Windy MEL: is there a 'limit'?

[Melburnian1]

As the BOM predicted, this afternoon and early evening at MEL has been very windy. Since 1500, northnortheast or for most of the time north wind speeds have ranged from 50 kilometres an hour to 70, with gusts of up to 89, now reducing to 62kmh.

Aircraft are built to counter huge stresses and to operate in many and varied weather conditions.

Delays to inbound flights are typically 20 to 40 minutes with lots of go arounds to the east of Mansfield and a little to the east of Bendigo. Some flights are later, particularly if they did not depart their origin airport on time. MEL is on single runway operation.

Notwithstanding the skill of commercial pilots and the huge amount of testing that all planes go through prior to acceptance to ensure that they can cope in many weather conditions, is there a continuing wind speed, gust or perceived risk of 'wind shear' at which the controllers in the MEL tower might decide to order inbound flights to be diverted and departing flights to be held on the ground?

 

[markis10]

Controllers have no right to order diversions, it's up to the pilot in charge, in the case of Melbourne it's unlikely the wind will get high enough to be over the crosswind limits of most aircraft.

 

[Melburnian1]

markis10, typically what is that 'crosswind limit' in kmh or knots for 737s, 777s, 747s and A380s? I assume that there are some variables.

 

[markis10]

markis10, typically what is that 'crosswind limit' in kmh or knots for 737s, 777s, 747s and A380s? I assume that there are some variables.

As a general rule above 30kts for most aircraft, while taxing limits are in the vicinity of 60kts, were are talking cyclonic winds.

 

[JessicaTam]

Controllers have no right to order diversions, it's up to the pilot in charge, in the case of Melbourne it's unlikely the wind will get high enough to be over the crosswind limits of most aircraft.

Can the controllers limit/prevent take-offs? Or is that also up to the pilot?

 

[markis10]

Can the controllers limit/prevent take-offs? Or is that also up to the pilot?

At the end of the day a pilot has the ultimate say re conditions for take off and landing, an airport may be "closed" but still have aircraft movements.

 

[straitman]

As the BOM predicted, this afternoon and early evening at MEL has been very windy. Since 1500, northnortheast or for most of the time north wind speeds have ranged from 50 kilometres an hour to 70, with gusts of up to 89, now reducing to 62kmh.

Aircraft are built to counter huge stresses and to operate in many and varied weather conditions.

Delays to inbound flights are typically 20 to 40 minutes with lots of go arounds to the east of Mansfield and a little to the east of Bendigo. Some flights are later, particularly if they did not depart their origin airport on time. MEL is on single runway operation.

Notwithstanding the skill of commercial pilots and the huge amount of testing that all planes go through prior to acceptance to ensure that they can cope in many weather conditions, is there a continuing wind speed, gust or perceived risk of 'wind shear' at which the controllers in the MEL tower might decide to order inbound flights to be diverted and departing flights to be held on the ground?

Melburnian1,

Just to be aware of a couple of points of terminology and scales.

The answers from markis10 are all referring to knots which is what the pilots use and you were using kph. (89 kph=48kts, 70kph=38kts and 50kph=27kts)
See: Conversion calculator.

Also look up the terminologies as at Bendigo and Mansfield the a/c are holding or in holding patterns. A go around is when an a/c is on final approach and then applies power and aborts the approach. Whilst some passengers seem to think that holding or a go around is something significant it is all just part of the parcel as far as the pilot is concerned and is nothing to be concerned about. It is something the pilot learns to do as early as during the first few flights of training.

 

[Melburnian1]

straitman, thank you: I was aware of the difference between knots and kilometres an hour. It is odd that the USA and UK (a small minority of the world's population) still dominate aviation bodies and hence the latter has not mandated a change switching to the use of kilometres an hour. Australia metricated in 1973, so apart from occasional lapses in using imperial measurements to describe a person's height (but not their weight), most of us no longer use the 'old scales' - but avaition is subject to international conventions and agreements.

