Indianguy From , joined Dec 1969, posts, RR: Posted (10 years 5 months 6 days 4 hours ago) and read 7388 times:
What is average flight profile of a 747-400 i mean takeoff and descent speeds, angles etc?
I recently had my first flight on a 747-400, a short flight of about 3 hours. The aircraft first levelled off at around 5/6000 feet(just below the clouds) and then climbed to 31000 feet. The climb was pretty shallow (meaning the nose wasnt pointing steeply towards the sky!).
The descent was pretty interesting. The engines noticeable throttled back and the aircraft pretty much nosedived steeply to 15000 feet or so where we kept circling before beginning a more leisurely descent.
Are such "fighter plane" antics quite common on the 744, or was it the pilot having a bad hair day (there was atleast one lady in the cockpit/box-office!)? It was raining lightly at both ends. Could this be a factor?
XFSUgimpLB41X From United States of America, joined Aug 2000, 4103 posts, RR: 38 Reply 1, posted (10 years 5 months 6 days 3 hours ago) and read 7330 times:
Sounds more like that was climb and descent restrictions from ATC than the airplane/pilots. The circling that you entered was called a holding pattern- it is flow control into an airport...probably caused by the weather at your destination.
Modesto2 From United States of America, joined Jul 2000, 2726 posts, RR: 6 Reply 3, posted (10 years 5 months 6 days 1 hour ago) and read 7277 times:
Flight profiles specific to an aircraft, such as initial cruising altitudes, would not be illustrated in a 3 hour flight. As others have stated, your observations were merely air traffic control restrictions and instructions or standard procedures...nothing more.
B747skipper From , joined Dec 1969, posts, RR: Reply 4, posted (10 years 5 months 5 days 23 hours ago) and read 7243 times:
The 747-400 is no (much) different in flying than the "classic" 747s... A few years ago, was invited in Seattle to fly a 400 - did 3 landings in Moses Lake and Boeing Field... Was no much different in "hand flying" and numbers...
A 747 heavy weights would climb at some 330-335 KIAS, and if light, it climbs at 285-290 KIAS as best rate speeds... rotation on takeoff (initial climb) is some 13 degrees when heavy, and some 18 degrees when light... Rotation itself is done at 10 or 11 degrees, so not to scrape the tail. And I have yet to get a bad landing... very easy and stable to land as well, just stay on the numbers.
There is no "oh my Gosh that big airplane" flying or handling it. The 747 is a nice stable aircraft to fly... or do you think I am God himself...? - When I train pilots to fly the 747 - I just say "easy to fly, but watch out and learn to taxi it" before you put your main gear in the dirt in the corner of a taxiway...
In airplanes - all is in proportion - power and weight - and by the way, the 747 is a wonderful glider - 22:1 ratio... I bet your Cessnas only get 15:1...
Osteogenesis From Germany, joined May 2003, 647 posts, RR: 2 Reply 5, posted (10 years 5 months 5 days 21 hours ago) and read 7185 times:
22:1 Does that mean 1 Km (or whatever you want) down every 22 Km you travel? It would mean about 220 Km if you have to glide from 10000 meters. What would be the ideal speed for gliding a 747? Do you have to extend the flaps?
FlightSimFreak From United States of America, joined Oct 2000, 720 posts, RR: 0 Reply 6, posted (10 years 5 months 5 days 21 hours ago) and read 7182 times:
Skipper... I live a mere .8 flying hours by 172 from Moses Lake. It is a favorite cross country destination of mine because I get to see JAL 747s and other heavies including Boeing test aircraft and C-17s in the pattern, along with the occasional F-18 or other fighter. Next time you go there, drop me an e-mail, perhaps I'll fly up there and end up in the pattern with you.
B747skipper From , joined Dec 1969, posts, RR: Reply 7, posted (10 years 5 months 5 days 18 hours ago) and read 7129 times:
Dear Osteogenesis -
Correct, from 10,000 meters, you glide 220 km...
The speed would be approximately Vref+70 kts (best L/D) lift over drag...
Typical glide speed, heavy would be 220, and light would be 180 KIAS...
Flaps would be up... flaps down is extra drag...
Mr.BA From Singapore, joined Sep 2000, 3423 posts, RR: 22 Reply 8, posted (10 years 5 months 5 days 17 hours ago) and read 7127 times:
Let's say if you've just reached initial cruising altitude of FL 280 after taking off at MTOW and all four engines failed at the same time. I understand this possibility is so very remote but I wonder what is the procedure? Do you try to keep level at FL 280 while all engines are cut off and wait for the speed to drop to around 220 and then try to glide? Is it possible to glide back to the departing airfield?
And flying the B747, when landing in crosswind and the crab angle's pretty a lot, do yuo recommend de-crabbing the plane or touch down crabbed and centre it after touchdown? Just to hear your opinion.. thanks
B747skipper From , joined Dec 1969, posts, RR: Reply 9, posted (10 years 5 months 5 days 16 hours ago) and read 7107 times:
Dear Mr. BA... by now, you get to be a 747 expert...!
