747 takeoff
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747 takeoff
Recently whilst on a 747-400, both outbound and return there was a rather loud bang from below (Both legs I was sat over the wing, 46A and 48J) - The noise didn't really bother me, I'd heard about it somewhere before (Youtube video I think).
Can anybody tell me what that bang is? - My first guess would be the gear, but I'm not too sure..
Thanks
Can anybody tell me what that bang is? - My first guess would be the gear, but I'm not too sure..
Thanks
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The bang you hear is the nose gear oleo extending on rotation. If it is slightly over serviced it will tend to do that. Nothing to worry about at all. Perfectly normal.
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The bang you hear is the nose gear oleo extending on rotation
I believe there is often also a slight judder/vibration which can be caused when the main gear wheels stop rotating just after take-off.
Paxing All Over The World
As the aircraft rotates (lifts off), the springs on the landing gear naturally extend to their greatest extent. Given the strength of the springs, there is a bit of bang as they reach the end of their travel. The same would happen if your car suddenly left the road on a hump-back bridge!
Only diff - in your car you would not have time to notice the bang as you worried about the heck was going to happen next!!! Sitting in your seat as (something like) 350 tons is lifted off the springs, you notice the 'bang' but it is a nice bang!
Only diff - in your car you would not have time to notice the bang as you worried about the heck was going to happen next!!! Sitting in your seat as (something like) 350 tons is lifted off the springs, you notice the 'bang' but it is a nice bang!
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Thanks, I assumed it was perfectly normal anyway, mainly because an emergency didn't follow haha.
I've only noticed it on 747, not on any other aircraft and I've flown on my fair share of 738's!
I've only noticed it on 747, not on any other aircraft and I've flown on my fair share of 738's!
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I've noticed it on every 737 I've been on (and thats a fair few now) including from the front few rows of a 739, the double bump from the main gear is quite apparent even at the front...not been as obvious on the Babybus though...
No springs in modern landing gear, I'm afraid: rapid strut extension on rotation is due to the pressure of the oleo nitrogen charge as it is no longer supporting the load.
Paxing All Over The World
Thanks for giving the nitty gritty, stevef, I had stuck with plain language and should have put the >'< around - springs.
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Where are the "experts" here...?
Any highly qualified/current Microsoft Airlines veteran 747 captain here...?
Come on, please help. You gentlemen do know better -
xxx
Everyone knows that there are 3 reasons - (sometimes more) -
One "klonk" for the doors closing.
Another "klonk" when wing gear (outer gear) tilts up for retraction positioning.
And one other "klonk" for the gear full down or up (extension/retraction).
That is for the 100-200-300-SPs...
In the 400s, the "klonks" sound more like "bang-boom" -
At least if you sit on seats 45A or 45K.
My FOM indicates that the sounds are within Annex 16/3 noise limits.
xxx
And extra "klonks" if I let that darn F/O land (he logs 2 or more landings)...
Happy contrails
Come on, please help. You gentlemen do know better -
xxx
Everyone knows that there are 3 reasons - (sometimes more) -
One "klonk" for the doors closing.
Another "klonk" when wing gear (outer gear) tilts up for retraction positioning.
And one other "klonk" for the gear full down or up (extension/retraction).
That is for the 100-200-300-SPs...
In the 400s, the "klonks" sound more like "bang-boom" -
At least if you sit on seats 45A or 45K.
My FOM indicates that the sounds are within Annex 16/3 noise limits.
xxx
And extra "klonks" if I let that darn F/O land (he logs 2 or more landings)...
Happy contrails
Paxing All Over The World
BelArgUSA I am not sure which answer best suits:
- Do your parents know that you are playing with the internet?
- Don't the doors also make a Klonk when they OPEN to allow the gear to retract? That is because the doors are in multiple sections.
- Congratulations, you ARE the number one 747 nerd in PPRuNe!
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Whoa there, PAXboy! BelArgUsa is 64 yrs and in the twilight zone of knowing everything, but remembering nothing! At 65 he will be eligible for 'The Home for the Bewildered and Incontinent'! -so go easy on him.
AdamC "one should only turn left on boarding an aircraft" - so buy a first class ticket and the only noises you will hear will be the popping of Champagne corks and your own gentle snoring!
AdamC "one should only turn left on boarding an aircraft" - so buy a first class ticket and the only noises you will hear will be the popping of Champagne corks and your own gentle snoring!
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Any highly qualified/current Microsoft Airlines veteran 747 captain here...?
Well I did once land a 737 on an aircraft carrier using MSFS.
It was easy, just set the wind to 130 knots down the deck and hovered to a nice gentle touchdown.
You pilots are overpaid , flying is easy
Well I did once land a 737 on an aircraft carrier using MSFS.
It was easy, just set the wind to 130 knots down the deck and hovered to a nice gentle touchdown.
You pilots are overpaid , flying is easy