Take Off N1 Thrust question

[Thomas Richter]

Hey, I rarely do more than 35-40 on the straight! Except maybe in O'Hare when the really really long straights almost demand at least 50 -- and I'm sure I've seen them doing it for real too!

Pete

It seems we need "radar traps" to brake you bit down on Taxi ways

[Ray Proudfoot]

Hey, I rarely do more than 35-40 on the straight! Except maybe in O'Hare when the really really long straights almost demand at least 50 -- and I'm sure I've seen them doing it for real too!

Pete

And I never even mentioned your name Pete! Just as well they don't have Gatso cameras on taxiways

[Ray Proudfoot]

The ATC asks you:"Are you ready for an immediate departure?"
You must have finish all the check lists (and BEFORE T/O) to be really ready.

Once you get the clearance...

From Holding Point you start entering the Main RWY by advancing the Throttle to 40%. Until you line up with the runway the engines should be stabilized. Then TOGA.

So the use of main runway is limited.

Themis

Thanks Themis. Clearly no brakes are applied and checklists are completed in double-quick time.

You've been very helpful, thanks.

[Thomas Richter]

Thanks Themis. Clearly no brakes are applied and checklists are completed in double-quick time.

You've been very helpful, thanks.

You will also find this.
*******************************
To initiate taxi, release brakes, smoothly increase thrust to minimum required
for the aircraft to roll forward and reduce thrust to idle. Under normal
conditions, 45% N1 should be considered the maximum N1 for breakaway
thrust. Do not start a turn until sufficient forward speed has been attained to
carry the aircraft through the turn at idle thrust.
Thrust use during ground operation demands sound judgment and technique.
The air blast effects from the high bypass engines at relatively low thrust can be
destructive and cause injury. Avoid following other aircraft too closely. Jet
blast is a major cause of foreign object damage.
The tendency is to taxi faster than desired. This is especially true during runway
turnoff after landing. The appropriate taxi speed will depend on turn radius and
surface condition. Nose wheel scrubbing indicates excessive steering angle
and/or taxi speed for surface condition. The normal straight away taxi speed
should not exceed approximately 20 knots. Speeds in excess of this, when
combined with long taxi distances, cause heat buildup in the tires. When
approaching a turn, speed should be slowed to the appropriate speed for the
conditions. On a dry surface, use approximately 8 to 12 knots.
===============================
Later .
===============================
SETTING TAKEOFF THRUST
A rolling takeoff is recommended. As the aircraft is aligned with the runway,
the Pilot Flying will smoothly advance both throttles to approximately 40% N1
(thrust settings between 35% and 45% N1 are satisfactory) and allow the
engines to stabilize. The throttle position will be about ¾” forward of idle.
Unrestricted advancement of the throttles can cause asymmetric thrust with
directional control problems, especially on slippery runways.
Caution: The nose wheel steering (tiller) should not be used above normal
taxi speeds (20 knots).
After the engines are stabilized, the PF will manually advance the throttles
toward the takeoff power setting, and engage TOGA when satisfied that engine
acceleration is normal. ....
*******************************

[Ray Proudfoot]

Thanks Thomas. After our tour of G-BOAC Pete D and I spent a short amount of time trying these procedures with the PMDG737-900.

With the aircraft aligned down the runway I advanced the throttles to 40% N1 and after a few seconds engaged TOGA. The engines took quite a long time to reach N1. Longer than seems safe if I'm honest. With a lightly fuelled aircraft it was 2/3 down a 10,000ft runway before we got airborne. I would have expected it to get to Vr around half-way down.

[Peter Dowson]

With the aircraft aligned down the runway I advanced the throttles to 40% N1 and after a few seconds engaged TOGA. The engines took quite a long time to reach N1. Longer than seems safe if I'm honest. With a lightly fuelled aircraft it was 2/3 down a 10,000ft runway before we got airborne. I would have expected it to get to Vr around half-way down.

I was also surprised at this, as it hasn't happened to me that I've noticed -- it is usually too quick and overshoots a bit. Mind you, I'm using FSX now, not FS9.

Of course we both got it wrong today in any case -- as Thomas said

" After the engines are stabilized, the PF will manually advance the throttles toward the takeoff power setting, and engage TOGA when satisfied that engine acceleration is normal."

I do actually manually advance at the same time as engaging TO/GA, but possibly we are both trying to engage TO/GA too early in any case?


Regards

Pete

[Ray Proudfoot]

I was also surprised at this, as it hasn't happened to me that I've noticed -- it is usually too quick and overshoots a bit. Mind you, I'm using FSX now, not FS9.

Of course we both got it wrong today in any case -- as Thomas said

" After the engines are stabilized, the PF will manually advance the throttles toward the takeoff power setting, and engage TOGA when satisfied that engine acceleration is normal."

I do actually manually advance at the same time as engaging TO/GA, but possibly we are both trying to engage TO/GA too early in any case?


Regards

Pete

Hi Pete,

Yes, I was possible a bit too eager to try this during your short stay but I didn't have access to this forum for the precise rules. I will try again and advance the throttles slowly and as N1 approached I'll engage TO/GA.

It wouldn't be as much fun if it worked first time anyway.

PS. I've reviewed the pictures of today's Concorde tour and some are quite good. The one of you sat in seat 2D has come out well. I hope the one I took of you in the captain's seat turned out okay.

Cheers,

[Peter Dowson]

PS. I've reviewed the pictures of today's Concorde tour and some are quite good. The one of you sat in seat 2D has come out well. I hope the one I took of you in the captain's seat turned out okay.

I've had a quick look and I think they are okay. I'll sort out the better pix and email you copies -- at about 2Mb they could mount up but I know you have a good broadband connection so you'll be okay.

Best regards

Pete

[Ray Proudfoot]

I've had a quick look and I think they are okay. I'll sort out the better pix and email you copies -- at about 2Mb they could mount up but I know you have a good broadband connection so you'll be okay.

Best regards

Pete

Thanks Pete. Look forward to seeing them.

Cheers.

[themis]

With the aircraft aligned down the runway I advanced the throttles to 40% N1 and after a few seconds engaged TOGA. The engines took quite a long time to reach N1. Longer than seems safe if I'm honest. With a lightly fuelled aircraft it was 2/3 down a 10,000ft runway before we got airborne. I would have expected it to get to Vr around half-way down.

I've noticed this to my latest flights using PM. (N1 Slow at TOGA) I think Thomas mentioned in a previous post that is a well known bug, and Enrico will fix it soon.

Themis