Altimeter full real.

[IvanK]

Here you go in attached zip a PDF Gravesend included. Revised Formating as well.

It would also seem that the QNH varies with the time of day. Thats what I am seeing on the ATAG server anyway.

[Viper2000]

Originally Posted by IvanK

I think you will find the Brits to use QFE as a general rule.

It very much depends what we're doing.

Gliding, I'll just zero the altimeter as part of the pre-flight checks. This isn't necessarily going to be the same as QFE because QFE is updated in discrete intervals along with the ATIS (though one generally doesn't fly gliders from somewhere which has an ATIS).

But looking at it another way, if you set QFE in a powered aeroplane, you won't necessarily find the altimeter set exactly to zero when you're sat on the tarmac, because real objective of the exercise is to make sure that everybody is at the same height in the circuit so that they can all see each other, and nobody descends onto anybody else's head. Assuming about 30'/mb, and a rate of pressure change of about 1 mb/hour, you might get a 30' error relative to the ground, which is quite acceptable for visual flying. But this means that QFE isn't the same as simply zeroing your altimeter on the ground.

Powered, I'd be inclined to use QFE for flying in the circuit, but otherwise, it makes pretty good sense to use QNH, not least because the regional pressure setting is a QNH.

In the end, this is just a function of the fact that the maps are made by reference to mean sea level as a datum line, because it's effectively universal.

Earlier today I was flying aerobatics in a Bulldog with the altimeter set to QNH for the entire sortie from engine start to engine stop. The obvious advantage is that you don't have to worry about making a mistake when switching between QNH and QFE or vice versa.

[jimbop]

Resurrecting and old thread but thanks for the list IvanK - just what I was looking for!

[VBF-12_Gosling]

Chaps

I have gone a bit further with my Enroute Supplement. 616Sqn now has a Flight Planning Office:
616Sqn Flight Planning Office

There is a fair amount of useful information in the website as well.

Its still not quiet fininshed and there are a few more runways to enter etc...

The lower charts are clickable for printing too.

Gosling
Lt RNVR
616Sqn

[mcler002]

I really need to get into the details of all this stuff (considering ive just purchased xplane 10 and looking forward to microsoft flight) get myself a few aviation books, better controls etc.

Anyway at the moment im trying to get the hang of bombing (in the Blenheim) and i now assume that the figures above (Height differences) also play a crucial role in bombing?

Atm i have created a simple practice bomb route via multiplayer (see attached mission) with a blenheim & he111 @ 10000ft (roughly) and another blenheim @ 19000ft (roughly). So far using the calculations given to me from BlackDog (Thread title - Work out TAS from meters? For bombing) i still appear to be bombing short from the target. So my question is?

a) Should i create a mission where i take off from an airbase? (where i can set the correct altitude)

b) Since my target is Le Touquet airfield, would i need to add/ subtract the difference in altitude? would this make a big difference?

Other than that. I hope in the future that the full mission builder could have both FT/KM and MPH/KPH for the different armies rather than just the 'German' unit measurements

Ross

[mcler002]

Ross

[mcler002]

Did a small test and i managed to hit more or less on target

Will explain later on in the next few days

Cheers

Ross

[jimbop]

Yes, please share. I think many of us are waiting for the patch and hoping it brings bombing goodness! At the moment it is harder than it should be.

[Blackdog_kt]

Originally Posted by mcler002

I really need to get into the details of all this stuff (considering ive just purchased xplane 10 and looking forward to microsoft flight) get myself a few aviation books, better controls etc.

Anyway at the moment im trying to get the hang of bombing (in the Blenheim) and i now assume that the figures above (Height differences) also play a crucial role in bombing?

Atm i have created a simple practice bomb route via multiplayer (see attached mission) with a blenheim & he111 @ 10000ft (roughly) and another blenheim @ 19000ft (roughly). So far using the calculations given to me from BlackDog (Thread title - Work out TAS from meters? For bombing) i still appear to be bombing short from the target. So my question is?

a) Should i create a mission where i take off from an airbase? (where i can set the correct altitude)

b) Since my target is Le Touquet airfield, would i need to add/ subtract the difference in altitude? would this make a big difference?

Other than that. I hope in the future that the full mission builder could have both FT/KM and MPH/KPH for the different armies rather than just the 'German' unit measurements

Ross

I think going above 5000ft with the Blenheim is going to stretch it a bit. It has no autopilot and the higher you are, the harder it is to align the target because the cockpit framing obstructs the view out ahead: by the time you can see the target, the higher you are the less time you have to align it.

It could be possible to bomb from 10000ft or so but you would need other people with you to bomb as a group and saturate the area, as it's not that easy to hit right on the bullseye any more.

As for the altimeter differences, for optimal results yes, they should be taken into account.

What you need to bomb accurately is:

1) Your GS (speed relative to ground): This is indicated (IAS) converted to true (TAS) airspeed at your current altitude and then also corrected for wind. For example, if your TAS is 250mph but you have a 20 mph headwind, you GS is 230mph.

2) Your altitude above the target: This means you need to know your altitude above sea level and the target's altitude above sea level.


So, if i'm flying at 10000ft and bombing a target that is on a hill 1500ft high, i will calculate and use a TAS value for 10000ft (no idea what we can do about wind yet to get GS in the non-automatic sights), but the altitude i will input on the bombsight will be my altitude - target's elevation = 10000 - 1500 = 8500ft.

[bravoalpha]

If the weather goes dynamic you can still use the "basic tools" for bombing: a map, and the stopwatch. From your direction and the IAS, and from your path you can calculate the wind, the GS, and correct your path.
Height is not so easy to figure out if the pressure is changing, but ground objects, roads or areas has a length and with on the map and in the sight. The scale of them gives the AGL.
Of course there could be different wind layers with wind effect on the falling bombs so nothing could guarantee the perfect hit!