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    Re: Bygrave and Chichester
    From: Tom Sult
    Date: 2009 Aug 02, 16:38 -0500

    I agree with what you have said but the crash data for 336/337 is no  
    better than other twins.
    Thomas A. Sult, MD
    IntegraCare Clinic
    On Aug 2, 2009, at 3:58 PM, Greg R. wrote:
    > Not to speak for Gary, but the pusher/puller configuration has  
    > what's called
    > "centerline thrust" - i.e. if you lose an engine, the thrust vector  
    > stays on
    > the centerline - theoretically making the engine-out procedure  
    > easier to
    > handle (ditto for a single-engine, though the engine-out procedure  
    > is a lot
    > more cut-and-dried...  ;-)).
    > Wing-mounted twins have a more-complicated engine-out procedure -  
    > not only
    > identifying the dead engine, securing/feathering it (also true of
    > centerline-mounted engine configs), but also maintaining a slight  
    > bank angle
    > to compensate for the thrust imbalance caused by the dead engine.
    > http://en.wikipedia.org/wiki/Critical_engine
    > Not sure if the Vmc (minimum-controllable velocity) restrictions  
    > would apply
    > to A/C with centerline-mounted engines, that's probably a question  
    > for Gary.
    > --
    > GregR
    > ----- Original Message -----
    > From: "Greg Rudzinski" 
    > To: "NavList" 
    > Sent: Sunday, August 02, 2009 12:16 PM
    > Subject: [NavList 9297] Re: Bygrave and Chichester
    > Gary,
    > How would the Cessna 336/337 perform if one engine fails? Is there an
    > advantage to a pusher puller configuration over a single or wing
    > mounted twins?
    > Greg
    > On Aug 2, 11:18 am, Gary LaPook  wrote:
    >> Well, I would agree with you Douglas, as judged from our  
    >> perspective in
    >> 2009, that Chichester may have been "reckless." But as judged from  
    >> the
    >> standards of aviation pioneers almost 80 years ago, I prefer the word
    >> "bold." If you look at early pioneering efforts, Lindberg, Perry, Sir
    >> John Franklin, Columbus etc., they all appear reckless as viewed  
    >> through
    >> our prism of time. But that is what pioneering is all about, taking
    > chances.
    >> Regarding you preference for twin engine flying, the accident  
    >> statistics
    >> show that they are more dangerous than singles, pretty
    >> counter-intuitive. Flying a twin when both engines are operating is  
    >> just
    >> like flying a single, it only gets interesting when one quits. Then  
    >> the
    >> pilot must deal with a greatly reduced performance envelope and
    >> asymmetric thrust causing control difficulties. If the pilot  
    >> doesn't do
    >> everything exactly right he ends up crashing and the crash happens  
    >> at a
    >> higher speed than would have occurred in a single. By US  
    >> certification
    >> standards (I expect they are similar in Britain) a single must have a
    >> stall speed below 60 knots while a twin can have a much higher speed.
    >> This means that a pilot trying to crash land a twin must fly above  
    >> the
    >> stall speed resulting in a higher impact speed and much more kinetic
    >> energy to dissipate (varies with velocity squared), can we say "torn
    >> aluminum" and "mangled bodies?" I've litigated airplane crashes for  
    >> the
    >> last twenty years and I have seen my share of bent aluminum and  
    >> autopsy
    >> photos. (BTW, a Cessna 310 Twin fits in a box on a standard pallet,
    >> about five feet square and three feet deep after it impacts the dirt.
    >> Airplanes are mostly air surrounded by an aluminum skin, just like an
    >> empty beer can and they squish just like a beer can..)
    >> After the loss of one engine the airplane has little or no climb
    >> capability. It will only climb or maintain altitude if the pilot does
    >> everything right. If he doesn't get rid or the drag form the flaps,  
    >> the
    >> landing gear and the windmilling propeller immediately then he is  
    >> going
    >> down.
