ALPHA Halifax Question

[Swanoir]

Hello all

I usually stick to the civil side of things but I'm in the middle of reading 'Bomber Boys' at the moment and wanted to have a go at some bomber flying. I've been enjoying the Alpha Halifax, and in conjunction with the book I've found a renewed respect and sheer awe at what these young lads went through for their country.
Anyway, I've noticed that as soon as I try to climb past 10,000ft the engine power just drops off. I like to think I'm a fairly competent virtual pilot but I can't see what I'm missing. I know the heavies didn't go high by today's standards but a Halifax should comfortably get to at least 18,000ft and presumably past 20.
So my question is, what am I doing wrong?
I have searched the forums here but haven't turned anything up, apologies if this has already been answered.
Many thanks.

[TSR2]

I'm not familiar with the Halifax, but I know we had quite a job getting DG's Mossie up to altitude due to the way the sim handles pistons with superchargers from memory. I know this might sound stupid, but are there any de-icing options on the Halifax?

[Swanoir]

That did cross my mind. I can't see anything on the panel, but I was wondering if I assigned a key/button to de-icing if it would make a difference. But what makes me think that's not the case is that no matter what the weather/time of day it seems that 10,000ft is the magic number. Surely performance drop-off is variable depending on various factors?
Thanks for your help anyway!

[TSR2]

Its very difficult to model on certain engines. The thing that was tricky with the mossie was carb heat. Its automatic on the real aircraft by virtue of where the carbs are situated, but that's a merlin which is a very different beast to the big radial on the Halifax. I'm thinking it might be a super charging issue? Where the Hercules on the Halifax supercharged? Either that or carb / fuel icing.

[EDIT] Yes, supercharged air cooled

[DaveB]

Hiya

It's also worth noting the age of the model you're flying mate.. it doesn't come with all the tricks of the trade you find hidden in more modern models. The real Halifax engines were supercharged and I can't remember such jiggery pokery available on the Alpha model. It is normal for engine performance on conventionally aspirated engines to tail off above 10k and the climb to max bombing alt in a Halifax would have been a slow one.. even with the supercharger engaged and gills fully closed at 15k.

Paul Edwards did an FD for our VA version. Have you tried that? It's designed more for the CMk8/Halton than the Halifax but it may serve your purposes better

ATB
DaveB

[Swanoir]

Thanks Dave, I'll have a look at that. I just tried a flight where I stepped up from 9k, to 10k, then to 12k but I stalled before I made it to 11k! Very strange...
It's not the end of the world but interesting nonetheless.
Thanks again all.

[DaveB]

I've just blown the cobwebs off the VA Halton and took G-ALEF up to 15k without problems. I checked the aircraft weight at 10k and it was still over 1000k over MTOW I can't remember if the original Alpha Halifax has prop/rpm controls but these are important to get the aircraft where you want it to go (the VA version has them). At FL150, I was cruising at around 2100rpm/+2.5 boost. Climb rate throughout was no more than 600fpm. I DID have an FD Brian Withers did for the Alpha Halifax.. I'll see if I still have it

ATB
DaveB

[Swanoir]

I've just taken the VA Halifax all the way up to 26,000ft with no problems, so there's obviously just an issue with the Alpha model. Not a problem the CBFS version is much better anyway!

Thanks again for the help.

[DaveB]

Rgr that mate.. no problem

ATB
DaveB

[cstorey]

Just as a matter of interest, the real life aeroplanes ( both Bristol and RR engined ) had two stage geared superchargers to maintain boost pressure as atmospheric pressure fell off , and AFAIK it was necessary to change from low to high gear at the 12000 to 15000 feet altitude region . I imagine this is difficult if not impossible to model in FS