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Use your iPad to help with weight and balance calculations

October 22, 2012/in Tips and technique/by studentpltnews

How much can you trust TAFs?

October 12, 2012/in Tips and technique/by studentpltnews

TAFs are a valuable pre-flight planning tool, and they are created by experts who carefully consider a variety of different models and weather reports. But don’t be seduced by the precision of these forecasts. As you conduct your pre-flight weather briefing, consider the TAF a single data point, and nothing more.

Use your iPad to help with weight and balance calculations

October 22, 2012/in Tips and technique/by studentpltnews

How much can you trust TAFs?

October 12, 2012/in Tips and technique/by studentpltnews

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Use your iPad to help with weight and balance calculations

October 22, 2012/in Tips and technique/by studentpltnews

Aviation W&B Calculator makes it easy to precisely the load the airplane

There are many ways to calculate airplane weight & balance with an iPad, but the best method we’ve found yet is with the Aviation W&B Calculator app. Available for $9.99 in the app store, this app makes it a breeze to perform routine weight & balance calculations. After instantly calculating takeoff/landing weight and center of gravity, the app also plots your center of gravity (CG) on an aircraft envelope. The app is especially useful when trying to maximize an airplane’s utility, allowing you to experiment with various loading configurations and instantly display the results on a CG graph.

Entering aircraft data

When you open the app for the first time you’ll see an extensive list of aircraft weight & balance templates, including those for most Cessna, Piper and Cirrus aircraft. The templates include all of the data needed to perform normal calculations, including the standard aircraft arm locations, weight limitations and each aircraft’s unique CG envelope. Don’t worry if your aircraft isn’t listed – there’s an option to ‘Build Your Airplane’ and create a custom template and CG envelope based on the numbers from your POH. And if your aircraft is similar to one of the included templates, you can quickly modify it and create a new template. You’ll also find additional templates for download on the app developer’s website created by other pilots with the app.

The next step is to enter your airplane’s unique data into the aircraft template. The app will prompt you for the tail number, basic empty weight & arm, and an optional value for start & taxi fuel burn. Each template includes the standard aircraft arm for each station measured in inches, and you can adjust these if necessary based on your particular configuration. One thing we really like here is that the app forces you to save this data, which is a big time saver for the next time you need to perform a calculation for that particular airplane.

The Large graph clearly displays CG location

Performing a weight & balance calculation

After saving your aircraft’s empty weight & CG, it’s time to enter the weights of the pilot, passengers, baggage and fuel. The app instantly calculates the zero fuel weight, ramp weight, takeoff weight and CG, and uses red/green color coding on the values to indicate whether or not they’re within limits. The Envelope feature brings up the aircraft’s CG graph, and plots your center of gravity on the grid. A helpful summary screen displays both the the CG graph and weight calculations, along with a small table listing max weights for the aircraft and any applicable baggage limitations. The data here is nicely organized, and you’ll find shortcuts at the top of the screen to email, save or print the information (useful for sharing with a copilot).

When you return to the app for a new calculation you can use the the Tail Number Quick Search function on the home screen to access your saved airplanes. After a few button taps you’ll be at the data entry screen again where you can adjust the weights for that day’s flight. The one feature that seems missing on the home page is a favorites list, where you could select a saved tail number and go right to the weight entry page.

The Aviation W&B Calculator is a must-have for pilots, useful for a wide range of aircraft from single-engine piston airplanes to corporate jets. It makes quick work out of weight and balance calculations, and displays the results on clear, easy to read graphs. And at $9.99 it’s a great deal too. Download the Aviation W&B Calculator app here.

How much can you trust TAFs?

October 12, 2012/in Tips and technique/by studentpltnews

Learning about weather is one of the most important things you can do as a student pilot (or as an experienced pilot, for that matter). And one of the first weather products you’ll encounter is the Terminal Aerodrome Forecast (TAF), which predicts the weather at specific times for many larger airports. This forecast includes wind, ceiling and visibility–sort of like a METAR in the future.

But just like any weather product, TAFs take some interpreting to get the most value out of them. With that in mind, here are some tips to keep in mind when reading a TAF.

TAFs are valid only for the airport area. An airport 25 miles away is pretty close in flying terms, but can be a million miles away in weather terms. Be careful not to extrapolate too much when reading a TAF–terrain or other local conditions may mean that nearby TAF is worthless for your flight. This is especially true with localized weather events, like ground fog or scattered thunderstorms. Technically, a TAF is only valid for the area within a 5 statute mile radius of the airport.
Focus on the trend more than the exact times. The TAF says the ceiling will go from 800 feet to 5000 feet at precisely 10am. Does that mean that a 10:05 departure is a good idea? Probably not. It’s likely that the forecaster will get the trend right (i.e., improving ceilings), but nailing the timing is fiendishly difficult. Focus on the general trend you can expect, but be conservative with timing.
Don’t pretend the weather is better than it is. Put another way, current weather information always trumps a forecast. So if the TAF suggested the wind wouldn’t pick up until later, but the latest METAR says it’s gusting to 25 knots, don’t ignore reality. It’s likely the forecast was wrong. Some pilots have been known to take off in poor weather conditions simply because the TAF (that could be hours old) promised it wouldn’t be that way. Be more skeptical.
The age of a TAF matters. Related to the last point, the older a forecast, the less reliable it is. So the age of the TAF you’re reading matters (and is published right at the beginning of every one). Fortunately, TAFs are released on a regular schedule (0000Z, 0600Z, 1200Z, 1800Z), so you can plan when to check the weather. If it’s 1710Z, go ahead and read the TAF, but check back after the 1800Z forecast comes out. In particular, see what changes the forecaster made–is the trend getting better or worse since the last forecast?

Here’s one final tip–did you know that not all TAFs are created equal? Most TAFs forecast conditions for the 24 hours after issuance. But at certain large airports (usually commercial airports that get a lot of long-distance international flights), the forecast period is extended to 30 hours. This is needed for pre-flight planning when a flight could last 18 hours. Use this to your advantage–a longer range TAF can be helpful for planning the night before a flight.

Also, some airports–including Chicago, Atlanta and New York–update their TAFs every three hours instead of every six hours. This is because of the high volume of flights that use these airports, where a more precise and current forecast is essential for planning. Here again, as a general aviation pilot, you can use this to your advantage if you’re flying close to one of these airports.

Too many pilots have learned the hard way that just because a TAF said it would be good weather, doesn’t mean it actually will be.

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Use your iPad to help with weight and balance calculations

How much can you trust TAFs?

Use your iPad to help with weight and balance calculations

How much can you trust TAFs?

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Use your iPad to help with weight and balance calculations

How much can you trust TAFs?

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