Survived my first engine failure on takeoff

gismo

gismo

Touchdown! Greaser!
Joined
Feb 28, 2005
Messages
12,675
Location
Minneapolis
Display Name
Display name:
iGismo
I flew out to Hutchinson (in a nice T34 BTW) to pick up the Porterfield which just got annualled there tonight. After checking the plane over and dumping in some fuel I fired up, ran a mag check and trundled down the runway. The takeoff was normal until the engine lost power and started running very rough at about 200 AGL. Fortunately the runway is 4000 ft long and I had elected (as usual) to depart from the very end so there was plenty of room to set back down. Once I taxied off the runway the engine smoothed back out (it was rough at idle at first). I got stopped and ran back up to full power (all 65 horses) briefly and it remained OK but when I let it run wide open for more than about 30 seconds it started acting up again.

Back at the hangar we tied the tail down and found that it would consistently start to run rough and backfire (on either mag) after several seconds of WOT. I drained a pint of fuel from the tank sump and found a tiny bit of debris but no water was there or in the gascolater. The mechanic is going to pull the carb's inlet screen tomorrow to see if something is blocking the fuel. The only related maintenance items were a new cork fuel level float (coated with spar varnish) and a replaced primer (injector) that had broken somehow making the engine hard to start. Hopefully it will be something simple and obvious.
 
Glad things turned out OK Lance. In my uneducated opinion it certainly sounds like something fuel delivery related.
 
When that happened to me, I was 500AGL and headed away from the airport. But I managed to put it down on some concrete 4 miles away at the bigger, towered field as it quit completely on short final.

The balance tube on the intake manifold had fractured and the carb was sucking air.
 
If you've been running MoGas I'd also look at the fuel lines, heck, even on 100LL if they're old enough. I've had the interiors deteriorate and restrict flow.
 
So glad that it worked out, Lance. Nice work...
 
Nice work, Lance. Wonder if the new primer is leaking somehow or there's an air leak in the system.
 
Henning said:
If you've been running MoGas I'd also look at the fuel lines, heck, even on 100LL if they're old enough. I've had the interiors deteriorate and restrict flow.
Click to expand...
I grant that this can happen, but my experience is the restriction is likely to be noticed almost immediately, as in it won't even start or runs rough from the get to.
I'd be looking for a vent restriction, among other things.
 
jnmeade said:
I grant that this can happen, but my experience is the restriction is likely to be noticed almost immediately, as in it won't even start or runs rough from the get to.
I'd be looking for a vent restriction, among other things.
Click to expand...

A former cow-orker had the engine fail on takeoff due to this - apparently it ran fine until he went WOT...

(Former as in "where I used to work" not as in "dead" - he landed OK.)

But that's not to say that it couldn't be a restricted vent.
 
Cow orking is illegal in many states. Probably a good thing he doesn't do it anymore.
 
Nicely done, Lance. Glad that it worked for you.
 
Nice job Lance. Glad you got down nicely. Best of luck on getting the problem fixed.

Dave
 
Nice work. Super idea taking the full length. I've not had a failure after lift off yet, I hope I handle it as well as you did.
 
Ah yes, the dreaded after-liftoff engine failure at 45 kts with only 3,200' remaining.:D

Glad you were able to make the peanut butter come out even with the jelly, and hope the fix is simple and obvious.
 
jnmeade said:
I grant that this can happen, but my experience is the restriction is likely to be noticed almost immediately, as in it won't even start or runs rough from the get to.
I'd be looking for a vent restriction, among other things.
Click to expand...


I've seen it 3 times now where the swelling was such that a trickle could fill the gascolator but not keep up with full power demand, YMMV.
 
wabower said:
Ah yes, the dreaded after-liftoff engine failure at 45 kts with only 3,200' remaining.:D
Click to expand...

More harrowing than the dreaded 7-engine approach in a B-52!
 
Good work, Lance. I am always glad to hear of positive outcomes. Once again it has been proven...FLY THE AIRPLANE. Thanks for the reminder.
 
I often wonder how I'll handle a real engine failure compared to the simulations. OEI after take-off simulated with 1 passenger will be quite different from the real deal at gross.

Great job, excellent decision making.
 
wabower said:
Ah yes, the dreaded after-liftoff engine failure at 45 kts with only 3,200' remaining.:D
Click to expand...
Yeah, the thread title was deliberately over the top compared to the actual event which beyond the "is this really happening" jolt was pretty much a non event.

