I have a question for anyone familiar with flying the 747-200.

According to news stories in the media reporting the crash of a
MK Airlines 747-200 freighter at Halifax Canada awhile ago, the
investigators found that the airspeed was some 55 kph low. It was
noted that the engines had been operated at a power 'inconsistent
with the a/c weight' (as if the engines are normally operated at
a power governed by the a/c weight during takeoff).

Is this true for this a/c?

I've never heard of this. Any a/c that I'm familiar with
certainly don't modulate takeoff power according to their weight.

Is it done on the 747?
--

-Gord.
(use gordon in email)

<< I have a question for anyone familiar with flying the 747-200.
>><BR><BR>

The 747 with or without the tailhook??

Sorry, just a little holiday humor. Ohh so many guys here that are flying the
big winged buses, wondering about their future.
P. C. Chisholm
CDR, USN(ret.)
Old Phart Phormer Phantom, Turkey, Viper, Scooter and Combat Buckeye Phlyer

Gord Beaman > wrote

> I've never heard of this. Any a/c that I'm familiar with
> certainly don't modulate takeoff power according to their weight.

It can be done for most all jet transport category aircraft.
It is called the "reduced takeoff thrust" procedure. Most
airlines have FAA approval to use this procedure in order
to extend engine life. It's all about "creep units", RPM,
and EGT or TIT. Keep the RMP and EGT as low as possible for
extended engine life.
It goes something like this......
From the runway takeoff limit chart, determine the maximum
allowable temperature for the actual weight. Then use that
assumed temperature to determine the takeoff power setting.
This will produce takeoff performance equal to a takeoff at
maximum weight for the actual temperature.
I'll scan the procedure out of my Boeing manual if this is
not clear enough.

Bob Moore
VP-21 VP-46
ATP B-707 B-727
PanAm (retired)

Bob Moore > wrote:

>Gord Beaman > wrote
>
>> I've never heard of this. Any a/c that I'm familiar with
>> certainly don't modulate takeoff power according to their weight.
>
>It can be done for most all jet transport category aircraft.
>It is called the "reduced takeoff thrust" procedure. Most
>airlines have FAA approval to use this procedure in order
>to extend engine life. It's all about "creep units", RPM,
>and EGT or TIT. Keep the RMP and EGT as low as possible for
>extended engine life.
>It goes something like this......
>From the runway takeoff limit chart, determine the maximum
>allowable temperature for the actual weight. Then use that
>assumed temperature to determine the takeoff power setting.
>This will produce takeoff performance equal to a takeoff at
>maximum weight for the actual temperature.
>I'll scan the procedure out of my Boeing manual if this is
>not clear enough.
>
>Bob Moore
>VP-21 VP-46
>ATP B-707 B-727
>PanAm (retired)

Thanks Bob, and that's quite clear, no need to scan it at all. I
just had never heard of it being done before. Seems like a
somewhat unsafe thing to be doing with a high value machine in a
highly critical phase of its flight.

Perhaps 'unsafe' isn't the correct word here, my point is that I
feel that it might be unproductive to operate the a/c closer to
it's maximum capabilities just to save some 'wear and tear' on
the engines? I'd think that you're not availing yourself of that
'extra performance' in case of an engine failure at a critical
time. I suspect that it'd take a hell of a long time to make up
what they lost in that one crash. (not even to mention the seven
crew-members)
--

-Gord.
(use gordon in email)

"Gord Beaman" > wrote...
>
> Thanks Bob, and that's quite clear, no need to scan it at all. I
> just had never heard of it being done before. Seems like a
> somewhat unsafe thing to be doing with a high value machine in a
> highly critical phase of its flight.
>
> Perhaps 'unsafe' isn't the correct word here, my point is that I
> feel that it might be unproductive to operate the a/c closer to
> it's maximum capabilities just to save some 'wear and tear' on
> the engines? I'd think that you're not availing yourself of that
> 'extra performance' in case of an engine failure at a critical
> time. I suspect that it'd take a hell of a long time to make up
> what they lost in that one crash. (not even to mention the seven
> crew-members)

Well, this is just an example of the reality that belies the "safety is
paramount" theory... Reduced T/O thrust and non-optimum noise abatement climb
profiles have been made "standard" to put economics and politics ahead of actual
safety considerations...

