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Questions tagged [landing-gear]

The wheels of an airplane. Sometimes replaced by floats or skis.

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17 votes
3 answers
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Would spinning bush planes' tundra tires in flight be useful?

Short take off and landing bush planes are often fitted with very large diameter and width tires, so called tundra tires so that rough terrain can accomodate to the plane when both meet. Sometimes ...
jkztd's user avatar
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0 votes
0 answers
156 views

Is it against the regualtions to install a dummy set of landing gear during aircraft maintenance?

We will be removing a set of landing gear for overhaul, so we are arranging a set of unserviceable landing gear to keep the aircraft mobile. I would like to know if doing so is against any FAA or EASA ...
Ng Wilson's user avatar
0 votes
1 answer
103 views

Are landing gear bay doors meant to help high lift devices at producing lift, when gear is extended, regarding airliners?

Watching some video of one Mig-31 taking off, one can see those doors circled in red in the picture sourced from it, are those meant to produce net lift and reduce take off and landing distance/speed? ...
jkztd's user avatar
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23 votes
1 answer
6k views

Why was the nose gear of Concorde located so far aft?

Was this because of the drooping nose preventing it from being placed anywhere further up?
Boeing787's user avatar
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3 votes
1 answer
366 views

Nose wheels with camber [duplicate]

What is the reason for the inward slanting nose wheels on a Lockheed Constellation? Are there other aircraft with same design.
Leon Bredenkamp's user avatar
1 vote
1 answer
238 views

How do you clean B737 Wheel Wells?

just wondering, is there any tools used to clean main/nose landing gear bay? I was thinking some machine with steam water or hot water high pressure and solvents. wondering what is the best cleaning ...
Samer AlKasaji's user avatar
10 votes
6 answers
4k views

Has a commercial aircraft ever taken off with its landing gear up?

In the extremely scientifically accurate movie Airplane the Autopilot takes off with the gear up. Has this ever happened? Could any commercial or 4+ passenger GA aircraft do this, say with a 1%+ ...
Nate Lowry's user avatar
1 vote
2 answers
397 views

Landing gear drag and weight calculations

I have read numerous books and researches, but I couldn’t find any formulae that actually work for how to calculate the following (for commercial aircrafts): 1- Drag coefficient for a retractable ...
John Howell's user avatar
33 votes
4 answers
4k views

Why was the skid landing gear located so far aft on the X-15?

The X-15 famously used a pair of steel skids as the main landing gear rather than conventional wheels, which saved weight, allowed the skids to be mounted externally (where wheels and tires would have ...
CameronSS's user avatar
  • 595
3 votes
1 answer
463 views

How would a wheel-well stowaway have performed on a Concorde?

There have been many news reports of stowaways who hide in the wheel wells of subsonic airliners and survive the flight. I assume this would not be survivable with a Concorde because they'd be unable ...
Giovanni's user avatar
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17 votes
2 answers
6k views

Why does the 767’s main landing gear appear spaced considerably farther apart than airplanes of a comparable size?

Below is a comparison of the 767, 787, and A350 main landing gear. The larger distance on the 767 also appears to make the airplane lower to the ground.
Charles Nicholson's user avatar
14 votes
4 answers
4k views

Why should an overheated wheel be approached from the front/back and not in line with the axle?

According to the CAAIP (Civil Aircraft Airworthiness Information and Procedures):/ 10.4 Tests have shown that the safest extinguishant to use is a dry chemical agent and this must be used whenever ...
PaintDryer's user avatar
0 votes
1 answer
203 views

who can do an overhaul of landing gear?

A manufacturer requires the landing gear of an aircraft to be overhauled at a 10 year interval. Can any maintenance facility perform this work or does it need to be an approved facility. This is for a ...
Mark's user avatar
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9 votes
2 answers
2k views

How much momentum is lost through the wheels when landing?

I am idly curious whether any significant proportion of a landing plane's momentum is lost through wheel braking vs. everything else like thrust reversers, aero drag, etc? If I have to pick a plane, ...
Azor Ahai -him-'s user avatar
11 votes
1 answer
792 views

On the A330 why does switching off the ADRs require alternate LG extension and inhibit nose wheel steering?

In the incident examined in this video the pilots experienced an unreliable airspeed indication due to pitot tube blockage in an A330. They followed the abnormal checklist for unreliable airspeed ...
TomMcW's user avatar
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5 votes
3 answers
666 views

Why does the hydraulic pump of retractable-gear GA aircraft run continuously throughout the gear cycle?

The POH of a Cessna T210N (which is a retractable-gear aircraft) states that the hydraulic pump will run 1 - 2 times per hour to restore system pressure bleed down, and whenever the gear up / down ...
TheEagle's user avatar
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16 votes
3 answers
3k views

Landing gear: why is there a maximum altitude for safe retraction?

According to this article, the Dash 8 has a "maximum altitude for safe retraction". This wording implies that there is some danger of retracting the gear above a certain altitude. Is this ...
Igby Largeman's user avatar
19 votes
2 answers
4k views

Why do the 747's wing gear tilt while airborne, but not its body gear?

