# 757/767 Takeoff Performance Issue

**URL:** <https://forum.navigraph.com/t/757-767-takeoff-performance-issue/24604>\
**Category:** Dispatch\
**Created:** [October 21, 2026, 6:43pm UTC](https://forum.navigraph.com/t/757-767-takeoff-performance-issue/24604 "2026-10-21T18:43:09Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ual744](https://avatars.discourse-cdn.com/v4/letter/u/d26b3c/32.png) [@ual744](https://forum.navigraph.com/u/ual744)\
**Post date:** [October 21, 2026, 6:43pm UTC](https://forum.navigraph.com/t/757-767-takeoff-performance-issue/24604/1 "2026-10-21T18:43:09Z")

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Hello, testing the BB757, I came across this issue with the 757/767 takeoff performance calculator in SimBrief. I believe Jason is already going to relay this, but figured I would make a post as well, just in case.

Anyways, Would it be possible to remove the options for TO1 & TO2 in the SimBrief Takeoff performance calculator. Unlike the 737/777, on the 757/767 TO1 and TO2 are NOT fixed derates. Rather, they’re all the exact same as TO just with either CLB1 or CLB2 pre-armed.

Currently, if one selects Optimum and SimBrief spits out a TO2, SimBrief is falsely applying an 80% fixed derate to the Takeoff performance numbers. As you can imagine, this is going to affect distance calculations, runway limits, etc. So, considering that there is absolutely no difference (EPR-wise) between TO, TO1, and TO2 in the 757/767, it would be best if those options were just removed altogether, since they will do nothing but throw off unsuspecting users.

 ![IMG_6604](https://europe1.discourse-cdn.com/flex013/uploads/navigraph1/original/3X/4/1/41ce942bbf88fb7974323dcd8a8fc320d7054ba4.jpeg)

 ![Screenshot_20261021_135637_Chrome](https://europe1.discourse-cdn.com/flex013/uploads/navigraph1/original/3X/e/e/eecde762e6049605aaab29ae2ad2a4193bd22db9.jpeg)