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Full power take off

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Old 29th Jan 2015, 17:20
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Full power take off

Coming back from IBZ in September, the flight back was on a Thomson (First choice) B767 G-OOBM, normally used for long haul flights, the Captain announced on departure he was performing a 100% power take off and the aircraft would climb at a far steeper rate until 'levelling' at 2,000 feet, glad we were warned as we properly went up like a space shuttle, I would have been thinking he was trying to test the stall warning or something.
in over 100 flights I've never been in a full power take off before, is it a check you can just carry out whenever you get the chance with a light fuel load or does it have to be carried out after a certain number of take offs?
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Old 29th Jan 2015, 17:38
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There is a requirement for operators that normally do derated takeoffs that they do a full rated takeoff every so often to demonstrate the engines still have the necessary performance margins to obtain full takeoff power.
It varies by operator - basically the operator puts together a plan of how they will demonstrate the engines still maintain adequate performance and the regulatory authority reviews and approves their plan.
I often do flight tests on very light aircraft where we do a full rated takeoff - and yes it is very impressive
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Old 29th Jan 2015, 18:23
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Aw, comm'on they were just having a bit of fun.

Or is that not allowed nowadays.

Oh, I forgot, it probably ruined someones honeymoon, upset their granny etc..

A DC10-30, with fuel for LGW, performs quite well out of GLA, with very few passengers, at full power!!!

The VC10 was even better!!

Good job I'm retired.
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Old 29th Jan 2015, 19:39
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A 747-400 going LHR-LGW was also good fun!
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Old 29th Jan 2015, 19:45
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I have flown across the Atlantic nearly 100 times, Comet, 707 DC8, 747, DC10, MD11 and 777, but nothing has ever impressed me as much as a VC10 and I have never yet experienced a full power take off. Sounds fun! Older bro and I were used to Comet, 707 and DC8 long before our first VC10, still talk about it sometimes.
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Old 29th Jan 2015, 20:13
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Let us not forget that a "full power" takeoff is theoretically the standard. This is what the aircraft is calculated for, it also maybe paradoxically uses less fuel than a derated takeoff.

However, a reduced power takeoff is desirable because it greatly reduces wear and tear on the engine. Running the hot section a few 100°C cooler during takeoff does wonders for the engines lifetime and although it increases the fuel usage a bit, has a noticeable effect on engine maintenance costs. Also, a reduced power takeoff may well be a bit more quiet - on the DH8, this is definitely noticeable in the cabin.

A full power takeoff is required periodically to ensure that the engine will still deliver rated power without shooting any limit. When and how often depends on aircraft and maybe also company: here, on the DH8 every first flight of a flying day is at normal takeoff power; the Fokker 70/100 requires the same only once a week, so Monday is TOGA day and the first flight of the week is done using TOGA power.

There are several points that forbid the use of reduced takeoff power. Those are again type dependent, but generally include:
- the presence of icing conditions during departure;
- predicted or observed windshear on departure;
- a contaminated runway;
- a wing with deicing fluid on;
- some technical malfunctions depending on type;
- tailwind above a certain limit;
- and also if there is an itching in the captains small toe telling him not to reduce this time.

Of course, this results in increased field length requirements both for the stop and the go case and also in lower climb gradients until acceleration/thrust reduction altitude. So for a given weight, performance is lower with reduced takeoff power and - seen from the other side - one will get less weight out of a runway while still meeting the performance requirements. So one will obviously only reduce power to a point where all the performance requirements can still be met (there typically is a range between maximum and minimum takeoff power) and depart with maximum power when performance requires this.

It is a case-by-case decision that may have to be documented for maintenance reasons but typically not justified to the company.
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Old 29th Jan 2015, 20:23
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If you thought a 767 full power was something, it's not as impressive as a light 757 on a full power launch or an obstructed runway go-around.


Short of being in a fighter jet, I don't think there is any way to change elevation by that many feet in so very few seconds, short of jumping off a cliff, except in a 757 you go up not down. It put a grin on the face of everyone on board.


I seem to recall that the pilot lined up at the end of the runway then came over the intercom to say that he wanted the cabin crew to make sure everyone was well strapped in before taking their seats and then suggested that we lean back and enjoy the ride. Then he spooled up the engines to the extent that we might well have been skidding down the runway despite the brakes being on & when he let them off, I'm sure that we took off round about the point in a normal takeoff that the engine spool-up starts. Astounding. Still puts a smile on my face.....
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Old 29th Jan 2015, 21:45
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Did it on an Orion Airways B737-300 positioning (empty) from Manchester to Birmingham. Amazing!
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Old 29th Jan 2015, 22:00
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1980s GLEAR positioning LHR-MAN 28R for departure was at 6000ft by the runway end (or so it appeared!)
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Old 29th Jan 2015, 22:47
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Some carriers used to do it on the 1st of each month - not sure if that was fact or popular culture!

