Re: British Airways jets still flying despite fatal fault.
- From: "PDR" <peter.rieden@xxxxxxxxxxxxxxxxxxxxx>
- Date: Sun, 20 Jan 2008 14:32:53 -0000
"Joe Lee" <invalid@noaddress> wrote in message
news:4792a437$0$21104$da0feed9@xxxxxxxxxxxxxxxxx
"Palindrome" <me9@xxxxxxxxxxx> wrote in message
news:g8xkj.43944$392.19860@xxxxxxxxxxxxxxxxxxxxxxxxx
Joe Lee wrote:
"Steve Firth" <%steve%@xxxxxxxxxxxx> wrote in message
news:1iaz782.wyn9nb102wy4gN%%steve%@xxxxxxxxxxxxxxx
Cynic <cynic_999@xxxxxxxxxxx> wrote:
No he's not, he's citing a problem with a GE engine as a precedent forHe is quite correcty suggesting that software errors are perfectlyI take it that you're not seriously suggesting that such flaws canI take it your not seriously suggesting that RR fit the GE FADEC?
only
ever exist in aircraft fitted with GE engines ?
possible, and have occured.
a
problem with a RR engine.
No I'm not, in fact I can't even see what it is i've said that would
lead you to that conclusion, but I do note you are the only person here
who is struggling to understand what I said.
Incidentally, the answer to your question "I take it your not seriously
suggesting that RR fit the GE FADEC?", is no & I said nothing to lead
you to believe that I was. I suggest my drawing attention to the fact
that the events had occurred only on 777's fitted with GE engines would
have led a reasonable person to that same conclusion.
I do get the impression that FADECs in general have caused more than
their fair share of mishaps. At least this time there won't be some RAF
Air Marshalls around to ensure that the pilots get the blame.
Absolutely yes & that's something to be grateful for.
As you probably know Des Browne is due to report shortly on his 'findings'
into the cause of the Chinook tragedy. I am hopeful this will culminate in
the air crew finally being absolved of blame.
I hope not (although I fear it will). As a (lapsed) pilot and an engineer I
have followed this story from its inception, and I have to say that I'm in
complete agreement with (AM) William Wratten. There has been a smokescreen
of irrelevent detail which has clouded the public view and obscured the
fundamental details, together with the understandable grief of the pilots'
families and the utterly bizzare idea that the phrase "don't speak ill of
the dead" has any relevence to a technical investigation.
Let's look at what happened.
1. A group of people used a Chinook to go to a meeting on the mainland. Why?
Well the meeting was actually a "jolly" - an excuse for an excursion on
expenses. There was no technical or operational reason for not using
commercial air (or car & ferry) transport, but doing so would have required
authorisations and that would have had people asking whether the trip was
necessary and whether it was necessary for everyone to go. So they bypassed
the normal grandfather scrutiny process for "business trips" by persuading
their buddies in the RAF to give them a lift. It was against the regs for
them to ask, and it was equally against the regs for the RAF to oblige, but
things were pretty lax in NI so they got it through. One is intrigued as to
why, when they apparently had so little confidence in this aircraft, the
crew were so easily induced to embark on this "unnecessary" flight. Aircrew
negligence item 1.
2. The helicopter in question was the subject of a number of operational
limitations, some of which can be ignored in "wartime ops" because the
balance of risk & benefit is the very core of the military equation, and
explains why a military aircraft can operate in different ways to a civil
one. Amongst these limitations were the absence of any clearence for
operating in Instrument conditions (IMC) and a prohibition of operations in
areas of Know Icing. During the subsequent flight the aircraft did both of
these. This was not a "wartime op" and nor was it planned with sufficient
rigour for it to be used as a simulated training exercise for such - there
are (again) laid down procedures for such things which were not followed, so
the aircrew broke the rules again because a local culture had developed
amongst the pilots that things like the limitations only appled to lesser
mortals. Aircrew negligence item 2.
3. Much has been made of some technical issues with the engine systems of
the aircraft. These were certainly a concern, but were completely irrelevent
to this accident. The failure mode in question caused "turbine runaway" -
essentially the engines racing to beyond max power and revs. In the event of
one or both engines suffering this the recovery procedure is to pull as much
collective pitch as possible to load up the rotors and prevent them
overspeeding (which could cause the blades to come off). As you might
expect, this causes the aeroplane to climb, and climb rapidly. When this
planet was created one of the basic planning consent requirements was that
the hills should be placed on the ground rather than in the sky (health &
safety executive requirement), and so it is not possible for an aircraft
which has to suddenly climb rapidly to hit a hill that it wasn't about to
hit anyway. From the crash site it was established (rather objectively, with
photographic evidence available to all who care to look for it) that all the
rotor blades were still attached at the time of impact, that they were
turning at a normal speed and that the engines were developing power at the
time they hit the hill. All of these things can be established irrefutably
by a crash investigator within minutes of arriving at the crash site with
his/her hands metaphorically still in the pockets. The "hows" are a bit
technical, but again the stuff is all accessible using google for those who
care to look. So we can clearly see that the technical problems were
completely irrelevent to the crash.
4. So what happened? Well the flight was badly planned, at heights and
speeds which were in breach of the aircraft's Release To Service (RTS) and
the squadron's standing procedures. The flight entered cloud and stayed
there, despite the prohibition of IMC, rather than performing a VMC recovery
(as required by procedure) and climbing above the cloud to find VMC
conditions in which the aircraft could be recovered to a safe location. It
was also in known icing conditions at the time, and again the crew did
nothing to fly out of it. The really bizzare thing is that they didn't even
slow down. One of the handy features of a helicopter (as distinct from a
fixed-wing aircraft) is that it can fly at virtually ANY airspeed, and so
the crew could have slowed to 20-30kts while they turned back (or whatever
other VMC recovery they had planned in their rather deficient flight
planning process). They could even have come to a dead-stop in a high hover
if they wished, but no - on they went at 150+kts at a very low level in a
manner that was exciting, but unjustifiably dangerous.
5. We'll never know the precise reason they hit the Mull, but the Mull's
height was known and should have been identified in the Minimum Safety
Altitude (MSA) calcs in the flight plan. Apparently they weren't, but again
that's a pilot competency issue. There are currently two theories (one
likely and one less so), both involving navigation errors, with the popular
one being the use of an offset visual waypoint navigation technique which is
prohibited in these circumstances precisely because any mistake in
identifying the landmark used can have dire consequences.
So the bottom line is that the aircraft should not have been where it was,
when it was, at the height & speed it was doing. In theing there at that
height and speed it was exposed to high risk of accident from any subsequent
error, and the responsibility for its being there was solely the
responsibility of the aircrew who were (as staded by William Wratten, the
flag officer resposible for maintaining professional flying standards in the
RAF) therefore grossly negligent. The fact that they died in the crash can't
change that.
Cynic - as another pilot (and one with far greater experience than me) I'd
be interested in any commentary you have on any of the above.
This from last Mon.
<http://www.theherald.co.uk/features/letters/display.var.1965188.0.Chinook_disaster.php>
Another reference to a suitably learned journal I see. Well I guess that
puts the pilots and engineers properly in their place - their analyses are
clearly hopelessly skewed by the fact that they actually know what they're
talking about...
PDR
.
- Follow-Ups:
- Prev by Date: OT whats the time
- Next by Date: Re: Man needs CRB check to look at his own son
- Previous by thread: Re: British Airways jets still flying despite fatal fault.
- Next by thread: Re: British Airways jets still flying despite fatal fault.
- Index(es):
Relevant Pages
|
