Loss of power after takeoff

[cnoe]

I agree with the suggestion to load your data onto Savvy's free service and superimpose RPM, MP, etc. onto the graph.

I've experienced minor post fill-up water contamination and you'll typically hear/feel the engine lose a little power. Such minor events can subside quickly and never return.

I hate topping off on a cross-country as you never really have enough time to wait for water to settle to the sumps.

 

 

[carusoam]

A sticking exhaust valve will give similar lack of performance on departure.  It can loosen up and perform normally.  Or it can bend and get really stuck.   I Would think that a stuck valve would show up on the JPI pretty readily.  As would many of the other things that are being suggested.  Are you sure you have the right day's data?

The other thing that is available is an app that measures your T/O distance using a WAAS source.  If your climb rate is going to be nil, your T/O distance approaches infinity.  Recording solid data like this you have something to add to your JPI data.

What you are describing is not normal.  Departing a second time without knowing what isn't working is in line with being a test pilot.  Planning to do it again?  Sounds like unnecessary risk taking.  But I am only stating what I think I'm reading.

I've had the stuck valve, water in the fuel, no FF, no JPI, Generator failure, and still went to test fly a bad plane.  Now there is a resource like MS, I can recognize when something isn't right.  Just sharing what I think I know...

You haven't mentioned what is straight ahead, in the event of a needed landing space. Or who is going to be waiting for you at home...

Also, tell me that missed something. I probably did...

Best regards,

-a-

[Yetti]

I have done a couple of high speed runs down the runway as a way to test.  They have a better known outcome.

[MARZ]

I'm thinking that it was a quick turn on a hot engine - the length of time sitting to take on fuel could have vaporized fuel giving the poor performance at first and then clearing later.

[carusoam]

On the original question...

Full throttle (right?), 27" MP at 2700 rpm produces a lot of power, unless the prop's stops are no longer set properly.

Too coarse, you probably won't reach 2700 rpm without hearing the strain.  Too coarse is usually a failure that keeps planes from being able to go around after a gov failure.

Too fine, it would be able to exceed 2700 rpm, easily without producing thrust.

Ingesting air bubbles or water droplets will disrupt the usual flow of fuel.  Power loss tends to be uneven as the bubbles pass through. Vapor usually causes problems with the FF readings by getting caught in the sensor's spinning wheel.

Having the ignition timing drift would also show up on the EGT and CHT data.

Just PP ideas, I am not a mechanic.

Best regards,

-a-

[kevinw]

I'm thinking that it was a quick turn on a hot engine - the length of time sitting to take on fuel could have vaporized fuel giving the poor performance at first and then clearing later.

I've thought a lot about this and I believe it is fuel related. This in combination with flaps and gear down and also increased weight led to the poor performance. I drained a good amount of fuel from the sumps this morning and dumped it. Whatever the problem was came out of it. While my airport is outside of town and in the event of an engine out there are safe areas to land it probably wasn't a good idea to take off again without a mechanic checking it over. I did it though because the issue was gone and I felt comfortable enough to test fly it within close proximity to the airport. This was very strange and I will be very careful over the next several hours I put on the engine.

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[carusoam]

Just have a solid well thought out plan...

This is from one of today's threads.  Power loss on T/O.

Best regards,

-a-

[FlyDave]

If the 830 reported everything normal and the plane didn't sound strange but you just weren't climbing, could this have been an atmospheric issue?

At my home airport I consistently get a downdraft right above the airport and within 1,500' of the end of the runway I pop out of the end of the downdraft and gain 500-600 fpm and, as Jackie Gleason used to say, "Away we go". Could there have been a descending air mass over the field for a few minutes? What were the winds aloft?

[MB65E]

Not that this is the issue... I would turn the propeller up. If you think of the percentage of RPM increase 50 rpm will give you. Say the engine makes power from 1700 to 2700 rpm...at that a range, 50rpm is a good percentage of performance increase. 

Also, check the inlet screen on the fuel servo for debris. Replace the O-rings while you are in there. Keep sumping, it sounds like you had a slug of something go through there. 

But, I have taken off on one mag before...

