Osprey vs. Harrier

"benjym" wrote:

What we do know is that the harrier replacement (JSF) will
incorporate
innovations to reduce v-stol pilot workload currently under
development here in the UK. A Harrier prototype has been fitted
with
fly-by-wire controls and a flight management computor capable of
practically landing the plane automatically - the most dangerous
regime of v-stol flight. Controlling parameters like nozzle angle,
thrust, pitch, speed, landing gear etc the computor can land the
aircraft from approach configuration with one button push from the
pilot. Maybe this kind of thinking could be applied to the V-22?

When the V-22 Osprey is landing combat grunts on a hot LZ, do you
really want a computer landing the aircraft slowly and safely? If
not, how and when do you train the pilot to land quickly under those
circumstances?

Tony Williams wrote in message
m...
(ANDREW ROBERT BREEN) wrote in message
...
In article ,
John Halliwell wrote:

The problem with the Osprey is the inability to demonstrate the
problems
have been fixed. It's a very complex creature and Bell/Boeing are
determined to try to fix it (tilt-rotor being their pet technology)
rather than look at other alternatives which may have fewer built in
problems.

I'm aware I've said this before, but it seems an awful complicated
way of avoiding building a Rotodyne..

Ah, the Rotodyne. I don't know if you saw it but there was an article
in June 'Air International' saying that the gyrodyne may be on the way
back. A company called Groen Brothers Aviation are proposing this as a
low-cost, low risk approach,initially by converting existing
fixed-wing aircraft to have a rotor on top. Believe it or not, one of
their key targets for such a conversion is the C-130 Hercules!

Saw some film a few nights back on the TV of a WWII era jeep
with boat tail and rotor a few feet off the ground. Looks like the
idea was to tow them in separate during air assaults.

"Felger Carbon" wrote:

:When the V-22 Osprey is landing combat grunts on a hot LZ, do you
:really want a computer landing the aircraft slowly and safely? If
:not, how and when do you train the pilot to land quickly under those
:circumstances?

Well, there is actually some question whether it CAN be landed quickly
under ANY circumstances that aren't called a crash.

--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney

(Tony Williams) wrote:

:"Stephen D. Poe" wrote in message ...
:
: To quote a recent article:
: "They know this drill all too well because the Harrier is the most
: dangerous airplane flying in the U.S. military today.
:
: Over the last three decades, it has amassed the highest rate of major
: accidents of any Air Force, Navy, Army or Marine plane now in service.
: Forty-five Marines have died in 143 noncombat accidents since the corps
: bought the so-called jump jet from the British in 1971. More than a
: third of the fleet has been lost to accidents.
:
:As a matter of interest, how does that compare with the accident rate
:experienced with conventional naval/marine planes flying from
:carriers?

AV-8 12/100,000 flight hours
F/A-18 3/100,000 flight hours

So the AV-8 accident rate is about 4 times higher than conventional
carrier air. To put things further in perspective, over 2/3 of the
AV-8 accidents are mechanicals and less than 1/3 are pilot error.
Reverse that for most other carrier aircraft (around 2/3 of the
accidents are pilot error).

Looking at those numbers, what you see is that the pilot error rate
for the AV-8 is around twice what it is in the F/A-18 (an aircraft
noted for the heavy workload it imposes on the pilot - a significant
number (in fact it's the highest single cause) of F/A-18 Class A
accidents are CFIT). So the AV-8 is significantly harder to fly. You
also see a mechanical accident rate of something like eight times that
of the F/A-18, so the AV-8 is *hugely* less reliable. This is
probably only to be expected from the significantly more mechanically
complex AV-8 (hover is hard), particularly given the much older engine
technology and the fact that there is only one engine.

As a benchmark, the old F-8 Crusader used to run an accident rate of
around 14/100,000 flight hours.

--
"Insisting on perfect safety is for people who don't have the balls to
live in the real world." -- Mary Shafer, NASA Dryden

(Moggycat) wrote:

:"Stephen D. Poe" wrote
:
: "They know this drill all too well because the Harrier is the most
: dangerous airplane flying in the U.S. military today.
:
:Correction on behalf of Peter Rieden and co:
:
:"The Harrier is flown by some of the most dangerous pilots in the U.S.
:military today."

