I work at KSZP, 2665x60, and watched a guy bring a Turbin Commander 680 in, and out of the airport today. Needless to say, I was impressed. I did not think he was going to make it back out. He taxied back to the end of 22, ran it up to full power, let her go and off it went. But, I had the nervous pit in my stomach as he passed the 2/3 point of the runway and haden't rotated yet. There is a 30 ft high berm at the depature end of 22, and he had no more than 10 feet of clearance between it and the gear. I though there was no way. But to the guy how got it off, good job. I was impressed.
Turbine Comander 680 off a 2600ft strip
- Thread starter mshunter
- Start date
darrenf
resident denizen
If your perception of distance between the gear and the berm is accurate, that is way too close, and I am NOT impressed. :drool:
DPApilot
GUYSH! GUYSH! GUYSH!
:yeahthat::banghead::whatever:
CN94559
New Member
:yeahthat: x 2
Good point. It appeared that he left it "stuck" so he would have the speed he needed in case of an engine failure. I thought he could have had it off sooner. If you were there, you may have had a different opnion. He appered to lift off at around 135-145kts. I know that that airplane can get of at a lower speed than that. I don't that that aircrafts specs, but I do know he didn't have a balanced field length.
OhioStatePilot
Well-Known Member
This might be a dumb question, but why would one try to build speed on the ground in that event instead of lifting into ground effect to accelerate?
Extra speed is extra enegry. Also gets you farther away from Vmc.
OhioStatePilot
Well-Known Member
Right, that makes perfect sense to me, I'm simply stuck between holding the takeoff roll on the ground vs. pushing over and holding it in ground effect before climbing out. I'd think ground effect would give a similar margin of safety with better acceleration...
jml2992
Pigeon Mutilator
Really glad that all went down with both of those props still turning. Sounds like a failure at any point after v1 and that guy would become one with the sod. For the love of pete, people, those funny books in the back aren't just for there folks to have something to read while they're on the can.
averyrm
Well-Known Member
Right, that makes perfect sense to me, I'm simply stuck between holding the takeoff roll on the ground vs. pushing over and holding it in ground effect before climbing out. I'd think ground effect would give a similar margin of safety with better acceleration...
Vmc on the ground is lower than Vmc in the air because the landing gear will help with directional control. Though why someone would leave it "stuck" until 145knts I wouldn't be able to tell you.
BrewMaster
Well-Known Member
Maybe I'm looking at this wrong, but wouldn't Vmc on the ground be 0 kts?
TFaudree_ERAU
Mashin' dem buttons
Seeing as how SZP doesn't have any IAPs, there is no 10-9 (airport diagram) or obstacle notes. The only thing I could find is on airnav.com stating:
16 ft. trees, 200 ft. from runway, 125 ft. right of centerline;
+8 FT BLDG 55 FT FM RY END;
+9 FT BUSHES 130-200 FT FM EOR 60 FT RIGHT
Are either one of those the obstacle that you mentioned?
16 ft. trees, 200 ft. from runway, 125 ft. right of centerline;
+8 FT BLDG 55 FT FM RY END;
+9 FT BUSHES 130-200 FT FM EOR 60 FT RIGHT
Are either one of those the obstacle that you mentioned?
jrh
Well-Known Member
Try taxiing with one engine at idle and one engine at full power and see how long you can maintain directional control then
I don't know what Vmc on the ground is, but it's definitely higher than 0.
jrh
Well-Known Member
I've already gotten in to discussions about this here on JC in the past, but why is this type of flying considered unacceptable in a twin yet acceptable in a single?
It's all a matter of risk management. People fly singles out of short strips all the time without having balanced field lengths. If the engine quits in a single shortly after rotation they'll be screwed just as much, if not more so, than in a twin.
As long as the pilot knows that an engine failure during those first few seconds of flight will probably mean death, and accepts that as a risk he is willing to take, I don't see a problem with it.
youngpilot85
New Member
Know a guy who flies his commander into a 3000ft runway at an airport back home in the Caribbean (TDCF-Cane Field Airport {Dominica}). Almost similar to you, it feels like he takes forever to rotate. But unlike your airport, no obstables at the end over which he departs. After making a slight left turn, he is over the Caribbean Sea. Departing to the south is a different story. 
Murdoughnut
Well sized member
:yeahthat: x5
BrewMaster
Well-Known Member
Boris Badenov
Fortis Leader
As someone mentioned, he might have been holding out for higher airspeed in case of engine failure. Or just hotdogging. I met a guy who's gotten a mitsi marquise (same engines, much higher wing loading, I'd imagine) in and out of a 2400ft grass strip (lightly loaded) with no problems at all. With flaps 40 (not approved, of course), it'll fly off at 90kts or so without even pulling. At low weights you could comfortably get off the ground in 1500ft or less. Naturally, I use flaps 20 and suck them up as fast as I can at the expense of wallowing to the end of a long runway then going up like a saturn V, but the aircraft is capable of a lot, lot better. Judge not lest thee be judged or all the facts are in or something. The whole point of this class of turboprop (for the private owner) is that you don't need 10,000ft of pavement to get high cruise speeds.