Certification vs Operation

[FOD]

Midlifeflyer,
Your answer is much appreciated, this is something a faced a while back and always wondered about it. Thanks

 

[FOD]

So say it is 40C outside and my performance charts only go to 35C and I took off, would I be breaking the Regs and operating outside of the limitations?

But wouldnt i be breaking part 91 because i cant compute my takeoff and landing distance?

 

[midlifeflyer]

But wouldn't I be breaking part 91 because I cant compute my takeoff and landing distance?

In part, its one of those "is it mandatory" issue.

Here's what the regs say about it:

==============================
§ 91.103 Preflight action.

Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight. This information must include -

(b) For any flight, runway lengths at airports of intended use, and the following takeoff and landing distance information:

(1) For civil aircraft for which an approved Airplane or Rotorcraft Flight Manual containing takeoff and landing distance data is required, the takeoff and landing distance data contained therein; and

(2) For civil aircraft other than those specified in paragraph (b)(1) of this section, other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport elevation and runway slope, aircraft gross weight, and wind and temperature.
==============================

Assuming the data is not "defined" as a limitation, what happens when we're between (1) and (2); An required AFM that doesn't cover the situation? Do you have to make a no-go decision or can you rely on (2) to cover the difference.

My guess (and it's only a guess) is that you can use "other available information" to take up the slack if the data is not clearly a limitation. I'm saying that because of the "familiarity" language - way to casual to be read as "shall abide" or "must do." "Familiarity" at least to me, suggests that I may use the data as a starting point and apply reasonable principles and experience. At least I hope so: it's an issue we face pretty often flying in Colorado.

 

[727gm]

...Travolta's B707 is actually probably certified under CAR 4, which preceded FAR 25.

 

[Peanut gallery]

Not Exactly

The confusion is between certification standards, and operating rules. There is no correlation.

You must comply with published limitations. A performance chart shows what the aircraft can do under a specific set of circumstances, and one would be foolish not to avail one's self of that information if accurate...but it's not necessarily a limitation.

Weather the aircraft is certificated under Part 23 or Part 25 is largely irrelevant to how you operate it, as neither are operating rules. Both Parts 23 and 25 are standards which must be met by the aircraft in the certification process. What you do with it is up to you, within certain bounds.

I would hate to be in front of an Administrative Law Judge arguing this one. If you operate outside of the certification standards for an aircraft including performance data (which is principally what part 25 was devised for) and the FAA is going after you I can offer no legal defense except to advise you to try to settle for a Civil Penalty, before you get in front of a Judge.