There were 747 "gliders" a few times, I recall the British Airways running into ashes of volcano in Indonesia... Boeing has a procedure for that, since the rotation of the engines (windmill) is important to maintain adequate hydraulic pressure for operation of the flight controls - that is a first concern... Remember, all flight controls are hydraulic in the 747, no cables...
In the scenario you present, you are correct, FL 280 is a typical initial level for a heavy 747, you should remember that a heavy aircraft "glides better" than a light one... kinetic energy - 9,000 meters, yes, likely that if the pilots remember how to glide, they will be able to make it back to departure field.
I flew in the military, and occasionally "play pilot" with executive jets... an instrument that I miss in the 747 is the angle of attack indicator, as the Learjets have... that wonderful (and simple) instrument would show the pilots the best L over D... the airliners fail to have an AofA indicator, regrettable. When I fly the "Fearjet" I dont care about speeds, I fly with AofA indicator, to tell me what speed to use, i.e. for approach "1/3" in the green is Vref.
Crosswinds - I looked how "George" (named "Otto" in Germany ), the autopilot, flies a coupled approach: crab angle until the flare. I personally keep the crab until 35 feet AGL, then reducing the power to full idle (keeping a little extra power on the upwind side) then at 10 feet AGL, I "kick" the rudders to align the aircraft to the centerline during the flare. That flare is a little firm, compared to my normal landings, since I do not wish the aircraft to drift from centerline, and "float" forever. In any case, the 747 "by PFM - pure f***ing magic" always lands rather smooth.
The only practical consideration in crosswind is "banking an aircraft" with the nose high (4 engine jets with wing mounted engines) since that attitude brings the outer engines (1 or 4) closer to the ground. I do not indulge in a "wing low" attitude and keep "nose high"... could spell disaster.
Mr.BA From Singapore, joined Sep 2000, 3423 posts, RR: 22 Reply 12, posted (10 years 5 months 5 days 12 hours ago) and read 7057 times:
"Dear Mr. BA... by now, you get to be a 747 expert...!"............ Thanks for the nice words.
Very much thanks for such a detailed explanation! Very nice and interesting to read. One more thing on the "kicking" of rudders to align the nose to the centreline on the runway, do you keep the rudder at that position after touchdown and put the ailerons into the wind or do you release the rudder back to it's centre position? I noticed that the B744 wings are actually more "flexible" than the B747 classics which are a bit more "stiffer" (sorry can't find any other better words to use ). The other day I witnessed a B744 landing in direct crosswind of about 20 knots (sorry we don't get many classics here ) and the pilot did not "de-crab" - He touched down with the crab angle, used the rudder to bring his nose back to the centreline almost simultaneously and put the ailerons into the wind and what a sight... the outboard engine almost struck the tarmac.
I've seen B747s putting almost full ailerons into the wind even the spoilerons came up for take-off in crosswinds while the rudder corrects the heading. One question, I understand pilots will gradually put the ailerons back to the neutral position as they gain speed and as they near rotation. But won't it affect the plane? Releasing the ailerons will prevent a flip but won't the aircraft drift on the runway?
Putting ailerons into the wind and having the rudder at the opposite... always thought that was the best way to keep an aircraft straight on the runway in crosswinds... or are there better ways?
Step climbing are not really necessary for a 3hr flight. I think most airlines (or is it Boeing, I read it somewhere) don't recommend step climbs or rather, climb to a higher altitude when destination is just an hour or so away, wouldn't make much of a difference in fuel savings. And for a 3 hour flight, even if the B744 is at it's Max ZFW with it's 3 hour of fuel can make it to FL 370 or so.
Thanks a lot really appreciate all the help.. ya the B747 master
Positive rate From Australia, joined Sep 2001, 2143 posts, RR: 1 Reply 13, posted (10 years 5 months 5 days 11 hours ago) and read 7026 times:
What is the max- XWIND limitation for the 747 on a dry runway? Also at what speeds does XWIND first become noticeable in a 747? I'm assuming that say a 5-10 kt XWIND would be barely noiticeable wouldn't it? Given the high speed at landing and the huge mass of the airplane?
B747skipper From , joined Dec 1969, posts, RR: Reply 14, posted (10 years 5 months 5 days 1 hour ago) and read 6975 times:
Max crosswind 747 demonstrated 30 knots...
I say again (and all airplanes do the same) slower climb speed for light weight aircraft, high speed for airplanes at maximum weight...
Rate of climb intially averages 2,000 fpm... to some 10,000 feet or so, then reduces progressively... the last 2 or 3,000 feet to cruise level might be only at 500 fpm climb... I generally count on a 35 minutes climb to level off at a cruise level of 290 or 310... again, all depends on weight, there are no "standard" numbers applicable -
After landing in crosswind, correct, we turn the wheel towards the wind, to RH is the wind is from RH... The rudder remains deflected initially, but as the speeds reduce after landing, 60 or less, the deflection does not help any longer. I do not find the 747 any "more" or "less" difficult to handle un crosswinds than any other 4 engine jet I flew, the 707s and the DC8s...
Friends, I am going for ski vacations 2 weeks in Bariloche (that is a ski resort in the Andes, in Argentina) - it is winter here... I might not be reading much of you during that time period... since I have to listen to my wife and my daughter (my son and I will speak airplanes...)