    >> I'll give you some examples. About seven years ago a Cessna 310 was
    >> taking off from Laverne airport just northeast of Los Angeles on July
    >> 4, 2002, Independence Day. One engine quit right after takeoff and  
    >> the
    >> pilot did not do everything right and the plane crashed on top of a
    >> bunch of picnickers celebrating Independence Day in the park near the
    >> airport resulting in the deaths of the two occupants of the plane,  
    >> two
    >> deaths of the picnickers and severe injuries for nine other people on
    >> the ground. See the accident report at:
    > http://www.ntsb.gov/ntsb/GenPDF.asp?id=LAX01FA152&rpt=fa
    >> The left propeller control was found "one inch aft." In order to  
    >> feather
    >> the propeller it is necessary to pull the prop control all the way  
    >> aft,
    >> about eight inches. Since the pilot did not move the prop control all
    >> the way aft the prop did not feather and the plane could not maintain
    >> altitude with the left engine windmilling creating a lot of drag. It
    >> turned out that the pilot had done exactly as he had been instructed.
    >> His instructor's technique for practicing engine out emergencies  
    >> called
    >> for the student pilot to just pull the prop control back one inch to
    >> demonstrate that he had identified the failed engine and that he  
    >> would
    >> have feathered the prop in a real emergency. But in a high stress
    >> situation people do what they have practiced so four dead people,
    >> including two little children, and nine serous injuries.
    >> Another case I worked on involved a Piper Navaho hauling sight seers
    >> around Hawaii. One engine packed it in and because the mechanic had  
    >> not
    >> used the proper method to adjust the wastegate controller on the  
    >> other
    >> engine, the remaining engine was not developing full power so the
    >> airplane could not maintain altitude on the one engine. So even  
    >> though
    >> the pilot was doing everything right he still had to ditch in the sea
    >> near Hilo and one little old lady, celebrating her fortieth wedding
    >> anniversary, rode the plane to the bottom of the sea. See report
    >> at:http://www.ntsb.gov/ntsb/GenPDF.asp?id=LAX00FA310&rpt=fa
    >> Another case I worked on involved a Twin Otter powered by two Pratt &
    >> Whitney turboprop engines. The underground fuel tank from which the
    >> airplane had just been refueled was contaminated with water (it  
    >> looked
    >> like mud) and one engine stopped right after the nose was raised  
    >> due to
    >> ingesting the water. The pilot then did everything wrong and  
    >> feathered
    >> the wrong engine, shutting down the one operating engine. This  
    >> resulted
    >> in 16 deaths of the occupants.
    >> See:http://www.ntsb.gov/ntsb/GenPDF.asp?id=LAX93FA149&rpt=fa
    >> Having two engines gives one the sense that he has redundant  
    >> systems and
    >> that it is unlikely to have two reliable systems fail at the same  
    >> time.
    >> So, if an engine should fail once every 5,000 hours then the chance  
    >> of
    >> two such engines failing at the same time should be only once every
    >> 25,000,000 (5,000 times 5,000) hours. But that assumes that the two
    >> systems are completely independent from each other which is rarely  
    >> the
    >> case. First, obviously, both engines are being operated by the same
    >> pilot and any error on his part can result in the loss of both  
    >> engines.
    >> Both engines received the same fuel so if one tank has contaminated  
    >> fuel
    >> they both do. They were refueled at the same time so if the pilot  
    >> runs
    >> one out of fuel then the other will follow moments later. The same
    >> mechanic worked on both engine and if he screwed up one then he  
    >> probably
    >> screwed up the other one too. I remember watching a Cessna 310 take  
    >> off
    >> from Chicago Midway airport one day. Right after takeoff one engine
    >> failed and the pilot was able to bring it around and land safely. The
    >> plane taxied up to my hangar with one prop stopped and my friend Bill
    >> jumped out and walked right past me. I asked him, as he passed,  
    >> what had
    >> happened and he said he couldn't stop to talk as he had to "go and  
    >> clean
    >> out his shorts." I don't think he was talking figuratively since he  
    >> went
    >> immediately into the men's room. The next day when I saw him I asked
    >> again and he said he was doing a test flight after the mechanic had
    >> adjusted the propeller governor and right after takeoff that one
    >> propeller had gone into feather uncommanded which resulted in the  
    >> loss
    >> of power from that engine. As he was bringing the plane around to  
    >> land
    >> he said that all he could think about was that the mechanic had just
    >> adjusted _both_ propeller governors and he was waiting for the  
    >> other one
    >> to go into feather too.
