Philb From Ireland, joined May 1999, 2915 posts, RR: 14 Reply 1, posted (8 years 4 months 6 days 4 hours ago) and read 8961 times:
Take off is an exact science. Each take off is based on calculations which include the total aircraft weight, the runway slope and adhesion, the wind component, the height above sea level, the temperature and the pressure.
The power setting needed is then calculated along with the V1, V2 and rotate speeds and the distance needed to achieve these. Mmost jet aircraft take off on 75% - 80% power wherever possible to maximise time between major engine overhauls and to save fuel.
In hot conditions, at high airports and/or when an aircraft is operating at maximum weight for the runway, the time to rotation can be comparatively long.
Mexico City is renowned for long take offs. In the 1960s and 1970s some of Mexicana B727s had JATO (Jet Assisted Take Off) bottles to assist the engines and these were regularly used.
Even low and cold runways can see long take offs. I was on a BA 747-200 ex LHR for Miami in March 1988. The wind component changed, we returned to the gate, off loaded some freight and even then only rotated at 57 seconds which, on 28R at LHR (as it was then) takes you a long way down towards the reservoirs!
GoldenArgosy From United States of America, joined Jun 2005, 123 posts, RR: 0 Reply 2, posted (8 years 4 months 6 days 4 hours ago) and read 8942 times:
I don't know what it was in seconds or minutes, but last February I was on Singapore's 340-500 taking off from Newark bound for Singapore. At a certain point my heart started racing because I thought the thing would never leave the ground. Seriously, there must have been a foot or two left of the runway before it became airborne. That was by far the longest and most worrisome roll I'd ever experienced.
Udo From , joined Dec 1969, posts, RR: Reply 5, posted (8 years 4 months 6 days 4 hours ago) and read 8871 times:
I once had the pleasure to take off in a fully loaded Iberia A340-300 from Madrid on a hot evening (bound for Miami). Don't know how long it lasted in seconds, but after a while I thought we would be driving to Barcelona rather than getting airborne...
Hrhf1 From Canada, joined May 2005, 105 posts, RR: 1 Reply 6, posted (8 years 4 months 6 days 3 hours ago) and read 8793 times:
A fully loaded AC 762 from Las Vegas in July certainly took some time to rotate the day I was on it. Temperature was about 114F, (45C) and at 2200' it made for a loooooong roll. No exact time, but I'd guess it was 50 seconds minimum....hence 14500' of runway. Add to that the convection heat bouncing the aircraft around right after takeoff and you had some antsy pax! It was good fun!
Cartoonranger From United Arab Emirates, joined Aug 2005, 89 posts, RR: 0 Reply 7, posted (8 years 4 months 6 days 3 hours ago) and read 8751 times:
The RAF still go off in Bahrain with VC-10's at 152 tonnes +45 degrees C Outside Air Temp. The take off roll is truly monumental. Of course performance dictates that losing a donk above V1 should not be a problem, but having glared the runway end lights squarely in the face on more than one occasion i always prayed that it wouldn't happen as i severly doubt she'd want to fly.
SA7700 From South Africa, joined Dec 2003, 3116 posts, RR: 26 Reply 8, posted (8 years 4 months 6 days 3 hours ago) and read 8699 times:
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Fully loaded flights in JNB can take up a huge chunk of the runway. I have heard that QF sometimes delay their departures (SDT18h00) out of JNB in order for the temps to come down and the payload restrictions to be lowered.
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ACDC8 From Canada, joined Mar 2005, 7620 posts, RR: 38 Reply 9, posted (8 years 4 months 6 days 3 hours ago) and read 8648 times:
The longest take-off roll I've ever experienced was in 1991. We were taking off from YYC's RWY 34, which is 12,675 feet, on one of KLM's 747 combi's. Anyway, we were sitting at the end of the runway, brakes on, full power, sat there for a few seconds, brakes off, and off we went. We were just rolling and rolling for what seemed like the longest time, by the time we finally got in the air, we were just crossing the other end of the runway!
I think one of the reasons we needed such a long take-off roll was due to the fact that they stuck a helicopter (minus the rotors) in the back of the airplane! So we must have been pretty well maxed out with weight!
Goingboeing From United States of America, joined Dec 1999, 4875 posts, RR: 18 Reply 11, posted (8 years 4 months 6 days 3 hours ago) and read 8590 times:
I don't know how long the roll was, but I was on a Piedmont flight from CLT-DFW back in the mid 80's. My coworker (who also travelled a lot) was sitting next to me and the engines spooled up and we started to roll. And roll. And roll. And roll. Finally she looked at me with a panicked look on her face and said "Shouldn't we be in the air by now?" I said "yes" (although we were still rolling down the runway) when FINALLY the plane rotated and we took off. Scared the living sh*t out of me.
