- Last Updated: 26 April 2017 26 April 2017
At our last Bull Creek meeting I mentioned that several of our members had recently been forced, by powerplant problems, to return to Serpentine in a hurry.
A couple of them have been good enough to jot down their memories so that we can all learn from their experiences.
I thoroughly commend their bravery and level-headedness, not only in getting their aircraft back to earth safely, but in having the guts to share their experiences so we can all benefit.
Finally, can I please remind you that the most frightening that can happen is to lose power shortly after take-off. Your best possible preparations for this are to think carefully before each flight what you will do when the engine stops or falters, to be aware of possible forced landing sites nearby, and to practice gliding approaches whenever you get the chance.
The first thing to remember is to shove that nose straight down into the gliding attitude. Not doing that is what killed John Bird.
There are boards in the clubhouse with photographs of the local area off Serpentine's runways ends. If you look at them, you can decide which fields are safest to use for a forced landing before you have to do it for real. I know from experience (because I have done it) that it is all too easy in the fright of an engine failure to go for the tiny field ahead and on the left, when there is actually a much better one out on the right, perhaps partly hidden by the nose.
OK now for the interesting bit, first from a member whose identity may become obvious...
I lined up on Runway 23 and applied about two-thirds throttle (I usually do this on 23 until I get past the 'pot-holes'), then smoothly brought in full power as we passed the displaced threshold.
Abeam the clubhouse the manifold pressure was good (28-29 inches) RPMs were good (2750-2800) and temperatures and pressures all in the green. The airspeed came alive at 60 Kts. I was airborne by John Knight's hangar, and shortly afterwards selected the gear up. Everything was going as planned until at about 100 feet the engine suddenly lost power and the 'noise back there' decreased in line with the power loss.
I probably spent a second in total disbelief. I think I said the pilots' usual expletive, but that didn't seem to help as the trees at the far end looked like they were getting bigger. I knew I had to do something, but had no time to devise a plan. I wish I had thought about the possibility earlier, before taking off.
This is where I got lucky (very lucky as it turned out). For some reason I eased the throttle back (because it obviously wasn't doing much good in the Full Power position), but nothing happened. With not too much else to do, I eased it back in again. This time I got a Big Surprise as I felt the power kick back in. At the time, I had absolutely no idea why this was happening.
Some of the rest is kind of hazy. I quite clearly recall thinking 'DON'T TURN BACK TO THE FIELD'. I knew the grass runway 09 was close on my left, and decided a gear-up belly flop on the grass was preferable to letting down into the trees.
I remember throwing it into a fairly hard left turn (to make the grass strip). About then the power died again and the nose pitched down, so I pulled back on the stick in response. At no time did I have any concern at all about 'spinning-in' because of the Velocity's safe low speed handling.
Do you remember all those Practice Engine Failures we did last year? Well, I had done several more since, so I was confident in the anti stall/spin characteristics of the Big V, and in my ability to crank it around at low level if I had to.
Anyway, back to 'the event'. Adjusting the throttle had worked once already, so I was more than willing to give it another go. Luck was still with me and, sure enough, the power came back on. Of course the nose instantly pitched up in response, so I managed to climb a bit. I haven't a clue how much. I don't think I ever looked at the instruments or gauges. (Maybe I should have).
A spectator told me afterwards that I managed to get to 300-400 feet on the close-in downwind. Anyway, the grass strip passed under the nose and I guess it was no longer an option.
About this time the engine lost power again, she pitched down again, and I didn't need anyone to tell me what to do with the throttle (this was becoming second nature by then).
The rest of the short flight consisted of more of these 'power off - power on' scenarios (I don't know how many, its all a bit of a blur now). I do recall thinking that the canard was stalling as there was lots of pitching moment as power was doing its on again - off again thing (but, thinking about it now, I suspect the pitching was power related, rather than the Velocity's 'pitch buck' stall).
One thing that sticks very clearly in my mind was my pathetic attempt at a radio call, saying that "I was returning for an immediate departure..... eh I mean landing". I think my voice was up a few octaves.
