A few 747 questions

[VSI9k+]

1) What is the zero flap approach speed in a 747?
2) What is the typical landing distance when flaps are used and when flaps arent used?
3) Are there numbers as to how much more runway will be used per knot increased on approach?

Thanks in advance

 

[Pantherjon]

1> FAST
2> LOTS OF PAVEMENT; LOTS AND LOTS AND LOTS OF PAVEMENT USED UP
3> Aint a runway long enough if your too hot on approach, unless landing at Edwards in the lake bed

Just name me Mr Sarcasm today..lol

 

[Draginass]

A flaps up approach would be an emergency procedure. It's actually not even covered in the Boeing flight manual because of the remoteness of the possibility. Flaps can be lowered hydraulically or electrically, hence no need for a procedure.

If it were necessary getting as light as practical would be prudent to slow the approach speed as much as possible (205k tire limit speed, I think). Lightweight, say 370k lbs, no cargo, an approach speed of Vref+70 would be ok (say 120k + 70 = 190k approach speed). In this case, the brakes are well capable of stopping the airplane, even without over temping them.

If the airplane had a full payload the landing weight, even with minimum fuel could still be 600,000 lbs. A flaps up approach at that weight would need a very long runway with the sure expectation of tire overspeed and blown fuse plugs due to excessive brake heating. In other words . . . real ugly.

 

[Junkflyer]

At heavy landing weights ref is around 160 kts, with zero flap you would add 80 kts which would put you well over tire speed plus a ridiculous amount of runway. On the 74 its always the more the merrier when it comes to runway length. You can squeeze into 8000 feet or less (depending on weight of course) though the pucker factor increases as length decreases.

 

[nosewheel]

One Exception is.. at Al Kaleeta we can do 5000 ft at max wt., blow all the tire's and still keep our job's. :nuts:

 

[Bjammin]

Sounds like your studying for a Cathay interview.

Never even practiced a zero flap landing, lots of backups to keep this from happening.

8000ft is about the shortest you want to land even when light. Again have no idea about no flap.

The landing charts we use are based on flap position, wind speed, field pressure, and abnormals. There is no correction for speed as they assume your flying your flap ref speed.

 

[AirBadger]

Air Force 1 uses the 8000' runway at CNW. Also have seen C-5s and other 747s doing touch and goes on the 8000' rwy. Granted I'm sure they were extremely light.

 

[C-150ETOPS]

South African Airways flew one into a 4900' long runway for a museum.

It was also 50' wide


http://www.saamuseum.co.za/saams_aircraft.htm

 

[philsquares]

1) What is the zero flap approach speed in a 747?
2) What is the typical landing distance when flaps are used and when flaps arent used?
3) Are there numbers as to how much more runway will be used per knot increased on approach?

Thanks in advance

1) You have non choice on using flaps. It's either 25 or 30 flaps.

2) For a 250 ton aircraft, using auto brakes 2, auto spoilers and reverse it's 6750. That's from the 50' TCH.

For every 10 knots above VRef you add 630'.

As was already stated, there is no No Flap numbers since it's almost impossible to get into that situation.