A hypothetical situation, and a doubt

In article t,
says...



Scuse me.. I'm not a multi driver... let alone a 747 pilot...

but if I lost 25 percent of my power I think that I would notice some
performance loss...


Remember, you are not using 100% power for TOGA, and you have FADEC which will
compensate immediately. Of course you will notice, because the systems will
tell you in unmistakeable terms - but it's a non-event compared with a light
twin, where control is going to present a real challenge.

GF

Are you a multiengine pilot?



"Greg Farris" wrote in message
...
| In article ,
says...
|
|
snip

--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.

| PS. I am not a 747 pilot either, and will obviously
welcome corrections from
| those with more experience. I only state what I believe to
be the case from the
| aviation experience I have, and from what I read and try
to learn from others.
|
| GF
|

Peter Clark wrote:

It was BA which took a 747 all the way from LAX to the UK on 3 after a
loss on takeoff just a few months ago.

Peter,

I'm neither speaking for BA nor indeed know the particulars of the
incident you mention, but if the AutoPilot had been switched on shortly
after rotation and landing gear retraction, chances are that the pilots
wouldn't even have noticed the engine loss if it occurred during the
automatic flying phase, and you'd be unnecessarily harsh on BA. Bob
Moore once related me a fascinating similar occurrence when he was PIC
and had an attractive visitor in the flight deck when one of the 4
turbines of his B-707 went blimp (albeit temporarily) and nobody in the
flight deck as much as realized it. And that wasn't even a modern-day
aircraft. Over to you, Bob

Ramapriya

On 9 Apr 2006 08:38:41 -0700, wrote:

Peter Clark wrote:

It was BA which took a 747 all the way from LAX to the UK on 3 after a
loss on takeoff just a few months ago.

Peter,

I'm neither speaking for BA nor indeed know the particulars of the
incident you mention, but if the AutoPilot had been switched on shortly
after rotation and landing gear retraction, chances are that the pilots
wouldn't even have noticed the engine loss if it occurred during the
automatic flying phase, and you'd be unnecessarily harsh on BA. Bob
Moore once related me a fascinating similar occurrence when he was PIC
and had an attractive visitor in the flight deck when one of the 4
turbines of his B-707 went blimp (albeit temporarily) and nobody in the
flight deck as much as realized it. And that wasn't even a modern-day
aircraft. Over to you, Bob

I wasn't attempting to be harsh on BA, I was just pointing out to the
poster who mentioned being onboard a turnaround in a BA 747 10+ years
ago, that they had appeared to miss reading about the incident on Feb
19 2005 where they continued on from LAX on 3 for an 11 hour flight.
Or the subsequent flight where that same aircraft lost the same engine
6 days later, 3 hours into a 14 hour leg from Hong Kong back to the UK
and continued on.

As a multi-engine pilot, I can't think of any way that you would not
know that one of the engines was failing to produce power for an
extended period of time, autopilot or not. I'm sure Bob can give
details on the 707 incident if he's interested, but even in a light
twin a temporary issue might go unobserved. However, in light twins
(piston engines) it's quite obvious when one completely stops giving
power for an extended period because the autopilot will attempt to use
ailerons to maintain heading, giving a really strange flight attitude,
and it will need to be disconnected to allow the pilot to overcome the
yaw and roll forces coming from the remaining engine while setting
rudder trim, feathering the prop, etc etc etc. If you're hand-flying
it when it stops, the need to stomp on the rudder is a quick giveaway.
As for transport category, I'm not too sure, I'd have to go play
around in a sim since I don't have a type rating yet, but in the case
of the 400 there would minimally be EICAS caution messages and the
conspicuous lack of data in one of the 4 engine readings in the upper
display. Someone more up on the type can tell us whether the yaw
dampers have enough authority to overcome the engine out issue, but
eventually they'd have to dial in rudder trim.

Specifically addressing the incident I was alluding to, they did know.
In both cases, they shut it down themselves, and I seem to recall that
for the LAX takeoff they even declared an emergency, circled for 20
minutes, and then headed out for the UK.

http://www.washingtonpost.com/wp-dyn...2005Feb28.html
http://www.post-gazette.com/pg/05061/465083.stm
http://www.usatoday.com/travel/fligh...itair-la_x.htm
http://www.iht.com/articles/2006/03/30/news/fly.php

Take care.
P

On 2006-04-08, Greg Farris wrote:
[one engine loss]
done by the book. In a 747 you should hardly notice any performance loss.

