View Full Version : Take-Off in Stormy Conditions
LandASAP 2nd November 2009, 23:37 Just found this Video:
Taking off during the typhoon from the airport to Gonkoge April 19, 2008 (Aeroflot, flight SU596) - Passenger Seat Video - Avsim R Us (http://snipurl.com/t0z2o)
Seems a very strange situation for me. Never saw a plane taking off with spoilers deployed. Seems that the pilot gave some full input to the aileron during take-off run. Can anyone confirm that this is a comon practice during crosswind/storm conditions? The overall situation seems very dangerous to me!
BTW looks like a Aeroflot B767....
Greetings
FL370 Officeboy 2nd November 2009, 23:47 It certainly looks to me like he's holding nearly if not full left wing down aileron in. Suggests a crosswind from the left and a pretty hefty one.
I think I'd rather have been sat in the crew room with a cup of tea!
Avman 2nd November 2009, 23:50 Tell you what, I (as SLF) would have stayed in my hotel and waited a day or two!
RingwaySam 3rd November 2009, 00:46 Tell you what, I (as SLF) would have stayed in my hotel and waited a day or two!
You're not the only one! :O
Doors to Automatic 3rd November 2009, 00:56 I'd have been sat on the toilet after that departure - thats if I hadn't "evacuated" all over the seat! :p
Was that lightning just after lift-off?
purplehelmet 3rd November 2009, 02:02 blimey thats scary, surely he should of waited for the storm to clear?
(in god and pilots we trust)
LandASAP 3rd November 2009, 03:31 For me, the storm is not the important thing... The Spoilers extended on one wing during take off run scares me (I know that is becaus of the aileron, but pilots should also know that). Is there any procedure which would allow that? So, you have drag, you lost lift on one wing... How could the pilots determine correct VR speed in this configuration? Do the pilots know, how the airplane reacts during lift off in this configuration?
Greetings
Doors to Automatic 3rd November 2009, 11:50 How could the pilots determine correct VR speed in this configuration?
I'm guessing they added a fair bit onto the official Vr speed - something which appears to be borne out by the long take-off run. They would probably not go derated if they had any sense either.
Evening Star 3rd November 2009, 13:18 Very impressive, although I do wonder if a video camera counts as the electrical equipment one should not be using during take off and landing.:hmm:
Avman 3rd November 2009, 14:05 Maybe not, but in reality thousands of pax video/film their take-offs and landings every day. Pilots shouldn't miss their destination, but they do. :E
gd44 3rd November 2009, 20:12 For me, the storm is not the important thing... The Spoilers extended on one wing during take off run scares me (I know that is becaus of the aileron, but pilots should also know that). Is there any procedure which would allow that? So, you have drag, you lost lift on one wing... How could the pilots determine correct VR speed in this configuration? Do the pilots know, how the airplane reacts during lift off in this configuration?
Its a standard manouver for a crosswind take-off. In this case the wind is from the left, so to counteract the wind, which will be pushing the aircraft to the right, the pilot will put the left wing into wind using the rudder as nesecary to maintain the centerline.
As the airspeed builds during the take-off run, you slowly centeralise the control column and rotate. This manouver will not effect the V-Speeds significantly, what will effect them is the runway conditions.
What you've got to remember is that on these large aircraft the "Spoliers" act in a number of ways, but achieve the same goal. In this example they are acting as "Spoilerons".
Hope this Helps :ok:
Skyfan 5th November 2009, 11:16 Sure it's all 'present and correct' technically but b*gg*r me that looks interesting. Was waiting for the boundary fence to appear and I'm only watching it.:ok:
Teevee 5th November 2009, 11:20 I don't know if anyone can help me on this but whereabouts is that airport as I don't recognise the name and was that really a typhoon or just a bit of a storm blowing through. I know that on that date the South China area experienced its first typhoon of the season and wondered if there was a tie-up?
pressman 5th November 2009, 12:04 it is definately not SOP for boeing to do this , Boeing FCOM advises against this , poor airmanship displayed to take off with spoiler deployed . There would be no V1 correction here , however Vmcg is badly affected by spoilers deployed so much , a couple of units aileron should have been used along with keeping it straight using rudder , take the crab into the air and correct once airborne .
Hogg 5th November 2009, 12:26 This takeoff seems perfectly normal at what may have been a max xwind (wet) windspeed.Roll spoilers are interconnected with the ailerons, so as to perform in harmony with them. In many aircraft roll spoilers deploy as a function of airspeed.
The reason roll spoilers are often required on high-speed aircraft is because they operate across such great speed ranges — such planes must resolve high-speed aerodynamics with the slow flight required for safe takeoffs and landings. Planes fly fastest with small, thin wings and high wing loading. Safe take-offs and landings, on the other hand, require high-camber, high-lift wings, with low wing loading. In essence, two different airplanes are required: one that can go fast, and one that can get everybody off the ground in less than ten miles of runway!
This challenge is resolved through extensive use of big flaps and leading edge devices (LEDs) which effectively convert the wing from a high-speed shape to a low-speed, takeoff-and-landing shape. The problem is that in order to make wing size (and drag) small for optimum cruise speeds, the flaps must extend across as much of the wingspan as possible for adequate low-speed effectiveness. With all those flaps installed, there’s little room left on the wing for ailerons. Small ailerons may be fine for high speed cruise, but they’re often too small for adequate roll response at low airspeeds, like when taking off and landing. One solution to this problem is to put multiple ailerons on each wing, separately activated as a function of airspeed. The other solution is to install roll spoilers to help the ailerons. (The Boeing 767 utilizes roll spoilers AND two ailerons per wing — the outboard ones are locked above 240 kts).