-Matt

[Shadrach]

13 hours ago, N601RX said:

You mentioned the fuel flow had not been calibrated, was the manifold pressure calibrated?  To me it seems the takeoff MP was low for the 1100 ft of elevation your data files shows. If its reading correctly it seems like your throttle is not completely opening the butterfly in the servo. RPM was also about 40 rpm low, possibly due to lower engine power or perhaps a governor problem.  The engine seems to be running smoothly and on both mags just at a reduced power.  Also to help with future problems I would decrease the sampling rate from 6 seconds to 1 second.  It will help diagnose transient events if you ever have any.

Agreed, all CHTs and EGTs look to be right where they should be, but MAP and FF look odd (notice calculated HP maxes at 76%). How did it climb after the "issue"? My drome is 300ft below yours, but I would expect to see around 29" or more on a near standard day. What were conditions? The M20J POH says you should be pulling 26.5 and 14.2gph whith everything Firewalled at 4000'. At 2000 it says 28.1 and 14.9gph.

Incidentally, the voltage regulator could be adjusted up a bit, 13.6 is low. It should be over 14v.

This does not read like a prop cycling issue. It was 61df and the airplane had already been flown for nearly an hour. Plus it's a 4 cylinder lycoming not a P&W radial with a huge prop hub, cycling the prop does little more than establish control continuity (and suck stones into the prop). Plus, it would have caused an obvious RPM change. Once the governor comes on line, the prop automatically changes pitch to maintain RPM regardless of power, the engine does not do the same for the prop. Problems with prop/governors usually show up on the tach and are usually audible as well.

It reads like this issue was external to engine performance. Like a wind-shear or a gust.

[Shadrach]

5 hours ago, MB65E said:

Not that this is the issue... I would turn the propeller up. If you think of the percentage of RPM increase 50 rpm will give you. Say the engine makes power from 1700 to 2700 rpm...at that a range, 50rpm is a good percentage of performance increase. 

Also, check the inlet screen on the fuel servo for debris. Replace the O-rings while you are in there. Keep sumping, it sounds like you had a slug of something go through there. 

But, I have taken off on one mag before...

-Matt

Worth doing, but not a huge amount of HP ( say 5-6HP). Your percentage of usable power calculation doesn't really tell the story. The POH shows that at sea level, all other things being equal, there is a 6% power loss for reducing RPM from 2700 to 2600. That delta shrinks as MP goes down.

[kevinw]

10 hours ago, FlyDave said:

If the 830 reported everything normal and the plane didn't sound strange but you just weren't climbing, could this have been an atmospheric issue?

At my home airport I consistently get a downdraft right above the airport and within 1,500' of the end of the runway I pop out of the end of the downdraft and gain 500-600 fpm and, as Jackie Gleason used to say, "Away we go". Could there have been a descending air mass over the field for a few minutes? What were the winds aloft?

We discussed this at the airport yesterday as a possible but seems odd. Don't know the winds aloft but it was a reasonably windy day. I'm by no means an expert but in my 15 years of flying I've never experienced this before but then again in aviation we're always learning something new. I'm beginning to wonder if I'll ever know exactly what happened. One thing is for sure, I had everything firewalled 300 ft AGL and could not climb.

[kevinw]

Once again thanks for all the input. While I may never know for sure what exactly happened I'm getting a lot of good info on the MP, voltage and RPM readings. Sounds like the voltage regulator should be adjusted, the propeller turned up a little and the MP is suspect. As far as MP goes, I read that the gauge should be checked by setting the altimeter to the field elevation, note the setting in the Kollsman window, subtract 1" from this number for every 1000' above sea level and the MP gauge reading should be "close". Anything different is an error in the instrument. Then take this static MP reading, subtract 1" and this is the MP reading you should get on takeoff roll. I've done this in the past and it checks. So if this information is correct, the MP we should be getting is really based on the atmospheric conditions in our respective areas, right? Once again, the procedure above is just something i read online so it could be wrong. And by the way, N601RX asked if the MP was calibrated in the EDM830 and yes it was. It is exactly in check with the steam gauge.

[ArtVandelay]

13.6v is fine if batteries are charged, only get 14+ when they are discharged.