About two-thirds of the way around the 180 descending left turn towards the threshold of 23, I selected the gear down. This was a mistake! It was too soon. I remember thinking 'Idiot, you're not going to make the runway now!'
The airspeed was low and we were dropping like a brick. I did the 'throttle thing' one last time and got just enough power to make the runway. I landed so slowly that I could have exited at the clubhouse taxiway (I have never come even close to doing that before!).
I think the entire flight lasted less than 60 seconds!!
The engine behaved beautifully on the taxi back to my hangar (although my legs were a bit wobbly).
Prior to shut down, I checked for carb ice but there were no indications of any. When I went to turn off the electric fuel boost pump I found it was already off. Did I turn it off on the taxi back? I can't remember. Had I turned it on during the run-up? I can't remember. There are bits and pieces of that very short flight that I just cannot recall for the life of me.
I can tell you that I was VERY glad to get back in one piece!
Lessons I learned:
- Double check the essentials before entering the runway for take-off Controls/boost pump/mags to BOTH etc....
- Think ahead ... What will my ACTIONS be if I lose power at rotation, or at 100 feet, or at 500 feet?
- If you have an emergency (especially at low level) DO SOMETHING. Try anything to get the engine back, but most importantly, KEEP FLYING THE AEROPLANE.
- PRACTICE EMERGENCY PROCEDURES REGULARLY!
- If your Aircraft has a carburettor with an accelerator pump, just bear in mind that it could save your life one day, as might the primer.
As a side note, after shut down (with the boost pump OFF), the engine monitor still indicated maximum fuel pressure. I set the Mixture to Rich and pumped the throttle a few times to see if the pressure dropped ... it didn't.
The next day, the fuel pressure still indicated 9 psi (the maximum). This turned out to be a poor electrical connection on the sensor, so it showed max fuel pressure, even when there wasn't ANY.
Talk about an accident being a 'series' of events:
If I had in fact taken off without the boost pump ON, and if the fuel pressure sensor was working properly, then I should have got an audio alarm and a display saying "FUEL PRESS LOW". This would at least have prompted me to check the boost pump was on.
I am still checking out the fuel system, but I have not found the culprit yet ......... maybe it was ME!!
And now another story: Some notes on the power out landing that Gwyn and Stewart experienced recently.
Gwyn experienced a bounced landing on Runway 23, and in the recovery must have grazed the prop tips. We actually found three small marks on the runway, sawdust lines about 500 mm apart.
The strike went unnoticed, and the touch and go was completed with a normal take off and climb, turning south at 500 feet. Nothing abnormal was noticed: no vibration and no noise nor sense of the strike. Stewart says that the landing was firm but not hard.
On reducing to cruise power about two miles south of the field at approximately 800 feet, severe vibration occurred. Gwyn immediately shut down the engine. They established best glide speed, and decided to return to the field.
Stewart took control, and they made an uneventful return, most of the way back with one stage of flap, then two stages once they were certain of achieving the field. Then they flew three large S shapes to lose height and a sideslip on final as they were still high, even after that distance. The landing was fast but uneventful.
It was a copy book recovery. Full marks go to Stewart for a job well done. Few of the planes at Serpentine would have had the good glide angle to make the field from that height and distance, bearing in mind that a 180 degree turn had to be made to get back. I'm rather glad I made the choice of that particular wing for the Jabiru J250. (120 square feet with a two metre greater span, as against the standard 79 square foot wing.)
There was minimal damage to the prop tips, but the entire forward glass skin of one propeller blade detached during the power reduction, causing the vibration. The skin delaminated cleanly without leaving even a single glass fibre attached to the surface, and the torn edge of the glass near the centre of the blade showed little evidence of resin penetration.
I'll send the prop off to Jabiru as they may be interested to see this for quality control purposes.
Gwyn was mildly shaken but not stirred by the experience. She is determined to finish her training, and is somewhat the richer for the experience.
So there you are, two of a number of power losses members have suffered recently. Neither was a cut-and-dried engine failure, they seldom are. Both pilots concentrated on retaining control of their aeroplane, and both pilots made a successful forced landing back at Serpentine.
BUT. Both pilots regularly practice forced landings. Do you?
Safe flying to you all,
SABC Safety Committee