747 Shuttle Carrier Aircraft (SCA) approaching Endeavor

[GTElwood]

The 747 is really powerfull and agile, expecially without all those common liners stuff off.

I've talked a bit with a 747 pilot, and he sad to me how agile an smooth was flying that plane, expecially during requalification flights (short flights/few fuel/no passengers/baggages).. he sad that was really fun to ride a 747 in that conditions.

Anyway the orbiter it's lightweight despite his volume, and before mating a lot of devices onboard are removed.

*Geocam2=LMAO .. ^__^

[Jabbajawz4life]

Why do they put the shuttle on top?

[NikitasGuitars]

as opposed to?

[geocam2]

Stenciled on the mounts on top of the 747 are these words "CAUTION PLACE ORBITER HERE BLACK SIDE DOWN. LEFTY LOOSEY RIGHTY TIGHTY"

[Jabbajawz4life]

Why do they put the shuttle on top?

[jerryaltman]

I always ask how a 747 could carrie a Space Shuttle. by just looking both on ground, we get impression it's impossible.

[NikitasGuitars]

the 747 is really only providing forward thrust. the shuttle actually flies on its own to some extent thanks to being mounted on the 47 at a much higher angle of attack. So the 747 isnt "carrying" it per se.

[mach25man]

I know this is a year old but I had to comment. There is very minimal lift from the orbiter. The drag caused by being mounted to the 747 far out weighs any lift by the orbiter. The 747 is doing all the work here.

[NikitasGuitars]

How exactly can drag outweigh lift? Obviously there is a lot more drag, sure, and the engines have to work harder. Maybe this is a question of semantics... I think it's more accurate to say the orbiter is being "pulled" rather than "lifted" by the 747. Remember the orbiter is technically a glider...

[mach25man]

I know the guy who calculates the weight & CG for these ferry flights. He says there is only about a 1000 lbs of lift created in the equation. Its a delta wing, the air flow is not exactly right bolted to th 747 and they only do about 280 kts or so.

[NikitasGuitars]

Explain to me how they separate the two midair then.

[mach25man]

Well, 30 years ago when they separated for landing tests, the 747 was flown is a shallow dive or nose down attitude. That profile is not flown for cross country ferry flights. It has not done separation flights since the late 70's.

[NikitasGuitars]

It seems to me from watching the separation videos that they separate right around 250 kts or so. It appears they fly a shallow dive to gain speed and to also provide the 747 with an easier escape after separation. So nose down attitude or otherwise the orbiter seems to glide just fine at around 250 kts. 30 less than your stated 280 for ferry flights. Plus it just doesn't make sense to me from a structural or a fuel economy standpoint to have all the load on the 747's wings.

[NikitasGuitars]

The orbiter has wings and can fly, why wouldn't they let it do that? It only has to lift itself.

[mach25man]

The 747 can lift almost twice the weight of the orbiter. Its not really doing anything it cant already do. I tend to believe the guy who actually caculates this. Yes the orbiter glides as it sinks but how much lift is it producing ?

[NikitasGuitars]

Enough to lift itself at that airspeed and angle of attack obviously. Im done arguing about this.  We obviously both know we're right. Have a good one.

[discovery995]

first to comment,awesome video