when a plane is landing why does the landing gear come out like 5 minues before we touch the ground
2007-08-16 08:11:47 · 12 answers · asked by ng18 5 in Cars & Transportation ➔ Aircraft
Landing gears are lowered as per procedures outlined in the aircraft check lists.
The aircraft manufacturers specify the point and time at which to lower the gears. This is done to ensure that safety and fuel factors are not compromised.
The point at which gears are to be lowered and locked in position, has been carefully calculated with enough safety margins and provisions catered for. A prematurely lowered gear (by virtue of producing a lot of drag) would increase fuel consumption thus increasing operating costs unnecessarily.
To conclude, the landing gears come down at a point which is safe and also minimises extra fuel consumption.
2007-08-16 21:51:16 · answer #1 · answered by al_sheda 4 · 0⤊ 0⤋
All good answers. I'll just add this. In a large swept wing jet aircraft, we like to shoot what's called a "stabilized approach". That means we want to be able to transition from the approach to the landing with very little if any maneuvering low to the ground. To be stabilized means to be in the landing configuration, gear down, full flaps and on speed and on glide slope no lower than five hundred feet above touchdown and preferably by one thousand feet. This takes time so the gear needs to be lowered early on because you cannot add full flaps until the gear is down and locked. Once the gear is down and full flaps are extended, it still takes a little time to stabilize the airspeed and get the power set to hold that speed and stay on the glide path. If you do it all right, all you'll need to do when you are over the runway is pull the throttles to idle and she'll fly herself onto the pavement.
2007-08-16 13:37:25 · answer #2 · answered by Anonymous · 3⤊ 1⤋
Landing gear is kept retracted during flight for aerodynamics. Less air resistance means more speed and less fuel used. When the gear is extended for landing, it helps to slow the plane down and helps it to lose altitude.
2007-08-16 13:48:26 · answer #3 · answered by Aldo the Apache 6 · 0⤊ 0⤋
Landing gear creates drag and slows the airplane down, which is not efficient in regular flight (extra power needed to keep speed, which can create higher fuel lost). Pilots extend the landing gear on final approach (descending towards runway~5 miles out), which is the final stage when the plane is directly in front of the runway and has to fly SLOW to have a SAFE LANDING.
2007-08-16 08:26:37 · answer #4 · answered by chessloser24 2 · 7⤊ 1⤋
For a large commercial jet liner, there is rather a long checklist of things that happen during landing. One thing you DON'T want happening is for the flight characteristics of the airplane to be changing close to the ground. Since dropping the gear adds drag, the change could throw off the landing if not compensated for well before.
You also want to make sure that not only is the gear down, but it is locked in place.
If you have an engine failure close to the ground, you don't have time to drop the gear. For a commercial airline, 5000 feet is VERY close to the ground.
2007-08-16 08:21:51 · answer #5 · answered by Elana 7 · 4⤊ 3⤋
Chessloser has it correct. Drag. You wouldn't want to fly from Seattle to Chicago with the gear down. It would be a long(er) flight because the aircraft can't fly at its maximum speed.
An airplane can only go so fast with the gear down. If it goes faster or exceeds the limit of airspeed with the gear down, special inspections have to be accomplished to ensure there is no structural damage to the airplane and the landing gear.
2007-08-16 09:20:30 · answer #6 · answered by tequila_mike 3 · 1⤊ 2⤋
Better that that 5 seconds AFTER you touch down!
Pilots follow checklists in all phases of flight from pre-flight inspection to post-arrival and engine shutdown. Approach and landing are no different. "Gear Down & Locked" appears several times in most checklists to ensure that the gear are down and locked before landing.
2007-08-16 08:17:01 · answer #7 · answered by Bostonian In MO 7 · 8⤊ 2⤋
You'd be surprised at how many pilots have landed and forgotten to put the gear down.
2007-08-16 08:35:38 · answer #8 · answered by Anonymous · 3⤊ 3⤋
so that the air has time to flow over the wheels and get them up to speed. therefor not causing the tires to get flat spots on them, like they would if the wheels were completely stopped when they make contact with the run way.
2007-08-16 23:05:44 · answer #9 · answered by Anonymous · 0⤊ 1⤋
Putting it down helps slow the plane down.
2007-08-16 10:32:13 · answer #10 · answered by Airmech 5 · 1⤊ 3⤋