Ask Captain Lim

Hey Captain Lim,

Well, before I ask you my questions, I have to say that I have been an avid reader of all the FAQ you have answered. It has extensively broadened my knowledge on many aspects of the industry as well as aviation in general, and other knitty gritty theoretical parts of flight.

Well, I am from Singapore and currently undergoing my flight training in Canada. It has taken me a pretty zigzag road to get to where I am right now and I want to move on further from here.

Anyway, I wanted to find out how pilots estimate time enroute to their destination and whether they do it from one checkpoint to another, or is it simply from point A to point B, like how we do it here, using the circular "whizwheel" (a handheld slide rule computer) as they call it, to estimate time enroute as well as from one checkpoint to the next.

I know it is totally computerized for the airline pilots. Do you simply key in the checkpoints and then get it to estimate the time that will take the aircraft to travel from one point to the other with respect to the current groundspeed of the aircraft? Or, is there some arithmetic and thinking required as in the training aircraft?

I believe what we are doing right now is basically to have a feel of what calculation of time enroute is all about and to get a feel of actually calculating the time ourselves, which brings us really to the basics of flying. So, is this the same in the airlines or simply key in the information and get the answers?

Well, I have got another question that I have been trying to find out about by myself. In Canada, we use the METAR's, TAF's, GFA's to get the oncoming weather. I have tried to look that up for many parts of the world, inclusive of Singapore, for their current METAR or TAF but I don*t seem to have come across any.

I have got sites, like weather underground, to give really basic weather information. In Canada, www.navcanada.com is a popular site for all pilots to check and get weather updates. How do we get current weather updates for places like Singapore and other aerodromes around the world?

Last, but not least, I hope to send you more questions. These questions might just be questions that could be chucked aside, but definitely, I have learnt a whole deal more, visiting your website than I could have accomplished on my own.

I hope this website continues to grow for many like-minded individuals like myself who have got flying running through their veins or even the layman who wants to know a little bit about flying or even the industry.

Keep the good work up Captain Lim!

Chopra.

Hi Chopra,

In modern jetliners, position reports are all computerized. Thanks to the FMC (Flight Management Computer) on the planes! You need not have to crack your head when the ground controller asks you for the estimate of a certain waypoint. Yes, I know you need to use your head or the circular whizwheel whilst you are still under training to calculate the estimates. This is all part of the basic training that all aspiring pilots have to go through.

Well, in the actual plane, all you need is to program the routes on the FMC before hand and then key in any additional waypoints as required in flight. The *distance-to* and estimates based on the current wind are instantaneously calculated. How wonderful!

Normally, to get the METAR (a French abbreviation meaning "aviation routine meteorological report) and TAF (Terminal Aerodrome Forecast) of a station, an airline has to subscribe to this service.

However, you can also get the forecast free from NOAA*s National Weather Service Aviation Weather Center - METAR from here and TAF from here. To get the forecasts for aerodromes around the word, you need to know the 4-letter ICAO station identifier. For example, typing "WSSS" in the box for Singapore Changi International Airport, the forecast now is:

WSSS 271530Z 35003KT 310V020 9999 FEW018 SCT070 BKN300 26/25 Q1012 NOSIG

Well, you need to know the codes to interpret the forecast. Very simply, they are as follows:

WSSS = Changi International Airport

271530z = Date and time of report in GMT - 27th December, 1530 hours GMT

35003KT 310V020 = Wind - 350 degrees at 3 knots, direction varying from 310 to 020 degrees

9999 = Visibility more than 10 kilometers

FEW018 = Less than a quarter of the sky covered by clouds with base at 1800 feet

SCT070 = Half sky covered by cloud with base at 7000 feet

BKN300 = Three quarter cloud cover with base at 30,000 feet

26/25 = Surface temperature - 26 degrees Celsius, dew point - 25 degrees Celsius

NOSIG = No significant change in the forecast

Happy flying!