Another Weather Radar Question

[TiPwEiGhT]

Hi folks,

I fly the S92 helicopter and have notice we sometimes have a large green painted area off to the far right of the screen(50-60 degrees). First time I noticed it I persumed a rain shower but it remained there after a 180 turn. Since then I have seen it across the whole fleet.

Just wondering what could cause it? My thoughts are possibly ice on the radome during flight? Or some interference cause by electrical components close by?

Any thoughts welcome.

Thanks, TiP

[A37575]

Just wondering what could cause it

Next time you see it take a photo of the radar screen including the settings.

Then send it to the radar manufacturer for their opinion. We did this with a 737 Bendix radar where there was a re-occuring problem with radar range effectiveness. Usual scenario was big CB's first appeared on the screen at 30 miles at high altitude despite the CB being visually seen at 100 miles and closer.

Despite frequent write up of the defect, it was always ground tested - serviceable. The manufacturer (Bendix) replied immediately, advising the problem was certainly water leaking into the radome and at high altitude the inside of the radome was coated with ice causing attenutation. On descent into warmer temperatures the ice melted and the attenuation disappeared. Hence the reason why the maintenance people were unable to fault the radar on the ground.

Following the Bendix letter, the maintenance people looked into it and found evidence of radome surface deterioration allowing moisture to enter. Problem was fixed and the radar was perfect after that.

[TiPwEiGhT]

Thanks for the replies chaps. I will take some pictures and approach the CP or Fleet Tech Pilot with them!

Thanks!

[Centaurus]

I will take some pictures and approach the CP or Fleet Tech Pilot with them!

The advice was to seek the opinion of the radar manufacturer. Chief Pilots are known to give personal opinions on such technical matters when it is expert data you need.

[blind pew]

Yup - go to the manufacturer
Have worked under many chief pilots and technical pilots who got the job because no one else wanted it and not because of ability.
Had a very serious navigation fault over the North Pole on the DC 10.
Resulted in having to disconnect the NAV mode - which wasn't allowed - and intercept the correct track using Lat/Long. Getting it wrong we would have run out of fuel.
Reply to a technically explicit voyage report was a photocopy of a manual page stating that I was not allowed to disconnect the Nav mode above 65 degrees.
Eventually the problem went to Douglas who couldn't answer it either.
Suspect it was a programming glitch as of 30 odd polar flights I did it was the only one that went over the geographical pole.

Most office wallahs are there because they don't like flying and they want weekends off, technical competency ain't in the job description.

[nitpicker330]

So true. I had an X 744 Chief Pilot try to tell me that "0" on the Radar Tilt was the Longitudinal Axis of the Aircraft and not the Horizon as sensed by IRS 3 ( I think it was 3 )

He was a Dick**** of the highest order