Except it's not true, since over 2/3 of all Harrier Class A accidents
involve mechanical faults in flight rather than pilot error.

(That's over 8/100,000 flight hours, so even if you eliminate ALL
human error from the Harrier numbers, the accident rate is still
almost 3x the *total* accident rate for the F/A-18.)

--
"Insisting on perfect safety is for people who don't have the balls to
live in the real world." -- Mary Shafer, NASA Dryden

Fred J. McCall wrote:
Iain Rae wrote:

:Fred J. McCall wrote:
: Peter Skelton wrote:
:
: :On 8 Aug 2003 04:42:50 -0700, (Moggycat) wrote:
: :
: :Correction on behalf of Peter Rieden and co:
: :
: :"The Harrier is flown by some of the most dangerous pilots in the U.S.
: :military today."
: :
: :It's a training problem - marines don't have to take perisher.
:
: Then explain how over 2/3 of the major accidents are mechanical
: failures and not human failures, if it's a pilot training problem.
:
:well, there's no need to limit the blame to pilots, from the article in
:question:
:
:"The accident inquiry concluded that a circlip, a semicircular fastener,
:was incorrectly installed by mechanics on the gas turbine starter,
:setting off a chain reaction that led to the engine failure."

So the game is to just keep changing the statement when the preceding
one proves up wrong?
well, the statement was
"It's a training problem - marines don't have to take perisher."

you're the one who limited it to pilots.


Yeah, that shows a lot of intellectual integrity....

Well, if that's how you want to tar yourself go ahead.

Felger Carbon wrote:

"benjym" wrote:

What we do know is that the harrier replacement (JSF) will

incorporate

innovations to reduce v-stol pilot workload currently under
development here in the UK. A Harrier prototype has been fitted

with

fly-by-wire controls and a flight management computor capable of
practically landing the plane automatically - the most dangerous
regime of v-stol flight. Controlling parameters like nozzle angle,
thrust, pitch, speed, landing gear etc the computor can land the
aircraft from approach configuration with one button push from the
pilot. Maybe this kind of thinking could be applied to the V-22?


When the V-22 Osprey is landing combat grunts on a hot LZ, do you
really want a computer landing the aircraft slowly and safely? If
not, how and when do you train the pilot to land quickly under those
circumstances?

Why not let the computer(s) land it quickly and safely? A trite comment
admittedly but if you have a philosophical problem with automation
rather than knowledge of the actual technical difficulties then consider
that "driver aids" in racing cars allow the drivers to extract
considerably more performance from their vehicles and be far more
aggressive with them than if they had no help. You are right to allude
to training needs. If you're going to automate something then it had
better work under all likely circumstances, because otherwise its
dominant effect is to adversely impact operator currency for occasions
when it really matters. I suspect that in the "hot LZ" situation you
describe that you'd want a pilot controlling things, with automation to
keep everything within controllable limits. The pilot can then do what
humans do well, assess the situation, make decisions and innovate,
whilst being spared the jobs we're not so good at, like keeping a
variety of little instrument needles out of a variety of red-zones
whilst being shot at.

"The Harrier is flown by some of the most dangerous pilots in the U.S.
military today."

That's what they'd say, too.

In article , Fred J. McCall
writes
Now, the mechanical rate shouldn't come
as a surprise to anyone with two neurons to rub together, given that
the AV-8 is older technology, more mechanically complex to begin with,
and only has a single engine so any engine failure pretty much toasts
you.

VSTOL JSF has only one engine and is even more mechanically complex.

--
John

On Sat, 09 Aug 2003 08:11:18 GMT, Fred J. McCall
wrote:

So the game is to just keep changing the statement when the preceding
one proves up wrong?

Yeah, that shows a lot of intellectual integrity....

Why was it necessary to take a discussion of facts and turn it into a
discussion of rhetoric?