Depends how heavy the B747 is. There is an 'I Learned about flying from
that' article in one of the books published by Flying magazine where a
B747 lost one engine due to a compressor stall on takeoff out of London
Gatwick. They were at maximum takeoff weight when it happened. They
almost rolled it into a ball - it took them a couple of miles just to
get out of ground effect (one of the passengers recalls looking through
the windows of a nice Georgean mansion as they roared past, with the
trees waving in their wake).

--
Dylan Smith, Port St Mary, Isle of Man
Flying: http://www.dylansmith.net
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de
Frontier Elite Universe: http://www.alioth.net

Dave S wrote:
Scuse me.. I'm not a multi driver... let alone a 747 pilot...

but if I lost 25 percent of my power I think that I would notice some
performance loss...



I am a multi pilot but I've never flown anything bigger than a cabin class twin.
So I asked my father, who flew various large aircraft for the USAF from 1943 to
1967. He wrote:

"There are just two issues involved in losing an engine in a four engine
aircraft.....thrust and control. The C-54 was designed to function almost
completely normally on three engines. I don't remember the actual numbers,
but assuming normal cruise to be 160 mph on four, you might lose as much as
10 mph if one fan went out. IOW, the impact on performance would have been
negligible.

In terms of lateral control, especially near or on the ground, loss of an
inboard would have been preferable to loss of an outboard.

When you got into loss of two engines, it got a lot more sticky if they were
both the same side. If you lost one on each side, it wouldn't make hardly
any difference whether one was inboard and the other outboard or vice versa
as long as you remembered that your operating outboard engine would have a
tendency to want to turn the plane towards the inboard. Apart from that,
you were running essentially a twin with not too much margin of error left
for you."

I assumed if you lost both engines on one side, you'd be in the same situation
as if a twin lost one engine.... you would have an immediate and unmistakable
change in your flight situation requiring some sort of action. What I didn't
know was how much stronger the reaction from a four engined aircraft might be if
it lost an outboard vs an inboard engine.



--
Mortimer Schnerd, RN

VE

Greg F. wrote:

Remember, you are not using 100% power for TOGA, and you have FADEC which will
compensate immediately.

Not using 100% power for takeoff? I don't fly jets but that sounds odd
to me. What T/O power setting are you suggesting is used in a 747? Is
it whatever the engine controller will allow when the power levers are
firewalled?

Also, the FADEC controller will not compensate in the way you think.
IIRC it adjusts fuel flow rate to maintain temps, EPRs & rpm parameters
to stay within limits. It's there to efficiently manage power and keep
a ham-fisted pilot from smoking the engine's hot section. I doubt it
will have any effect in a engine-out go around as it won't allow the
engine to exceed parameters.

wrote

Greg F. wrote:
Remember, you are not using 100% power for TOGA, and you have FADEC
which will compensate immediately.

Not using 100% power for takeoff? I don't fly jets but that sounds odd
to me. What T/O power setting are you suggesting is used in a 747? Is
it whatever the engine controller will allow when the power levers are
firewalled?

Transport Category Jets normally only use 100% power for takeoff if
the weight/temperature/runway require it. Reduced Thrust Takeoffs
are the norm. Reduced takeoff thrust is calculated to provide the
same safety margins as if the aircraft were weight limited on a short
runway using full thrust.

On the B-727, it was APR (automatic power reserve) that automatically
set the engines to full thrust in the event that any engine lost thrust
during takeoff.

Takeoff thrust is achieved well before the thrust levers reach "firewall".
During 25 years of airline jet flying, I never saw the thrust leverd
"firewalled".

Bob Moore
ATP B-707 B-727
PanAm (retired)

Bob Moore wrote:

On the B-727, it was APR (automatic power reserve) that automatically
set the engines to full thrust in the event that any engine lost thrust

during takeoff. snip Takeoff thrust is achieved well before the
thrust levers reach "firewall".
During 25 years of airline jet flying, I never saw the thrust leverd
"firewalled".

I was hoping you'd weigh in on this Bob : )

I'm guessing the pre-FADEC JT3s and JT8s on the 707 & 727 had to be
carefully monitored during an APR enabled takeoff, as they could easily
be overtemped? Nice thing about the FADEC is that it won't let you burn
up the engine. Maybe the newer equipment has a different T/O procedure
than the old birds with respect to thrust lever position?

Will

Gee, now I'm not so worried about just flying behind a single fan!

smackey
C172 pilot