Re: A brief commentary

From:         Rick Hughes <rmhughes@iinet.net.au> (Rick Hughes)
Organization: iiNet Technologies (Perth, Western Australia)
Date:         07 Jul 96 14:15:58 
References:   1 2
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In Article <airliners.1996.1083@ohare.Chicago.COM>,
jsteele@AZStarNet.com (Jerry Steele) wrote:

>While I was in an Airbus 340 from Munich to Chicago, just off Newfoundland at
>39000 ft we encountered some chop. In my over 25 years of being a passenger
>this certainly was far from severe. Nonetheless, the crt monitor at the front
>of the business class section where they display flight data, as well as every
>seat video display, and the cabin lights flickered violently on and off
>several times as the turbulence rocked the aircraft.

>If I were to guess, being an electronic engineer, I'd say it seemed as if the
>110 volt power bus was getting hiccups (it seems as if these items would all
>be powered by that bus or something similar). Either shorts or bad contact
>somewhere (either of which could conceivably be a fire risk by the way).
>Hopefully everything in the cockpit is powered by the 28 volt system and were
>unaffected.

Can't comment on what caused the electrical glitches you saw on that
particular flight ... all I can say is that in nearly 2 years of
operating the A340 through all sorts of turbulence, I've never
experienced anything like that and have never had any reports of such
phenomenon from passengers OR cabin crew.

>Nonetheless, this was unnerving and left me with a poor impression of the
>A340. Especially since on my way over I had an impeccable, and incredibly
>enjoyable flight on a 777. Which by the way, had considerably better takeoff
>acceleration and climb. Now I realize aircraft performance is usually
>optimized for given airports and air traffic control, so such comparisons may
>be meaningless. But upon checking the power to weight ratios of the respective
>aircraft it seems as if the 777 does have far more power than the A340 (both
>were fully loaded by the way).

>Any comments on the power glitches observed?

As for the 'power glitches' ... they're not glitches at all.  You're
comparing a 4 engined aircraft optimised for ULH operations with a
large twin. Compare the A330 with the A340 and you will find exactly
the same difference, perhaps even more so if you compare the RR Trent
powered A330s with the A340.

A large twin must take into account the total thrust loss of one
engine (50% of installed thrust) on takeoff as against the quad which
need only allow for total thrust loss of one engine (25% of installed
thrust).  Twins require a greater thrust to weight ratio for
certification.  End of story ... it's hardly a 'glitch'.

As for your superlatives describing your B777 experience, I am very
pleased to hear that you enjoyed the flight so much<G>!  However, the
way you so enthusiastically endorse the local product is typical of
the somewhat one-eyed attitudes (now don't get upset <G>) of many of
the substantial number of Boeing devotees in this forum ... the very
point the originator of this thread was perhaps trying to get at.
Nothing wrong with that, so long as we all keep a balanced viewpoint
and don't start spreading mis-informed opinion as per your comments
above.

I fly for an outfit that operate a substantial number of Boeing
aircraft and an increasing number of Airbus aircraft as well.  For
those who manage to keep their minds open, they benefit from seeing
the good in BOTH designers products.  As I've said in this forum
before, both Boeing and Airbus make good aircraft ... but it is a
horses for courses situation. Generally speaking,  the Airbus products
are top notch, very economical to operate and liked by both crew and
passengers ... as much as the Boeing products are excellent and
thoroughly deserve their place in the inventory.  There are routes we
wouldn't dream of putting an A340 on and there are routes a B747 is
totally unsuited to.  The trick is being able to keep an open mind and
selecting the appropriate aircraft for the route.  If an airline can
get that right, profitability is almost ensured.

As for the different philosophies of Airbus v Boeing ... I'm with Jon
Ward ... I'm not going to get drawn into that.  Suffice to say that we
all have our personal opinions which do not necessarily make one
better than the other.  The average airliner is so complex that there
will always be some items that are perceived to be better
designed/implemented by one manufacturer than another.  Again, many of
the guys I fly with have flown numerous different types and the
majority genuinely enjoy flying the Airbus types every bit as much as
they did the Boeing types they spent years on.

Rick Hughes
Perth
Western Australia