29 May 2000, 01:46 AM
Join Date: Aug 2001
Location: Western Australia
To explain a little about the Camel's stall characteristics (correct me if I go astray) ((yeah, like you wouldn't **G**))
Being tail heavy the Camel could get into a climb if not checked. This nose high attitude of course reduces speed. The actual motion of the nose lifting causes a gyroscopic force to act to the left and the prop torque provides more left force, this (in the absence of dihedral, particularly) has as a secondary effect, a roll left. This causes a gyroscopic effect to act lifting the nose further. (there's a theme developing here!!). At some point one of two things will happen.
1. From a relatively low speed start and because
of the massive lift loss on tilting the aerofoil, the outside (right) wings will reach critical AOA and the aircraft will spin "rather nicely" to the right.OR
2. From a high speed start the aircraft will flip on its back and begin to autorotate (in the abscence of control input)to the left at a high airspeed. Can't see that happening in a Camel with its low top speed.
Now option 1 is OK if you have height (about 1000ft to recover from three rotations) but option 2 is not great in an aircraft with a VNE of 180mph!!
Remember that here we are talking about Gyroscopic effect NOT engine torque. That only plays a part when revs are changed and acts to the left on the Camel. Gyroscopic effect only operates when there is a force imparted on the Gyroscope BUT in the Camel this is almost all the time as a constant downward force is required to counterbalance the tailheaviness. This gives a 'constant' force acting to the right in level flight even!!
As Ira points out, there is very little in a Camel's design to impead any of these forces nor to warn you when they about to take over. Nor is there the excess control authority to help you recover that there is in most modern aircraft.
I think it was Grieve who was killed in December 1917 when his Camel's elevators appeared to jam "up". He managed to fly back to the aerodrome in a semi stalled, nose high condition, and at 800 feet cut the engine to put the nose down. Good move, solid decision, soundly based and well thought out. AND completely wrong. The beast TAILSLID, spun and made a striking abstract art piece in the middle of the 'drome.
Nowadays you can't get certification (at least here) for anything that doesn't drop the nose the minute it stalls. (BTW, dont stall a 172 with four people on board, devil of a job to get the nose down!!)
Cam, the Nieups had much better balance. Whilst they did not have the fixed tail, it is not this alone which overcomes the yaw slip. Their design meant that more resistance to that motion was offered by the aircraft operating with normal airflow around it. To take up on the example previously given, the normal family saloon will not happily spin, much more likely to skid to a halt sideways or roll over when liberty is taken, but those little F1 beasties go like tops and there is not much "wobble" before they go. In control / out of control, black / white (Mansell's Adelaide shinnanigans with the blown tyre aside).
Better weight distribution in the Nieup's also means that what little dihedral there is has a greater effect. The Gyroscopic effect was also comparitively lighter, same with the Pup (which had dihedral.
Most things tend to keep going the way they are going (inertia) but the Camel had more excuses to depart and less reason to stay on course than most.
Lest any modern pilot think a spin was a cute trick to do on a Saturday afternoon (as it is now in an Aerobat) consider this: Most Camel accidents WERE spins, nearly 4 years elapsed from the Camel's introduction to the final hearings on the type's spin characteristics and in another great combat aircraft stressed for high G manuvoers : the Spitfire, deliberate spins were strictly prohibited!!!!
See Ira, it's not only you who has Tolstoyian pretentions**G**
regards to all
Not here are the goblets glowing,
Not here is the vintage sweet;
'Tis cold as our hearts are growing,
And dark as the doom we meet.
But stand to your glasses, steady!
And soon shall our pulses rise:
A cup to the dead already-
Hurrah for the next that dies!