There are actually some limited cases (e.g., contaminated runways, to reduce
Vmc) where reduced thrust takeoffs are "safer" than full-thrust takeoffs, but
they are the exception to the rule.

Gord Beaman > wrote

> Perhaps 'unsafe' isn't the correct word here, my point is that I
> feel that it might be unproductive to operate the a/c closer to
> it's maximum capabilities just to save some 'wear and tear' on
> the engines? I'd think that you're not availing yourself of that
> 'extra performance' in case of an engine failure at a critical
> time.

Gord, I post the following excerpt from the excellent book,
"Handling the Big Jets" by D.P. Davies, the Brit who certified
the B-707 in Britian as Chief Test Pilot for the United Kingdom
Airworthiness Authority.

---------------------------------------------------------
The overall safety level of reduced thrust take-offs is
something which bothers some pilots, who believe that the
average exposure to `near critical' take-off conditions
is increased. The proof that this worry is groundless is,
as one would expect of something produced by performance
experts, long and detailed. However, the following is a
brief outline:
When reduced thrust is used for take-off the risk per
flight is decreased because :
(a) The `assumed temperature' method of reducing thrust
to suit take-off weight does so at constant thrust/weight
ratio, and the actual take-off distance, take-off run and
accelerate-stop distances at reduced thrust are less than
at full thrust and full weight by approximately 1 % for
every 3°C that the actual temperature is below the assumed
temperature.
(b) The accelerate-stop distance is further improved by the
increased effectiveness of full reverse thrust at the lower
temperature.
(c) The continued take-off after engine failure is protected
by the ability to restore full power on the operative engines.
Furthermore, although there is inevitably a slight increase
in average risk, this increase is minimised by two factors:
(a) A significant percentage of take-offs are at weights close
enough to R.T.O.W. not to warrant the use of reduced thrust.
(b) The excess margins on lighter-weight take-offs are largely
preserved by the maximum thrust reduction rule.
In any case it is anticipated that more than adequate
compensation will be provided by enhanced engine reliability.
--------------------------------------------------------------

BTW Gord, just in case you are not that familiar with civilian
jet transports, takeoff thrust does not equate to full throttle.
T.O. thrust is set in acordance with pressure/temperature charts
always with some throttle left to account for the hot/high day.


Bob Moore
VP-21 VP-46
ATP B-707 B-727
PanAm (retired)

>
>> I've never heard of this. Any a/c that I'm familiar with
>> certainly don't modulate takeoff power according to their weight.
>

Bob's explination is 100% correct we use reduced Takoff power to save wear and
tare on the engine these engines are running in excess of 10,000 hours before
removal.
I fly a 727 at fedex, We generally fly at weights above the passenger carriers.

The option of max thrust is always availabel but in my case in the 727 the
plane flies fine with engine out at reduced power. Max power is always avilable
then in extremis there is red line power as well as firewall power.
The weird thing is we use a Laptop that is programed with the modex as well as
all the airports and runways we are authorised to operate out of so it is
really easy to compute T/O performance as well as trim setting.The two things
we arn't provided is the takoff distance or a line speed check #.
I asked in training and they really don't seem to think those are things we
need to know. The reason more 727's arn't crashed is because the plane flies
better than the sim.
Sparky

"John R Weiss" > wrote:

>"Gord Beaman" > wrote...
>>
>> Thanks Bob, and that's quite clear, no need to scan it at all. I
>> just had never heard of it being done before. Seems like a
>> somewhat unsafe thing to be doing with a high value machine in a
>> highly critical phase of its flight.
>>
>> Perhaps 'unsafe' isn't the correct word here, my point is that I
>> feel that it might be unproductive to operate the a/c closer to
>> it's maximum capabilities just to save some 'wear and tear' on
>> the engines? I'd think that you're not availing yourself of that
>> 'extra performance' in case of an engine failure at a critical
>> time. I suspect that it'd take a hell of a long time to make up
>> what they lost in that one crash. (not even to mention the seven
>> crew-members)
>
>Well, this is just an example of the reality that belies the "safety is
>paramount" theory...

