The spin info is completely accurate…he left some aircraft-specific stuff out, but that is how we got out of spins.
The T-37 is fairly unique in that it is side-by-side and had a large amount of fuel in the wings. The side-by-side fuselage tends to develop lift at the nose when spinning making it more difficult to get the nose down in recovery…hence the spin strakes on the nose to spoil the lift. Having fuel in the wings caused problems too in that the rotation of the spin slews the fuel out to the tips. Thus it develops a goodly amount of rotational momentum that the rudder itself can’t overcome. Thus, the procedure to bring the stick full back: reduces the rotational momentum by getting the CG and spin axis as far apart as possible (ice skater spreading her arms out). Then opposite rudder for one turn—to further reduce the rotational momentum. Then stick abruptly full forward to drive the nose down and reduce the AOA below stall. This transitions any remaining rotational momentum into roll momentum which is easily controlled with aileron… I imagine the Lancairs would behave in a similar manner… The tail configuration has a lot to do with things too…how much rudder is effective at stall AOA…
The best flying job I had was being a Spin Demo pilot—showing instructors all the bad habits of the T-37 in the spin… Got to show them stick only recoveries (that sometimes didn’t work), show them how using slow anti-spin controls would actual accelerate the spin to the point where it would not recover (and make your eyes spin like crazy!…about 2 rotations per second!), etc, was a blast! We did 7 spins in a 1.0 sortie….did that a couple of hundred times with instructor trainees… what a blast…
Jeff Linebaugh
From: "Mark Ravinski" <mjrav@comcast.net>
Date: November 16, 2006 1:11:09 PM PST
To: "Lancair Mailing List" <lml@lancaironline.net>
Subject: [LML] Fw: Air Force Spin Doctrine
Reply-To: "Lancair Mailing List" <lml@lancaironline.net>
----- Original Message -----
To: Lancair Mailing List
Sent: Thursday, November 16, 2006 8:32 AM
Subject: Air Force Spin Doctrine
Listers,
Let me share some spin training info with you. Consider it a return on your tax dollars.
The Air Force (in the 70's) used T-37 jets for spin training and these Cessna aircraft were specifically designed for this requirement. Everything I have seen in my 360 suggests that the spin entry and recovery characteristics are similar to the T-37. I have not let my 360 enter a developed spin because the Lancair factory and POH suggest that it is not recommended. From my experience, I know that aircraft of the same make and model can spin very differently. Even variations in loading and fuel distribution can have an effect.
A "developed" spin is a stable rotation that may take about 3 or 4 turns with the nose bobbing up and down, to some extent, after the initial entry. I know that some aircraft simply cannot ever recover from a developed spin.
I don't need to know if mine is one of them.
I did want to explore the stall / spin entry / recovery scenario. This is within POH limitations. I have done deep stalls in numerous configurations to spin entry and recovery - maybe 100 times in the 360 never letting the spin develop past the start of rotation. Recovery has always been immediate on opposite rudder application.
The Air Force procedure is designed to recover from any spin - even inverted or IMC.
1: Throttle idle.
2: Rudder and aileron neutral.
3: Stick ABRUPTLY full aft and hold. (this step is intended to right the aircraft from an inverted spin).
4: Determine spin direction and ABRUPTLY apply full opposite rudder. (The gyro turn needle was found to be the most reliable method for this - even more so than outside reference due to possible pilot disorientation.)
5: One turn after opposite rudder, stick ABRUPTLY full forward and hold. (the "abruptly" here is important because if not done briskly enough, an accelerated flat spin could develop.
6: Recover from the resulting dive.
This procedure is guaranteed to recover within one turn of going abruptly full forward stick. However, out of hundreds of spins I've logged there was once it didn't. The student went through the steps correctly and the plane kept spinning. I took it and followed the procedure again - my best performance - and when I went full forward on the stick it took over two full turns to recover. I wrote that plane up as having a problem.
We were very close to having to bail.
This sort of flying, like many others, is not something to be learned without an instructor. Some stalls and spin entries can be very disorienting. I highly recommend some unusual attitude, stall, spin avoidance training.
Most pilots who do this as part of an aerobatics course have the time of their life and say it's the most worthwhile instruction they've ever had.
Mark Ravinski
N360KB 1394 hrs.
EX Air Force T-37 driver