How to detect snow showers with Radar?

[Checks]

Currently flying SPIFR in a helicopter which doesn't have any de-ice equipment (which is standard for civilian helicopters). Once winter comes we essentially become a VFR program until spring.

We have a Bendix/King 2000 radar set in the aircraft. Being an ex-freight doggie, I am very proficient with using the radar to avoid thunderstorms/rain. I am have not however, figured out the best settings to pick up snow showers. Currently flying near one of the Great Lakes and lake effect snow bands are very prevelant this time of year. During the day, it is pretty easy to just look out the window and see and avoid. At night, over rural terrain, it is a different animal. I would love to be able to use the radar to assist in snow shower avoidance.

Anybody have any tips/hints?

 

[FN FAL]

Don't quote me on this, but for some reason, airborne radar isn't going to pick up already frozen precip.

You may want to get one of those new fangled, real time uplink based weather systems for your copter.

 

[EagleRJ]

Snow is just not that reflective on radar. When you're able to paint a snow shower, it will appear as a faint green return close to the aircraft, but by then, you'll probably be able to see it in your lights. Keep the beam tilted as low as you can without painting the ground, since most of the moisture is at lower altitudes in the winter.

The only other thing you can do is watch for obscuration of lights on the ground to avoid the heaviest flurries.

How much ice can helicopters pick up? Is main rotor/ tail rotor icing the main concern, or is it just icing on the canopy?

 

[Checks]

Thanks for the replies. I have been trying to keep the distance to less than 10 miles and the gain all the way up. Tilt with bottom of beam parallell to ground. It has been hit or miss so far.

Never been in icing in a helicopter since most arent certified for icing conditions but I have heard it sucks really bad because the blades pick up ice and then start shedding ice assymetrically. Rotor system gets all out of balance. I dont want to find out for myself

 

[Kaman]

Hello,
In my other life in the military I was an airborne RADAR operator, and typically most of the rf energy will be scattered by heavy snow and little echo will be recieved by the antenna. If you do see snow on RADAR it will appear to have little if any contour and depending on the vintage of the set. The best rechnique is to turn the intensity as low as possible and the gain to where you just see echos on the scope. Again, I operated a RADAR that was tuned to detect objects like a submarine periscope, so it was very sensitive to ground/sea clutter. Features like MTI and FTC will improve a RADAR sets ability to handle in-close returns and pick out moving targets.
As someone mentioned, icing in a helicopter is a VERY bad thing. They have a lot of things sticking out to pick up a load of ice quickly and wiht potentially fatal results. We lost an SH-60B while I was on active duty that picked up ice crossing the mountains between LA and Vegas. Killed all on-board. Even though it was equipped for icing we were not authorized to fly into known icing.

Regards,

ex-Navy Rotorhead

 

[FN FAL]

At night, over rural terrain, it is a different animal. I would love to be able to use the radar to assist in snow shower avoidance.

Anybody have any tips/hints?

Maybe these guys could give you a hint about flying at night with low vis in a non IFR helicopter...http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001212X21657&key=1

One, lake effect snow isn't going to cause you much problems with icing, unless you climb up into the clouds...which are not going to have very high tops anyway.

And Two, with aircraft radar, you are not going to be able to scoot around bands of lake effect snow. You might have a chance of painting wet snow, found in frontal type snow storms where there may be some liquid water ahead of the front and some association with sleet. But even then, you aren't going to be flying a VFR only helicopter during those conditions.

Once again, I'm going to suggest the wx uplink systems that are on the market. They give you radar and satellite products that will show snow showers. And I also recomend the AVIDYNE moving map system or something like it. At least then you got real time ground based radar displayed right in the cockpit along with the moving map of the Avidyne...which displays the position of your aircraft over a VFR sectional or WAC chart.