    >> In the case of over water ferry flights on which the plane is heavily
    >> overloaded with fuel, the single engine ceiling may be below sea  
    >> level.
    >> This means with such a heavy load that the plane cannot maintain
    >> altitude if just one engine fails and a ditching is inevitable. In  
    >> this
    >> case a twin is quite a bit less safe than a single since with two
    >> engines you have twice the probability of an engine failure, 2 per  
    >> 5,000
    >> hours using my prior example.
    >> gl
    >> douglas.de...@btopenworld.com wrote:
    >>> My interest in the Bygrave helical slide rule too Gary, was  
    >>> stimulated
    > when I read Chichester's book 'The Lonely Sea and the Sky' many  
    > years ago.
    >>> I have been hoping ever since to find one, perhaps one of them would
    > turn up in an antique shop or 'car boot sale', but now realise that  
    > fond
    > dream is far from ever becoming a reality.
    >>> It is very strange that they are now so incredibly rare  
    >>> considering they
    > must have been made in reasonably large numbers from the early  
    > 1920's up to
    > the mid 1930's, and were also an official piece of navigating 'kit'  
    > for
    > aircraft navigators in that period for the RAF, so must have been  
    > made in
    > fairly large numbers rather than just a relatively few for  
    > experimental
    > purposes. They were also available to buy privately. So what  
    > happened to
    > them all? It's most odd.
    >>> Even the most arcane scientific apparatus and instruments are  
    >>> usually
    > preserved or survive in private hands to be sold on or given away to  
    > others
    > rather than just binned.
    >>> Are all those RAF Bygrave slide rules still locked away in some old,
    > musty, forgotten RAF or government store at the back of dusty shelves
    > awaiting some storekeeper to find them and be told to put them in an  
    > auction
    > of ex-government surplus. (Still dreaming you see !).
    >>> Whilst the skill and amazing endeavour of what Chichester achieved  
    >>> is
    > not to be denied an any way, (and you have now confirmed by your own
    > practical flying test in a Tiger Moth); which was immediately  
    > apparent to me
    > when I read of the exploit, and it has continued to amaze me still -  
    > with
    > what he wrote I was also filled with the astonishment and feelings  
    > that
    > Chichester was idiotically reckless in what he did,..(I think) to  
    > the point
    > of insanity.
    >>> Given that he writes in a style which is deliberately meant to  
    >>> make his
    > story not just interesting but no doubt boost his (Chichester's)  
    > reputation,
    > and sales of the book, and hopefully have the reader clutching the  
    > book with
    > white knuckles in anticipation of events unfolding; nevertheless, he  
    > exposes
    > a devil-may-care attitude of quite serious stupidity and ignores  
    > issues of
    > high importance which any right-thinking person would not consider
    > reasonable, and certainly not anyone who knows anything about flying  
    > and the
    > consequences involved in flying solo in a single engined aitrcraft  
    > with a
    > 'dodgy' engine over large stretches of water.
    >>> ----------
    >>> I had a personal friend who taught me to fly, he was the Chief  
    >>> Flying
    > Instructor at Bembridge flying school, and who very nearly lost his  
    > life
    > when the donkey of the Cessna 150 stopped en route, mid - Solent, as  
    > he was
    > flying back to Bembridge from Goodwood, (The Solent is the sea -  
    > only four
    > miles of water between the Isle of Wight and the mainland) -and after
    > turning downwind towards the mainland to maximise his ground  
    > traverse, he
    > did not make it and was...
    >> read more �
    > >
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