[Marauder]

Kevin -- one other thought. Years ago I got behind the power curve on an aborted landing. I was producing full power but was caught in a situation where I was not climbing. In my case it was an extreme situation because I was caught in ground effect and it took all of mental commitment to push the nose over at 10 feet off of the ground to build airspeed.

Not saying that is what happened here, but with all of the visibility on the engine performance from the analyzer, those talking about environmental factors may be onto the cause.

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[kevinw]

2 minutes ago, Marauder said:

Kevin -- one other thought. Years ago I got behind the power curve on an aborted landing. I was producing full power but was caught in a situation where I was not climbing. In my case it was an extreme situation because I was caught in ground effect and it took all of mental commitment to push the nose over at 10 feet off of the ground to build airspeed.

Not saying that is what happened here, but with all of the visibility on the engine performance from the analyzer, those talking about environmental factors may be onto the cause.

Sent from my iPad using Tapatalk

This is very possible. If the fuel was contaminated there would be several other airplanes with similar issues. Like I mentioned earlier, it was a windy day and the CFI thought it was possible that getting caught in a downdraft with full fuel, gear down and flaps at takeoff position could have led to what happened. It's not easy to push the nose forward when you see houses 200' below you (they are at a slightly higher elevation than the airport) but I did it, then cleaned it up and was eventually able to make a shallow climb out. I wonder if I would've retracted gear and flaps sooner that would've helped. The reason I didn't is the problem began almost immediately after liftoff. Thanks for your input, I hope that is the case.

[kevinw]

19 minutes ago, teejayevans said:

13.6v is fine if batteries are charged, only get 14+ when they are discharged.

Good to know. I keep it on a battery minder so it is always fully charged. Thanks.

[carusoam]

When struggling to climb, cleaning up the flaps would take a lot of thinking... (Thinking is what I'm doing here...)

If you see the flaps ware in the wrong position, taking action is best done at a measured pace.

Doing things too quickly or not at the right air speed, you are dumping lift when taking out the flaps.  Are you sure you want to do that?

Done with the gear? Put them away... Unless the additional cognitive load of multiple decision making is already too high.  It may be Better to leave everything in place and focus on flying/landing the plane.  An error would be measured by where the stall occurred.

See if this makes sense...

1) Run-up was performed.

- JPI shows an even increase in EGTs when going on each single mag.  (Do you check/see this?)

- prop tested 2-3 times rpm drop, oil pressure drop, then returns, (MP moves..)

- This is a solid test of the ignition hardware and prop systems.  It is a lesser test of some other things that go along with it.

The real test of power output occurs after the throttle is pushed in... (Somebody mentioned partial throttle T/O in a Bravo the other day.  Partial throttle is unable to test the full throttle power this way)

2) T/O roll starts.  (Mooney pilots can check power output using these important signs)

- Airspeed comes alive.

- MP is at it's usual max (something less than atmospheric pressure due to restrictions to air flow)

- RPM is solidly at redline.  From my (actually measured) IO550 experience,  losing 200rpm = 10% less power (less FF), and a 50% longer T/O run in my LB. (280 vs 310 hp, 2500 vs 2700 rpm, 1200' vs 800' run, approx 28 vs 31 gph)

- FF is at it's usual max (another good reason to have this device)

Take in these values early in the T/O run before committing to flight.  Finding an anomaly quickly is good for rejecting a take-off.

Seeing all these values in their proper location is a comforting sign that proper full power is being supplied.

-------------

Environment thoughts.....

Being caught in a downdraft is unnerving, they can last an uncomfortably very long time. Climbing into wind sheer (tail wind or less head wind) can have a similar effect.  Got my experience in a C172 training for the IR in the dark, over hilly (NJ mtns) terrain.  Maintaining airspeed for best rate of climb and getting out of the area.  We were at the best rate of climb and sinking a couple of hundred feet per minute.

This time of year, DA starts to show its effects. Make sure you understand the effects of OAT on both power production and lift production. (Indelible PMemory)...

Check with your CFI and mechanic if you have questions on these second level of power output checks.  If you have not been going into this much detail prior to take-off, these will ultimately improve your level of comfort.

to be extra clear, I am not a CFI or mechanic, just an ordinary (sort of) PP...

Best regards,

-a-

[kevinw]

17 minutes ago, carusoam said:

When struggling to climb, cleaning up the flaps would take a lot of thinking...