The 747's sixteen main-landing-gear wheels are distributed over four bogies: two four-wheel wing gear, mounted underneath the inboard wings, and two four-wheel body gear, mounted under the fuselage ...
Vikki's user avatar
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20 votes
3 answers
5k views

Is landing gear-up against the regs?

Typically, landing a plane gear-up results in costly damage, which easily triggers the NTSB reporting requirement. However, as a glider pilot I can easily see how landing a glider gear-up would cause ...
Kenn Sebesta's user avatar
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10 votes
3 answers
4k views

How does the landing gear downlock mechanism work?

How does the landing gear downlock mechanism work? Especially when it's operated without hydraulic pressure or other energy sources. How can it keep the landing gear down and locked, during a gravity ...
Spitfire01's user avatar
6 votes
2 answers
4k views

Why don't small aircraft produce tyre smoke when landing, but big aircraft do?

On almost any recording of big aircraft landing, a huge cloud of smoke can be seen. This even applies to the relatively small Cessna Citation. But I never saw such smoke, at least not visible one, on ...
TheEagle's user avatar
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15 votes
4 answers
5k views

What causes a Cessna 172 and its gear to shake violently after landing and braking?

I am sure this was due to my own ignorance on proper technique, but immediately after landing in a Cessna 172, I applied brakes and some moderate aerodynamic braking and experienced an awful and ...
Ryan Griffith's user avatar
2 votes
2 answers
339 views

Did any Cessna Centurion ever have floats or amphibious floats?

Most of the Cessna aircraft are also available with floats / amphibious gear. But I could find no information of a Cessna Centurion with floats or amphibious gear. Is the Centurion really not water-...
TheEagle's user avatar
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3 votes
1 answer
3k views

How is the debris deflector on the DC-9-80 ("MD-80")'s nose gear kept from striking the ground during landing?

The DC-9-80 (marketed as the "MD-80") has, mounted to its nose gear, what I presume to be a debris deflector (a sled-shaped device to keep the nose gear from kicking up pieces of gravel or ...
Vikki's user avatar
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3 votes
1 answer
225 views

What do the numbers and letters mean in landing gear tire sizes?

I've got these two tire sizes: 27 x 8.5 R12 16 PR, H42 x 15.0 R21 26 PR. Can someone tell me what each of these numbers and letters mean? Also, if the diameter of the rim of the wheel is not included ...
stevederekson555's user avatar
1 vote
0 answers
48 views

Why do the landing gears of Boeing 767 and certain Airbus aircraft tilt down? [duplicate]

I need help and some explanation on why are they sometimes tilted down instead of up.
Pagong27Gaming's user avatar
5 votes
1 answer
1k views

When is it appropriate to foam a landing strip? (example JB292)

Background: I recently watched the Channel5 documentary on JetBlue 292 with their famous sideways landing gear. At around the 8:00-mark you see footage of the actual landing: Main landing gear intact ...
Acasta's user avatar
  • 53
12 votes
2 answers
2k views

Are some tail wheels made out of solid plastic?

Are any tail wheels on small planes made of hard, rounded, plastic-like material?
Matt's user avatar
  • 121
0 votes
1 answer
2k views

Why does it feel like a plane stops in mid-air during approach?

At some stage while on approach to an airport in a commercial jet, it feels like the plane is almost coming to a complete stop in mid-air. Is this maybe as a result of the flaps engaging or the ...
shaz737's user avatar
14 votes
4 answers
4k views

Why are/were there almost no tricycle-gear biplanes?

A friend recently asked me: are there any tricycle-gear biplanes? After hunting around, we found the Waco AVN-8, but that's all. This causes me to ask: is there an aerodynamic or other design ...
Jemenake's user avatar
  • 299
1 vote
2 answers
303 views

How much energy does unretracted landing gear consume?

I am interested in finding energy consumption (% kN) of unretracted landing gear (on a jet fighter) per hour. Although the shape and size tell us how much drag is being produced I need a general rule ...
Thomas's user avatar
  • 53
1 vote
2 answers
291 views

Two- and three-wheel undercarriage in the same airplane?

Are there any airplane types which have the capacity to land in a tricycle configuration and a tail dragger configuration in consecutive landings? I have one example in mind but wonder whether there ...
Peter Kämpf's user avatar
23 votes
2 answers
5k views

What operation is this aircraft performing?

While reading Wikipedia about Ust-Kut Airport, I've run into the following picture: I'd like to know which operation is depicted here? This doesn't seems to be a take-off, as per my very limited ...
trejder's user avatar
  • 4,162
6 votes
2 answers
735 views

Why do landing gear bays in commercial aircraft not have a fire extinguishing system?

Landing gear bays in modern commercial aircraft have fire detectors installed, but there is no fire extinguishing/suppression system in this area. What is the logic behind having fire detection in ...
Mad Max's user avatar
  • 405
6 votes
2 answers
1k views

Diamond DA42 - Do you need the electric master on to extend landing gear?

