Mailing List lml@lancaironline.net Message #32240
From: <RWolf99@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: Noncertified Airplanes
Date: Tue, 04 Oct 2005 10:28:14 -0400
To: <lml@lancaironline.net>
Hamid --
 
Some points to ponder.
 
1)  The B-737 is certified to FAR Part 25.  The C-172 is certified to FAR Part 23.  The Aircraft Functional Hazard Analysis is the process by which both designers say "this failure mode has these consequences, and therefore is allowed to happen only every xxx flight hours".  The Part 25 airplane has an extra zero on the number of hours, therefore, the B-737 can be quantitatively stated to be 10 times safer than the C-172.
 
2)  We'd probably discover that the accident statistics (per hours, per flight, probably by any measure) tell us that the B-737 is actually much more than 10 times safer.  There are more reasons for this than just pilot training.
 
2a)  B-737s are almost all operated under FAR Part 121 operating rules.  C-172s are almost all operated under FAR Part 91 operating rules.  The Part 91 operator can launch in zero-zero weather, start an approach if the weather is below minimums, and even fly VFR at night.  The Part 121 operator cannot do the first two, and while they might legally be allowed to fly VFR (I just don't know the rules on this one) I'd be astounded if an airliner *ever* flew on a VFR flight plan.
 
2b)  Airliners are almost always flown under positive control in sanitized airspace.  That's what the Class B airspace is all about.  Midairs just don't happen to airliners.  (Yeah, I know it has happened, but I hope you get the essential point here.)
 
2c)  You just don't fly a B-737 without an ATP.  You can fly a C-172 solo with a student pilot's license.  This is the issue that you were raising.  Hopefully I have shown you that there are other factors -- design requirements and operating restrictions -- that add to the training requirements to improve the safety of the airliner over the bug-smasher.
 
3)  I have no idea whether anyone would pony up the cash to buy a maximally safe kitplane.  This is a key issue -- the market may be demanding an inexpensive, though less safe, airplane.  However, I don't know that anyone has offered an alternative.  It certainly didn't work for Malcolm Bricklin! 
 
Keep up the healthy discussion!
 
- Rob Wolf
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