Glad you were able to make the peanut butter come out even with the jelly, and hope the fix is simple and obvious.
Click to expand...
I was hoping the mechanic would find a smoking gun but so far no joy on that. He drained about a quart of fuel from the system at several points (gascolator, carb inlet, bowl drain, etc), found very little debris in the gascolator or carb inlet screen, and determined that fuel flows freely from the carb bowl drain. After that he ran the engine at full power much longer than I found it took to precipitate the problem and the engine ran fine.

I went to the airport today and flew a few circuits around the airport at various power settings and everything seemed to be normal. Flew back home after that keeping an eye on potential landing fields more than I usually do. One possibility is that the new fuel level float (which is slightly larger in diameter and floats better) might be able to restrict airflow into the tank more than before when the tank is full (I'd just filled the tank before the problem flight) I think the filler cap is vented and I'm going to check that out along with confirming that the tank will vent adequately when it's full.
 
LearDriver said:
Was it a complete failure or a partial power landing?
Click to expand...
Once on the ground I had enough power to generate a fast taxi although it almost quit twice on the way back to the hangar. The power loss was somewhat gradual and progressive. It's possible that I had sufficient power to remain aloft at a low airspeed but I think it was all done climbing when I closed the throttle to land. Since I still had 1500 ft of runway ahead I didn't waste much time/runway trying to coax more power from the engine.
 
gismo said:
Once on the ground I had enough power to generate a fast taxi although it almost quit twice on the way back to the hangar. The power loss was somewhat gradual and progressive. It's possible that I had sufficient power to remain aloft at a low airspeed but I think it was all done climbing when I closed the throttle to land. Since I still had 1500 ft of runway ahead I didn't waste much time/runway trying to coax more power from the engine.
Click to expand...

You did it right. I was just wondering if you were making any power at all. I had something similar happen a couple of months ago at a flight school/ rental outfit. Coming through 500 agl the power dropped down between 1800 and 2000. The company wouldn't tell me what went wrong or what the fix was. So im not renting there anymore. Your situation just made me curious. Glad you made it work out well.
 
Good job, Lance... Re-emphasizes the "nothing more useless than the runway behind you" and utilizing full length even if you know you can takeoff with less!
 
Still no smoking gun on the power loss. I pulled the new float and found that there's no way it could block the venting of the tank and no other cause has surfaced. I've got around 5 hrs on the plane now with no further incidents and aside from some increased incentive to pay attention to potential landing areas it's back to normal for me.
 
Henning said:
Have you done a flow check?
Click to expand...
Yes, all the way through the carb (out the drain) and it was flowing more than a quart a minute (full power FF is about 6 gal/hr). And the problem occurred with a full tank which means the head was at maximum.
 
gismo said:
Yes, all the way through the carb (out the drain) and it was flowing more than a quart a minute (full power FF is about 6 gal/hr). And the problem occurred with a full tank which means the head was at maximum.
Click to expand...

Hmmmmm...., when it died did it sound rich or lean?
 
Henning said:
Hmmmmm...., when it died did it sound rich or lean?
Click to expand...
When I demonstrated the problem while tied down on the ramp the observers stated that there was no black smoke and the "backfiring" sounded like it was too lean. Sounded lean to me as well. The fact that in every instance of the problem the onset of symptoms came some time (20-60 seconds) after applying full power, with normal smoothness initially. That's awfully consistent with insufficient fuel flow to the carb and a drop in the level inside the float bowl.
 
LearDriver said:
How clean are the tanks of debris or water?
Click to expand...
There's only one tank. No water was found when we drained the tank and gascolator after the problem occurred. There was a very small amount of debris (tiny particles) in the tank and gascolator but nothing I'd consider adequate to obstruct flow. The system is totally gravity feed so a collapsed hose is unlikely as well.
 
gismo said:
When I demonstrated the problem while tied down on the ramp the observers stated that there was no black smoke and the "backfiring" sounded like it was too lean. Sounded lean to me as well. The fact that in every instance of the problem the onset of symptoms came some time (20-60 seconds) after applying full power, with normal smoothness initially. That's awfully consistent with insufficient fuel flow to the carb and a drop in the level inside the float bowl.
Click to expand...


Yes it is, had to ask though. A clogged bleed circuit in a carb can do similar things, I'm not familiar enough with the structure of your carb to say...hmmm.... So, next comes the tank vent system with a mud dobber nest in it or some other not rightness that needs to flow more than a quart to show.
 
Last edited:
You must log in or register to reply here.
Back
Top