your legs to the seat until = separation to prevent flailing. I know of at least one F-14 RIO who = punched himself out over the water in excess of 600 knots and was never = found. Bottom line though, TAS was never a limitation in any ejection = seat I rode in. Skip Slater ------=_NextPart_000_0030_01CA7719.B22B4B70 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Mark,

I beg to differ on the TAS = vs IAS=20 effect on Vne. A good example is the ES. It has a Vne of = 220=20 KIAS. However many turbocharged ES's (as well as the Columbia = 400) can=20 fly up in the mid 20's at a TAS of around 225 all=20 day. I'm guessing that at that speed, the IAS is = somewhere in=20 the vicinity of 150-160. Until you reach a critical mach = number (I=20 don't even know what that is for my ES), IAS is the number you need = to=20 worry about with regard to flutter.

As for the military guys = punching out=20 at high speed, you're mistaken. I have a few thousand hours in = ejection=20 seats and TAS has nothing to do with opening shock - it's IAS we = worried=20 about. In the Navy jets I flew, our chutes had a limiting IAS = beyond which=20 you could rip out the parachute panels if you deployed = them. The=20 other issue was flailing injuries to your body from wind blast at = high=20 speeds. I know of at least two Viet Nam ERA POW's who = had=20 serious knee damage when they punched

out of their A-4's at high speed = (=E2=80=BA400=20 KIAS) after being hit by SAM's (John McCain was one of = them).

I seem to recall max speed = to punch out=20 in my plane was 450 knots IAS. Most seats employ a small = drogue=20 chute that deploys after ejection to stabilize and slow you down a bit = before=20 pulling out the main chute. In the McDonnell Douglas Escapac = seats I=20 flew, the seat had an altitude sensor that wouldn't release you = from the=20 seat until you descended below a preset altitude. My memory is a = bit=20 scratchy here, but I believe it was somewhere around 20,000'. You = could=20 always manually release yourself too. At low altitudes, you = separated=20 immediately. Martin Baker seats worked differently, but still = had a=20 max IAS for ejection. In F-14's you wore leg restraints=20 that held your legs to the seat until separation to prevent=20 flailing. I know of at least one F-14 RIO who punched himself out = over the=20 water in excess of 600 knots and was never found. Bottom line = though, TAS=20 was never a limitation in any ejection seat I rode in.

Skip = Slater

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