Ask Captain Lim ~ All about Aviation

Dear Sir,

Thank you for those long and detailed answers!! I would be happy with even shorter answers so as not to take up all your time. I have 2 questions.

1. Why are flights postponed when there is strong wind warnings on the ground. Don't planes regularly fly in winds in excess of 100 mph?

2. If just the wing goes into a big well defined puffy white cloud, will there be turbulence?

Regards,

Tim,
Boston MA, USA.

Hi Tim,

1. Every aircraft model has a cross wind take-off or landing guidelines on the ground. For instance, on a Boeing 777, the maximum crosswind landing guideline is 45 knots (52 mph) on a dry runway but restricted to 35 knots (40 mph) if the sideslip landing technique is used (to ensure adequate ground clearance). So if the forecasted wind is in excess of the above guidelines, flights are delayed or postponed, especially during periods of hurricanes. It is true that planes are flying in wind in excess of 100 mph regularly. This is only when they are in the air but never during take off or landing!

2. Yes, whenever an airplane flies into any clouds, there will be some turbulence. The severity of the turbulence would depend on the type of clouds. Big well defined clouds like cumulonimbus (CB) are the worst whereas clouds like stratus (layer) or cumulus are more gentle. This is because the updraft and downdraft are greatest in the CB or thunderstorm clouds.