Landing above Flight Manual max demonstrated crosswind limit
*sigh*
The usual amateurs come out of the woodwork again. (Not you, JT)
The certification process for the average light aircraft did not require it to be tested on crosswind landings until it breaks. The certification process merely required a demonstrated crosswind number that didm't break the aircraft. Any number will do. Provided it's a demonstrated number, that's good enough from a certification perspective.
I do laugh at those who seem to be suggesting that the certification basis for aircraft that have been around for decades is ascertainable against contemporary test guidance.
The usual amateurs come out of the woodwork again. (Not you, JT)
The certification process for the average light aircraft did not require it to be tested on crosswind landings until it breaks. The certification process merely required a demonstrated crosswind number that didm't break the aircraft. Any number will do. Provided it's a demonstrated number, that's good enough from a certification perspective.
I do laugh at those who seem to be suggesting that the certification basis for aircraft that have been around for decades is ascertainable against contemporary test guidance.
Thread Starter
Thank you all for your well considered opinions. Very much appreciated you took the time to discuss the subject of crosswind limits.
Interestingly, I found myself browsing through my various RAF and RAAF Pilot's Notes of wartime types. In all those documents e.g Mosquito, Beaufighter, Lincoln, Dakota, Tiger Moth, B17 Flying Fortress and others there was no mention of crosswind limits. Seems you found out the crosswind limit by default although by then you probably had a ground loop on your hands
Interestingly, I found myself browsing through my various RAF and RAAF Pilot's Notes of wartime types. In all those documents e.g Mosquito, Beaufighter, Lincoln, Dakota, Tiger Moth, B17 Flying Fortress and others there was no mention of crosswind limits. Seems you found out the crosswind limit by default although by then you probably had a ground loop on your hands
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Lead Balloon:
Incorrect. A x-wind component of 0.2 Vso is the minimum that must be demonstrated, as has already been stated in this thread. 
The certification process merely required a demonstrated crosswind number that didm't break the aircraft. Any number will do. Provided it's a demonstrated number, that's good enough from a certification perspective.
A x-wind component of 0.2 Vso is the minimum that must be demonstrated, as has already been stated in this thread.
As has already been stated in this thread, I do laugh at those who seem to be suggesting that the certification basis for aircraft that have been around for decades is ascertainable against contemporary test guidance. And even aircraft that are subject to a 0.2 Vso X-wind demonstration requirement are not thereby "limited" to a X-wind component of 0.2 Vso. The OP's question was about limits.
PS: I found this commentary by an experienced instructor to be informed by practical reality:
The "Demonstrated Crosswind" is a meaningless certification requirement indicating that on the day the aircraft was FAA certified that was the maximum wind available. ...
Aircraft that are certified under FAR Part 23.233 requires the aircraft to be safe for operations in 90-degree winds up to 0.2 Vso. Vso is the slowest speed an aircraft is controllable in landing configuration, at approach speed, no brakes and no special pilot skills. For a 60-knot speed with the C-150 this equates at 12 kts. These are minimums. This means that anything beyond a 12-kt. 90-degree crosswind exceeds the design expectations for an average pilot. If during the certification trials of a given aircraft, only ten-knot winds were available then that is the limit of the demonstrated crosswind component. This does not appear to be a very realistic criteria.
Aircraft that are certified under FAR Part 23.233 requires the aircraft to be safe for operations in 90-degree winds up to 0.2 Vso. Vso is the slowest speed an aircraft is controllable in landing configuration, at approach speed, no brakes and no special pilot skills. For a 60-knot speed with the C-150 this equates at 12 kts. These are minimums. This means that anything beyond a 12-kt. 90-degree crosswind exceeds the design expectations for an average pilot. If during the certification trials of a given aircraft, only ten-knot winds were available then that is the limit of the demonstrated crosswind component. This does not appear to be a very realistic criteria.
ATR points out, however, that the airframer does not define the crosswind limit because it is not part of the certification.
Although the operating manual features demonstrated values, ATR states: “Typically operators define their own crosswind limits and incorporate those within their standard operating procedures."
Although the operating manual features demonstrated values, ATR states: “Typically operators define their own crosswind limits and incorporate those within their standard operating procedures."
Last edited by Lead Balloon; 7th Oct 2016 at 21:33.
When you make a decision to do something, always imagine how you would explain it to a board of enquiry if something went wrong. How would you justify to an investigator why you decided to land with an excessively strong crosswind and ended up off the side of the runway with the landing gear collapsed ?
An experienced pilot would be expected to exercise better judgement and an inexperienced one would be expected to know his limits so you can't win.
Whilst an insurance company may pay out, they may go after the person that caused them to pay out. Of course you have read all the fine print in the policy, and are up to speed on all aspects of the insurance laws ?
An experienced pilot would be expected to exercise better judgement and an inexperienced one would be expected to know his limits so you can't win.
Whilst an insurance company may pay out, they may go after the person that caused them to pay out. Of course you have read all the fine print in the policy, and are up to speed on all aspects of the insurance laws ?
The point you seem to be overlooking is that the "demonstrated crosswind" number tells you nothing about what will constitute an "excessively strong crosswind".
Precisely.
An aircraft can end up off the side of the runway, due to crosswind, with the landing gear collapsed, despite having landed with a crosswind below demonstrated.
An aircraft can be landed safely with a crosswind in excess of demonstrated.
What counts as "excessively strong"? It depends.
An aircraft can end up off the side of the runway, due to crosswind, with the landing gear collapsed, despite having landed with a crosswind below demonstrated.
An aircraft can be landed safely with a crosswind in excess of demonstrated.
What counts as "excessively strong"? It depends.
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Lead Balloon, you wrote:
I say cobblers.
Don't be silly. This thread was specifically started on the basis of the demonstrated x-wind in the AFM. So that's a clue that we are actually talking about the situation where the aircraft was indeed tested to asses its x-wind performance during the certification process. I quoted the AC 23 Flt Test Guide because it is so clearly the most relevant doc in the context of this thread - being appllicable to GA and commuter aircraft.
So, just to be clear, are you now saying that your original post in this thread:
...didn't apply to the Metro of the OP and you were actually referring only to aircraft certified before the 0.2 Vso became a requirement? Also when was that out of interest?
" demonstrated crosswind limit" actually means the crosswind that an aircraft has been demonstrated as being able to land without structural failure, if the pilot applies no control inputs to counteract the crosswind in any way.
As has already been stated in this thread, I do laugh at those who seem to be suggesting that the certification basis for aircraft that have been around for decades is ascertainable against contemporary test guidance...You seem to be suggesting that that is the certification basis for every aircraft ever certified, from Tiger Moth to A380.
So, just to be clear, are you now saying that your original post in this thread:
" demonstrated crosswind limit" actually means the crosswind that an aircraft has been demonstrated as being able to land without structural failure, if the pilot applies no control inputs to counteract the crosswind in any way.
