EFATO at Shobdon
Joined: Nov 2004
Aviation Qualifications: ATPL
Posts: 621
Likes: 137
From: UK
Carb icing might just about be possible at high 20s Celcius, but not likely unless exceptionally humid.
Given the temperature, I suspect fuel vapourisation to be far more likely, especially if MOGAS was used instead of AVGAS.
Evidence of either is difficult to find after the event, except possibly finding small amounts of water in the carb after any icing has melted.
Given the temperature, I suspect fuel vapourisation to be far more likely, especially if MOGAS was used instead of AVGAS.
Evidence of either is difficult to find after the event, except possibly finding small amounts of water in the carb after any icing has melted.
Joined: Jan 2012
Posts: 366
Likes: 10
From: Below transition level
Carb ice more common in warm humid wx. Only time I have ever encountered it was doing power check in SEP prior to departure. Conceivable that ice present in carb inlet manifold came loose on opening throttle and caused obstruction.
Well handled by PIC.
Well handled by PIC.
Last edited by Fostex; 1st July 2020 at 18:10.
Joined: Jan 2004
Posts: 5,658
Likes: 501
From: Canada
If the cause of the loss of power was carb ice then it was definitely not well handled by the PIC. Given that the least likely case for the development of carb ice is with full throttle operation, there was carb ice, probably a lot of carb ice, present at the start of the take off run. Therefore the engine would not have made the minimum static full throttle RPM of 2280 for the C 152. This should have resulted in a low speed reject.
I find it disappointing that few pilots verify full power is being developed at the start of the takeoff run. This will not be redline RPM but the POH specified static RPM which will be considerably less than redline. Note this is for fixed pitched props. For variable pitch props the engine should make field baro MP minus half inch, on takeoff.
I think one of the generalizated failings of flight training is that much time is spent on how to react to an engine failure yet very little on how to ensure the engine doesn’t fail in the first place. A review of accident reports where there was an engine failure shows that approximately 80% of the engine failures were caused by the actions or inactions of the pilot
This engine failure falls in the 80% group because appropriate and timely action by the pilot will always succeed in addressing a power loss caused by carb ice.
I find it disappointing that few pilots verify full power is being developed at the start of the takeoff run. This will not be redline RPM but the POH specified static RPM which will be considerably less than redline. Note this is for fixed pitched props. For variable pitch props the engine should make field baro MP minus half inch, on takeoff.
I think one of the generalizated failings of flight training is that much time is spent on how to react to an engine failure yet very little on how to ensure the engine doesn’t fail in the first place. A review of accident reports where there was an engine failure shows that approximately 80% of the engine failures were caused by the actions or inactions of the pilot
This engine failure falls in the 80% group because appropriate and timely action by the pilot will always succeed in addressing a power loss caused by carb ice.
Last edited by Big Pistons Forever; 1st July 2020 at 23:41.
Joined: Dec 2018
Posts: 16
Likes: 0
From: UK
I hear that the engine was producing varying levels of power down to the ground, and the pilot was able to hop over a ditch in the field after touching down.
Top work! Not often you see little old Shobdon on the main page of PPRuNe!
Top work! Not often you see little old Shobdon on the main page of PPRuNe!
Joined: Dec 2001
Aviation Qualifications: ATPL
Posts: 3,766
Likes: 424
From: GA, USA
With some guesstimate numbers of 30C and slightly higher then standard pressure the Density Altitude comes to about 2000’
https://wahiduddin.net/calc/calc_da.htm
What are the chances of having taxied and done the run-up and takeoff with the mixture full rich?
I’m leaning ( pun intended ) in the direction of Big Pistons Forever.
https://wahiduddin.net/calc/calc_da.htm
What are the chances of having taxied and done the run-up and takeoff with the mixture full rich?
I’m leaning ( pun intended ) in the direction of Big Pistons Forever.
Joined: Jan 2012
Posts: 366
Likes: 10
From: Below transition level
I take your points on board regarding the causal factors for the incident BPF, all of which are valid. However I was talking about the pilots handling of the incident once EFATO had occurred. No panic or stall/spin, maintained airspeed and landed safely in a field with no damage to him/her self and no apparent damage to aircraft. That is a good recovery and I am sure that lessons will be learned from it.
Joined: Oct 2018
Posts: 1,074
Likes: 94
From: Uka Duka
If big pistons is correct in his assumption, and I believe he might well be, if things had been done as per the chklst - the PIC wouldn't have had to deal with the EFATO in the first place.
Mind you, it appears that he did deal with it extremely well.
Mind you, it appears that he did deal with it extremely well.
Joined: Aug 2015
Posts: 599
Likes: 61
From: ex 5Y. Now G
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....
I find it disappointing that few pilots verify full power is being developed at the start of the takeoff run. This will not be redline RPM but the POH specified static RPM which will be considerably less than redline. Note this is for fixed pitched props. For variable pitch props the engine should make field baro MP minus half inch, on takeoff.
I think one of the generalizated failings of flight training is that much time is spent on how to react to an engine failure yet very little on how to ensure the engine doesn’t fail in the first place.
.....
....
Joined: Mar 2018
Posts: 2,265
Likes: 1,176
From: Central UK
Gotta love those 'tie downs'.
I never got my head around the notion that an aircraft with a 500Kg empty weight and a wing able and allowed to lift 3000Kg (ie MAUW x 4.4g) is in any way inconvenienced from blowing away or flipping over by 25Kg of water under each wing - half the weight of a large pilot.
Seems no more than wishful thinking to me!
I never got my head around the notion that an aircraft with a 500Kg empty weight and a wing able and allowed to lift 3000Kg (ie MAUW x 4.4g) is in any way inconvenienced from blowing away or flipping over by 25Kg of water under each wing - half the weight of a large pilot.
Seems no more than wishful thinking to me!
Joined: Dec 2001
Aviation Qualifications: ATPL
Posts: 3,766
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From: GA, USA
Joined: Oct 2007
Posts: 1,831
Likes: 16
From: Moray,Scotland,U.K.
If that is a C150 with an O-200 then carb ice doesn't surprise me. I was taught "carb heat off after landing". A Group member had been taught "carb heat off on short final, ready for go-around".
I tried it. Fortunately a full-stop landing. The engine spluttered when I opened the throttle to do a 180.
I often start the take-off run with carb heat hot. I've had vapour lock with mogas. Confirmed by opening the gascolator drain - froth came out.
( O-200 carb ice experience in Jodel DR1050 and Bolkow 208C.)
I tried it. Fortunately a full-stop landing. The engine spluttered when I opened the throttle to do a 180.
I often start the take-off run with carb heat hot. I've had vapour lock with mogas. Confirmed by opening the gascolator drain - froth came out.
( O-200 carb ice experience in Jodel DR1050 and Bolkow 208C.)
