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Avoiding thunderstorms is a simple question of life or death. VFR pilots avoid them visually, and IFR pilots flying in IMC use on-board weather radar to detect and avoid them, it’s that easy. That being said, what is the need for a lightning detector, a.k.a. Stormscope ? Lightning occurs only in mature cumulonimbus, but these clouds also represent a danger for light aviation earlier in their development. Stormscope measures the distance to the strike on the base of the received power, assuming that all strikes dissipate the same energy, which is obviously not the case. Stormscope can take a strong and distant strike for a weaker but closer one, and vice-versa.

As you probably did not guess from the above, I’m a fan of Stormscope, and I’m not alone, given the number of units sold. As for all equipment, Stormscope is as good (or bad) as the pilot using it. Installing a weather radar in a single engine airplane is not easy, as the nose is usually occupied by the engine. The cost and weight of a radar also make it prohibitive for single engine piston aircraft. Single engine turbine is something else, as they are heavier, and operate at higher altitudes. While Stormscope is not a tool to avoid cumulus and CBs while flying IMC, it can bring precious information for strategic planing, and is in some respects better than radar.

It’s operation is easier (see the post from Sam in the links section of this post), and it provides information up to 200 Nautical Miles, on 360 degrees. Radar range depends of altitude, and detection usually covers an area from 45 degrees on the left to 45 degrees to the right. Evaluating the distance to a CB when flying VMC is not easy. Stormscope offers basic ranging, and valuable information about the development of the situation. When the screen becomes too populated with too many dots in the direction of flight, knowing what is going on behind the plane (in the airspace known as “escape route”, or “Plan B”) makes decision making easier.

The first time I changed from a Stormscope equipped plane to another one, I got a surprise: one was gyro-slaved, and the other not. This sounds like chinese to you ? Let me clarify that. When a strike occurs, the Stormscope measures its the range, and relative bearing, to display a dot on the screen. A gyro-slaved device receives heading from the flux-valve, so if the aircraft’s heading changes, the whole display is updated, so the position of the spots remains valid. With simpler (non-slaved) devices, the dots simply stay where they are. If you decide to turn because your Stormscope shows CBs in front, and don’t reset it, it’ll look the same after the turn… Here again, make sure that you know your on-board equipment, before you start your flight.

The picture below shows a classical (gyro-slaved) Stormscope. It is the small screen to the left of the control-colum, below the slip-skid indicator. The buttons control the range, and allow to clear the memory. This aicraft is equipped with a GNS430, but it was not coupled with the Stromscope.

Modern cockpits, like the G1000, allow for a full integration. The strikes can be displayed on the MFD, in a 90 or 360 degrees display, alone, or combined with map, topography, or terrain warnings. If you look in details the inset on the PFD on the second photo, you’ll see the Stormscope symbol, but not strikes (that was a nice day…).

A reminder about glass-cockpit integration. It’s not because strikes are displayed on a nice, wide screen, integrated with other information that the detection is more accurate. All the drawbacks and advantages I mentionned earlier relate to the detection technology (see the wikipedia entry in the links section), not to the display system. A wrong measurement remains wrong, even when displayed on the nicest screen in the world.

Interestingly, the conlusion is one more time the same: know your avionics, or it will kill you. Don’t mistake a Stormscope for a weather radar, know how to use it, build some experience, and you’ll remain on the safe side. This applies to so many things in aviation that it is probably a golden rule…

Read more:

Sam from Blogging at FL250 on using weather radar

AOPA Pilot paper (June 1997) about sparks detection

www.stormscope.net - have a look at the FAQ

Wikipedia, about lightning detectors

Being well prepared is the key to succesful flying. As many “golden rules”, this one is a bit general. With this post, we’ll see how it applies to flights over two hours. If your usual flights are shorter, there are a couple of additional things to consider before launching yourself in a long flight.

First things first, take care of yourself. Get something to drink, and some food if your flight is planned over your usual lunchtime. Dehydration and hypoglycemia can develop rapidly, and there is no room in a cockpit for their symptoms. But don’t turn your plane into a flying snackbar. Too much food and drinks will also have negative effects. Shall I really advise not to forget a “pit stop” before take-off ?

Longer flights require better fuel management, and consumption tracking. When flying short legs, switching tanks at each stop is fine, but this strategy is not adapted to long flights. Don’t forget there is a maximum allowed fuel imabalance. Switch tanks regularly, and don’t forget to note the appoximate remaining fuel, and time of the change. Doing so, you’ll quickly find out if you’re loosing fuel, or consuming more than expected.

While preparing your flight, remember that you’ll be far away from your homebase. If you’re a rental pilot, make sure to have the phone numbers of the club / school / FBO maintenance guys at hand. Do you know the local procedures for refueling away from home ? Bringing some oil is also a good idea, it’s not always that easy to find in remote places. By the way, do you know which oil grade your plane needs ?

With longer flights, the risk of getting a weather surprise increases. While in cruise, keep informed about weather at your destination. If your plane is not fitted with an XM Weather receiver, you can listen to VOLMET frequencies, or ask flight information centers, or air traffic controllers. Shall a diversion become necessary, you certainly want to know it as soon as possible.

Another possible hazard resulting from longer flights is boredom. This is particularly true when flying IFR, but long VFR segments can also be slightly boring. It’s fine to take a small “mental break” periodically, think of something else, relax your brain, but keep focused on your imoprtant pilot’s tasks. And don’t forget that the more demanding part of the flight comes at the end…

Don’t fall in the time trap. A two hours en-route segment does not means that you can postpone the approach briefing and preparation to the last second. You’ll feel really silly if, after two hours with not a lot to do, you get behind the plane because you did not prepare yourself in a timely manner.

I hope these tips will help you, and if you’ve additional ones, feel free to post a comment. I wish you fun, enriching, and safe long flights…

Studying weather is never boring, there are more surprises than rules. I continue to learn, and persist in trying to perfect my forecast skills. Obviously, the surprising nature of weather can be less enjoyable… thus the need for sharp skills.

Here is a chance to impress all of us with your good weather skills. I selected two untypical METARs, and I wait for your comments.

The first one was for Dijon, on the 29th of July 2005: 290500 LFSD 290500Z 32004KT CAVOK 20/19 Q1015 TEMPO 3000 SHRA=

Do you see something unusual ? CAVOK and SHRA at the same time ? How do you explain that ?

Geneva, 20th of December 2005: 302020Z 21004KT 160V240 1600 PL OVC020 M03/M04 Q1013 23490593 TEMPO 1000 +SN VV005

Can you interepret all the information in this METAR without using any reference material ? I’m not referring only to the 23490593, which is a runway report. No, what I find interesting in this METAR is the present weather code “PL”.

The only thing this challenge will bring you is a better knowledge of METARS, and a short moment of glory when the other will read your comments. I admit that I did not knew the PL myself, so when I found it I rushed to my favorite reference booklet, published by the Swiss Federal Office for Meteorology.

If the two questions above are too easy for you, feel free to also comment about which of the “PL” and “IC ” weather codes present the higher risks. Now, the floor is yours, let’s see what you’ll have to say.