When do engines fail on takeoff?

[JohnB]

As we all know, the most common time for engine failure in flight is on takeoff which I answered correctly on a recent ac checkout. But when? A CFI told me that takeoff is correct, but more correctly he said engine failures are most likely to occur during on takeoff at the first reduction in power after takeoff. Is this true? It seems logical. Would be curious from those of you lucky enough to survive an engine failure if your engine failed after a power change? It would seem a good way to try to avoid this is not to touch anything related to reducing from full power until you are at an altitude you can safely return to the airport. I already do this but it’s not one of my takeoff checklist items to make sure I do.  Or is this power reduction theory an OWT? I know that some of our Mooney’s can have an over boost condition at full power and I’m wondering maybe a mechanical adjustment /stop might be a better way to combat this rather than us backing off power in early takeoff if the power reduction theory is true. 

After reading about what seems like a flurry of recent fatal crashes by experienced pilots just after takeoff, and having just lost a fellow Long Beach pilot to a takeoff accident last week, this topic is on my mind and avoiding this occurrence if possible I think would be a good thing to know how to do if anyone can share any tips/ experience lessons. 

[carusoam]

Initial training in the 90s clearly stated no power changes until reaching TPA... C152. CPC standardized Training....

Problems are expected with the change of pressure and forces associated with power reduction,

Real life.  Got a stuck valve on departure in my old C, WOT...  probably about 800’agl. No changes made, Drat!

Lowered nose immediately, planned to land straight ahead...

No engine monitor to indicate the problem.

Plane was nearly maintaining altitude, near seal level airport. Returned to next available runway to land.  X style runway layout...

Great Transition Training exercise... My CFI flew the plane, I was doing the problem solving, agreeing/stating that the plane was expendable, not the people...  Everything worked out ....

Partial engine failure at 800’ agl, no instruments to indicate its a partial failure, your only choice is to land straight ahead, until your engineer determines that partial power is available, then the next decision is how much?

The stuck valve and 3/4 of power production = about 50% actual power with lots of vibration....

Don’t give away the land straight ahead plan any too quickly.

One PP opinion only, 

-a-

[DonMuncy]

26 minutes ago, JohnB said:

As we all know, the most common time for engine failure in flight is on takeoff ..... but more correctly he said engine failures are most likely to occur during on takeoff at the first reduction in power after takeoff. 

Has anyone ever seen any statistics or studies that support this theory.

[carusoam]

Consider the things we have a lot of experience with...

1) Fuel issues... water, jetfuel, dirt in injectors, air leaking in the line...

2) Magneto issues

3) spark plug issues 

4) air blockage... leaky air induction, blocked exhaust

5) lost engine controls... broken control connections

6) Lost oil / pressure... split oil cooler weld, something stuck oil drain, cracked case

 

These are some of the usual partial engine failures or delayed failure we have seen...

 

Catastrophic engine failures...

We have seen, a broken prop tip depart an MSer’s plane...

I have seen a non-mooney, melted piston from engine ping on departure... Mixture too lean... pistons can melt through very quickly.

 

Broken cylinders can be dicey... loss of oil, interference with piston motion....

 

i think the engine failure upon power reduction may have been more related to crankshaft strength, torque and lubrication... There was always a discussion on what happens if the prop departs, loss of power and change of WnB....

CPC, Cessna Pilot Center was teaching this topic to cover all planes, not just lycoming 4 bangers...

 

young CFIs in a boiler room environment, between students, would be discussing all of the variations and potential solutions....

 

Still PP ideas only, not a CFI...or mechanic...

Best regards,

-a-

[JohnB]

34 minutes ago, carusoam said:

Initial training in the 90s clearly stated no power changes until reaching TPA... C152. CPC standardized Training....

Problems are expected with the change of pressure and forces associated with power reduction,

Real life.  Got a stuck valve on departure in my old C, WOT...  probably about 800’agl. No changes made, Drat!

-a-

Thanks for sharing Caruso. Must have been a harrowing experience for you. This is something I think I do instinctively not touching power until high enough,  unless there's a reason to reduce power (overboost etc) but hearing that it might contribute to takeoff engine failure is eye opening

22 minutes ago, DonMuncy said:

Has anyone ever seen any statistics or studies that support this theory.

I would love to see some statistics on this one! I looked online couldn't find any, but someone would have had to break this down sometime!

[carusoam]

John, 

Not so harrowing, Training was fresh, CFI on board, lots of flatland ahead, had insurance...

Borrowed some tools, checked spark plugs, did a run-up, flew home...

Whatever the problem was fixed itself.... (not really)

I was flying home with an unknown, a bent valve shaft...

unlike new cars, old planes don’t protect the pistons from valve interference.

Got an OH’d cylinder and new valves to go with it... the piston had a permanent dent in the top.

Learning experiences... Don’t assume modern automotive engineering applies to old aviation machines.

Get an engine monitor when able!

