Here’s a post I made on the Taking Flight fear of flying forum discussing what the pilots would be doing prior to departure on an imaginary MIAMI to LONDON HEATHROW flight.  While you are going through the unique pleasures of security, immigration, customs and then shopping in the fabulous departure lounge your pilots are busy…

About an hour before your flight goes your pilots will show up to the airport to study the weather for the flight, and for the destination. They’ll get a full information briefing package from their ground handling agent in Miami, constructed in conjunction with the airline’s flight dispatch department.

The flight plan they are given shows a route chosen based on minimum fuel burn for the flight, chosen from several route options and in consideration of the high-altitude wind forecast for the flight.

Sometimes the forecast will show poor weather at the destination, or the possibility of poor weather (given as a “probability”), and extra fuel may be already planned to cover such eventualities. For example, on your flight to Miami the airplane went into a “holding pattern” (circling, looping, whatever you call it), which requires extra fuel (planned for and carried). Other considerations also come into play, such as the pilot’s knowledge that “holding” is quite common flying into Heathrow not because of weather, but just because it is such a busy airport and aircraft commonly end up in a holding pattern for 15 minutes or so awaiting their turn to land (extra fuel is carried for this expectation).

Quite often the pilots choose to uplift extra fuel based on their own assessment of the risks of weather deteriorating enroute (and several other considerations). The Captain’s right to do this is inviolate, and economic considerations on the price of fuel have nothing to do with it. A good Captain will also seek the opinions of the rest of his pilot crew on the flight. Thus an added safety net exists based on the crew’s own operational experience.

The fuel uplift amount also contains some buffers to cover unforeseen circumstances (such as headwinds stronger than forecast or tailwinds weaker than forecast).

This fuel order is passed to the refuelers who commence refueling, and the catering trucks load the food and drink for the flight, and the toilets are emptied of “juice”. The ground engineers give the airplane a thorough inspection, top up the oils, etc., and sign off the airplane as being in good condition.

As a final series of checks, leading up to the time of push-back, the pilots do a comprehensive series of checks of instrumentation on the flightdeck, and one will do a “walk-around” (walking around the airplane with a flashlight giving it a good visual inspection, looking for very specific “health” items and also just a general “look see” to make sure that the plane is in tip-top condition.

All of this stuff happens EVERY time you fly.

Looking at the destination weather forecast for London Heathrow…

Code:

TAF EGLL 152258Z 1600/1706 27005KT 9999 SCT030
     PROB30
     TEMPO 1604/1607 7000
     TEMPO 1703/1706 8000

we see that the forecast for Heathrow (code EGLL) was produced at 2258 GMT time (called UTC time, or “zulu” time) on the 15th. It covers the 30 hour period from midnight at the start of the 16th (“1600” being 0000 on the 16th), going through to 0600 on the 17th. (because the UK is on summer time, 11.46am is 1046Z, so IS covered by this forecast.)

For the entire period the average wind is forecast to be from 270 degrees at 5 knots (about a 7 mph breeze from the west, “27005KT”), visibility will be in excess of 10km (“9999”), and the cloud layer will be scattered at 3000 feet (“SCT030″… scattered means less than half the sky obscured.

For TEMPOrary periods in the early morning (0400 to 0700) the visibility MAY reduce to 7km (“PROB30″… with a 30 percent probability of this occurring)… a little early morning haze, burning off to a clear day. The same thing is forecast the next morning (8km visibility from 0300 to the end of the forecast period 0600).

So, it looks like a lovely day in London!

From the prevailing wind the pilots would be expecting to land toward the west at Heathrow (into the wind being the preferred option).

In their briefing package they’ll also get an overview of the enroute weather (weather systems, upper level winds, turbulence probability estimations etc).

The pilots also do a lot of “what if” planning, and will look at the weather in Miami (so they know which runway to expect for departure, again into wind being preferable), and the weather at the airports they will pass during the flight (so they always know where they can go if the need arises).

All this while you are enjoying your Chihuahuas at La Carreta!