The Lancaster as a potential nuclear bomber in 1945

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I've already explained that the one minute referred to the TO run alone. I assumed this would be obvious as this is when the engines are going to be running at full throttle.

Warm up for ten minutes = about 1-1.5GPM/engine or about 40-60IG and then 1 minute max power for TO = 1/60 x 500IG/hr = 8.3IG and then we get between ~50-70IG

Taxi time? And you're running up each engine individually so multiply that by 4 and consider the other 3 engines sitting there at idle
 
I've already explained that the one minute referred to the TO run alone. I assumed this would be obvious as this is when the engines are going to be running at full throttle.

Warm up for ten minutes = about 1-1.5GPM/engine or about 40-60IG and then 1 minute max power for TO = 1/60 x 500IG/hr = 8.3IG and then we get between ~50-70IG

Yeah, but you are burning fuel before then. Make yourself more clear, before you get snarky with people for no reason.
 
Taxi time? And you're running up each engine individually so multiply that by 4 and consider the other 3 engines sitting there at idle

You're trying to argue that WW2 combat mission were impossible because they had to burn 20% of their fuel before TO.
 
Again, how long do you have to run the engines at full throttle to burn 20% fuel? This is a straightforward question.

And how long do YOU think it takes to start up, warm up, taxi, complete ground runs, complete pre take off checks and then taxi into take off position? Forget about the fuel consumption!
 
Yeah, but you are burning fuel before then. Make yourself more clear, before you get snarky with people for no reason.

Fine. Now please answer the question: How long do you have to run the engines at full throttle to burn 20% of the fuel?
 
And this is a straightforward answer. I'm not saying fuel burn is 20%. Care to show me where I did? Thats a straightforward question. Knock it off with the snarkiness.

OK, if fuel burn isn't 20% then why not take issue with that statement? The fact is that no matter how you cut it, fuel burn up to TO will be ~2%.
 
Some data I dredged out of the books on the Grand Slam carrying Lancaster, which might help understanding the issue regarding operating in an overloaded situation - and let's face it, the Lancaster's MTOW did increase carrying the Grand Slam, but not all Lancasters could carry the Grand Slam, only specially modified ones.

Take off figures for the B.I Special with an MTOW at 72,000lbs - note, this is for information only and not designed to prove a point - I've been adding these snippets about the Special Lancs because they are very different to normal service aircraft owing to the modifications made to them.

Take off at 72,000lbs, 1,080 yards, with +18psi boost, 3,000 rpm and 20 deg flap. Landing at 60,000lbs, 1,070 yards, with full flap. Estimated tropical summer conditions increase these distances by 25%.

With a weight of 70,000lbs, max rate climb is 590 fpm at MS gear and 370 fpm at FS gear. Full throttle height MS, 10,300 ft, FS, 16,200 ft. Tropical summer conditions show a marked reduction in these figures: 370 fpm at MS gear, 170 at FS gear. Full throttle height 8,800 ft MS, 14,700 ft FS. These figures are based on ICAN standards.
 
OK, if fuel burn isn't 20% then why not take issue with that statement? The fact is that no matter how you cut it, fuel burn up to TO will be ~2%.

I explained that in post 511. You would know that if you would read first, think, then respond. My issue was not with the fuel burn. I don't know if it is between 2% and 20%, which I stated in post 511. I took issue with your 1 minute to take off post, and that is what I was commenting on.

Your stuck on this high all mighty attitude, and don't realize that maybe you need to communicate your thoughts better instead of getting an attitude with everyone that comments to you.
 
OK, if fuel burn isn't 20% then why not take issue with that statement? The fact is that no matter how you cut it, fuel burn up to TO will be ~2%.

It was me who said 20%, not Adler. I have explained why I mentioned 20% and you've taken it in a completely different direction.

I'll repeat it so you get it this time:

With aircraft that are heavily laden, around 20 percent of their total fuel load is used just to get off the runway (a value roughly calculated in a class exercise using a 747, its total fuel load and its MTOW versus its speeds and acceleration).
 
Hello, where did I say 20%????

Where did I say you did? I am asking a straightforward q
Also remember for what its worth, takeoff power does not stop once the wheels leave the ground. You have to think of climb out too.

Note to a specific person: no mention of 20% fuel burned.

Do you agree with this statement from post 533?

"With aircraft that are heavily laden, around 20 percent of their total fuel load is used just to get off the runway..."
 
I do not know if this will help?

In some of the Bomber Command operational records I have found, the usual time on the ground from engine start to the start of the TO run was considered to be a minimum of 20 minutes for bombers operating in formations. However, the planners were supposed to use a ground time running of 30 minutes as a minimum to take into account that not all WUTOs went according to plan.
 
I do not know if this will help?

In some of the Bomber Command operational records I have found, the usual time on the ground from engine start to the start of the TO run was considered to be a minimum of 20 minutes for bombers operating in formations. However, the planners were supposed to use a ground time running of 30 minutes as a minimum to take into account that not all WUTOs went according to plan.

Interesting and although I threw the 20% figure in there, I'm backing away, but this, from a purely informative position is interesting and demonstrates the time required to get these big birds into action. It also explains that after WW2, Bomber Command got former Fighter Command guys in to train bomber crews into the quick reaction mindset of getting airborne within a few minutes, with GPUs and ground handlers at the ready at dispersal pans next to the runways.
 
Where did I say you did? I am asking a straightforward q


Do you agree with this statement from post 533?

"With aircraft that are heavily laden, around 20 percent of their total fuel load is used just to get off the runway..."

I am really getting tired of this. I already stated I do not know in post 511. I never took issue with your fuel burn percent. Do you understand that??? I have no dog in that fight. Without doing fuel burn calculations I do not know. If I was a betting man, I would not bet at 20%, but I can see it being higher than 2% for a heavy 4 engined aircraft.

But yeah I agree with 533, in that I never said it was 20%. Kapeesh? Or do you wanna keep the snarkiness going?
 
Where did I say you did? I am asking a straightforward q


Do you agree with this statement from post 533?

"With aircraft that are heavily laden, around 20 percent of their total fuel load is used just to get off the runway..."

I'll answer your question - YES! If we're talking large turbine aircraft like a 747, B-1 or a B-52 considering taxi and run-up times

So now a straightforward question AGAIN!

How long do YOU think it takes to start up, warm up, taxi, complete ground runs, complete pre take off checks and then taxi into take off position? (a normal WW2 bomber)
 
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