Have a few go/no go pieces of data to be confirmed prior to rotation...

A full run-up with engine monitor, confirming all plugs, both mags...

Full power, full rpm, full fuel flow, before Airspeed comes alive....

Share your questions with MS, your mechanic, your Airport friends, before flying a plane with questions...

Best regards,

-a-

[carusoam]

John,

Special note for Bravo and other turbo owners... an exhaust failure of a weakened pipe, or Loss of a  v-band clamp may happen on departure, but not related to a change in throttle...

The full rich mixture burning after the exhaust valves is incredibly hot and getting hotter while under pressure...Leaking flaming exhaust is like a cutting torch while you can’t see it.

Somebody posted a pic of that first tube in their Bravo exhaust. Indicating that it would be wise to measure the tube thickness over time.  They had poked a hole through the pipe with a tool.

Bill Gilliland taught us this experience... Mike Elliot has the first hand experience if you are not familiar.

Best regards,

-a-

[carusoam]

Other bad days related to MSer take-offs

Canopyman lost some power and attempted the fatal u-turn.

Patrick miscalculated T/O length required for a high DA day. Not enough power to clear the trees.

A great military pilot experienced a power on stall, recovering at ground level headed at a House.... survived and detailed his experience on MS.

Our French Canadian Rocket pilot didn’t get the honor of a full investigation.  The engine out accident happened on a go around after a long flight returning home...

Unfortunately, I don’t have the memory skills to detail the issues properly, and with the respect they so deserve.

Having these conversations hopefully slows the rate of this list getting any longer...

We live, we learn, we share,

-a-

[kmyfm20s]

Because take off is the first opportunity to find out something is wrong with the engine:) Jokes aside I agonize over this as well. I would much rather have some assurance that I make it to 1000’ Agl than have a parachute. I am a big believer in getting the engine up to operating temperatures before take off. I recently had a mag fail and it of course was at take off but I don’t consider that an engine failure. I have heard the power reduction theory also. If you listen to the APS guys reducing power by rpm and not manifold you will put more stress on the connecting rod and crank by initiating the combustion event earlier in the stroke. My speculation but I think a lot of people simple reduce rpm after they take off and leave the MP all the way in and could be an explanation.

[Tommy]

11 minutes ago, kmyfm20s said:

Because take off is the first opportunity to find out something is wrong with the engine:) Jokes aside I agonize over this as well. I would much rather have some assurance that I make it to 1000’ Agl than have a parachute. I am a big believer in getting the engine up to operating temperatures before take off. I recently had a mag fail and it of course was at take off but I don’t consider that an engine failure. I have heard the power reduction theory also. If you listen to the APS guys reducing power by rpm and not manifold you will put more stress on the connecting rod and crank by initiating the combustion event earlier in the stroke. My speculation but I think a lot of people simple reduce rpm after they take off and leave the MP all the way in and could be an explanation.

So it's better to reduce RPM than reducing Manifold?

The way I see it is that get to 1000ft as quickly as you possibly can without frying the engine so you have options. It would be nice to know what is the best / least harmful way to climb but I am afraid many theories simply lack empirical evidences. The only objective measurement that you have is CHT. Even that is an indirect measurement of the beating that your engine is taking. 

[kmyfm20s]

6 minutes ago, Tommy said:

So it's better to reduce RPM than reducing Manifold?

The way I see it is that get to 1000ft as quickly as you possibly can without frying the engine so you have options. It would be nice to know what is the best / least harmful way to climb but I am afraid many theories simply lack empirical evidences. The only objective measurement that you have is CHT. Even that is an indirect measurement of the beating that your engine is taking. 

The classic teaching is reduce MP before RPM. To my knowledge reducing rpm alone and not MP causes the combustion event to happen earlier in the stroke before top dead center. Causing more PSI on the up stroke than the down stroke. This increases stress on the crank, connecting rods and potential for detonation. I’m not an Mx!

[ArtVandelay]

Has anyone ever seen any statistics or studies that support this theory.

Sounds like an OWT handed down by CFIs. Most CFIs will yell at you if you start leaning in a climb too. Engines fail on takeoff because it’s maximum power,RPMs and that’s maximum stress and requires maximum fuel flow, possibly just after refueling.

[FloridaMan]

Mine quit at 200ft post maintenance due to FOD going through the #4 cylinder. I suspect the FOD rolled to the back of the intake when I pitched up. I declined an intersection departure on a 10,000 ft runway and landed in the field at the end. The seemingly overly cautious decision to decline that intersection departure may have saved my life and the airplane too. 

[PTK]

5 hours ago, kmyfm20s said:

The classic teaching is reduce MP before RPM. To my knowledge reducing rpm alone and not MP causes the combustion event to happen earlier in the stroke before top dead center. Causing more PSI on the up stroke than the down stroke. This increases stress on the crank, connecting rods and potential for detonation. I’m not an Mx!

