How ASA Digital Flight Timer works?

[acuba 290]

hi
i got this timer as present and understand everything except of Approach function. It has 6 and 6 memory fields, but how it works? I don't understand it in manual... In which cases i need this function?

http://www.flightstore.co.uk/images/prod/prop_1_4787.jpg

[acuba 290]

so if it for instrument approach, can you maybe explain me how to use it just to understand? ;)

[IO540]

An N-reg requires a clock installed to be IFR legal anyway.

I used to play with various timers but in the end never used any of them for anything - other than switching tanks and that was only in spamcans whose gauges were useless.

I guess timing approaches is just that: start the stopwatch at the FAF and knowing your GS you know when you should be at the MAP, from the time alone. Very rough of course.

Another, more complicated, scenario is when you are given an approach clearance with the expected time for the approach, from a hold. I've never had to do this, but IIRC one goes around the hold and drops out of it at the appropriate time and commences the approach.

Timing an approach itself is something you will get lots of views on. The view in JAA-land, I am told, is that if you fail to time an approach (any approach) you will fail the checkride. Then I speak to airline pilots and they never time anything... I would time an approach which specifically is timed, but there are only a few of those around (that have no DME alternative). One argument for timing regardless is in case of loss of navigation instruments during the approach, allowing one to go missed.... but then you won't find your way back to the beacon anyway.

[drauk]

acuba 290, for what little it is worth (I wouldn't bother with it for the reasons already given on this thread) the idea is that you set the timer for the approach, in advance of commencing it. You can have it count down from that figure. Or you can not bother setting it in advance and just count up from zero, which is much like what the stopwatch does. If there is more than one timed segment that you need you can put each time in a different memory. There are 12 memories - the distinction between each set of 6 is arbitrary, but it is 6 for destination and 6 for home.

Go to the memory slot you want to set by pressing the approach button and turning the knob, then push the knob and set the time for it. Then when you want to use it go to that same memory slot and push the start button on the top.

Like I said, I wouldn't bother. Just use the stopwatch.

[soay]

Another reason for not bothering is that the beeper on those timers is so feeble that you won't be able to hear it go off. It's also far too easy to accidentally press its buttons, particularly in turbulence.

[englishal]

I use an egg timer or a G1000:)

The reason you time your approach is as as described by IO. You start it at the FAF, when the time reaches that dictated by your ground speed read off the approach plate (i.e. say 2 min 22 seconds at 100kts) you execute a missed approach if you don't have the runway in sight.

You also time your departures, in the US your IFR clearance will typically say something like:

"Climb and maintain 3000, expect 10,000 after 10 minutes"

In which case you start the timer on the take off roll, and if you loose radio contact you continue with your assigned clearance - after 10 minutes you climb to 10,000' etc......

[High Wing Drifter]

There is always the Bendix King ADF countdown timer function, easier to use in the sense that when it hits zero you go-around, a tad fiddly to set up on a bumpy short outbound leg.

IO,
I think you'll only fail a section if you fail to start the timer on an approach that requires it. In my case it was an item for the de-brief that I didn't use it on a DME approach.

[IO540]

or a digital representation := :O

[tangovictor]

slightly different thread i know, however is the asa cx-2 digital pathfinder worthwhile ? vfr uk
thanks
tv