Climb Segments?

[dbchandler1]

Can anyone explain to me what is meant by climb segments? do they mean like initial climb, cruise climb, etc... also does anyone know if a forward or aft CG effects fuel consumption? thanks fellas

 

[Say Again Over]

Someone with more knowledge will fill us in but I think it goes like this:
1st- Starts at 35' and ends at gear retraction 2nd- Starts when gear is retracted and ends not less than 400' above runway, 3rd- starts not less than 400' above runway and continues when flaps retracted while accelerating to V2 + 50 at takeoff thrust, FINAL- extends to 1500 AFL or more at a constant speed of V2 + 50, flaps up, with Max cont. thrust.

 

[MauleSkinner]

Someone with more knowledge will fill us in but I think it goes like this:
1st- Starts at 35' and ends at gear retraction 2nd- Starts when gear is retracted and ends not less than 400' above runway, 3rd- starts not less than 400' above runway and continues when flaps retracted while accelerating to V2 + 50 at takeoff thrust, FINAL- extends to 1500 AFL or more at a constant speed of V2 + 50, flaps up, with Max cont. thrust.

Close
First segment starts at liftoff, ends at or above 35' with gear retracted.
Second starts at the end of the first, and goes to not less than 400' or 1500' above the runway (depending on airplane and certification details). This is also the segment used to clear departure obstacles, so it can extend as high as the MEA.
Third segment is a level-off to accelerate to cleanup/final climb speed.
Final segment is an "enroute" climb...cleaned up, accelerated, and clear of obstacles. Speed for the final segmentis determined by the manufacturer.

As Say Again indicated, takeoff thrust is normally maintained through the third segment, at which time max continuous is set. If you are in second segment to the MEA, you can quite possibly exceed the time limit for takeoff thrust (usually 5 minutes), in which case you would need to make a thrust reduction at the time limit, rather than at the end of third segment. This, naturally, increases the complexity of the calculations

Calculations for the takeoff segments are based on an engine failure at Vef, which is at or below V1 (depending, again, upon the rules that the airplane was certificated under), with continued takeoff in the engine-out configuration.

Fly safe!

David

 

[Trogdor]

I always thought the first started at 35' AGL. That is where the takeoff maneuver ends.

 

[Say Again Over]

MauleSkinner, Nice post, thanks for the explanation.

 

[Benhuntn]

Second question: does CG affect fuel mileage? Yes it does in a small way. An aft CG will slightly increase mileage, since the stab will be more aligned with the flight path reducing drag.

 

[Headwind]

Climb segments apply to part 25 aircraft.

 

[onthebeach]

Why speculate when you can read the reference, and get pictures?

The reference is advisory circular 25-7, which you can find at faa.gov.

There is a table in paragraph 14 which shows points, speeds, power, and configuration for each of the climb segments.

 

[Brett Hull]

The reference is advisory circular 25-7...

That's not an Advisory Circular, that's War & Peace, FAA stlye(457 pages)!

 

[VVJM265]

The reference is advisory circular 25-7, which you can find at faa.gov.

There is a table in paragraph 14 which shows points, speeds, power, and configuration for each of the climb segments.

Always knew the definitions from other sources, but the FARs aren't exactly clear (imagine that!) and have wondered if there was an FAA "source document." Obviously missed that circular; thanks for posting.

There's hope for the board after all...

 

[Andy Neill]

Speaking of performance, can anyone give me the model of a two-engine aircraft that meets the provisions of 121.193(c)(2)(ii)? I can't think of any.

[Edited erroneous reference]

 

[MauleSkinner]

Climb segments apply to part 25 aircraft.

...and CAR 4 aircraft.

 

[MauleSkinner]

Speaking of performance, can anyone give me the model of a two-engine aircraft that meets the provisions of 121.119(c)(2)(ii)? I can't think of any.

Um...I see 121.119 as being "weather reporting facilities", and it doesn't have a paragraph (c).

 

[Andy Neill]

You're absolutely correct!

Would you believe 121.193(c)(2)(ii)?

Thanks for the catch.

 

[MauleSkinner]

You're absolutely correct!

Would you believe 121.193(c)(2)(ii)?

Thanks for the catch.

Umm...a two engine aircraft that can climb with two engines inoperative?

 

[Andy Neill]

Hard to do,....ain't it?

So tell me mister discount airline pilot guy (or 737/757/Airbus....) are you compliant or not?

 

[MauleSkinner]

Hard to do,....ain't it?

true, but all a 2-engine airplane has to do is comply with 121.193(c)(1), and they're exempt from (c)(2)

(c) Aircraft certificated after August 29, 1959 (SR 422B). No person may operate a turbine engine powered airplane along an intended route unless he complies with either of the following:
(1) There is no place along the intended track that is more than 90 minutes (with all engines operating at cruising power) from an airport that meets the requirements of § 121.197.

Fly safe!

David

 

[Andy Neill]

Thank you, sir. I have learned something today. I've been harping on this for years and have never noticed the "either of" phrase in 193c1.

 

[MauleSkinner]

Thank you, sir. I have learned something today. I've been harping on this for years and have never noticed the "either of" phrase in 193c1.

Now if somebody would just correct all the misconceptions I have

Fly safe!

David