landing flap settings at a class "G" airport

[sleddriver71]

FAR 91.126 "Operating on or in the vicinity of an airport in class 'G' airspace.

(c) Flap settings. Except when necessary for training or certification, the pilot in command of a civil turbojet-powered aircraft must use, as a final flap setting, the minimum certificated landing flap setting set forth in the approved performance information in the Airplane Flight Manual for the applicable conditions. However, each pilot in command has the final authority and responsibility for the safe operation of the pilot's airplane, and may use a different flap setting for that airplane if the pilot determines that it is necesary in the interest of safety.

What is the basis of this requirement? Is it a noise issue? Does it have to do with the aircraft requiring a lower power setting because of having less drag with minimum flaps thereby creating less noise? I thought maybe it had to do with determining runway requirements based on the minimum flap settings but, re-reading the FAR, it doesn't mention that this is for planning purposes but to actually use the minimum flap setting.

 

[MauleSkinner]

My understanding is that it's a noise issue...less flap, less drag, less thrust, less noise. The same applies to the "at or above glideslope to 200 feet" requirement at a tower-controlled airport with an ILS to the runway of landing.

Most of the jets I've flown only have full-flap landing distance charts, though...rules of thumb can be applied for other settings but I've always assumed that the "minimum certificated" meant the manufacturer has provided charts.

Fly safe!

David

 

[sleddriver71]

Thanks David, I just don't remember seeing that in the FAR's before. That sounds like the most logical answer though...

 

[MauleSkinner]

Thanks David, I just don't remember seeing that in the FAR's before. That sounds like the most logical answer though...

You read it on an internet message board, so it MUST be true!

 

[Seadogrun]

However, each pilot in command has the final authority and responsibility for the safe operation of the pilot's airplane, and may use a different flap setting for that airplane if the pilot determines that it is necesary in the interest of safety.

Here's your catch all. Isn't it almost always in the interest of safety to use full flaps? I think so.

 

[Amish RakeFight]

I think you guys are misinterpreting this. When they say "minimum," they don't mean use the least amount of flaps as opposed to using too much flap. More flap is always better (let's not get into the X-wind discussion). It results in a slower approach and a shorter rollout.

Rather, I think the intention is to use at least the minimum prescribed in the AFM for landing. This reduces your stall speed, landing roll, etc. etc.

By not using the minimum flaps as per the FAR cited, you would be operating in a more perilous way, so to speak.

 

[nosehair]

This is priceless. This is a very good example of how an FAR can be interpreted in two completely different ways...and nobody is tweaking a word!

It is completely impossible to understand which way the reg is meant to be without reading the preamble to understand what the meaning of "minimum" is.

 

[Amish RakeFight]

Maybe Avbug could clarify this. I'd be willing to buy his interpretation.

 

[midlifeflyer]

This is priceless. This is a very good example of how an FAR can be interpreted in two completely different ways...and nobody is tweaking a word!

It is completely impossible to understand which way the reg is meant to be without reading the preamble to understand what the meaning of "minimum" is.

...although if Amish is right, this is a particularly badly worded reg. Otherwise I just can't see how the words could be read that way, with or without the context.

"must use the minimum" just does not mean "must use at least the minimum"

But either way, I can't imagine the reason behind it.

 

[SSDD]

...although if Amish is right, this is a particularly badly worded reg. Otherwise I just can't see how the words could be read that way, with or without the context.

"must use the minimum" just does not mean "must use at least the minimum"

But either way, I can't imagine the reason behind it.

Less flaps=less power required=less noise.