Help with literary description of helicopter flight

[Writer1]

I have to write a helicopter scene and have no vertical experience. Would someone be able to answer a couple of quick questions?

1. Can a Hughes D500 helicopter from the 1980s, or any helicopter for that matter, stay stable in the air for a few moments without a pilot actively flying the machine? If not, if the pilot was pulled away what would happen to the helicopter?

2. Does a Hughes D500 have a hatch or door that closes the body? If so, does it slide to one side or open in or out?

3. Do Hughes D500s have a pilot and a passenger seat up front and space for two seats in the back?

Thanks!

 

[Whistlerpilot]

1) No. Helicopters very rarely have autopilot. If the pilot stops actively flying the helicopter it will get into an unrecoverable attitude within seconds. If the pilot was pulled away from the controls the helicopter would crash. Usually they roll to the right, (American helicopters) sometimes the nose goes up sometimes down when the controls are dropped depending on attitude, airspeed, etc. It might break apart before getting to the ground.

 

2) A 500 has 4 doors that are hinged from the front, 2 on each side. They open out, somewhat like a car door.

 

3) The 500 is usually configured to seat 5. Pilot in command sits front left, and there can be seating for 2 passengers to the right of the pilot. The back cabin is usually set up with seating for 2.

 

http://en.wikipedia.org/wiki/MD_Helicopters_MD_500

 

Most screen writers have the helicopter spin out of control then explode. Thanks for asking, it's often painful for pilots to read or watch what non pilots come up with.

[helonorth]

BTW, it's a 500D.

[eagle5]

A CFI and I once cruised in an R44 for 10min. without touching the controls,...he said his record was 18min.!

 

I don't know about the 500, but in the 300 my CFI had me let go of the cyclic for a moment (to check the trim) and it didn't do anything crazy, just leaned to one side,...until I adjusted the trim of course!

[aeroscout]

The best literary descriptions I have heard of helicopter flight is...

1 They don't fly, they beat the air into submission.

2 A helicopter is a loose collection of parts flying in close formation.

[Whistlerpilot]

So after posting I went out to pick up the Geologists I had dropped off this morning. Since I had no one on board I experimented with letting go of the cyclic to see which way the 206 Longranger would go. It consistently rolled left from 50 to 100 kts, and with just me on board pitched nose up. That was in under a second and if uncorrected would invert in no time. With 3 px I did a subtler test and it still rolled left but stayed level.

 

I know if the rotor system is unweighted (negative g) you will roll right having experienced that before. Seems like with a loaded rotor it rolls towards the retreating side. Will try the Astar next time I'm in it to see if it rolls right.

 

Perhaps a 500 with the cyclic trimmed out nice would stay level longer. On the other hand any movement in the helicopter like the writer is suggesting will weight shift the ship in the direction leaned.

 

I'm still going with 1) No... but to many variables to say for sure which way the helicopter will go.

[ridethisbike]

I watched the pilot for the Sea Shepherd (Whale Wars TV show) let go of the cyclic in his (I THINK) MD 500 and nothing crazy happened. I think it's aircraft and system usage dependant (ie SAS, autopilot, force trim etc)... side note: if the pilot got pulled from the controls, the change in CG would also have an affect, but it would be a negligible amount, all things considered

 

 

I know for a fact the 22 rolls left and pitches up with trim off. Trim on did the same thing but way slower.

[Writer1]

Thank you very much for the detailed replies. The information was extremely helpful. Appreciate it!

[Nearly Retired]

Pretty much all helicopters are naturally unstable and need a pilot at the controls 24/7. However, some do better than others. Take the Bell 206. I fly it with enough cyclic friction that the stick does not move if I take my hand off it. On a smooth day, I can get a 206 to fly hands-off for long time periods of time with just gentle nudges on the pedals to keep it straight and level. (People don't believe me about this until I show them.) Sometimes out in the Gulf of Mexico when I worked for PHI, I'd be driving along with my arms folded, and it'd be flying so well by itself that I only begrudgingly took over for the descent and landing. You can let go of the cyclic and collective, but the pedals cannot be left alone.

 

A 206 will even hover hands-off if you get the frictions right. I like demonstrating this to pilots who studiously and intently fiddle with the cyclic in the hover, making those constant, tiny corrections they *think* are so necessary. Newsflash: They aren't. All you're doing is wearing out that little ball that the cyclic mounts into under the pilot's seat.

 

That's not to say you can climb in the back and get a sandwich. Oh, and it doesn't work in all helicopters.

 

The BO-105 was particularly unstable in cruise (80% torque), even though it had a trim system for the cyclic. The trouble was that the trim had a half-inch or so of free play in all directions. So no matter how carefully you trimmed the thing up, you could still move the cyclic quite a bit before you bumped into the trim springs. I timed every Bolkow I ever flew to see how long it would fly hands-off. The best one was about seven seconds before the ship tried to turn itself upside down. Maybe eight. Very frustrating and tiring to fly for long distances, which I was doing at the time, going back and forth from New Orleans to a drilling rig that was waaaaay out in the Gulf.

 

I used to complain that the Bolkow was such an unstable helicopter at 120 knots. Other pilots would disagree, saying that it was wonderfully stable! at 100 knots. Which it might be. But who in the hell flies at 100 knots?? Even 120 knots ain't exactly zipping along like the Concorde (or, as the Brits say, "like Concorde").

 

I've never flown a 500D, but I'll bet I could get one trimmed up well enough that it could fly hands-off for a while. But...like any helicopter, once it's disturbed from straight and level flight, it just continues to diverge until it's either upside down or hits the ground in a steep dive.

 

Someday we'll have cheap, light stability systems that keep our helicopters upright for us (or even just give us the same stability as an airplane has). But I'll probably be long dead and gone before that happens.

[Wally]

I have to write a helicopter scene and have no vertical experience. Would someone be able to answer a couple of quick questions?

1. Can a Hughes D500 helicopter from the 1980s, or any helicopter for that matter, stay stable in the air for a few moments without a pilot actively flying the machine? If not, if the pilot was pulled away what would happen to the helicopter?

2. Does a Hughes D500 have a hatch or door that closes the body? If so, does it slide to one side or open in or out?

3. Do Hughes D500s have a pilot and a passenger seat up front and space for two seats in the back?

Thanks!

 

 

1. Yes, some helos will maintain attitude until disturbed. I've done the same experiments that "Nearly Retired" related with similar results. The aircraft rigging has to be correct, the controls have to carefully set, and no the airflow has to be uniform. The time in stable flight depends on how exactly the pilot centers everything, but eventually on axis will diverge. Any turbulence or weight change, and the helo attitude changes, diverging with time. Yaw is strongly divergent in all axis.

I can feel and see attitude changes as my crew moves around inside the Astar, corrections are unconscious for me, but I think the aircraft would not return to trim. Very little time in a 500, but when I taught in it's little brother- the 300, one could fly it by leaning in the seat. No snap-rolls or hammerheads, nice gradual attitude change. One would have to fine tune the result, yaw and pitch don't seem to synch to the changes.

 

3. Already answered, but nobody has pointed put the the 500 front and back seating areas have very little passageway between them, almost 2 separate cabins.