If you see they are in the wrong position, taking action is best done at a measured pace.

Doing things too quickly or not at the right air speed, you are dumping lift when taking out the flaps.  Are you sure you want to do that?

Done with the gear? Put them away... Unless the additional cognitive load of multiple decision making is too high.  It may be Better to leave everything in place and focus on flying/landing the plane.  An error would be measured by where the stall occurred.

See if this makes sense...

1) Run-up was performed.

- JPI shows an even increase in EGTs when going on each single mag.  (Do you check/see this?)

- prop tested 2-3 times rpm drop, oil pressure drop, then returns, (MP moves..)

- This is a solid test of the ignition hardware and prop systems.  It is a lesser test of some other things that go along with it.

The real test of power output occurs after the throttle is pushed in... (Somebody mentioned partial throttle T/O in a Bravo the other day.  Partial throttle is unable to test the full throttle power this way)

2) T/O roll starts.  (Mooney pilots can check power output using these important signs)

- Airspeed comes alive.

- MP is at it's usual max (something less than atmospheric pressure due to restrictions to air flow)

- RPM is solidly at redline.  From my (actually measured) IO550 experience,  losing 200rpm = 10% less power (FF), and a 50% longer T/O run in my LB. (280 vs 310 hp, 2500 vs 2700 rpm, 1200' vs 800' run)

- FF is at it's usual max (another good reason to have this device)

Take in these values early in the T/O run before committing to flight.  Finding an anomaly quickly is good for rejecting a take-off.

Seeing all these values in there proper location is a comforting sign that proper power is being supplied.

-------------

Environment thoughts.....

Being caught in a downdraft is unnerving, they can last an uncomfortably very long time. Climbing into wind sheer (tail wind or less head wind) can have a similar effect.  Got my experience in a C172 training for the IR in the dark, in hilly terrain.  Maintaining airspeed for best rate of climb and getting out of the area.  We were at the best rate of climb and sinking a couple of hundred feet per minute.

This time of year, DA starts to show its effects. Make sure you understand the effects of OAT on both power production and lift production. (Indelible PMemory)...

Check with your CFI and mechanic if you have questions on these second level of power output checks.  If you have not been going into this much detail prior to take-off, these will ultimately improve your level of comfort.

to be extra clear, I am not a CFI or mechanic, just an ordinary (sort of) PP...

Best regards,

-a-

Thanks for posting all this info; it's very beneficial. Most of this I do but I have to admit some I don't. For example I watch the RPMs in the prop check but not the oil pressure. I also need to do a better job of really watching the gauges on takeoff roll as you describe, and I will from now on. I've relied perhaps too much on what the engine "sounds" like versus diligently scanning the gauges other than a quick glance at fuel pressure and temps. I'm actually glad my annual is due next month so I can have the power outputs checked.

[carusoam]

There is a lot going on during the roll.  My Mooney instructors have been all eyes forward, reviewing these details at a timely pace. Maintaining the centerline is key.  They have the checklists memorized, And then review them anyway.  

The Take-off checks are similar to GUMPS.  They have to be memorized because the time isn't available.  Reading while driving down the runway probably would be bad....

At first, I found it challenging to check all the details and maintain centerline and know when the airspeed comes alive.  (Typical of falling behind the plane as the throttle gets pushed in)

Once you adsorb the whole process, It makes a nice (positive) self test of you!

Best regards,

-a-

[jlunseth]

My home field, KFCM, is on a plateau and a south facing takeoff means you are going out over basically a cliff, a long drop down to the Minnesota river of several hundred feet.  Sometimes we will get downdrafts at the takeoff end of the runway.  Some years ago I took off in a Warrior and saw an instantaneous ten knot drop in airspeed.  Ten knots when you are right at takeoff speed is quite a lot.  I just dropped the nose and all was well, but I had lots of room below to make it work.  I have seen that at other plateau airports.  Typically it is short duration, maybe less than a minute.  Plane is performing well, but basically you are taking off into the back side of a microburst.  Possibility.  I don't see anything in the data that looks suspicious, but it would be better to check the data against data from another takeoff that went well.  Stuck valve, bad mag, even bad fuel, all those things should show up in the data.