Yep, I agree...and further, I think they're right to do so too.
I've said this before (and gotten slapped down for it) I think
a/c are too safe now...we need to allow the safety factor to
slowly float downward until it's close to the 'safety factor plus
the financial risk factor of the automobile'. At that point the
passenger will still be much safer in an a/c than an automobile
because of the much higher financial risk factor of the aircraft.
BUT the cost for an airline ticket won't be so prohibitive that
lots of people will drive rather than fly. Or are the airlines
fully utilizing the available airspace in North America therefore
there's no opportunity to increase air traffic?


Reduced T/O thrust and non-optimum noise abatement climb
>profiles have been made "standard" to put economics and politics ahead of actual
>safety considerations...
>
>There are actually some limited cases (e.g., contaminated runways, to reduce
>Vmc) where reduced thrust takeoffs are "safer" than full-thrust takeoffs, but
>they are the exception to the rule.
>

John, I recall that you're a qualified 747 F/E or Pilot so can
you tell me whether replacing aerodynamic trim of the tailplane
with fuel weight to reduce drag during cruise is still being
done?...I never seem to hear of it anymore, also what's the
proper nomenclature for that?
--

-Gord.
(use gordon in email)

Bob Moore > wrote:
>--------------------------------------------------------------
>
>BTW Gord, just in case you are not that familiar with civilian
>jet transports, takeoff thrust does not equate to full throttle.
>T.O. thrust is set in acordance with pressure/temperature charts
>always with some throttle left to account for the hot/high day.
>
>
>Bob Moore

Very interesting Bob, thanks. I certainly won't be arguing with
HIM any time soon and yes, I'm familiar with less than full
throttle 'full power'. I'm very familiar with large radial recips
most of which have very definite power limits well short of the
firewall. But we always used those limits no matter what
conditions prevailed and I didn't know that large jet a/c used
anything less. I gather that the 747 freighter loss at Halifax
Canada had approx. the proper weight calculated but that It was
some 55 Km PH low in speed and that there was some controversy as
to whether he had used the whole runway.

--

-Gord.
(use gordon in email)

(Elmshoot) wrote:

>>
>>> I've never heard of this. Any a/c that I'm familiar with
>>> certainly don't modulate takeoff power according to their weight.
>>
>
>Bob's explination is 100% correct we use reduced Takoff power to save wear and
>tare on the engine these engines are running in excess of 10,000 hours before
>removal.
>I fly a 727 at fedex, We generally fly at weights above the passenger carriers.
>
>The option of max thrust is always availabel but in my case in the 727 the
>plane flies fine with engine out at reduced power. Max power is always avilable
>then in extremis there is red line power as well as firewall power.
>The weird thing is we use a Laptop that is programed with the modex as well as
>all the airports and runways we are authorised to operate out of so it is
>really easy to compute T/O performance as well as trim setting.The two things
>we arn't provided is the takoff distance or a line speed check #.
>I asked in training and they really don't seem to think those are things we
>need to know. The reason more 727's arn't crashed is because the plane flies
>better than the sim.
>Sparky

Thanks Sparky, I appreciate the education...
--

-Gord.
(use gordon in email)

Gord Beaman > wrote

> John, I recall that you're a qualified 747 F/E or Pilot so can
> you tell me whether replacing aerodynamic trim of the tailplane
> with fuel weight to reduce drag during cruise is still being
> done?...I never seem to hear of it anymore, also what's the
> proper nomenclature for that?

We never did the fuel thing in the B-707, but we did try
to keep as much luggage/cargo in the aft hold as possible
in order to accomplish the same thing.

