my one weakness with landing props are the reserve biplanes and thats it, the monoplane fighters and things are exceedingly easy to land compared to those abominations
I’ve also been in a 747 at TOGA power during a test runup without moving with only the parking brake pulled , your Dash 8 100% did not have it’s brakes on if its moving with only one engine burning.
Yes, you can’t hold a 747 in place continually, brakes only, at max power, but you aren’t going to be zooming down the taxiway like it would be in WT.
Such is standard practice for functionally any heavy load takeoff for any large, multi-engine aircraft during takeoff. If you don’t balance your engines before rolling you are going to yaw all over the place like its going out of style while rolling due to your newfound asymmetric thrust.
Engines degrade at variable rates, such leads to thrust lag and other quirks on takeoff, such has to be dealt with prior to rolling through running the engines slowly up to power before setting takeoff power.
Just take the famed AN-124 for example, ever wonder why they sit on the runway and just scream for a while before taking off? They have to balance the engines and it takes a while to happen. If it was in WT, such would not be possible and it would be rolling the moment they advanced the throttles, but IRL, it can sometimes take minutes at high power for a AN-124 to be ready to takeoff.
Edit : Went back and checked out the actual law of the land an I regret to inform you that your Dash 8 would not be able to be certified for flight as if it cant hold in place with no support and one engine at max power, it fails to meet the basic certification requirements for airworthiness under 14 CFR § 25.735(d).
Brakes and chocks applied - but the air/ground switch was accidentally applied, causing the spoilers to lower and the prop was provided enough lift over the wing to jump the chocks.
Fortunately the mechanic who had towed it into position had left the tractor and was inside in the jump seat… but the jump seat back rest was the cabin door and had been left open - so he ended up being thrown back into the cabin - fortunately with only minor injuries.
The aircraft was repaired by a team from DHC and had specific inspections on those repairs until it crashed in 1995
Usually only to 40-50% N1 or whatever that engine uses, and often done rolling rather than braked.
So nothing at all like trying to stay braked stationary at full power.
As already stated, even without chocks, to be a certified airframe in the US it would need to be capable of abiding by 14 CFR § 25.735(d), which is at a minimum, remaining in place with TOGA power on one engine with only the parking brake applied, no other configuration in play.
From your story, such would mean your aircraft was out of compliance from the getgo.
The only kneeboard I’ve ever used for the heavies I’ve been around was 60 to 75% depending on load and airframe, with a 25 second hold then set takeoff power, this is for C-17s mind you.
To that same end, rolling starts are very much so frowned upon unless you are advancing to takeoff power immediately, I will emphasize right now, DO NOT PERFORM A ROLLING STATIONARY STYLE START IN ANY JET AIRCRAFT!
If you need to balance your engines, the last place you want to be doing such is past the stripes, unless you are keen on having to ask the controller to get back into line.
Color me not surprised that performing a takeoff that has a high chance of you being ridiculed on frequency is not indicative of the actual type of takeoff I’m describing.