I wasn't referring to the holding patterns other than to show how they were contributing to delays. Thank you for clarification of the finer points. There was at least one missed approach at MEL last night.

 

[straitman]

straitman, thank you: I was aware of the difference between knots and kilometres an hour. It is odd that the USA and UK (a small minority of the world's population) still dominate aviation bodies and hence the latter has not mandated a change switching to the use of kilometres an hour. Australia metricated in 1973, so apart from occasional lapses in using imperial measurements to describe a person's height (but not their weight), most of us no longer use the 'old scales' - but avaition is subject to international conventions and agreements.

I wasn't referring to the holding patterns other than to show how they were contributing to delays. Thank you for clarification of the finer points. There was at least one missed approach at MEL last night.

No worries. Non aviation people often seem to get some of the info out of perspective and I'm just trying to help get it back.

The use of knots actually is more related to 1 degree of latitude being equal to 1 nautical mile and so is relevant to charts and mapping. Visibility, runway distances and many other things in aviation have changed to metric in line with 'everyone else'

Incidentally the change to metrics was over a period from 1970 to 1978 (except currency which was 1966). Significantly 1973 was when schools changed over.

 

[opusman]

1 degree of latitude being equal to 1 nautical mile

One minute maybe, otherwise the planet would only be 360 nautical miles around

 

[straitman]

One minute maybe, otherwise the planet would only be 360 nautical miles around

I'm glad someone undermeant what I stood to say :!:

 

[Magpie10]

All I know it was extremely gusty at the MCG last night, literally had to hold onto my seats for fear of taking off!

 

[medhead]

Actually if you read the national weights and measures act at least some and possibly all imperial measures can legally be used in Australia.

 

[nlagalle]

straitman, thank you: I was aware of the difference between knots and kilometres an hour. It is odd that the USA and UK (a small minority of the world's population) still dominate aviation bodies and hence the latter has not mandated a change switching to the use of kilometres an hour. Australia metricated in 1973, so apart from occasional lapses in using imperial measurements to describe a person's height (but not their weight), most of us no longer use the 'old scales' - but avaition is subject to international conventions and agreements.

I wasn't referring to the holding patterns other than to show how they were contributing to delays. Thank you for clarification of the finer points. There was at least one missed approach at MEL last night.

Nautical Miles and knots isn't related to the US or UK and them still being on the imperial system. In aviation we measure speed in knots, distance in Nautical miles, height in feet and horizontal separation in metres.. And i hope they don't change it from feet to metres in height/altitude. It's much easier that way.

 

[JessicaTam]

Actually if you read the national weights and measures act at least some and possibly all imperial measures can legally be used in Australia.

Whilst some imperial measures can be used, it is only in certain circumstances:

[TABLE="width: 484"]
[TR]
[TD]2.2[/TD]
[TD]foot[/TD]
[TD](a) altitude in aviation; or
(b) vertical separation in aviation; or
(c) submarine depth[/TD]
[/TR]
[/TABLE]

From the National Measurement Regulations 1999 Sch 2 Pt 2

 

[ftm]

Metric is used for vertical separation in China, Russia and the old Russian states. Works quite well. Just different.

Horizontal visibility in the US is also still in miles. But Statue Miles, rather than Nautical.

 

[Jane-Doe]

My VF domestic was landing in Melbourne at 7.30pm on Friday night. Given the warnings, it was not as bad as I had expected. The landing took 35 minutes, and we spent most of that time circling. Very shaky - but no stomach-churning "bounce".

A September landing in Sydney in 2012 gets the award for "shouldn't have been in the air". The tiny Embraer was pulled and jerked in every direction.

 

[scaredeycat]

Air Canada flight 143 (the "Gimli Glider") is a stark reminder of the hazards of confusing imperial and metric measures.

http://en.wikipedia.org/wiki/Gimli_Glider