Bob

Bob Moore > wrote:

>Gord Beaman > wrote
>
>> John, I recall that you're a qualified 747 F/E or Pilot so can
>> you tell me whether replacing aerodynamic trim of the tailplane
>> with fuel weight to reduce drag during cruise is still being
>> done?...I never seem to hear of it anymore, also what's the
>> proper nomenclature for that?
>
>We never did the fuel thing in the B-707, but we did try
>to keep as much luggage/cargo in the aft hold as possible
>in order to accomplish the same thing.
>
>Bob

Thanks Bob...
--

-Gord.
(use gordon in email)

"Gord Beaman" > wrote...
>
> John, I recall that you're a qualified 747 F/E or Pilot so can
> you tell me whether replacing aerodynamic trim of the tailplane
> with fuel weight to reduce drag during cruise is still being
> done?...I never seem to hear of it anymore, also what's the
> proper nomenclature for that?

I'm a 747-400 Pilot.

Some 744s were delivered with fuel tanks in the horizontal tail. They hold
10,000 Kg. I have not flown any airplanes with them installed, so I do not know
any fuel management specifics for them.

While it may be possible to "passively" manage the CG by retaining the tail fuel
as long as possible, I don't know if this is authorized. Also, AFAIK, there is
no way to move fuel to the tail tank in flight -- once transferred down, it
stays down.

"John R Weiss" > wrote:

>"Gord Beaman" > wrote...
>>
>> John, I recall that you're a qualified 747 F/E or Pilot so can
>> you tell me whether replacing aerodynamic trim of the tailplane
>> with fuel weight to reduce drag during cruise is still being
>> done?...I never seem to hear of it anymore, also what's the
>> proper nomenclature for that?
>
>I'm a 747-400 Pilot.
>
>Some 744s were delivered with fuel tanks in the horizontal tail. They hold
>10,000 Kg. I have not flown any airplanes with them installed, so I do not know
>any fuel management specifics for them.
>
>While it may be possible to "passively" manage the CG by retaining the tail fuel
>as long as possible, I don't know if this is authorized. Also, AFAIK, there is
>no way to move fuel to the tail tank in flight -- once transferred down, it
>stays down.
>

It's really amazing what poor info one can gather on these ngs
isn't it?...I know for a fact that I've been told by those who
appeared to be authentic 747 aircrew that moving fuel to and from
the tail tank was used to replace aerodynamic fore and aft trim
to reduce drag on long cruise legs. Apparently this reduced the
stability so much that it could only be done with a serviceable
autopilot. And that it was only done during cruise, never for any
other phase of flight.

I understand that the basic reason for the Soviet Aeroflot
aircraft inflight breakup and crash several years ago was due to
the captain's son horsing the controls 'out of autopilot' during
this phase of flight and the subsequent violent motions prevented
recovery until some major structural failure had occurred.

Thanks for the info John, I appreciate it.
--

-Gord.
(use gordon in email)

"Gord Beaman" > wrote in message
...
> "John R Weiss" > wrote:
>
>>"Gord Beaman" > wrote...
>>>
>>> John, I recall that you're a qualified 747 F/E or Pilot so can
>>> you tell me whether replacing aerodynamic trim of the tailplane
>>> with fuel weight to reduce drag during cruise is still being
>>> done?...I never seem to hear of it anymore, also what's the
>>> proper nomenclature for that?
>>
>>I'm a 747-400 Pilot.
>>
>>Some 744s were delivered with fuel tanks in the horizontal tail. They
>>hold
>>10,000 Kg. I have not flown any airplanes with them installed, so I do
>>not know
>>any fuel management specifics for them.
>>
>>While it may be possible to "passively" manage the CG by retaining the
>>tail fuel
>>as long as possible, I don't know if this is authorized. Also, AFAIK,
>>there is
>>no way to move fuel to the tail tank in flight -- once transferred down,
>>it
>>stays down.
>>
>
> It's really amazing what poor info one can gather on these ngs
> isn't it?...I know for a fact that I've been told by those who
> appeared to be authentic 747 aircrew that moving fuel to and from
> the tail tank was used to replace aerodynamic fore and aft trim
> to reduce drag on long cruise legs. Apparently this reduced the
> stability so much that it could only be done with a serviceable
> autopilot. And that it was only done during cruise, never for any
> other phase of flight.
>
> I understand that the basic reason for the Soviet Aeroflot
> aircraft inflight breakup and crash several years ago was due to
> the captain's son horsing the controls 'out of autopilot' during
> this phase of flight and the subsequent violent motions prevented
> recovery until some major structural failure had occurred.
>

