Millitary spin recovery?
Wish I had some time in an RV to chime in about their spins and recovery techniques... But with over 1500 Hrs as a T-34C instructor I spin regularly...
First of all some may need to review the difference between a spin and a spiral... if we (T-34C pilots) use aileron to enter during a spin we tend to get a spiral (the wing is not fully stalled in a spiral)... aircraft equiped with an AoA gauge can quickly reveal a spiral instead of a spin... important to know becuase spiral recovery technique is typicaly neutral controls, power to idle. Both look very similiar when just looking out side... especially at the entry and first few turns... we specifically get spin/spiral out of control flight training hops every 6 months.
In a spiral airspeed typically will continue to increase, and rapidly approach VNE... it very important to scan airspeed when attempting spins/spirals.
The aircraft wing is always completely stalled in a spin, yaw is applied for the entry and both must be maintained through out the entry, it will take a few rotations for the aircraft to settle into the spin... these first few rotations are called the incipient spin... usually positively nuetralizing the controls and reducing power to idle will recover from this phase (just like recovering from a spiral)... If you continue to keep the aircraft stalled and yawed through the incipient phase you then enter the steady state spin, Called 'steady' because both the airspeed and rate of rotation will typically stabilize out. Some aircraft are designed to not, or be very difficult to enter a steady state spin. The T-34 C was fitted with ventral strakes to dampen its rate of roll in a spin...
Side bar: looking at the RV-12 spin trials video on youtube it looked to me to show that aircraft to be very difficult to spin and quick to recover from the incipient and steady state... but all I had was the view out side and that isn't really worth much as I said about spirals earlier. Looking at various RV-7/8 videos on you tube showed them to have a somewhat faster roll rate than what I typically see in the T-34, though left vs right spins typically vary in roll rate due to the prop's direction of turn...
Once in a steady state spin the recovery depends on the aircraft, In the T-34C if you release the controls (called the millitary technique above) the stick/yoke will float around some point and the rudders will as well... making small oscilations round this point... Typically the aircraft will not recover with out positive inputs. In 6 years of spinning this aircraft I have not seen a single one recover on its own.
From my limited reading the 'self recovering' aircraft, are typicaly extreemly stabil platforms and extremly difficult to get to spin anyways... or fly by wire machines.
Hence my concern with the "military recovery techinque"... some fly by wire jets will recover themselves, I'll have to check with my F-18 buddies but I think the procedure is to neutralize the controls, not 'let go of the controls' but who cares how a fly by wire recovers anyways... this is an RV/light civil forum...
I've never seen anything taught other than the following when you get that "uh oh" I shouldn't have done that feeling:
If control inputs generate normal respones: you are in control and need to use appropriate unusual attitude/stall recovery technique.
If control inputs do not yield expected results, you are out of control:
1. Neutralize the controls / power to idle. (this should get you out of everything but a steady state spin).
2. Altitude check (you may be running out of options and need to bail out)
3. Check your instruments (an AoA guage helps here, along with knowlege of your steady state spin airspeed)
If you are not in a steady state spin, neutralizing the controls (center the rudder, elevator, aileron) will get you out. The aircraft's designed stability will recover the airfraft in a nose low attitude. Once the rotation has stopped, Look up, if you see blue sky pull, if you see ground roll, then pull. Check oil pressure and add power to get away from the ground.
If your instruments reveal you are in a steady state spin,
1. raise the gear and flaps
2 apply rudder opposite the turn needle
3 stick neutral or forward of neutral depending on the spin. The T-34 requires neutral for inverted spins, and just foward of neutral for errect (upright) spins due to the horizontal stabilizier blocking air flow over the rudder during an erect spin.
Next week I'll give a discertation on why its AERObatics, not ACRObatics when you perform them in a aircraft..
Sorry for the miss spellings... I'm bad at spelling and my two year old wants to go to PBS Kids.org!
Tom