Seen plenty of landing gear cams before, but never one from this perspective.

Figured some of you may enjoy it!

https://www.youtube.com/watch?v=7Y3lpgbTu6k

Thanks for sharing! Fascinating to see from that angle

Interesting to see how the wheels stop spinning seconds before retraction....I always thought that they continue spinning for a while even after fully retracted....

Gr8Circle wrote:

Interesting to see how the wheels stop spinning seconds before retraction....I always thought that they continue spinning for a while even after fully retracted....

Depending on the aircraft, most apply brake pressure to the main gear wheels when selected up. There are a lot of systems with components in the wheel well, for instance: fuel lines, hydraulic lines and accumulators, flap motors, flight control cables, fire bottles, just to name a few. The threat is that a damaged tire is still spinning while it is retracted into the well and wreaks havoc on the accessible systems. The nose wheel on the other hand usually just comes in contact with a rubber brake or snubber when retracted which stops rotation mechanically.

jetskipper wrote:

Gr8Circle wrote:

Interesting to see how the wheels stop spinning seconds before retraction....I always thought that they continue spinning for a while even after fully retracted....

Depending on the aircraft, most apply brake pressure to the main gear wheels when selected up. There are a lot of systems with components in the wheel well, for instance: fuel lines, hydraulic lines and accumulators, flap motors, flight control cables, fire bottles, just to name a few. The threat is that a damaged tire is still spinning while it is retracted into the well and wreaks havoc on the accessible systems. The nose wheel on the other hand usually just comes in contact with a rubber brake or snubber when retracted which stops rotation mechanically.

It's also the gyroscopic effects.

I was wondering - the 737 and ithers don't retract the wheels fully into the bay and have a door close on it.
On this video you can see the right gear doesn't seal fully as you can see a bit if light.

How much drag and especially noise does this make?
Obviously not enough to change the design (that would be a huge change)

Looks scary, even on video.

Which makes this even scarier!
https://interestingengineering.com/a-st ... wheel-well

I guess desperate people will do desperate things.

ReverseFlow wrote:

On this video you can see the right gear doesn't seal fully as you can see a bit if light.

How much drag and especially noise does this make?
Obviously not enough to change the design (that would be a huge change)

I noticed that too. It can't be the spec as designed so I'm guessing it's some bits that need replacing causing that imperfect seal.

Cool video! thanks, LAX772LR

wingman wrote:

ReverseFlow wrote:

On this video you can see the right gear doesn't seal fully as you can see a bit if light.

How much drag and especially noise does this make?
Obviously not enough to change the design (that would be a huge change)

I noticed that too. It can't be the spec as designed so I'm guessing it's some bits that need replacing causing that imperfect seal.

Those flap seals on the 737 are a common replacement item for aircraft during scheduled checks.

Being someone who has delved into the joys of EWIS in the past, the biggest thing that blows my mind is how solid those hydraulic lines and hoses seem to be. I can't even detect the slightest hint of vibration in those or any wire bundles routed around them.

slvrblt wrote:

Cool video! thanks, LAX772LR

No prob.

Here's the landing, from the same cam, if y'all wanted to see. It's pretty cool, seeing as the approach is over the Indian Ocean.

https://www.youtube.com/watch?v=9w6HOT35JMA

SEAorPWM wrote:

Being someone who has delved into the joys of EWIS in the past, the biggest thing that blows my mind is how solid those hydraulic lines and hoses seem to be. I can't even detect the slightest hint of vibration in those or any wire bundles routed around them.

All the plumbing in the wheel well is designed to withstand a tire that explodes after retraction. Oddly enough, bias ply and radials tires exert forces differently when they explode. When we converted our 737-800 fleet from bias to radial tires, a part of the mod was to replace specific hydraulic lines in the wheel wells with heavier wall tubing to be compatible with the radial tire failure characteristics.

jetskipper wrote:

Gr8Circle wrote:

Interesting to see how the wheels stop spinning seconds before retraction....I always thought that they continue spinning for a while even after fully retracted....

Depending on the aircraft, most apply brake pressure to the main gear wheels when selected up. There are a lot of systems with components in the wheel well, for instance: fuel lines, hydraulic lines and accumulators, flap motors, flight control cables, fire bottles, just to name a few. The threat is that a damaged tire is still spinning while it is retracted into the well and wreaks havoc on the accessible systems. The nose wheel on the other hand usually just comes in contact with a rubber brake or snubber when retracted which stops rotation mechanically.

Just to expound a bit more: there is a frangible fitting on the bottom of the wing-to-body fairing on the B737 (NG at least) that in the event a tire is experiencing tread separation AND still makes it near the wheel well, that spinning tire tread will shear the fitting off and that will remove hydraulic power from the retract cylinder (slight amount of fluid overboard - a hydraulic fuse isolates the rest of the system) to prevent the landing gear from retracting any further (gravity takes over and that landing gear assumes down and locked position). This would prevent said tire from getting into the wheel well and possibly ending up stuck due to the tire tread trying to liberate itself.

Another reason the brakes are applied at gear retraction (~500 psi) is the tires expand while rolling, so stopping the tires brings them back to their normal size so they can enter the wheel well without contact with anything

LAX772LR wrote:

Seen plenty of landing gear cams before, but never one from this perspective.

Figured some of you may enjoy it!

https://www.youtube.com/watch?v=7Y3lpgbTu6k

That is awesome! Gets me to thinking. I wonder if airlines would consider doing cameras like this that pilots can access when troubleshooting a problem? This view would be great for a situation the gear doesn't show down.

Technology is just still blowing me away.

F9Animal wrote:

I wonder if airlines would consider doing cameras like this that pilots can access when troubleshooting a problem? This view would be great for a situation the gear doesn't show down.

That's actually a pretty good idea... I wonder why they don't.

That could've been extremely helpful in an incident like FX1026:
https://www.youtube.com/watch?v=4IgAbGk7Jy4

Visually down doesn't mean locked!

wingman wrote:

ReverseFlow wrote:

On this video you can see the right gear doesn't seal fully as you can see a bit if light.

How much drag and especially noise does this make?
Obviously not enough to change the design (that would be a huge change)

I noticed that too. It can't be the spec as designed so I'm guessing it's some bits that need replacing causing that imperfect seal.

It's not designed to be a perfect seal, it's a brush seal. Just there to help smooth the surface by filling in the gap from the belly fairing to the wheels.