Hello thereHope everyone here is doing okay, my first post in a while.Just one question for you?At what times must aircraft operate their strobe lights. I heard that they are not aloud to operate in clouds but this can't be true as the other day on the approach into Manchester with low cloud and very low visibility I saw several aircraft operating their strobe lights. I know that they have them switched on during night time hours but as stated what other times must aircraft operate their strobe lights?RegardsJason

Jason,As I understand it the strobe lights are turned on when entering the runway at your departure airport and turned off when exiting the runway at your destination. I think it's at crew's discretion to turn the strobe lights off in clouds as the water drops in the clouds can reflect the quite bright strobe lights and make more harm than good by blinding the pilots.Hope it helps,

That is my understanding as well and what I was taught during private pilot training. Entering the runway: lights, camera, action (strobe/landing light on, transponder to mode C, roll onto runway).Lee Hetherington, PP-ASEL (KBED)

What does Transponder to Mode C mean, Lee? TA/RA?ThanksFrank

>What does Transponder to Mode C mean, Lee? Mode Charlie = that's to say acrive.Transponders are in standby until leaving the ground.>TA/RA?TCAS (Traffic Collision Avoidance System) mode is set to TA/RATraffic AdvisoryResolution AdvisoryThis mode of the tcas provides both:traffic proximity notificationtraffic collision resolution advisories, means the TCAS provides indications on the instruments to safely avoid threatening traffic.Hope this helps

>At what times must aircraft operate their strobe lights.I seem to remember this is covered in icao doc 4444.Pratically whenever aircraft is airborne.

Thanks, Claudio! When I put "TA/RA" in my mail, what I meant was"Does Mode C mean, set the transponder switch to TA/RA".I should have been clearer.As a matter of interest, in the case of aircraft with predictive windshear, the transponder must be set to STBY before leaving the ramp area. Any other setting will expose ground personnel to radiation hazard. Also, TA/RA should be set before entering the active runway.BR,Frank

Hi Frank,MOde C in the transponder means that the altitude reporting capability is available/active. That is, the controllers on their radar screens will see: your transponder code (or, if they have assigned a code to your flight number or registration, your flt/reg) and your alitude.Best regards

Thanks very much, Enrico.I didn't make my question clear enough initially.So...., :-)I know what Mode C means.I know what TA/RA means.What I was unsure about was what SETTING the transponder to MODE C meant.Claudio answered my question when he said that it means to activate it.Anyway, I'm grateful for all your replies :-)BR,Frank

Hi Frank, please note that Claudio was not fully correct in saying "Mode C=active". There are transponder units with a control panel that has: OFF/TEST/ON Mode A/ON Mode C". Sometimes controllers could ask you to squawk only Mode A (it happens when they have problems with altitude reporting decoding or if your transponder is sending erroneus data).Happy flights !

Oh, I see, Enrico! Thanks for the clarification!This is more complex than I thought.Mode A = Position information only?Mode C = Position, Altitude, Speed?I hear the sound of more posts on the way. :-)BR,Frank

Hi frank,Mode A=simply the Response to the radar interrogation: "I'm xxx and I'm here" (Note that the transponder doesn't say: I'm at xx degrees North, xx degrees East)Mode C=the above + Altitude.Transponders don't give the speed, this is calculated by the radar computer (if able !) as a ground speed between 2 or more successive radar responses.On an ATC radar you could then see (X=radar response indicating position):X - A1401 =mode A, only the squawk code X - ICAFD =mode A, squawk code "translated" in aircraft regX - DLH4019=mode C,"translated" in flt number M220 260 (M=medium,220 ground speed, 260= current level; an up or down arrow could be near the 260 level indicating climbing or descending)Best regards.Enrico.

Right, got that now, Enrico. You're a mine of information! :-)BR,FrankApologies to Jason for taking this thread way off topic!

Have been in Newark recently and what i noticed because will waiting for pushback, that a COA 777 at pushback, had the stobe and beacon on. Similarities i have seen in Zurich too. Some pilots looks like they turn Stobes on at pushback, others and i guess this is the correct way, when they taxi into TO position on runway.Sometimes it is even strange with landing lights. I have a cousin who is A330 captain @ swiss. He does the following:Landing lights on if there is no one in your way you could dazzleStrobes "on" on TO clearanceBeacon "on" when aircraft moves or engines are operatingWing Lights / Logo Lights "on" till end of climb in crowded airspaces for security reason. He's says no rule prohibits you to make you better recognisable for others. Is there a regulation? FAA should then know.If all is security related, then probably is airline policy and procedures.cheersMartin

>>At what times must aircraft operate their strobe lights.>>I seem to remember this is covered in icao doc 4444.>Pratically whenever aircraft is airborne.In the USA, you must have an anti-collision light on from engine start to engine shutdown - if you have beacons and strobes, then just the beacon is ok. If all you've got is strobes (like on some pipers or socatas), the strobes go on before start. If you can, leave strobes off when taxiing, especially at night, since they can mess up other pilots night vision.normal practice is to put as much light on as possible when below 10000 feet to enhance the ability to see-and-avoid collisions.in IMC, you may turn your strobes off if the reflections in the cockpits are a distraction. This is a BIG problem in little planes, less so in larger ones.