Finished it. (Up to chapter 71 anyways)
http://www.fanfiction.net/s/5782108/58/Harry_Potter_and_the_Methods_of_RationalityHarry angled the broomstick and began accelerating, upward and toward the center of the triangular space. His left hand, gloved to prevent direct contact between his skin and something which Professor Quirrell had Transfigured, held the switch of the control on the Muggle device.
Far above them, distant shouts rang out.
All right, you primitive screwheads!
Aurors on fast racing broomsticks angled out of the sky, diving straight down toward them, faint sparks of light already blazing downward as the first shots were fired.
Listen up!
"Protego Maximus!" shouted Bellatrix in a mighty, cracked voice, followed by a cackling laugh as a shimmering blue field surrounded them.
You see this?
From the decaying pit in the center of Azkaban, over a hundred Dementors rose into the air, appearing to some as a great mass of corpses, a flying graveyard; appearing to another as a conglomerate of absences that seemed to form one vast rip in the world as they slid upward.
This...
The voice of an ancient and powerful wizard bellowed a terrible incantation, and a great blast of white-golden fire shot out of the hole in Azkaban's wall, shapeless for only a moment before it began to form wings.
Is...
And the Aurors activated the Anti-Anti-Gravity Jinx that had been built into the wards of Azkaban, disabling all flying spells whose enchantment had not been cast with the recently changed passphrase.
The lift on Harry's broom switched off.
Gravity, on the other hand, stayed on.
Their broom's upward rise slowed, started to decelerate, began the process of turning into a fall.
My...
But the enchantments that kept the broom pointed in a direction and allowed steering, the enchantments that kept the riders attached and somewhat protected them from acceleration, those enchantments were still functioning.
BROOMSTICK!
Harry hit the ignition switch on the General Technics made, model Berserker PFRC, N-class, ammonium perchlorate composite propellant, solid-fuel rocket that had been mated to his Nimbus X200 two-person broomstick.
And there was noise.