Well yes but the aircraft concerned was not a 747
it was an Airbus A310

http://aviation-safety.net/database/1994/940323-0.htm

Keith

"Keith Willshaw" > wrote:

>
>"Gord Beaman" > wrote in message
...
>> "John R Weiss" > wrote:
>>
>>>"Gord Beaman" > wrote...
>>>>
>>>> John, I recall that you're a qualified 747 F/E or Pilot so can
>>>> you tell me whether replacing aerodynamic trim of the tailplane
>>>> with fuel weight to reduce drag during cruise is still being
>>>> done?...I never seem to hear of it anymore, also what's the
>>>> proper nomenclature for that?
>>>
>>>I'm a 747-400 Pilot.
>>>
>>>Some 744s were delivered with fuel tanks in the horizontal tail. They
>>>hold
>>>10,000 Kg. I have not flown any airplanes with them installed, so I do
>>>not know
>>>any fuel management specifics for them.
>>>
>>>While it may be possible to "passively" manage the CG by retaining the
>>>tail fuel
>>>as long as possible, I don't know if this is authorized. Also, AFAIK,
>>>there is
>>>no way to move fuel to the tail tank in flight -- once transferred down,
>>>it
>>>stays down.
>>>
>>
>> It's really amazing what poor info one can gather on these ngs
>> isn't it?...I know for a fact that I've been told by those who
>> appeared to be authentic 747 aircrew that moving fuel to and from
>> the tail tank was used to replace aerodynamic fore and aft trim
>> to reduce drag on long cruise legs. Apparently this reduced the
>> stability so much that it could only be done with a serviceable
>> autopilot. And that it was only done during cruise, never for any
>> other phase of flight.
>>
>> I understand that the basic reason for the Soviet Aeroflot
>> aircraft inflight breakup and crash several years ago was due to
>> the captain's son horsing the controls 'out of autopilot' during
>> this phase of flight and the subsequent violent motions prevented
>> recovery until some major structural failure had occurred.
>>
>
>Well yes but the aircraft concerned was not a 747
>it was an Airbus A310
>
>http://aviation-safety.net/database/1994/940323-0.htm
>
>Keith
>
>
>
Ok...thanks Keith, in the report that I read the tail tank trim
was being used. Are you saying that the A310 doesn't use tail
fuel trim?...and are you familiar with this system?
--

-Gord.
(use gordon in email)

Gord,
Concerning the weight shift and CG movemnt to get better cruise economy. The
MD-11 has that capability and is used operationaly at Fedex. There have been
some problems with the system. The MD is the most unsafe modern transport
catagory aircraft in history.
We had one make a hard landing and we learned after the crash that the wing is
designed to fail before the landing gear does resulting in the wing coming off
and the plane coming to rest upside down.
There have been some problems with the fly by wire lag in the flight controls
that resulted in PIO during the landing. I don't know anything more about the
specifics on these problms but I guess I will learn when I transition to the
Mad Dog in a few years.
Sparky

"Elmshoot" > wrotecom...
> Concerning the weight shift and CG movemnt to get better cruise economy. The
> MD-11 has that capability and is used operationaly at Fedex. There have been
> some problems with the system. The MD is the most unsafe modern transport
> catagory aircraft in history.
> We had one make a hard landing and we learned after the crash that the wing
> is
> designed to fail before the landing gear does resulting in the wing coming off
> and the plane coming to rest upside down.
> There have been some problems with the fly by wire lag in the flight controls
> that resulted in PIO during the landing. I don't know anything more about the
> specifics on these problms but I guess I will learn when I transition to the
> Mad Dog in a few years.

