Hi. I've been starting flights lately from various gates at Dallas/Fort Worth.  When I leave the gate and taxi to the runway, my aircraft comes to a stop in a straight position, but when I engage EPR, the plane begins skidding all over the runway and sometimes doesn't even take off.  How can I fix this?

When I leave the gate and taxi to the runway, my aircraft comes to a stop in a straight position, but when I engage EPR, the plane begins skidding all over the runway and sometimes doesn't even take off.
Are you setting up the CDU/FMC before takeoff? I always enter the V2 speed (from the Takeoff Page in the CDU) in the MCP and I've never had a problem with the 767 not having enough power to take off.

Do you use a joystick/yoke to increase the power before pressing the EPR button and then pull the throttle lever(s) on the joystick/yoke back to idle? If you are pulling the throttle lever(s) back to idle after pressing the EPR button, this will initiate an aborted takeoff - the autobrakes are applied and the spoilers deploy (if you are arming the spoilers before takeoff), bringing you to a stop. When I'm taking off, I line up on the runway, do the before takeoff checklist, the press EPR. I do not use my joystick throttle to start the takeoff run, because at some point I will puul it back to idle and the 767throttles will follow, unless I disable the joystick using the default keyboard command - CTRL+K. A note on arming the spoilers before takeoff - once the throttle levers are more than 20% you can arm them then. Arming them while stopped will most likely cause them to deploy immediately, which may be prevent you from taking off (the 767 might think it's an aborted takeoff).

To answer your questions, I prefer to use the mouse yoke function until the autopilot takes over, and I usually set up the FMC at the gate before pushback.  Thanks for the tips!

trevm wrote on Nov 20^th, 2012 at 1:09pm:

To answer your questions, I prefer to use the mouse yoke function until the autopilot takes over, and I usually set up the FMC at the gate before pushback.  Thanks for the tips!

So how do you throttle up at the start of the takeoff run? F3 or F4? Or is there a way to use the mouse for the throttle as well? It would be news to me if it does, but that's only because I hate using the mouse to control the plane because I always mess it up, the way it sounds like is happening to you when you say "the plane begins skidding all over the runway", that's what happens when I use the mouse. :(

When I taxi onto the runway, I usually disengage the mouse yoke and engage EPR.  This is when the 767 starts to skid.  When I perform a manual takeoff, I use F4 to throttle up.

One more thing:  On many of my 767 flights, the top of descent never appears!  What is going wrong?

trevm wrote on Nov 21^st, 2012 at 9:48pm:

One more thing:  On many of my 767 flights, the top of descent never appears!  What is going wrong?

It's a bug.

It usually happens to me on ILS approaches that are named ILSXXY or ILSXXZ OR if the first altitude constraint in the approach is /XXXXA or /XXXXB (be AT or ABOVE constraint / be AT or BELOW constraint). Although it can do it to me without those contingencies existing, but they are rare. Putting an AT constraint can fix this.

What I do to fix this is: Select a waypoint in the STAR (copy to scratchpad), then "paste" it into the waypoint above it, wait a few seconds, then click on LSK L6 <ERASE (DO NOT click on EXEC) and once I have done that, I get a TD and the 767 will descend and approach like it's supposed to.

I appreciate the help, but I would like to clarify a few things.  I assume a waypoint in the star is located under TRANS, and LSK is the keypad on the FMC.  Is <Erase the clear button, or is it separate?

trevm wrote on Nov 22^nd, 2012 at 1:20am:

I appreciate the help, but I would like to clarify a few things.  I assume a waypoint in the star is located under TRANS, and LSK is the keypad on the FMC.  Is <Erase the clear button, or is it separate?

Line Select Key (the 12 buttons on the both sides of the CDU display screen - 6 on the left, 6 on the right). L6 means Left side 6  (sixth one) from the top.

When you make a change to the Route, after you have ACTIVATED it, you get the green light illuminates on the EXEC button and the <ERASE appears beside LSK L6 to erase the changes and revert it back to what it was the last time you pressed EXEC.

Okay.  The instructions seem fairly simple, and I think that once I know a few more things, I can fix this.  Could you please explain how to copy a waypoint to the scratchpad and paste it into another waypoint?

To copy a waypoint into the scratchpad, click on the Left LSK beside it. That waypoint will now appear in the scratchpad. Now you click on either the Left LSK beside the 5 blank boxes (if you are filling a route discontinuance), OR you click on the Left LSK beside the waypoint that you want to move it to and replace.

Be aware that when you move a waypoint further up the list, all waypoints between the replaced waypoint and the moved waypoint are deleted/removed from the plan! Luckily, it does not take effect until you press the EXEC button, and the <ERASE at LSK L6 is available to undo the move/changes.

Hope you understand the explanation. If not, I'll show you using images.

I know that I must be driving you crazy, and I do apologize.  The images should be the final nail in the coffin.

Go here: Fix for missing T/D in CDU/FMS and have a read. At the beginning, I have used an image to show the Line Select Key (Left and Right). It's also a tutorial, that I have just finished, on how to fix a missing T/D.

I hope it helps.

Okay.  This worked once, and it performed well.  Then, when I tried it again, my heading display showed ----NM until the next leg of the trip.  My route also ends about 6 miles from the airport. What's happening?

trevm wrote on Nov 23^rd, 2012 at 12:40am:

Okay.  This worked once, and it performed well.  Then, when I tried it again, my heading display showed ----NM until the next leg of the trip.  My route also ends about 6 miles from the airport. What's happening?

Are you missing the Approach phase of your flight plan? By that I mean does the flight plan end at the last waypoint in the STAR, and the final few waypoints before the arrival ILS runway are missing?

If that is what you mean, then that will be covered in the next tutorial I plan to do later today.

What I meant was that my route ended a few miles from the origin airport, but I must've made a mistake.  It works fine now.

Thanks for all of your help!

Quick question.  Lots of times when my FMC creates a route based on SIDS and STARS, a waypoint called VECTORS is created, which seemingly terminates the route when I reach it.  Should I delete this waypoint or leave it be? :(

Don't delete the VECTORS in the route. I fly along the VECTORS for about 10nm, then make a turn towards (using heading select) the next waypoint, then when I'm heading towards the next waypoint, I click on it in the LEGS page (copy to scratchpad) then paste back at the top the same page, then press LNAV to follow the rest of the route.