Peter wrote:
I have done a zero-zero departure, with a crazy instructor at Shoreham many years ago, under the hood. It sort of worked, if holding the heading really carefully. Really carefully, unless doing it on the space shuttle backup runway But most GA planes don’t have a slaved compass system which is that accurate.
I’ve done it too, under the hood with an instructor. It’s not that difficult although of course not reliable enough to do for real. You don’t need a slaved compass if you read off the indicated heading on the DI carefully during lineup.
I would never trust the liquid compass (from which a non-slaved DI/HSI has to be periodically reset) to read within the 1 degree or so required to stay on the runway.
All one needs is some metal under the tarmac…
But we have wires crossed. Earlier I was making the point that you need runway lights to take off at night. And as stated, the instant you lift off, you have to transition to the AI, and maintain the pitch, until clear of obstacles. This is for both night and IMC.
Peter wrote:
I would never trust the liquid compass (from which a non-slaved DI/HSI has to be periodically reset) to read within the 1 degree or so required to stay on the runway.
No, but the DG. I wouldn’t trust the published runway heading either as the magnetic variation is constantly changing and the published runway data is not necessarily current within 1 degree.
So you set the heading bug to the whatever the DG indicates during lineup. It can easily read within 1 degree during the take-off run.
Yeah but in a zero-zero departure you can’t see [much of] the runway ahead.
Peter wrote:
Yeah but in a zero-zero departure you can’t see [much of] the runway ahead.
If it was really zero-zero, then you wouldn’t even be on the runway as you couldn’t taxi.
If it was really zero-zero,
Is the visibility ever really zero? Isn’t “zero-zero” just an indication that outside visual references cannot be of use for the maneuver, i.e. take-off or landing?
How do you find the aircraft in the first place 
?
PS: reminds me of one winter night flight at Stapleford, I flew but my car battery went flat as I forgot the lights ON 
Ibra wrote:
I flew but my car battery went flat as I forgot the lights ON
When you have to park your car at the end of the runway with the lights on to have an aiming point on takeoff, it’s definitely a little too dark for flying :-)
Just for the walkaround, one thing at the time ;-)
Sadly that landing with car lights story happened already…
https://www.gov.uk/aaib-reports/aaib-investigation-to-reims-cessna-f172n-skyhawk-g-bgsv
@Peter regarding thermal vision, I believe the acrylic windows will block the extension thermal signatures.
I really came close to buying a thermal scope for engine out scenarios at night, but after testing indoors I realized thermal doesn’t make it through windows, so one would need to hold the sensor out of the aircraft somehow.
One reason I’d love to have an experimental would be to mount a thermal camera externally and a screen in the cockpit for night ops.