[Shadrach]

3 hours ago, kevinw said:

Good to know. I keep it on a battery minder so it is always fully charged. Thanks.

That's a good practice. Perhaps check with your IA on VR settings.

This is what Concorde Battery recommends depending on temp. Do consider the OAT that you spend the most time in. I think that most N/A aircraft operate In OATs between 32 and 59 degrees hence my recommendation.

 

 

[Marauder]

2 minutes ago, Marauder said: Kevin -- one other thought. Years ago I got behind the power curve on an aborted landing. I was producing full power but was caught in a situation where I was not climbing. In my case it was an extreme situation because I was caught in ground effect and it took all of mental commitment to push the nose over at 10 feet off of the ground to build airspeed.

Not saying that is what happened here, but with all of the visibility on the engine performance from the analyzer, those talking about environmental factors may be onto the cause.

Sent from my iPad using Tapatalk

This is very possible. If the fuel was contaminated there would be several other airplanes with similar issues. Like I mentioned earlier, it was a windy day and the CFI thought it was possible that getting caught in a downdraft with full fuel, gear down and flaps at takeoff position could have led to what happened. It's not easy to push the nose forward when you see houses 200' below you (they are at a slightly higher elevation than the airport) but I did it, then cleaned it up and was eventually able to make a shallow climb out. I wonder if I would've retracted gear and flaps sooner that would've helped. The reason I didn't is the problem began almost immediately after liftoff. Thanks for your input, I hope that is the case.

My thoughts don't involve contaminated fuel. It involves the angle of attack that the plane is in. In my case, salvaging the landing forced me into a high angle of attack under full power while dirty (full flaps, wheels down).

If you never experienced the sensation of being "behind the power curve", it is an eye opener. I'm sure others can explain it better than I. In my case, it looked like a slightly higher than normal climb angle but with no resulting climb. It was like the plane was hanging off of the prop. I experienced low airspeed, nose up and no climb. I'm not sure this is what happened to you, but it does sound like a similar situation.

Keep us posted if it happens again.

Sent from my iPad using Tapatalk

[kevinw]

21 minutes ago, jlunseth said:

My home field, KFCM, is on a plateau and a south facing takeoff means you are going out over basically a cliff, a long drop down to the Minnesota river of several hundred feet.  Sometimes we will get downdrafts at the takeoff end of the runway.  Some years ago I took off in a Warrior and saw an instantaneous ten knot drop in airspeed.  Ten knots when you are right at takeoff speed is quite a lot.  I just dropped the nose and all was well, but I had lots of room below to make it work.  I have seen that at other plateau airports.  Typically it is short duration, maybe less than a minute.  Plane is performing well, but basically you are taking off into the back side of a microburst.  Possibility.  I don't see anything in the data that looks suspicious, but it would be better to check the data against data from another takeoff that went well.  Stuck valve, bad mag, even bad fuel, all those things should show up in the data.

I remember vividly the first time I took off to the south from FCM. It was about 10 years ago in a Warrior as well. Everything went normal but I didn't know about, or expect to see was the drop off you're referring to. I remember thinking as I passed over it....wow, a pilot would be in BIG trouble if he lost an engine on takeoff. Back to the data, I did compare it to previous takeoffs and it HP was down 2% and FF only .2 GPH, so essentially the same. I've been flying for about 15 years but only have 500 hours so I am far from an "experienced" pilot in my opinion. I've hit downdrafts in summer but at a safe cruising altitude. I've never experienced anything like this before in any aircraft. I'm 200' AGL and can't climb with full power. I'll chalk it up as a good learning experience.

[bonal]

15 hours ago, FlyDave said:

If the 830 reported everything normal and the plane didn't sound strange but you just weren't climbing, could this have been an atmospheric issue?

At my home airport I consistently get a downdraft right above the airport and within 1,500' of the end of the runway I pop out of the end of the downdraft and gain 500-600 fpm and, as Jackie Gleason used to say, "Away we go". Could there have been a descending air mass over the field for a few minutes? What were the winds aloft?

+1 on atmospheric. On the other end on approach at home when the normal afternoon wind is up we get little rollers of the hangars that will make the bottom fall out as you cross the numbers. Scares the hell out of the unaware.