ZBBYLW
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747 Landing Speeds (No Flaps)

Fri Oct 26, 2007 9:59 pm

Hey guys,

I was having a quick chat with a buddy and talking about different approach speeds with various a/c and the 747 came up with a touch down in and around 150ish. Anyhow we do know that because of the sweep back and higher speed design in this wing, they need lots of flaps. If you loose your flaps in a 747 whats the stall speed/approach speed you would use (rough speeds I dont care about a 5 not difference due to extra weight, just a typical landing weight).
Keep the shinny side up!
 
2H4
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Joined: Tue Oct 19, 2004 11:11 pm

RE: 747 Landing Speeds (No Flaps)

Fri Oct 26, 2007 10:05 pm

According to B747Skipper, Vref in a 747 at maximum landing weight (287,000 kg) with zero flaps is 223 Kias...

2H4

Intentionally Left Blank
 
AirportSeven
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RE: 747 Landing Speeds (No Flaps)

Fri Oct 26, 2007 10:13 pm

I'll have to do some digging to come up with a source, but I remember reading that there is no published no flaps landing speed for the 747 because the flaps are gravity driven for the first notch or so, and that the touchdown speeds with no flaps would blow out all the tires on the main landing gear.

Found it:

"Few airlines offer their pilots procedures for flaps-up landings in a 747, according to one pilot. Their manuals, however, provide data allowing crews to determine how much runway will be needed. They know what to expect: The aircraft will approach as slowly as possible, but will still be faster than the design limit for the tires. Most of the tires will fail during the touchdown. One airline has pilots practice making no-flaps approaches, but the training is never carried through to touchdown.

Given the available backup systems on board, it is unlikely a 747's flaps would ever fail to come down. For example, there are ways to substitute the use of electric motors for lost hydraulic power. In addition, when alternate flap-control measures are used, all leading edge flaps extend simultaneously as soon as the flap handle is moved from its Up detent. That lowers stall speeds by 20 knots and approach speeds, while still faster than normal, are then within tire limits."


"The Flap About Flaps", Alton K. Marsh. AOPA Pilot Magazine, August 2004.

[Edited 2007-10-26 15:18:52]
 
ZBBYLW
Topic Author
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Joined: Wed Nov 01, 2006 8:17 am

RE: 747 Landing Speeds (No Flaps)

Fri Oct 26, 2007 10:33 pm

Thanks guys! And this is my 1000 post on A.net!!!
Keep the shinny side up!
 
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Starlionblue
Posts: 17097
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RE: 747 Landing Speeds (No Flaps)

Sat Oct 27, 2007 6:11 am

Quoting ZBBYLW (Reply 3):
Thanks guys! And this is my 1000 post on A.net!!!

Come back when at the 10k mark.  Wink

Kidding. Congrats!
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
PhilSquares
Posts: 3371
Joined: Sun Mar 28, 2004 6:06 pm

RE: 747 Landing Speeds (No Flaps)

Sat Oct 27, 2007 7:04 am

Taken from the 744 FCTM (Flight Crew Training Manual)

All Flaps Up Landing
The probability of both leading and trailing edge devices failing to extend is
extremely remote. System reliability and design have reduced the need
for some traditional non-normal landing procedures. As a result, an all
flaps up landing NNC was not required for airplane certification and does
not appear in the Airplane Flight Manual or in the QRH.
Fly fast, live slow
 
ZBBYLW
Topic Author
Posts: 1612
Joined: Wed Nov 01, 2006 8:17 am

RE: 747 Landing Speeds (No Flaps)

Sat Oct 27, 2007 5:53 pm

Quoting Starlionblue (Reply 4):

Yea, well I mean at least I did not start my own thread in non-av about the 1000 Mark like some people do.

Quoting PhilSquares (Reply 5):

Thanks for that!

Anyone know what the 747 stalls at clean at MTOW?? Just for fun?
Keep the shinny side up!

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