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Windy!

I wonder who that Swedish law applies to. It is not an ICAO difference listed in their AIP, so I suspect it might apply to aircraft registered in Sweden.

If it applies to aircraft flying in Sweden, how am I supposed I know about it?

Biggin Hill

Not to worry, it applies to Swedish licensed pilots.

ESSB, Stockholm Bromma

Peter, it's enforced the same way as everything else in aviation, through accidents...

I should have been more clear to explain that the rule is applicable to license holders in Sweden, not visiting aircraft and their pilots.

ESSB, Stockholm Bromma

A rather old C172 I flew many years ago listed a max crosswind of the usual 15 KT in the LIMITATIONS section of the POH. It is the only one a have seen with that. It was very occasionally a nuisance since one could not always plan on the wind staying below that limit for landing. In reality, of course, that C172 was handling no different from all the C172s with 15KT max demonstrated instead of a hard limit. Of course Krister has a good point about max demonstrated crosswinds being there for a reason, but they do come in different flavours. The TB-9 for instance, has the same 25 KT max demonstrated as the TB-20, which has the same wing but is much heavier with higher landing speeds. I used the TB-9 for FI-training and would not like to go to 25 KT across in that type. On the other hand I think most experienced C172 drivers will agree that 15 KT crosswind needs not be regarded as a hard limit. Some Mooneys have a max demonstrated of 11 KT, and while they are not the best types for crosswind they are luckily not that bad. And the Grob 109 has a max demonstrated of 11 KT which it handles well with the wind from the left, but in a take-off with the wind from the right a XWC of 7 KT is a handful. What all this sums up to for me is that there is no substitute for proficiency on type.

huv
EKRK, Denmark

Perhaps some further explanations are due.

When planning a flight, performance calculations for the departure airport and destination airport shall be completed, and this includes wind. If the actual/forecast xwind at the expected time of departure/arrival exceeds that listed as max, or max demonstrated, a pilot may (should) not depart.

On take-off one simply waits until the wind is within limits. On arrival, if the wind is greater than max and exceeds the forecast the pilot may still attempt a landing, or better divert to his alternate listed in the operational flight plan.

The idea is that good planning should help you to achieve the golden rule: "A superior pilot uses his superior judgement to avoid the need to demontrate his superior skills."

I've witnessed an accident with a C172 where the xwind component was 5 knots (max, maybe less) and the pilot still managed to depart the runway sideways and collide with a fence... So much for rules.

ESSB, Stockholm Bromma

Krister, am I right that your point is that "max demonstrated" should be treated as a limitation? I think that is a very good idea generally. But my point was that sometimes "max demonstrated" is not always the best indication of the actual cross-wind performance of the aircraft. When I come to think about it, I think that the C172 POH actually states specifically that the "max demonstrated cross-wind component should NOT be regarded as a limitation" !

In which case it appears there is a contradiction between the POH and Swedish law :-)

huv
EKRK, Denmark

I think the reasoning is that a testpilot demonstrated to this "limit" and private pilots aren't test pilots so should stay within the numbers demonstrated

There is a design requirement to demonstrate crosswind capability of .2 Vso at a minimum. Manufacturers are required to demonstrate this capability for certification, and therefore state in the POH that this has been done. There is no liability incentive for the manufacturer to provide a faster wind speed value in the POH, as that faster speed is not required for certification. If 15 kts is required, and demonstrated, but Cessna says, hey, the plane can still do 25 kts, and someone runs off the runway at 18 kts, Cessna is needlessly in court for it. It's easier to just demonstrate what is required and state that.

If a pilot wishes to remain within the demonstrated value, that's fine (as long as they maintain the skills to handle crosswinds within demonstrated). A pilot might also choose to limit themselves for gross weight, or C of G position, if their self imposed limits are more conservative.

But, neither that (nor Sweden) should limit a pilot who would like to fly the aircraft in a faster crosswind, where the pilot and aircraft are capable.

Home runway, in central Ontario, Canada, Canada

It's easier to just demonstrate what is required and state that.

True, though a savvy buyer might well choose a plane with a max demo of 25kt over one with a max demo of 15kt.

I certainly would - having seem the dramatic difference it makes to the ability to go somewhere. Since 2002, zero trip cancellations due to crosswind.

Whether I would have cared in 2002, I don't know. Probably not, as I would not have known what a huge difference a 1300nm range has over say 900nm, or a 20k ceiling over say a 16k ceiling.

Socata had to demo only 12kt on the 0.2Vso basis, yet they chose to publish 25kt.

Administrator
Shoreham EGKA, United Kingdom

But, neither that (nor Sweden) should limit a pilot who would like to fly the aircraft in a faster crosswind, where the pilot and aircraft are capable.

Ah, yes but, how do you know that you're capable? You need to try, so essentially you become a test pilot... Just to clarify, the limitation applies to Private Pilots, and planning as it were. So, yes you can fly at higher winds, but you're not allowed to plan for it or depart into such conditions.

Many books say "Max demonstrated (but not limiting)" but in this case that last statement is overruled.

@huv, yes in a way because unless the wind is below the limit you have no business being airborne in the first place, i.e. that is the way the regs are written. BUT, if for some reason you accidentally find yourself in conditions exceeding the limitations you must still land at some point... And yes, there are times where even the "allowed" limit is beyond the capability of the pilot, as I mentioned.

I'm just telling you how it is. How many countries have a tailwind limitation? It's 5 knots for us...

ESSB, Stockholm Bromma

How many countries have a tailwind limitation? It's 5 knots for us...

Sounds like the Nanny State working overtime.....

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