Dodgy load sheets????
 

Hi,
I was on a DC10-30 from SEA to AMS the other day. About 7 seconds before Vr there was a sudden and very noticable increase in engine thrust (and noise) which lasted to about 5 seconds after climb started.
I guessed that the assumed thrust required for take-off was too low....possibly due to load sheet innacuracies??
Is this a common occurance that once accelerating down the runway that take-off thrust has to be adjusted once stabilised to give higher thrust (assuming reduced thrust take-off??) to reach V1 early enough.
Any pilots have to switch off EEC during take-off for temporary over-boost?? (p.s. I assume the DC-10 does not have EEC)
Again my questions are from a flying rookie.
Thanks.

"....I guessed that the assumed thrust required for take-off was too low....possibly due to load sheet innacuracies??.........

Wow, if you worked for AAIB you could save them a lot of time and effort.

Generally, in very large aircraft, engine power-up comes in increments, with a "stability-check" and then a bit more and then to the desired N1 limit (among other factors). That might explain your "sudden increase in thrust". Quite soon after takeoff, sufficient power is obtained and minimum safe altitudes are reached and thrust will be cut back, giving engine-efficient climb thrust settings. Doesn't seem out of the ordinary to me, but again, I wasn't there! ;)

Hope this helps,
SFly