Flight from Habana to KSC

[Overmind5000]

I started out in a Delta-Glider 4 on a Habana hoverpad, taxied to the runway, engaged the atmospheric autopilot, set my heading, about half an hour later, I reached Cape Canaveral, disengaged the autopilot, and went in for a manual landing. Either my landing gear was lot rolled out completely or my altitude drop rate was too much and I was too slow. Either way, My landing gear failed, I shut off everything in the ship and evacuated the crew. Boring at first, and a bit of exitement at the end.

 

[rocketman768]

Usually gear fails because you are going too fast when you open it. Only deploy your gear in the last 20-30 seconds of your flight when you are going slowest. Normal airliners only deploy the gear during the last 2,500 feet or so.

 

[Overmind5000]

Usually gear fails because you are going too fast when you open it. Only deploy your gear in the last 20-30 seconds of your flight when you are going slowest. Normal airliners only deploy the gear during the last 2,500 feet or so.

good point. Only problem is, I didn't have a little mini-hud showing my altitude in feet. By the way, the flight took place in real time.

 

[rocketman768]

good point. Only problem is, I didn't have a little mini-hud showing my altitude in feet. By the way, the flight took place in real time.

You don't need the hud. You should have had the Surface MFD up while you were landing. One reason is to look at the altitude and velocity, and the other is to keep an eye on the vertical rate of descent as you touch down (so you don't break your landing gear on impact). If I remember, 150 m/s is an ok velocity to deploy the landing gear of the DGIV. But even 150 m/s is relatively fast (290 knots) compared to the speed at which most jetliners deploy their gear (93 m/s or 180 knots). I can't find the speed at which the landing gear on the real shuttle is deployed, but it happens at 2,000 feet (610 m), and the forward velocity of the shuttle when it touches down is 98 m/s. So, make your own estimate from that.

 

[Overmind5000]

I now know I was going to slow horizontally and too fast vertically. I tried again last night, edployed my gear at least 30 seconds from touchdown and saw I was dropping altitude too rapidly.

 

[rocketman768]

I now know I was going to slow horizontally and too fast vertically. I tried again last night, edployed my gear at least 30 seconds from touchdown and saw I was dropping altitude too rapidly.

The way to do it is to try to maintain 125-150 m/s during the final stages of landing by changing the pitch of the nose. If you're unpowered, I think usually keeping the nose between -20 and -10 degrees usually does it. If you're powered, you can use the engine to keep your speed up while you do a shallower landing with your velocity vector at about -5 degrees. Of course, it takes practice to hit _both_ the right speed _and_ location .

 

[SlyCoopersButt]

It's not really speed you are to look at when you deploy gears or anything else. It's dynamic pressure you need to be weary of. The higher your elevation the faster you can go without breaking off things. The surface MFD tells you the dynamic pressure. Of course though, Touchdown at too fast of speed is always a bad idea. Below are some of the official ratings for DGIV.

-Max landing speed: 200 m/s
-Max landing vert speed: -3.5m/s
(depend of weight)
-Max landing weight: 19 ton
-Max gear dynPress: 38kPa
(250 m/s MSL)
-Max airbrake dynPress: 45 kPa
(280 m/s MSL)
-Max radiator DynPress: 0.5 kPa
-Other door DynPress: about 1 kPa
appart Hover and retro doors.