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RocketRob
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With a dish the size of a dinner plate, its hard to get the beam into a narrow "focus" on any specific part of a cell. It's kind of like your mag light set at the widest beam setting, it just doesnt put all the energy at the point that you would like to see. Therefore you have to tilt up, tilt down, adjust gain and then make an educated guess!
Brother Francis
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Rottweiller
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AAsRedHeadedbro
Havin' fun at the track!
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- Mar 10, 2002
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I agree with most of the above posts.
The radar works fine. Not great, but fine. It definitely requires the most work from the pilot with regard to tilt, gain, range management and interpretation of any of the regional airplanes that I have flown (EMJ, ATR and SF3), but that's because it has the smallest dish of the three. I have never poked my nose into a cell with this radar and I've flown all over the Deep South, the East, the Midwest, and Upper Midwest during thunderstorm season for the last few years in this jet.
The biggest problem I see is lack of real radar knowledge. I can't tell you how many times I've had the other pilot tell me "Look. There's a cell right out in front of us, but this P.O.S. radar's not painting' it!" When I've looked over at his screen, he's been right. However, four feet over to his left, my screen's been painting the cell for the past thirty miles. The difference? The other guy usually had his tilt set too high. This radar will barely paint the frozen upper reaches of a cell at all but it will paint the lower, wetter parts of a cell pretty well. Tilt the radar down into the meat of a cell and stay away from anything painting any color when you're up in the high flight levels and you'll be just fine. It's worked fine for me these past few years.
The radar works fine. Not great, but fine. It definitely requires the most work from the pilot with regard to tilt, gain, range management and interpretation of any of the regional airplanes that I have flown (EMJ, ATR and SF3), but that's because it has the smallest dish of the three. I have never poked my nose into a cell with this radar and I've flown all over the Deep South, the East, the Midwest, and Upper Midwest during thunderstorm season for the last few years in this jet.
The biggest problem I see is lack of real radar knowledge. I can't tell you how many times I've had the other pilot tell me "Look. There's a cell right out in front of us, but this P.O.S. radar's not painting' it!" When I've looked over at his screen, he's been right. However, four feet over to his left, my screen's been painting the cell for the past thirty miles. The difference? The other guy usually had his tilt set too high. This radar will barely paint the frozen upper reaches of a cell at all but it will paint the lower, wetter parts of a cell pretty well. Tilt the radar down into the meat of a cell and stay away from anything painting any color when you're up in the high flight levels and you'll be just fine. It's worked fine for me these past few years.
AAsRedHeadedbro
Havin' fun at the track!
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- Mar 10, 2002
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- 141
The radar itself is good. Its greatest technical limitation is the small antenna.
A ten inch antenna has an 8 degree beam width. So at 60 NM, the beam is 8 miles in diameter. It is difficult to paint detail at ranges beyond about 25-30 NM. In close, the wide beam is less of a factor. Used properly, you can get a decent general picture at longer ranges, but within about 25 NM you can tell the difference between an uncomfortable ride and a dangerous cell.
The real problem is the lack of understanding of how a radar (any radar) works.
At high altitude, tilting out the ground clutter at 35000 feet directs the beam through the upper portion of the cloud. Most of the moisture at these levels is frozen. Frozen precipitation is not a good reflector. Add to that the fact that the wide beam dilutes the finite amount of transmitted radar energy over a larger area, and the hazard goes undetected. The airplane penetrates a 45000 foot tall thunderstorm at 35000 feet and worlds get rocked. Obviously, since the radar never painted the weather the radar is bad, right?
If you take 1.5X altitude in 1000's (35000 feet= 35X1.5=52.5, then round to 50) and tilt the radar to get a ground return at that distance, the beam will be directed through the lower portions if the weather where the liquid precip will reflect efficiently. Any target that appears closer than the displayed ground return is precip. Any target that leaves a shadow in the ground return is dangerous. This works well above about 10-15000 feet with any radar/antenna combination, but is especially important on a 145 with its nearsightedness due to the wide beam.
Below 10000 the ground return is too close to the airplane for this technique to be useful, but you are low enough that under all but the most extreme circumstances (thunderstorms with snow instead of rain do occur) the precip is liquid and will reflect radar energy efficiently. But also, below 10000 you are most likely in the terminal area where the wide beam width is less of a factor. It is helpful to momentarily tilt down to look for attenuation shadows.
That was the long version. The short version is that the 145 radar works perfectly well in the hands of someone who knows how to use it and knows its limitations. You can plan at long range and you can knife fight at close range.
A ten inch antenna has an 8 degree beam width. So at 60 NM, the beam is 8 miles in diameter. It is difficult to paint detail at ranges beyond about 25-30 NM. In close, the wide beam is less of a factor. Used properly, you can get a decent general picture at longer ranges, but within about 25 NM you can tell the difference between an uncomfortable ride and a dangerous cell.
The real problem is the lack of understanding of how a radar (any radar) works.
At high altitude, tilting out the ground clutter at 35000 feet directs the beam through the upper portion of the cloud. Most of the moisture at these levels is frozen. Frozen precipitation is not a good reflector. Add to that the fact that the wide beam dilutes the finite amount of transmitted radar energy over a larger area, and the hazard goes undetected. The airplane penetrates a 45000 foot tall thunderstorm at 35000 feet and worlds get rocked. Obviously, since the radar never painted the weather the radar is bad, right?
If you take 1.5X altitude in 1000's (35000 feet= 35X1.5=52.5, then round to 50) and tilt the radar to get a ground return at that distance, the beam will be directed through the lower portions if the weather where the liquid precip will reflect efficiently. Any target that appears closer than the displayed ground return is precip. Any target that leaves a shadow in the ground return is dangerous. This works well above about 10-15000 feet with any radar/antenna combination, but is especially important on a 145 with its nearsightedness due to the wide beam.
Below 10000 the ground return is too close to the airplane for this technique to be useful, but you are low enough that under all but the most extreme circumstances (thunderstorms with snow instead of rain do occur) the precip is liquid and will reflect radar energy efficiently. But also, below 10000 you are most likely in the terminal area where the wide beam width is less of a factor. It is helpful to momentarily tilt down to look for attenuation shadows.
That was the long version. The short version is that the 145 radar works perfectly well in the hands of someone who knows how to use it and knows its limitations. You can plan at long range and you can knife fight at close range.
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