FLYiCRJ From United States of America, joined Jul 2005, 55 posts, RR: 0 Reply 12, posted (8 years 4 months 6 days 3 hours ago) and read 8574 times:
Last July I was on Continental's flight 15 from EWR - HNL. If you are familar with Newark airport you will understand what i am talking about here. We taxied to 22R started our take off roll and we were past the Fedex building before we rotated. We weren't more than 50 feet off the ground before the end of the runway came up. Now my question is because of our long T/O roll, what happens if they had to perform a rejected takeoff?
AirRyan From United States of America, joined Mar 2005, 2532 posts, RR: 6 Reply 13, posted (8 years 4 months 6 days 3 hours ago) and read 8544 times:
Pilot's opt to derate the takeoff rolls to save wear and tear on the engine as well as gas. I'm sure it's not just a decision of the pilot as much as it is often company policy per the condition.
As part of the pre-flight on your FMC you have 3 choices - normal full power and then two derated options. The computer takes into account your load, fuel, ambient temp, and runway length to calculate just how much power is needed to takeoff on that runway at that time with that load. Pilot's also have the option to derate the climb by two gradients as well.
Cartoonranger From United Arab Emirates, joined Aug 2005, 89 posts, RR: 0 Reply 15, posted (8 years 4 months 6 days 2 hours ago) and read 8481 times:
Sometimes aircraft will deliberately spend longer on the runway anyway. If there is a large obstacle at the end of a runway, it is often safer to leave V1 as late as possible. This is because, should you lose an engine you would be better off on the ground rather than trying to fly over it. For the VC-10 This is factored in Regulated Take off graphs which dictate what speed V1 will occur. It may be hard to believe but even heavy at 150 knots, most modern day aircraft have phenomenal stopping power so the actual stopping distance may not be as great as you think!
Runways can also have different Take Off Distance Available (TODA) and Accelerate Stop Distance Available (ASDA - i.e. 0 Kts to V1 and back to 0 Kts again)
Jeffry747 From United States of America, joined Jun 2005, 963 posts, RR: 2 Reply 19, posted (8 years 4 months 5 days 21 hours ago) and read 7898 times:
A while back I was in the UPS parking lot at SDF, which is situated at the departure end of 17L (8500ft). Had a full 741 going to ANC rotate with less than 1,000 ft left. This puppy cleared the blast fence by about 20-30 ft and thundered over my head low enough that I could almost count the lug nuts on the main landing gear, which were just starting to retract. Best takeoff I have ever seen.
ATA L1011 From United States of America, joined Feb 2001, 1367 posts, RR: 7 Reply 20, posted (8 years 4 months 5 days 21 hours ago) and read 7775 times:
Back in 97 on N195AT, L1011-1 from LAX to HNL that thing was loaded with over 300 people and the take off roll was 55 seconds, I remember us rotating just past the Tom Bradley Terminal on the South Side of LAX.
Vulindlela744 From United States of America, joined Jan 2000, 518 posts, RR: 0 Reply 21, posted (8 years 4 months 5 days 20 hours ago) and read 7510 times:
I flew from Miami to Cape Town back in '97. It was a non stop on a fully loaded 747-400 and it took almost the whole south runway to get airborne. That runway is almost 13,000 ft. It was really something.
N270ft From United Kingdom, joined May 2005, 85 posts, RR: 0 Reply 22, posted (8 years 4 months 5 days 20 hours ago) and read 7477 times:
In 1998, I was on A Virgin 747-200 "California Girl" From MCO-MAN. I seriously thought the plane would never leave thr ground.
Also, in 2000 I was on this same plane from LGW-EWR and they had to turn the cabin electricity off over Newfoundland because there was smoke in the cabin. The plane landed safely however, and I cringed everytime I saw that plane since.
Jmc1975 From Israel, joined Sep 2000, 3204 posts, RR: 16 Reply 23, posted (8 years 4 months 5 days 20 hours ago) and read 7405 times:
My longest takeoff roll: I flew from Atlanta to Cape Town nonstop in Jan. 2003 on an SA 744 (ZS-SAY). Although the outside temp. was at the freezing mark, the flight was restricted by 20 pax. About 45 seconds into our takeoff roll, the pax began to say things like "get up" and were in doubt if we would make it. I had an aisle seat on the side of the aircraft, which had a perfect view of the left winglet. As we began to rotate, I saw that winglet shoot up about 10 feet. As we lifted up, there was condsierable airframe shudder and we had a slow climbout as we barely clear the Georgia woods by the Chick-fil-a headquarters.