Psa182 From , joined Dec 1969, posts, RR: Posted (15 years 3 weeks 2 days 22 hours ago) and read 857 times:
Hello again, another question about takeoff power I read on here a few months back, that the A340 felt supremely gutless on takeoff, can anybody else please enlighten me on this? To be honest, i find it hard to believe that such an aircraft would be certified to fly, if it really does lack that much power. Surely, wouldnt it be too risky trying to takeoff in case of a single, or even a double engine failure? Would be great to hear from anybody about this matter. Anyone ever spoken to a pilot from this otherwise nice machine? Thankyou
Skystar From Australia, joined Jan 2000, 1363 posts, RR: 2
Reply 2, posted (15 years 3 weeks 2 days 2 hours ago) and read 789 times:
The A340 is certainly not known for being a rocket, it has a power loading of 4.39 (lbs/lbs st - 271,000kgs - CFM56-5C4). In comparison, the 772 has a power loading of 3.64 (656,000 lbs/297,824 kgs - PW4090). A 744 has a power loading of 3.85 (875,000lbs/396,895kgs - PW4056). For the Boeings, the figures will change depending on engine type. The A340's engines are much of a muchness. On the A340-300E, a 5% thrust bump is available for takeoff.
Whether it is underpowered, certainly compared to its competitors it is not laden with much power. From what I've been told by a CX captain (also flies the 333 with RRs, flew the 744 and the L1011, and 733 with AN), for the job, it is well balanced. Its main task is for long haul jobs and it does those very economically (uses less fuel than 777, but has two extra engines to worry about - maintenance). It may cruise slower than the Boeings, but that's a function of wing design. Compared to what a lot of people say, it's not that much slower, IMHO. M0.02 is not much of a difference, it's only noticeable because the sectors it flies are so damned long. Extra power will improve climb performance.
Even with a single engine failure, the A340 will still have a better power loading than a comparable twin.