For the Diamond DA42 (TDI) Learning my electric fire emergencies. Would it be wise to extend the landing gear before electric master is turned off? Does the (hydraulic) gear power pack require the ...
tedioustortoise's user avatar
-5 votes
1 answer
700 views

Why is there no alternative mechanism to extend and lock the landing gear in case of failure? [closed]

As we know, most passenger planes have redundant systems in case of failure of a mechanism. For example, in case of failure, that specific thing can be operated by another alternative method, ...
Deepak-MSFT's user avatar
6 votes
2 answers
1k views

Why is the landing gear lever not set to OFF on the ground?

Several older airliners (e.g. Airbus A300, Boeing 737 until the NG series, Boeing 747 until the -400 series) have landing gear levers with three positions: UP, OFF and DOWN. OFF (or NEUTRAL for Airbus)...
Bianfable's user avatar
  • 52.8k
0 votes
0 answers
55 views

Why is the assumed Lift-to-Weight-Ratio for the limit drop test for heavy aircraft (FAR-25) higher than for small aircraft (FAR-23)?

The FAR-25.725 assumes a Lift-to-Weight-Ratio L/W = 1 for the landing gear drop test while the FAR-23.725 assumes only L/W=0.667. This factor affects the load inertia factor n which is also needed for ...
Paul G's user avatar
  • 1
11 votes
2 answers
2k views

Is it feasible to add an aftermarket hydrofoil to a light aircraft?

Could long, aftermarket hydrofoils be added to the water-skids of a plane (like this Cessna with pontoons or smaller) Cessna 208 Caravan not designed to have a hydro foil, to increase its ability to ...
Justintimeforfun's user avatar
2 votes
1 answer
343 views

Are there all terrain landing gears for planes?

Is there a landing gear set up that will allow a single engine plane (also, allowing for tundra tires than what is not available for current water skids) to land on rough grass and water? The wheels ...
Justintimeforfun's user avatar
10 votes
2 answers
317 views

What is dual mode adaptive landing gear system?

Referring to the NASA document Design and Development of the Blackbird: Challenges and Lessons Learned. On page 31, there's a mention of dual-mode adaptive landing gear, which is quoted below. ...
Salmonbeing00's user avatar
0 votes
1 answer
1k views

How does the B777 Side brace locking mechanism work?

The B767 has jury strut actuators and their working is pretty straight forward. They oppose the collapsible geometry of jury strut and lock them in the over centre locking position. But for B777 this ...
Salmonbeing00's user avatar
11 votes
1 answer
3k views

Can the Landing gear be lowered when system A hydraulic pressure is lost in Boeing 737?

In the FCOM OF BOEING 737 HYDRAULIC SECTION I went through the part Landing gear transfer unit that it is used to raise the landing gear at a normal rate when system A EDP volume is lost. My query is ...
Anik Bhowmick's user avatar
1 vote
1 answer
178 views

How do rotor tangs lock into wheel keyways?

How do the rotor tangs lock into wheel keyways? Are there special keys on the outboard wheel half that allow locking the tangs in place? Also would be great if anyone could provide me with a image of ...
Salmonbeing00's user avatar
3 votes
4 answers
2k views

Why landing gears still need bungee springs?

While studying landing gear, I came across this term 'bungee spring' to which there was no definitive explanation in text with regards to its usage. So in the image, you can see for the jury strut/ ...
Salmonbeing00's user avatar
2 votes
2 answers
674 views

Are General Aviation tires filled with Nitrogen?

Long story short, I'm working on a concept for a book. We all know why commercial aircraft have nitrogen tires, but my question is if GA aircraft have nitrogen tires, or are they just filled with ...
Air Canada 001's user avatar
1 vote
0 answers
402 views

What is the linkage connecting the body landing gear on the C-130?

I can't seem to find a diagram that includes this tube linking the front and rear body gear on each side. Is it structural, or hydraulic, or maybe something else entirely? Image source: https://www....
zymhan's user avatar
  • 2,198
20 votes
2 answers
3k views

Would deploying the Space Shuttle's landing gear early have improved safety? [duplicate]

Due to the space shuttle orbiter’s high weight (potentially up to 110 tonnes [121 short tons] in certain abort scenarios, although nominally around 85 tonnes [94 short tons]) and abysmal subsonic ...
Vikki's user avatar
  • 27.8k
3 votes
1 answer
1k views

Do the A-320 landing gear extend if the mechanism is activated above a limiting speed?

I've been told that on the A-320, if the landing gear lever is lowered with the airspeed above a limiting speed, the system will not extend the landing gear. Further, once the aircraft is slowed to an ...
Ralph J's user avatar
  • 47.5k
0 votes
1 answer
376 views

Why do some fighter jets have double wheels in the front gear whereas some other aircraft have a single wheel?

The Typhoon has a single wheel in the front gear, but the Rafale or Gripen have double wheels in the front gear. What is the reason for this difference?
Mahedi Hasan's user avatar

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