If an aircraft is sitting on a conveyor belt.. that rotates in the opposite direction to the wheels, at the exact same speed as the wheels, will the plane take off?

I’m 100% with Creaking Door. Who gives a toss about the relative motion of the landscape? For one thing the earth is already spinning anyway, for another the analogy of taking off upstream on a river is also perfect. The issue is undoubtedly all about gaining airspeed and as the aircraft pushes or pulls itself relative to the air all is well. It will accelerate and take off.

But there is a factor that intrigues me, and I seem to be alone in this. The conveyor belt rotates at the same speed as the wheels. It must therefore be the same diameter as the wheels for the wheels and conveyor to be stationary relative to each other. Just picture two cogs, one bigger, one smaller. If the conveyor had a different diameter than the wheel, the wheel would have to skid on the conveyor or begin to rotate around it. Because the conveyor’s rotation is at the wheel speed.

So, if the conveyor is the size of the wheels, a wee bit of a push or pull external to the conveyor (ie. against the air) would see the aircraft roll off the conveyor and it can then do its own thing. Alternatively if the conveyor is of larger diameter than the wheel, all you need to do is rotate the wheels backwards (fit a little electric motor or whatever), and the conveyor will spin, at wheel speed, forwards. Given the conveyor’s larger diameter the aircraft will be accelerated vis-à-vis the air and in due course lift of.

Up, up and away …

And a few Kiwis to keep you Ozzies honest 😉

Heinkel HE-177

There are numerous online citings that the HE-177 Greif (also see thread on this forum) was capable of carrying 6,000kg (13,000lbs). Might take a bit of digging to prove/disprove that. cheers D

Most British bombers flew at night, so perhaps an enemy fighter wouldn’t have been seen at 50 cal range? Meaning for close range night fighting, .303 might have been a better option. A 4 gun turret could fire at upto 4600 rounds per minute, would this be better against a ‘flash before your eyes’ sighting of an attacking fighter?

All sorts of misconceptions in here …

1. RAF Bombers flew at night because they got slaughtered in daylight – in part because of poor defensive armament, in part because unlike the USAAF the RAF didn’t persevere and figure out formation tactics etc., and in part because the aircraft were vulnerable (little or no armour, etc.)
2. Taking learnings from how ineffective rifle calibre bullets were against armoured night fighters and the USAAF’s experience; a two gun .50 cal turret was developed and fitted to some Lancasters later in the war – it packed serious punch and was loved by its crews
see FN-82 turret http://en.wikipedia.org/wiki/Nash_%26_Thomson
and a surviving Mark VII Lanc http://www.raafawa.org.au/wa/museum/lanc/history.htm
3. The whole issue of firepower was nevertheless of relative minor importance in the very short duration, predominantly unseen, combats with night-fighters. By far the majority of bombers lost never saw their attacker – read any number of accounts. This particularly so later in the war with the development of schrage musik

cheers D

Various references I’ve read suggest the Herc engined Lanc was liked by its crews. Fast as noted above.

But in part they bought the speed through fuel consumption; I would imagine this would in turn cause a trade-off vis-a-vis the BI and BIII when it came to the distance/fuel/bomb-load calculation. Put that another way, the Merlin engined Lancs would be more “efficient” at their job (dumping bombs more-or-less on the enemy).