Noddys car 5th November 2009, 12:35 think you will find thats a departure from HKG..Can just make out CX city in the murk and a KA 744 on the ramp and the red fire trainer
Rainboe 5th November 2009, 12:41 Well that's when a pilot earns his pay! Good job. Dreadful conditions, but do you really want flights cancelled when the weather gets like this? He handled it perfectly, kept the wings level. The spoilers helped reduce the extra lift on the upwind wing. Conditions dreadful airborne- all very competently handled. I, as a 38 year in the industry pilot flying heavy jets, would send my family with this chap anytime. Until you have handled jets at crosswind limits on wet runways and know the effect, I would not criticise. It is the only way to do it when it is like that. I have flown VC10s and 747s in Monsoons, Typhoons, Hurricanes, 737s in Icelandic storms (it's always stormy up there). You may rest assured this pilot was not hazarding your life! Ignore the keyboard Monday quarterbacks!
fozzyflyer 5th November 2009, 12:55 Hogg,gd44
Trust me this is not normal!! As pressman rightly says this is certainly not a boeing sop. gd44, i think you are confusing this situation with light aircraft. If you "slowly centralised" the controls when still on the ground in a swept wing jet a/c you wouldn't see much of the centreline!
On 757/767 you hold up to two units of aileron input and keep the a/c on the centreline with the rudder pedals, hold the inputs until AFTER rotation then use whatever it takes to hold a steady crab and with ailerons.
Use any more than 2 units of aileron then the spoilers pop up which is a big no no (on the ground). Huge amount of drag and lack of lift......just what you want on takeoff!:eek: There are no "adjusted v1" figures or anything like it as you aren't supposed to do it! gd44, the spoilers do carry out a number of functions during different phases of flight, however you really don't want their help in any way on the takeoff roll! Whoever suggested the crew had "added a bit on" to the performance figures?:eek: The max x/wind for takeoff on 75/76 is around 30kts, this was either more than that (in which case they shouldn't have gone), or they weren't aware of the effects of holding too much aileron in (they shouldn't have gone)!
SloppyJoe 5th November 2009, 13:08 not sure about a boeing but should be the same as the airbus and in that you put in a correction towards the x-wind but not enough to deploy spoilers as this reduces performance quite a bit, they are used to stop after landing so will obviously have the same result on take off if deployed, ok not stop you but stop you going as fast as quick. If that was the only way to keep it straight then it would have been way out of limits.
22/04 5th November 2009, 14:07 The take off roll also seems long; about 1 min 12 sec. As I generally as pax time take offs I would have been getting worried about that, quite apart from anything else.
gd44 5th November 2009, 16:43 Thanks for clearing that up, I am indeed taking what I know from light aircraft and assuming that the procedure is going to be pretty much the same, from what you've said it is more or less the same, obviously with differences which you pointed out.
It is definetley a very interesting take-off.
Thanks for the help :ok:
wheelbarrow 5th November 2009, 17:32 fozzy and some others, these spoilers in the video are roll spoilers not ground liftdump spoilers. theyre inboard ailerons and very effective.
sometimes more than 2 units are required into wind to counteract a 20 knot gusting 30 in a crosswind.
i would be happy behind this pilot anyday, the techiques are somewhat different maybe on the smaller 757. 767 rocks.:)
ishe 5th November 2009, 18:14 i agree with wheelbarrow. The 747 is the same, roll spoilers come out with more than 15deg control input. Also watch the video you can see the spoilers moving up with the inboard aileron.
fozzyflyer 5th November 2009, 18:46 Wheelbarrow/ishe,
Just been looking at my FCTM and boeing tech manual which is supposed to cover 75/76 but only has system description for 757 for some reason. It states that "large control wheel inputs (generally >2 units as per control column indicator) can have an adverse effect on directional control at speeds close to V1(MCG) due to the additional drag of the extended spoilers".
According to the schematic of the 75 wing the most inboard panels (no's 5-8) are used to compliment the ailerons in roll (in lieu of the 76's i/b ailerons), but the outboard panels 1-4 and 9-12 are for air use only in roll, and are spoiler/lift dumpers on the ground. It would therefore appear that what is a "no no" on 75 is a "would advise against" on 76. I fly both but have far more hours on the little fella and didn't realise they were so different in that respect. Every day is a school day!:ok:
Ps yes the 76 does indeed rock, but it also flies too far for my liking!:zzz:
Groundloop 6th November 2009, 10:57 The take off roll also seems long; about 1 min 12 sec. As I generally as pax time take offs I would have been getting worried about that, quite apart from anything else.
Then stop timing take-off rolls and you won't worry yourself unnecessarily.:ok:
Evening Star 7th November 2009, 13:28 Maybe not, but in reality thousands of pax video/film their take-offs and landings every day.
And to think I felt bad last year after forgetting to take the meter battery out of my otherwise fully mechanical FM2n when shooting the landing at SVO.:8
The take off roll also seems long; about 1 min 12 sec. As I generally as pax time take offs I would have been getting worried about that, quite apart from anything else.
Until you have experienced the take-off under deep fresh snow from the non too lengthy runway at ROV you have nothing to worry about.;)
Groundloop :ok:
HeathrowAirport 7th November 2009, 14:14 Two words "**** That":ok:
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