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Recently, I have begun to spread out further around the world in FS2000. I had in my
hand the new
727 by E. Diaz and painted by Mike Baumann and wanted to flight test it to somewhere outside
the USA. I decided to try out South America. I have been there a bit, but mostly
only to Caracas in FS98. So I took an Eastern Air Charter flight in a 727-200
from MIA to Bogota, Columbia. Bogota was excellent! The big airport is over
8000 feet in altitude and landing there I could test out the 727's performance.
It was very noticeable, but not so much more than anyone who has done Denver before
in FS. The scenery will open your eyes, as FS2000 has some textures and formations
down there that you just won't find in the US. And using real weather, offered sparkling
blue skies, unlimited visibilities with a smattering of puffy cumulous.
From Bogota, I would depart for the most challenging place I've ever been to in FSland.
The "top of the world" at La Paz, Bolivia (SLLP). The trip would be about 3 hours and I had
my World Edition of Simplates 2000 standing by. I printed out the plate for the VOR/DME ILS
RWY 10. Wow. Right away it scares you. The inbound altitude to intercept the approach is 15,500.
Well, I guess I worry 'bout any Cessna gettin' in me way!" SLLP has no ATIS, so I had to get
a report off the net to get the real weather I was using. Two layers of broken cloud, one at 1500
and the other at 2500. Okay. Not too bad. As I got within descent range of 80 miles, the weather
was now undercast. Slowing to 300 kts at 18,000 feet, I began to penetrate many cumulous clouds.
Leveling off at 15,500 now about 20 miles out, I was under a layer and above a scattered deck below me.
All around the view was magnificent! Towering jagged, snow-covered peaks and grassy, green lowland valleys
with brown, deserty high plateaus everywhere else! Wow!
I saw the airport 10 miles out, with clouds hangin' in all around it. I figured I could do a visual for 10, so made a left downwind at 230 kts, then started to slow as I added the first two increments of flaps and gear came down. That's when I noticed the thin air. She was sinking at 2000 fpm just with the gear and a few degrees of flaps down! Powering up to nearly 90% kept me on the downwind. How loud! I was pushing just under cumulous now, with rising terrain meeting the clouds off my side. I knew I must do a close approach. I turned base. More sinking. Wow...what a lead weight! I might as well have had half the wingspan, right? On final I rolled out, about 7 out, at around 1500 feet. On rollout I could see clearly the field was a high plateau with steep valleys on either side. Shucks! They build the field on top of the world, and not in the valley! But there was steeper terrain just beyond, where the mountains go to around 15,000. On final, I needed 88% power just to hold a glideslope. At about 5 miles out my speed was 167 kts for a true airspeed on the GPS of 220! That's more than tire blowout speed! If I used full flaps, I could lower my landing speed, but then the drag might be so great, a go-around may
be impossible. So, I elected a flaps 20 landing where I might have an out if I needed. On short final, I trimmed the nose up as the "three holer" balanced out nicely on a glideslope at 152 kts. My TAS was close to 202. Sink rate was 1000 fpm. Okay, over the runway now, ease back the power slightly... and clunk... down already, not even with power off. Spoilers up. Nose to the ground. Still cranking out 127 kts... with TAS near 170. Reversers full, but not as effective as I'm used to. Lots of runway here, that's the good thing. I don't want brakes - they'll overheat. I came to a sluggish stop around the 10,000 foot mark down the runway. Whew. Fun! Lot's of fun!
You'll need so much power on final - almost the same as a noise abatement climb would be - 85 to 90%. As you can see, there is no room for extra power... you're basically coming down! Once you add flaps, and gear, you're "telling" the airplane it's going to land, and that is that. So make sure when you do "tell it", you're at least on a close base.
Departing the field was a horror show. With only 50% fuel, flaps set at 25, I advanced the power to max, while holding the brakes. I used a flaps 25 takeoff to make sure I could get airborne as fast as I could. Releasing the brakes, the noisy acceleration was anemic. It was like I was on one engine. After what seemed like forever, I got to 100 kts at about half-way down the 13,000 foot runway. Then slowly, 130 kts. Now I was at the last 2000 feet. At about the last 1000 feet, I pulled the nose up at 139 kts for a true airspeed takeoff of around 200! I left the ground at the last 200 feet of runway pavement. Wow! Looking out the side, I was just hanging there! I was sure going fast, but not climbing. Inching the nose up after I put up the gear, I began to climb at 158 kts. Around 500 fpm. All those flaps were just too much drag for this old bird to get over. With low valleys off my right, I rolled right a little, then began to retract flaps slowly - first to only 20, then 15. Acceleration at 170 kts was still slow. I was up to 1000 fpm however. I had to save the engines, so powered back to only 95%. I whizzed over alpine flats and hill tops. Eventually some 2500 feet AGL, I got all my flaps up and started accelerating back to 250 kts. Wow! What a ride!
So you try it! I am not sure if a less flap takeoff would help or hinder.
I then went back to La Paz two days later in a FLY! PMDG 757-200. Still, with real weather not too good, I descended over the snow covered fields and out of the clouds on an ILS. The 757 was slightly less draggy and I had about 82% power on final. Landing was easier, but still fast. If you don't keep power in, you will crash short of the runway. Keep that power in to hold your 500 fpm descent until over the pavement. As soon as you cut power, you're done flying. For good.
The air is so thin, you will need oxygen on the ramp! Even at this location where summers are normally roasting hot, the air temperature at La Paz hardly gets out of the 60's. However, that is enough to do density altitude damage. It is a blessing our FS2000 and FLY! sims model density altitude so well. Most flightsimmers don't think of this, and the challenge you'll get by going to one of these places! It is my sincere hope that you'll adventure yourself to this part of the world and enjoy some gorgeous scenery as well. (Note: in FLY!, using the new Ground Control Scenery by SKY! maker Jack Fearon, the Andes Mountains are really cool, with lots of snow and new tropical textures down low!)
Departing La Paz in a 188,000 lb 757 was much easier. (Note: full weight is 255,000 lbs) Running the power up to maximum thrust on a snowy runway, I accelerated rather quickly compared to the 727. At about the 6000 foot mark, I was at VR at near 130 kts, (flaps 20). I rotated up to 10 degrees, and started a "brisk" climb at 3500 fpm. Once reaching 1000 agl, I throttled back to 90% and lowered my nose and climb rate to only 1000 fpm while I accelerated and retracted flaps in steps. From here on out, it was a normal flight, with speeds and climbrates being slow, due to the transition from "dirty" plane to a clean one and eventually a 300 kt target climb speed - which soon became M.70 at this high altitude. So I found out the power of the 757 makes La Paz slightly more tricky than normal airports, but it doesn't act much more than a normal full weight takeoff would.
If you've never experienced the world of high altitude takeoffs and landings, I suggest you give it a try. If you're a small plane pilot, trying any of the airports in the western USA will give you a good sample, with Cessnas common even in the Rockies. If you're a jet driver, you may want to find airports above 8000 feet or so to get a really good sense of the changes you'll encounter. And then, for the very best, go to La Paz!
This demonstration is one of the best ways a flightsim can teach real pilots the effects of thinner air and density altitude. Without doing all this in a sim before, I would have never been able to experience the real thing, as I recently did in Telluride, Colorado (9100 feet). The actual flying wasn't as shocking as I would have expected, because I had done it so often in flightsim.
