another email virus to watch for

[MisterW]

Inertial navigation. Is that getting me to walk in a straight line?

No I thought it was trying to get SWMBO to read the map whilst you are driving

[Rik]

Here you go, MisterW is asking questions tomorrow http://www.navlab.net/Publications/Introduction_to_Inertial_Navigation.pdf

[Rik]

No I thought it was trying to get SWMBO to read the map whilst you are driving

[MisterW]

Here you go, MisterW is asking questions tomorrow http://www.navlab.net/Publications/Introduction_to_Inertial_Navigation.pdf

Excellent that Glenn. With all that info I think you should all build a system and Rik can test them out on his visit to Suffolk

[Rik]

I've already checked, we like the look of that place. The menu is very good.

[Glenn]

I've already checked, we like the look of that place. The menu is very good.

[Glenn]

Excellent that Glenn. With all that info I think you should all build a system and Rik can test them out on his visit to Suffolk

I'll get on to it.

[Rik]

http://www.idnetters.co.uk/forums/index.php?topic=21892.msg528625#msg528625

[Glenn]

Ah, I wasn't thinking laterally enough 

[Rik]

 

Check out the menu. I think I'd need three trips at least.

[Glenn]

I've just cancelled my cottage in the Peaks, I'm taking you up on your offer. 

[MisterW]

I've already checked, we like the look of that place. The menu is very good

Only minor issue is that the main building is right on the A140, it used to be a coaching house,
All the rooms, however are in 2 buildings away from the road but if you are a light sleeper then you might get disturbed by the
early morning traffic   

[Rik]

My ears go clothlike.

[JB]

Most inertial systems need some other form of position input to correct for this drift factor over the long term.

This is totally correct. In all modern aircraft the INS is just one tool (input) for updating the actual position over the ground. Data from the INS is compared with GPS data and also positional information calculated from numerous VOR's and TACAN's as the aircraft procedes along it's route. It's all about cross checking as is any element of a flight.

When the automated cross checking fails some form of manual intervention is needed to verify data. These days this is extremely rare.

[Rik]

Do they still carry sextants?

[Glenn]

Nimrods did.

[Rik]

I know they used them in WWII, so I was curious whether that complete manual fallback was still standard practice.

[Glenn]

When I left, the Nimrods were using;

GPS
INS
2 x Gyro magnetic compass
Magnetic compass
Sextant
Moving map projector

The main navigation tool was the INS

[Rik]

And if all that failed, they reverted to an AA road map.

[Glenn]

Not as bizarre as you think, if all else fails, use the mk 1 eyeball

[Rik]

I was being serious, if the were over land at the time. Follow a river or road time...

[Glenn]

It how we got home from Bermuda, the plane was ordered home, with only the standby compass (the magnetic compass) and one gyro compass working. We bumped into Scotland around Glasgow, then followed the A9 north.

I have been to Bermuda twice, the 1st time we were hit by a hurricane, then spent 2 weeks getting the plane fixed, new rudder and control rods for the elevators, plus failing electronics due to the humidity. The 2nd time, after we left, on approach in to the Azores, the plane suffered total power failure for around 15 seconds. Was it the triangle?

[Rik]

You mean you'd had too much Bass to drink?

[Glenn]

Before the hurricane, the flight engineer may have had one or two to many sherbets 

[Rik]