standard procedure?

BA have done 3-engined ferry (no passenger) flights on 747s.

MJ

I sure would like more information on WHY they do it. Taking off with a
inoperative high-bypass turbofan, with a 8 foot fan diameter, is like trying to
take off with spoiler/speedbrakes deployed.
When the first widebodies came on scene (747,DC-10,L-1011) there were
provisions to ferry an extra engine, i.e. 5 engined 747, 4 engined DC-10/L10.
"Even with a huge conical fairing" over the intake, a pilot said it was like
trying to take off with the parking brakes on and spoilers deployed. And it was
most uneconomical, thats why its not done.
I cannot foresee such a circumstance in which BA would fly a special cargo
flight to equip the inop engine with an airworthy fairing, to ferry an aircraft
back to repair/change it.

Longtailedlizard wrote in message
...
BA have done 3-engined ferry (no passenger) flights on 747s.

MJ

I sure would like more information on WHY they do it. Taking off with a
inoperative high-bypass turbofan, with a 8 foot fan diameter, is like
trying to
take off with spoiler/speedbrakes deployed.

The 747SP may be different, but 3-engine ferries on 747s are a 'standard
procedure'.
The crew must be qualified for it and the takeoff settings are different, as
you would expect.
(from the flight manual - as specified by Boeing):
Maximum takeoff weight not to exceed the maximum landing weight -
Flaps 10 takeoff preferred - Speed V1 replaced by VmcG* - typical is 120 kts
F/E sets maximum thrust on inboard engines and 1.2 EPR on operating outboard
engine -
Pilot flying lets aircraft accelerate, increases power on outboard engine
gradually -
Pilot not flying calls "VmcG" - at which maximum EPR is set (by F/E) -
(go-around EPR is used on that engine since speed is above 80 kts)
Pilot not flying calls VR, positive rate, V2 -
Pilot flying calls "gear up" and lets airplane accelerate to V2+30 to call
flaps 5...

VmcG is minimum ground control speed, and the above refers to an inop
outboard. A fairing is not required.

B.

The 747SP may be different, but 3-engine ferries on 747s are a 'standard
procedure'.

As I stated originally, "WHY", in the 21st century, engine changes are a
common procedure. At hub airports, most airlines have engine change crews. A
CF6/RB211/JT9 takes 6 maybe 8 hours to swap one out, and trim it up. In this
day and age, most airlines "pool" big ticket items, i.e. engines.
Major airlines have engines in stock or with a pool on all continents.
And when they don't, its just to cheap to ship one via FEDEX/UPS/Altas,
etc.(about 15K to ship one from Miami to Lima compared to a fully loaded 767
generating 150k, I would think a 747 would double that amount).
North/South America, Europe, Africa, airlines have no problem, in swapping
engines for another airline. I've done it many times for others and I know its
been done for us.
I guess what it comes down to is economics, if you can afford to fly bricks
around because a simple maintenence procedure has to be done at a certain
location, "WHY NOT"

Longtailedlizard wrote in message
...
I guess what it comes down to is economics

And logistics. If the plane goes u/s at a hub or a major airline base then
it could possibly be fixed in a matter of hours as you suggest. Stuck
somewhere in Africa or on a remote island (we're talking 747s), it could be
days just to get the spare there, most likely have to fly out your own mtx
crew etc. etc. All the while you have an AOG which is not generating revenue
and likely disrupting your schedule (few airlines have backups available).
Obviously each case is different, but I can come up with a number of
scenarios where getting the plane home is the best option.

B.

On 04 Oct 2003 22:21:53 GMT,
(Longtailedlizard) wrote:

BA have done 3-engined ferry (no passenger) flights on 747s.

MJ

I sure would like more information on WHY they do it. Taking off with a
inoperative high-bypass turbofan, with a 8 foot fan diameter, is like trying to
take off with spoiler/speedbrakes deployed.
When the first widebodies came on scene (747,DC-10,L-1011) there were
provisions to ferry an extra engine, i.e. 5 engined 747, 4 engined DC-10/L10.
"Even with a huge conical fairing" over the intake, a pilot said it was like
trying to take off with the parking brakes on and spoilers deployed. And it was
most uneconomical, thats why its not done.
I cannot foresee such a circumstance in which BA would fly a special cargo
flight to equip the inop engine with an airworthy fairing, to ferry an aircraft
back to repair/change it.


I don't know why, but I know we have (I'm a BA eng). No doubt it was
cheaper to 3-eng home than to get a replacement out to wherever it
was, factoring the extra time the plane's on the ground as well. It
wasn't a one-off. We've done it at least twice in the past 15 years or
so.

MJ

I don't know why, but I know we have (I'm a BA eng). No doubt it was
cheaper to 3-eng home than to get a replacement out to wherever it
was, factoring the extra time the plane's on the ground as well. It
wasn't a one-off. We've done it at least twice in the past 15 years or
so.

MJ


MJ,
I had no reason to doubt they do it, I was curious as to why. I just
figured, in the day of ETOPS, whatever logistics were in place to get a twin
fly'in again, would also could be used for a 747.
Also, maybe I misunderstood. Someone else wrote that 3 engine ferries were a
"standard procedure".
To me, "standard procedure" is the 12 to 15 engines that are changed weekly,
or one of the 30 or so tire changes daily.
So with the 2 or so ferries, that you seen in 15 years, I gather that when
its done, its done basically as a last resort.
BTW, do you work at LGW? Know any of the mechs over at AA?

On 06 Oct 2003 11:23:38 GMT,
(Longtailedlizard) wrote:

I don't know why, but I know we have (I'm a BA eng). No doubt it was
cheaper to 3-eng home than to get a replacement out to wherever it
was, factoring the extra time the plane's on the ground as well. It
wasn't a one-off. We've done it at least twice in the past 15 years or
so.

MJ


MJ,
I had no reason to doubt they do it, I was curious as to why. I just
figured, in the day of ETOPS, whatever logistics were in place to get a twin
fly'in again, would also could be used for a 747.
Also, maybe I misunderstood. Someone else wrote that 3 engine ferries were a
"standard procedure".
To me, "standard procedure" is the 12 to 15 engines that are changed weekly,
or one of the 30 or so tire changes daily.
So with the 2 or so ferries, that you seen in 15 years, I gather that when
its done, its done basically as a last resort.
BTW, do you work at LGW? Know any of the mechs over at AA?


Yes it was a last resort. Probably no spare engines, which has been a
growing trend over the years. And yes I do work at LGW
co-incidentally, but I don't know any AA guys, sorry.

MJ