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stepbk
02-25-2011, 09:30 PM
Hi guys

Hope everyone is doing well
Ive always used ILS to land the queen (747), but i was flying to some small airport last couple of days and they are not equiped with ILS. In the FMC, there RNAV. My question is, how do you programme the plane or how do you land the 747 using Rnav.


thanks in adavance


Happy Flying

JWS
02-26-2011, 09:38 AM
There are several ways. I refer to Bill Bulfers MCP guide (a must have!!) and let me summarize (there is more to it).

RNAV approach is flown in LNAV and VNAV (VNAV BARO). LNAV follows the waypoints towards the runway, VNAV the vertical path (according to the FMC). VNAV is easier than V/S because you don't have to adjust the MCP ALT (during stepdown).
Try to be fully configured before entering the final phase at FAF and at the APP spd. Before FAF set MCP alt at airport elevation (rounded off to the next hundred feet; so elevation of 134' becomes 200 in MCP alt.) BARO set at published MDA (for non-precison approaches; see chart)+50 feet. The green arc should help you with the monitoring. At DA disengage A/P and land manually.


Other way (CDAP: Constant Descent Approach Procedure; thanks to Mike Ray)
If a runway has no ILS there may be a VOR LOC DME navaid which can be used. Refer to your charts for the proper LOC course and follow that in VOR LOC. On the chart you'll see the FAF where the final descent starts. Let's say you alt is 2000'. FAF DME is 5.6. Fully configured, at VREF+windcorr e.g. 160 knots; alt hld 2000, set MCP at value given above (200). At 0.3 before FAF (= 5.9) start turning thumbwheel V/S to - 900, so nose over is at FAF. Keep green arc at beginning runway, adjust V/S accordingly (800/850). At MDA disengage A/P etc.

Vertical speed can be computed as follows:
1/2 groundspeed X 10 + glideslope correction

Glideslope correction= +50 feet for each 0.25 degrees that glideslope is greater than 3 degrees.
Example: 140 kts G/S and a 3 1/2 degree glideslope.
Descent rate should be 140/2=70 x 10 = 700 fpm. Glideslope correction (G/S is 2 x .25 degrees greater dan 3 degrees): add 100
So 700 + 100 = 800 fpm.


Happy landings.

JWS

saabpilot
03-01-2011, 12:56 AM
In depth description of correct VNAV approaches can be found at SmartCockpit:
http://www.smartcockpit.com/pdf/plane/boeing/B737/instructor/0056/

For RyanAir and B737, but procedures are of course applicable for B747 too. :D

Best,
Bjorn

www.boeing737sim.se

dodiano
03-01-2011, 01:05 AM
You want to do an RNAV Autoland bud??I don't think is possible. Or did I understand incorrectly !!

Regards,

Roberto

oal331
03-01-2011, 03:27 AM
I'm not a real pilot, but i think that RNAV is not an Autoland System (please correct me, if i'm wrong).
RNAV is a method of navigation only.
RNAV approach operates until LNAV/VNAV minima.

JWS
03-01-2011, 07:54 AM
You want to do an RNAV Autoland bud??I don't think is possible. Or did I understand incorrectly !!

Regards,

Roberto

As stated in my post: you disengage A/P and land manually. So no autoland!

JWS

saabpilot
03-01-2011, 08:50 AM
I'm not a real pilot, but i think that RNAV is not an Autoland System (please correct me, if i'm wrong).
RNAV is a method of navigation only.
RNAV approach operates until LNAV/VNAV minima.

Yes, it is a navigation method, but also an non precision approach method.
As such it have separate minima and landing is performed manually latest from the point where you according to SOP/AOM have to disengage the a/p.

(Not the actual minima where you either continue if positive rwy or app light contact or else make a go-around.)

As an example - see LOWI Innsbruck charts for RNAV 26.

Bjorn

dodiano
03-01-2011, 10:15 AM
As stated in my post: you disengage A/P and land manually. So no autoland!

JWS

Trut me I know that... Kinda asking Stepbk cause It looked in his post that he wanted to do autolands using RNAV.

stepbk
03-14-2011, 08:39 PM
hi guys

thanks for all repying. I wasn't after autoland, just a proper way to descent to destination. ie, proper descent. I found a DVD that talks about that. Angle of attack training, it talks about ILS approach, VOR approach.