I was lucky enough to jump-seat in at 757 from ABZ to LHR around 20 years ago. On the taxi out the captain informed me that we would be doing a full power take-off! Spectacular does not begin to describe it! We were rotating after about 15 secs, and climbed at 5000ft per min up to 41000ft where we remained for all of 2 minutes!
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Old 29th Jan 2015, 23:24
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1980s GLEAR positioning LHR-MAN 28R for departure
Watched G-BBEE (a Lear 25 I think) depart 28L in the late 1970s, held low with gear up past the T3 piers, then a climb that appeared near vertical to about 2000 or so whereupon it pitched forward into a more decorous ROC.
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Old 30th Jan 2015, 21:18
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757 rate of climb

In my time at MAN had a grandstand view from the stairwell of the old T1 office block of the (then) 24 end, and must have watched hundreds of arrivals and departures over the years.

One of the most memorable of those was what I assumed to be an empty BA 757 positioning flight, no doubt aided on the day by a brisk southwesterly, rotate at Bravo and was climbing at what looked like 45 degrees before link Charlie.

Impressive
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Old 31st Jan 2015, 00:25
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Wonder if it could have been bleeds off as well, we do these from time to time for crew training.
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Old 31st Jan 2015, 04:36
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One of the most radical for me was Cambridge to Stansted, relocating a PAX MD11 from a MX base with a short runway to fuel up for a longer flight. The boys driving set high thrust with brakes set, I was firmly put back in my seat when they kicked them off. I had the bird's eye view in the cockpit. Lots of fun and the shortest flight I ever had, think they said 9 minutes.

Another fun takeoff was in an empty MD11F with about 50k LBS of fuel and no freight, the pilots this time just wanted to have fun. After rotation we leveled off a bit allowing for airspeed, as they rotated the 2nd time I remember seeing 45 to 50 degrees nose up, had to fight the Gforce to keep my eyes on the instruments (PFD). Fun times as a flight mechanic I will never forget.
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Old 31st Jan 2015, 09:45
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For all the lightweight special circumstances trips I do think the mighty &% must reign supreme when it comes to something approaching normal service -back in the days of them on shuttles and LHR-CDG /AMS runs they would seem to be at an astonishing height passing the far end threshold -and of course for a pax interested in aircraft they made just a great noise.

Closest I have come anywhere else was an MD87-itself a pretty brisk performer with a sometimes startling deck angle as with all the MS80s. A mid Sunday afternoon departure from Turku/Abo in Finland's west coast back to Arlanda-not very far and not many Pax . Not a huge amount of noise due to the rear engines but a staggering rate of climb accompanied by a staggering but no doubt still legal bank rate as we departerd to the east and were hauled round in about a 230 degree climbing turn to the left seemingly (but probably not actually) inside the airfield boundary to roll out over what was now a tiny airfield below very very well on the way for the 20 odd thousand feet for the short hop across the Baltic.

A few words from the flight deck in Swedish to the effect that sometimes they had to practice a manually flown departure without the autopilot which was always interesting and looked forward to by the crew.
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Old 31st Jan 2015, 16:33
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Thanks for the posts on how good the take off on a VC10 was. As you can see from my nom de plume, I like them!

When a Thomson 757 takes off from Skiathos airport does it use full power?

I ask because when I've taken off from Shiathos' very short runway the plane, a 737-300, had to refuel at Thesalonika.
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Old 31st Jan 2015, 16:59
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I can still remember my first training trip in the rhs of the VC10 as a 23year old.

I 'drove' it across the peritrack from the BOAC base (you weren't towed in those days) with the traffic stopped, including a couple of red London buses.

The kick in the back as I applied power was pure magic.

The most wonderful aircraft I have ever flown.

I always thought of it as a 4 engined fighter, it was so overpowered!!
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Old 31st Jan 2015, 21:04
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Did a fam flight with Dan Air to Stavanger in one of their (at the time) new 146s. The BAe test pilot who was in the left hand seat did a full power departure from Stavanger; full load of 85 pax (plus me in the jump seat) and over 2,000 ft by the upwind end.
On another fam flight (jump seat once again) out of Palma in a Britannia 767 also with a full pax load, brakes off to FL370 took just 20 min - I timed it!
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Old 31st Jan 2015, 21:57
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brakes off to FL370 took just 20 min
Unlike this full power take off...

https://www.youtube.com/watch?v=VC8CsVpg64o
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Old 1st Feb 2015, 13:33
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anyone else spot this?

Following this thread I need to ask about Concorde's last flight. I was watching local reporting on the (very sad) last day of the great planes career in scotland and there was an article about the last flight from Edingburgh I think. I recall the clip showing a far higher climb rate than usual just after takeoff as it headed towards london. Must have been unbelivable for those on board as i swear it went straight up. Can anyone tell me if this happened / is even possible / i just imagined it. (yes i know straight up es exagerating but you know what i mean).
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