Assuming we’re talking about in climb as the airplane is climbing mp gradually reduces due to less O2. In climb I’m at full mp and redline RPM unless there is some noise restriction. I note target egt on take off and dial back mixture every so often. MP stays full from takeoff to setting up for landing. 

 

 

[Mooney in Oz]

4 hours ago, kmyfm20s said:

The classic teaching is reduce MP before RPM.

I don't touch anything on the climb out, except the mixture when appropriate, until reaching top of climb (as espoused by Bob Kromer).

[ArtVandelay]

I generally take off using 2650 RPMs, it’s seems much quieter (at least from the inside ) and start leaning by 2000’. I know the recommendation is 3000’ but here in Florida we can be at 2000’ DA while at sea level.

[jetdriven]

2650 RPM at fill throttle, all things equal, increase cylinder pressure and decreases performance. 

These engines are not made of glass.  Full throttle and 2700 rpm no limit. 

[ArtVandelay]

2650 RPM at fill throttle, all things equal, increase cylinder pressure and decreases performance. 
These engines are not made of glass.  Full throttle and 2700 rpm no limit. 

A. If they are not made of glass, then they can handle the pressure. Cylinder pressure is not an issue if it’s correctly timed. See other thread about STC using 10:1 helicopter pistons.
B. As I mentioned I do it to be quieter, most of my takeoffs are at dawn. We have enough problems with community’s wanting to close airports.

[jetdriven]

If your climb performance is a little lower then you are flying lower at every point down range. I guess I’m not convinced that reduced power climbs are any quieter.  They definitely cost more. 

[1964-M20E]

I heard many years ago that power changes contributed to engine problems but that was just hearsay.

My personal experience was while being vectored to the ILS approach in Orlando when I backed off on power the engine began to run rough.  I enriched the mixture and it smoothed out. My second power reduction about 2 miles before intercepting the localizer it began to run enough again.  I go full rich with the mixture no change, I add power back and it smooths out some.    Now the gears that started turning on the first power reduction went into over drive for the second power reduction.  Ceiling is about 10BKN I keep high and fast on the approach until I can see the runway and know I can glide there then I reduce power to land.  Turned out to be a loose intake tube on #3 which by looking at the engine monitor I know #3 was going cold during the power reductions and rough running engine.

I do know form personal experience with other engines when experiencing problems running them at full throttle the engine may not be making full power but it keeps running and depending on what you re doing and where you are at just run it WOT and do what you need to do and worry about the engine later.

[PTK]

44 minutes ago, teejayevans said:

A. If they are not made of glass, then they can handle the pressure. Cylinder pressure is not an issue if it’s correctly timed. See other thread about STC using 10:1 helicopter pistons.
B. As I mentioned I do it to be quieter, most of my takeoffs are at dawn. We have enough problems with community’s wanting to close airports.

The way I see it the airport was there long before houses were built. And those who don’t like it or can’t tolerate it can always sell and move. 

[Yetti]

If there is a correlation between takeoffs and engine issues.   What I would suggest is practicing pushing over the yoke when the fan stops.  It was very enlightening to me to practice this (up high of course).   I was not as smooth as I should be.   I think this is one of the things you should be ready for and have practiced it before you need to pull the skill out of your pilot bag of tricks.

[RobertGary1]

2 of my engine failures were at take off One was a servo failure that killed the engine when I touched the mixture. If the engine is making power I don’t touch anything below tpa. 

The other take off failure was a rod failure at around 2,000 feet  Not sure if it was coincidence it was at takeoff  

 

-Robert

[jlunseth]

Hmh.  I going to say that’s one of those OWT’s that may be the result of the fact that instructors fly school planes, the school planes are invariably heavily used and not always maintained as they should be.  Enough to comply with the regs.  Its a mix.  Plane overloaded and out of balance, stall spin on takeoff.  Someone did not close the baggage door on the nacelle of a twin, came open on takeoff.  If the power reduction theory were true, then engines would be failing with regularity during descent and final approach when the engine is powered down, and they don’t.  Takeoff is just the first full power exercise of the engine in any flight, so if something is ready to fail, that is when it happens most of the time.  Its also the primary point where the engine is operated at full power, so max stress.

It may be true that most engine failures are during takeoff, but most accidents are during landing, they are just mostly RLOCs, fatalities are not common, just some bent metal.

[Bob_Belville]

1 hour ago, Hyett6420 said:

i was taught 25/2500 at 500, flaps at 3.... primarily due to noise its only on reading on this forum that i learnt you should keep all wide open till climb out.  I suppose London is like Santa Monica, full of Nimby peeps.

 

Yeah, reduce to 25 square was the accepted wisdom in 1969 when I started flying a Mooney. And I know that many older pilots, including a friend who's a CFII, ATP, long time Mooney owner, still pull back the throttle and then the prop shortly after raising gear. But SOPs change. We also leaned to 25 ROP for cruise, and never, ever let the MP/RPM be over square.