[Keeping a semblance of "military" in the thread...]

So, you're gonna bid the MD-[9]11 so you can git kilt in a civil airplane after
all those years in [E]A-6s?!? Can I have your flight jacket?

>So, you're gonna bid the MD-[9]11 so you can git kilt in a civil airplane
>after
>all those years in [E]A-6s?!? Can I have your flight jacket?
>

John,
Now that you mention it, I must be nuts! Yep when I make the move I will be
chasing the $$ otherwise being in the right seat of the 727 has a lot of
benifits, although some how I spent another holiday away from home since I
ended up in Toronto for T-Day but my wife was very supportive. We just took a
one day delay. Heck after one deployment we had Christmas in Februaury.
Sparky

"Elmshoot" > wrote...
>
> Now that you mention it, I must be nuts! Yep when I make the move I will be
> chasing the $$ otherwise being in the right seat of the 727 has a lot of
> benifits, although some how I spent another holiday away from home since I
> ended up in Toronto for T-Day but my wife was very supportive. We just took a
> one day delay. Heck after one deployment we had Christmas in Februaury.

Well, bigger might get you the $$, but won't necessarily get you home when you
want... I spent T-Day in the right seat of a 747 between LAX and ICN. Somehow,
Australian ribeye at the Seoul Grand Hilton isn't quite smoked turkey. Come to
think of it, though, I was closer to my old Kamakura "home" than I was to my
current home...

On 11/28/04 1:18 PM, in article
, "Elmshoot" >
wrote:

>> So, you're gonna bid the MD-[9]11 so you can git kilt in a civil airplane
>> after
>> all those years in [E]A-6s?!? Can I have your flight jacket?
>>
>
> John,
> Now that you mention it, I must be nuts! Yep when I make the move I will be
> chasing the $$ otherwise being in the right seat of the 727 has a lot of
> benifits, although some how I spent another holiday away from home since I
> ended up in Toronto for T-Day but my wife was very supportive. We just took a
> one day delay. Heck after one deployment we had Christmas in Februaury.
> Sparky

Ah yes, Christmas with the company. Now THAT'S some whacky stuff.

--Woody

(Elmshoot) wrote in message >...
> Gord,
> Concerning the weight shift and CG movemnt to get better cruise economy.
SNIP:

FWIW the L1011 was operated that way - retaining fuel in the #2 outer
tanks moved the CG back in cruise flight to reduce horizontal tail
trim drag. This fuel was used later in flight, of course.
Walt BJ

"Gord Beaman" > wrote in message
...
> "Keith Willshaw" > wrote:
>

>>Well yes but the aircraft concerned was not a 747
>>it was an Airbus A310
>>
>>http://aviation-safety.net/database/1994/940323-0.htm
>>
>>Keith
>>
>>
>>
> Ok...thanks Keith, in the report that I read the tail tank trim
> was being used. Are you saying that the A310 doesn't use tail
> fuel trim?

Nope, I heard that the aircraft was out of trim but
not the details

> and are you familiar with this system?

Sorry I am not

Keith

(WaltBJ) wrote:

(Elmshoot) wrote in message >...
>> Gord,
>> Concerning the weight shift and CG movemnt to get better cruise economy.
>SNIP:
>
>FWIW the L1011 was operated that way - retaining fuel in the #2 outer
>tanks moved the CG back in cruise flight to reduce horizontal tail
>trim drag. This fuel was used later in flight, of course.
>Walt BJ

Thanks Walt, I hadn't heard of using 'wing fuel' that way but of
course it would work, might not be quite as effective as tail
tanks because of less moment being available at the wing tanks
--

-Gord.
(use gordon in email)