These are the kind of threads I read completely. I love to see a healthy difference in opinion over these little details because I can get some good information and it explains some small details that one might normally not look into.

What is considered "clearway"?  I haven't heard that term before.

These are the kind of threads I read completely. I love to see a healthy difference in opinion over these little details because I can get some good information and it explains some small details that one might normally not look into.

What is considered "clearway"? I haven't heard that term before.

Not quite a difference of opinion, really. More a misunderstanding coming out of misquoting facts.

 

The clearway is the area beyond the paved runway that has been made clear in the case of a runway excursion (airplane running off the end of the runway in this case). It's included in TODA as it's space available for the climb out and for emergency use.

 

Think of losing an engine in a heavy climb. Your climb performance will be degraded, but that's cleared space where you don't have to worry about trees and so on for that initial climb segment.

I also read that only way to find the clearway is to phone the airport manager as its not showing on the charts. Like i said thats what i read on my 737NG performance manual.

 

 

The clearway is an area beyond the runway end with the following characteristics:

• minimum 500 feet wide;

• centrally located around the extended centerline of the runway;

• must be under control of airport authorities;

• no obstacle protruding above 1.25% slope plane, except threshold lights located at the sides of runway with a height lower than 26 feet.

The clearway is the area beyond the paved runway that has been made clear in the case of a runway excursion (airplane running off the end of the runway in this case). It's included in TODA as it's space available for the climb out and for emergency use.

 

Think of losing an engine in a heavy climb. Your climb performance will be degraded, but that's cleared space where you don't have to worry about trees and so on for that initial climb segment.

 

Thank you for the explanations.

Just ask any questions you like

Having now used this for a lot of flight I cannot get over what a difference it makes, more takeoff than landings.

 

The 777 out of Dublin was so derated I thought , no way! worked perfect lol.

 

Really glad I bought it.

Just looking what's being written here, I think both Kyle and Vernon have correct statements, and are citing correct sources, but are interpreting things differently (which seems to be the primary reason of existence of the training department of my little commuter airline - interpretation of the rules. 

 

Kyle and Vernon: I think you're both correct in saying that TORA + clearway = TODA. The end of the TODA is when you need to be 35' in the air. 

I think Vernon's interpretation of TORA is a bit unclear. TORA is not neccesarily the full length of the runway, but more importantly, declared available. If some part of the runway isn't good enough to meet fancy legal criteria, then it may not be suitable, although this is most commonly seen with LDA and displaced thresholds. And the point about intersecting taxiway is important to. You can't take performance credit for 11,000 ft of runway if you start your takeoff run from the halfway mark!

I'm pretty sure you understand it correctly Vernon, I think that perhaps the way you wrote the original example was ambiguous and unclear.

It's good to see people discussing the segments of the climb here, because it is critical to understand the different components of a takeoff when you're actually crunching takeoff numbers. Thankfully tools like Topcat and TOPER make those calculations for you!

Really glad I bought it.

777F EDDF takeoff settings were supplied by TOPCAT. A D2 and assumed temperature at flaps 15. After looking at the recommended settings, I thought "ain't no way." But I went ahead anyway and entered the D2 and assumed temperature on the thrust limits page. Entered flaps 15 on the takeoff page and clicked on trim. No V-Speeds. Backed the settings down and finally got V-speeds in the FMC. TOPCAT should be right 100% of the time. I guess it's not and that is what humans are for.

What settings did you 'back down'?

 

The FMC might not have F15 and intersection perf data (I don't know, I don't use the 777), thus, you don't get reference speeds.

 

I don't know... Just thinking out loud...

 

Brian Nellis

TOPCAT is never going to be accurate compared to the aircraft. It's close enough for flight sim purposes though. It gives reasonable indications of performance with derates, so provides a realistic feeling experience. That's all I expect of it.

What settings did you 'back down'?

No derates, Flaps 5, Assumed temperature increased.

 

The FMC might not have F15 and intersection perf data

It does have 15. I don't know about intersection takeoff data. I am pretty sure it does but not like TOPCAT where the intersection takeoffs are listed. I believe the runway needs to shortened on the takeoff page.

I'd be interested to know what your TOW was and which runway you were using at FRA -- the 777, on the whole, is an enormously overpowered aircraft and D-TO2 with an assumed temperature doesn't seem necessarily unreasonable to me, especially on a long runway.

 

In the PMDG 747 and LDS 767 TOPCAT's always been spot on: I've never run out of runway and although I've not done many RTOs from V1, I'm confident that it would work from the point at which V1 is called.

I'd be interested to know what your TOW was and which runway you were using at FRA -- the 777, on the whole, is an enormously overpowered aircraft and D-TO2 with an assumed temperature doesn't seem necessarily unreasonable to me, especially on a long runway.

It seemed unreasonable to the FMC on two occasions. This occurred maybe six months to a year ago so I don't have any specific weights. Generally out of EDDF the TOW is around 710000 lbs. in the 777F. Cargo is 200000 and fuel is 190000 to 250000 depending on the destination.

Firstly (is that a word?), according to http://www.flightsimsoft.com/topcat/?p=types TOPCAT doesn't even support the PMDG 777, but several people are making references to it.

Is that page just outdated?

 

Secondly, if Aurasim had stayed in business they would have finished their 777 EFB. I know Airline2Sim acquired them, but since that acquisition I haven't heard or seen diddly for that EFB.

Too bad too. It would have been a huge success in sales.

 

 

TOPCAT doesn't even support the PMDG 777

 

There is a beta download.