Why do military aircraft have a lower landing gear than civilian? I have in mind the difference between a Lockheed C-130 Hercules and a Boeing or Airbus.
The first possibility that jumps to mind is that one is more comfortable than the other, which is more robust. But would an aircraft designer reduce robustness to provide more comfort?
For the aircraft you use as examples the aircraft height above the ground (landing gear height) is mostly a function of use-case and clearances.
For the Boeing and Airbus airplanes you mention, the gear need be long to accommodate the engines hanging under the wings as well as the minimum bank angle needed to avoid wing strikes.
On the other hand, the C-130 has the engines mounted up on a high wing and the aircraft needs to handle big slow heavy things like tanks being driven into the cargo. The need of the tanks specifically probably mandates the interior floor be pretty close to the ground, or you might need extremely long ramps to for the tank to ascend (and these would pose their own problems).
Easier to Load
As stated earlier, this is your primary reason. You have to be able to load in cargo from the ground. If you want to get troops and vehicles in fast to somewhere with minimum equipment, you want to be able to roll them of the aircraft, and the lower the aircraft, the easier this is done.
Shorter gear is stronger
The longer you make the gear, the more it will bend. Bad news if you're trying to land on rough ground.
More Cargo space
The shorter you make the gear, the less trouble you have finding space for it inside the aircraft, where you want to maximise the amount of space you have for cargo, especially for vehicles and the like. The anatomy of a cargo aircraft is that they are typically hollow inside, unlike passenger aircraft where they fold up into the center section.
Landing gear is heavy
Landing gear is very heavy, since its got to support the weight of the entire aircraft above. The shorter you make it- the lighter the aircraft gets.
Better use of ground effect
The low gear may bring the aircraft a little bit closer to the ground, maximising ground effect and lowering your landing speed, again very ideal for rough terrain.
Note: These don't only apply to military aircraft, but to a lot of commericial ones as well, since the benefits are the same. Look at the Dash-8, ATR 42/72, BAe 146 along with the rear-engined planes, and they all try to do this for these reasons, although ease of cargo loading might not come first on the list.
There is no difference between civil and military aircraft. Not the least because the civil and military transport aircraft are actually the same models. Many military planes have civil variants like Lockheed C-130/L-100, other military planes are derived from civil ones, e.g. C-135 is B707.
The difference depends on where the wings and engines are placed. All the aircraft actually have similar clearance from the ground. Just on some the lowest point is fuselage, on others it's the engines hanging down from the wings and on propeller driven ones it is often the propellers.
Cargo planes (like C-130, C-5, An-124 or An-224) are often built with high wings, so the fuselage is lower and therefore easier to load. This is also concern for regional airliners as they are designed to carry their own stairs. That's why BAe146, ATR-42 or Dash-8 are high-wing and other like Bombardier CRJ series have tail-mounted engines so they can also be lower. On the other hand low or mid-wing designs with wing-mounted engines have better aerodynamic properties, which is why that construction prevails for large airlines.
Why do military aircraft have a lower landing gear than civilian? I have in mind the difference between a Lockheed C-130 Hercules and a Boeing or Airbus. The first possibility that jumps to mind is that one is more comfortable than the other, which is more robust. But would an aircraft designer reduce robustness to provide more comfort?
Some light aircraft now have airframe parachutes. If a pilot does have to pull the chute on a Cirrus (for example), is the aircraft flyable or at least repairable after landing or is it a write-off? What G forces are involved in the impact? I realize that there are lots of possible variables here, but let's assume that the parachute deploys correctly and in plenty of time for a stabilized...). The airframe, seats and landing gear are all designed to absorb the impact energy.
The landing gear should be down in order to qualify as a stabilized approach. Other than that, what are the guidelines on when to deploy landing gear on approach?
) Category D: Speed 141 knots or more but less than 166 knots. (5) Category E: Speed 166 knots or more. So an aircraft category never changes because it is always Vref at max landing weight. What if I fly an approach at a speed that falls into a different category? For instance, a jet may land at significantly less than this speed if very light, or more than this speed if landing with less...FAR 91.3 says: Aircraft approach category means a grouping of aircraft based on a speed of VREF, if specified, or if VREF is not specified, 1.3 Vso at the maximum certificated landing weight
There are a couple of American military aircraft (the retired F-14 and the B-1 come to mind immediately), that have variable swept wings. I know that they keep the wings full out (roughly perpendicular to the body) during take off and landing, and they have the wings swept back for high speed flight. But I've never really understood why? I assume that at lower speeds the wings out... a variable swept wing? Or perhaps there isn't much of a gain and that's why most military aircraft don't have variable sweep?
As a follow up to "What is the measurement system used in the aviation industry?" which specified about measurement units during operations, another question that comes to my mind is: are there differences used in tools for maintenance and repairs for aircraft produced in different countries? Although things have been standardized these days, in the automotive industry you still get differences... common metric spanners. Does this apply also to aircraft? An example that comes into my mind would be the Avro RJ series.
as well land. But what about in a light, single engine plane (think Cessna 172 or Piper Cherokee)? Engine failures in small aircraft, for example, seem to be more common, so you have more accidents that start high above the ground. Thus, you usually have a few minutes before you're going to hit the ground and there's often only 1 or 2 passengers (rather than 100). Plus, you're usually already... out? It seems like a somewhat practical solution, yet I have never heard of anyone doing it. Why do pilots often try to find a road to land on or a lake to ditch in when trouble strikes instead
I'm pretty sure that there are no aircraft equipped with a brake on its nose wheel, however two of my colleagues think there might have been. Are there? Aircraft with retractable gear of course have devices to stop the wheels from spinning when retracted, but I'm asking about brakes used to stop or slow down the aircraft. Please don't consider aircraft with a tail wheel, gliders, experimental aircraft, or aircraft used for flight testing (certified aircraft only).
during landing, they would impact the ground during landing and, given the pitch, do more than scrape the ground and cause damage to the aircraft. However, DB Cooper's jump left the aft stairs open... the ground, was there sufficient damage to require repairs? (I meant this question to be more about the 727 than DB Cooper, but since his was the only landing with stairs open, there wasn't much room...I've never seen a 727's aft stairs open, but presumably, based on an Wikipedia image and common sense, they do reach the ground when the aircraft is on the ground. Furthermore, (as I understand
The airlines are always trying to jam more passengers into each plane. I'm smaller than today's average, and I'm still often uncomfortable in a standard Economy seat. It occurred to me... an airline couldn't introduce a cabin in which some or all passengers travel in a reclining, rather than sitting, position? Seems to me that it would be more comfortable (except for claustrophobes and those who really need to work during the flight). The enclosed space would inherently reduce some of the risks of passengers being thrown around in turbulence or an emergency landing; safety belts