Peter wrote:
In unusual attitude recovery the 1st thing you look at is the speedo andif increasing, close throttle (and if dire emergency, extend gear)
if decreasing, open throttle
Really? If already close to stall (or in a stall) opening the throttle will significantly increase your problem (due to torque). Power off stall is typically easier to handle than power on stall – already in a low HP SEP.
In a SET like the PC-12 there is the added factor of inertia of the engine: You might be well above stall speed when you start to add power but well below when the turbine has finally spun up. In such a situation the 1400hp will most likely kill you.
I do fully agree to libra: In any unclear attitude where you can not exclude positively that stall could be a factor, cutting power is a good idea. Or the other way round: You should only add power if you positively know that in your situation it is the right thing to do.
Just for fun, I googled “recovery from abnormal attitudes” and looked at the first four hits. (At least three were reputable web sites.) One was unspecific as to the exact action (“follow the AFM…”), but all the other three advocated increasing power in a nose-high abnormal attitude, although they did differ in the order of increasing power and lowering the nose.
Yes the “book recovery” from high nose attitude involve adding power but what does adding power allows you to achieve in terms of regaining control of speed & bank that you can’t achieve with the yoke/stick alone? (Other than “regain control (yoke) with minimal altitude loss” (power) )
Now what if I am blind and have no clue what aircraft is doing? both spin & dive recoveries both involve reducing power (except in funky aircrafts), stalls can be recovered dead easily without power and are very benign, unusual attitudes without power is like gliding aerobatics, practically, the only way to get the VSI to show -30kfpm is a PT6 engine running at full power, nature prevents you from reaching those speeds in free fall
Most aircraft are inherently unstable at high power, they likes to fly near VS or near VNE when bank & pitch are not within +/-5deg every 1s, without power you can put it +/-45deg bank & pitch and let go while smiling for few seconds, you lose height at -1kfpm but at FL250 or 5kft you have plenty of time to bring wings level…
I think only stall recovery on base & final leg require prompt use of power to achieve “minimal altitude loss” but honestly with the amount of loss of control accidents on go-around with full power and wrong position of the stick or trim, I am not convinced firing full throttle on base leg stall with sight of the ground is a healthy thing better keep it in control and take the height loss…
Recovery from unusual attitudes in a light twin is if in the climb add power level of and reduce power, if in descent reduce power and level off then gradually add power. It feels natural like driving a car up and down hills whilst maintaining speed.
I don’t need to reinvent the wheel.
You would be very unlucky in an IFR equipped aircraft to lose all instruments, primary or back up which give an indication of whether you are climbing or descending.
gallois wrote:
in a light twin
…equipped with counter-rotating props. Because if not, adding thrust short of a stall will – according to my understanding – end the controlled phase of flight. The same is true for single engine aircraft.
UdoR wrote:
The solution is simple. Trust the bloody instruments. But not so simple, either, because you shouldn’t trust them to 100%, because instruments can fail.
Korean Air lost a 747 near Stansted because of a faulty ADI. One of 3, the PF’s. Air France lost a 330 because 3 men in the cockpit could not agree which instrument showed correctly. Aero Peru lost a 757 “just” by loosing pitot static, so did Birgin Air. SR111 lost control when both PFD/NDs failed and the small stand by ADI was not visible in the smoke. The list goes on and on. Countless military planes, which usually do not have backup instruments, got lost to spatial disorientation.
Now these are multi crew airplanes with experienced crews. Face this situation alone and in IMC and yes, many will manage, others won’t. Because in many cases, failures do not appear obvious but gradually, so the first thing is to actually reckognize you got a duff and which one it is. 2 ADI’s won’t do the job, you need 3 in reality as you need to check them against each others. Majority wins. That is why I think something like a Dynon D2 is a good investment as a backup of the backup.
If you have a chance, go fly a full flight sim, bribe the instructor to put you max turbulence the rig can last and fail one of ASI or ADI. Good luck, but that kind of exercise might save your life.
As for this accident: Unless the loss of control was so brutal that the plane was unflyable by the time it came out of the clouds, I have severe doubts that an ADI defect did this. Trim runaway maybe if the plane became damaged and unflyable, but other than that, as I say, I have my doubts. Probably there is an elefant in the room which has not made an appearance yet.
May as told by Emir, a first spatial désorientation once IMC, leds to a first nose down attitude that wasn’t managed correctly, and could have broken a wing/tail or another contorl surface, that could explain such a dive…
@UdoR it is standard practice whether the aircraft has counter rotating props or not. My MEP revalidation every year has at least 2 recovery from unusual positions exercises.
If you are going up add power to get you over the brow of the hill, if you are going down reduce throttle to avoid VNE.
Without primary ADI you have back up ADI, VSI, ASi and Altimeter and their back ups in order to give you a hint whether you.are going up or down. Failure of all of them would be a problem in IMC.
Why do you think adding thrust ends the controlled phase of flight? In a car do you add throttle and drive a corner or do you keep your foot off the throttle? Try both and see the difference in control.
Mooney_Driver wrote:
Korean Air lost a 747 near Stansted because of a faulty ADI. One of 3, the PF’s. Air France lost a 330 because 3 men in the cockpit could not agree which instrument showed correctly. Aero Peru lost a 757 “just” by loosing pitot static, so did Birgin Air. SR111 lost control when both PFD/NDs failed and the small stand by ADI was not visible in the smoke. The list goes on and on. Countless military planes, which usually do not have backup instruments, got lost to spatial disorientation.
Five years ago a Canadair CRJ200 on a mail flight crashed in northern Sweden on a dark night. The FDR showed that the PF Inertial Reference Unit failed and the pitch indication on the PF PFD went from normal (1-2°) pitch to 90° pitch up in about 20 seconds. Then it decreased to -50° over a period of 35 seconds after which it again increased towards 90°. None of these indications had any relation to the actual pitch. The roll and heading indications were also incorrect, but less so. The PM PFD and the airspeed/altitude indications on the PF PFD were correct. Both crew members rapidly became spatially disoriented and the PF flew the aircraft into the ground at 500 kt.
If you are going up add power to get you over the brow of the hill
In gliders, we used to winch into low clouds, +45deg nose up entering low clouds with no power and 800ft agl bellow, you release cable push the nose and it will recover, unlike cars, you don’t need power to go over the bow of the hill, “you make your own hill” 
in fast jets, you better off with less power and bank the wings than going full power & pushing on the nose to go over the bow of the hill, unless you are happy to red out or lose consciousness…
I have yet to find a touring piston single or twin that flies +30deg where full power and maintains speed, other Cub180 and Extra300 where engine outclimb the wings? so at the end of the day you will have to push the stick to stay in controlled flight, so I am wondering what is the actual use of full power has in that high nose attitude recovery? and genuinely interested on where does it really help?
Light twins have nasty record of crashes where people were using lot of power on one side before using the stick and rudder, I am sure all those who “lost it” in cruise at FL100 would have been better off throttling back a bit until they process what is going on (in cruise it should not drop faster than a brick, even heavy twins fly nicely with all engines at idle for about 10min, plenty of time to figure out where to put the stick, which speed to fly and which rudder to use)
The same question why people lose control in twins? because they use too much asymmetric power which is very unforgiving to wrong pilot inputs (you should only add power when you know what you are doing with stick & rudder)
Airborne_Again wrote:
Five years ago a Canadair CRJ200 on a mail flight crashed in northern Sweden on a dark night.
Yes I remember. That was another example to be added to the above list. And they did have 3 ADI’s.
This is as good as any exercise to train in a sim. Wonder if sims are capable of this, but it should be a massive eye opener for many.
