Manifold pressure warning

Hello!

I have a 2020 SR22T. I’ve had the plane for 1 year and recently when I take off at full throttle I get a high mani pressure warning. It turns yellow and so I ever so slightly back off and it goes away. Same thing anytime when I climb at full throttle I always have to back off ever so slightly.

I tried to find this in the g1000 manual but came up dry. Can anyone advise? Thank you

Very common for the first flight of the day in colder weather. Keep the MP at 36.3 or so and FF around 40GPH and you’ll be golden. Also, I see this is in the guest category/ most don’t see that. Pony up the dough and join! It’s the best cirrus investment you can spend!

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It’s normal because of the cold weather. Just bump it back below 36.5 mp

For a small excursion like this I recommend leaving it alone. It will self-resolve in a minute, no harm whatsoever will be done, and fussing with and micro-managing the throttle while dividing your attention inside the cockpit is not a good idea during takeoff.

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Thank you. Definitely concerning when I see this on take off. Do you all leave full throttle or touch it back?

Also I’m in LA and even with cooler temp cruising at 30.5mp or less and ff at around 16.2 the TIT average 1650. Low hours on plane 660 total hours.

Did you not see my post? Given that it is barely an excursion, leave it alone. Concentrate on the takeoff rather than micro-managing the throttle. It will self-resolve within a minute or so. No harm will come of this.

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Yes saw it thank you. Do you have any thoughts on the other part of the question re TIT

POH also says that 420 degree CHTs are OK. IMO the risk of distraction during the most critical phase of flight isn’t worth a couple tenths of an inch of MP for one minute due to cold temperature in an engine where that excursion is without question harmless.

If it’s going beyond a couple tenths routinely, sure; get it adjusted. But if it’s just happening on a very cold day and momentarily, I’d leave it alone.

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That seems high, you might want to consider having Timing Checked or if you can post the full flight log data. But you should be well under <1580 at that FF

Actually the TIT on cruise are averaging 1640 to 1660 at 75% power. I lean below 30.5mp and about 16.2ff
It seems like it should run cooler especially since it is cooler oat.

A lot of people on this forum would advocate for TITs of 1580 or less of which I’m one. To do this you need to keep your MP at 30.5 (I actually run at 31.0 because my calibration is off) and lean until you get to 1580. If your MP goes down but you FF stays the same, the TITs will go up, because now you running closer to peak engine power.

Compared to my 22T G6, those are pretty high TITs for 30.5 MP and fuel flow of 16.2

When is the last time your magneto timing has been checked?

If I get a MAN PRESSURE CAS message on takeoff, it is a simple thing to adjust the throttle a bit. Manifold pressure and fuel flow are part of my scan on takeoff. Not a distraction at all. Ignore it and get a FUEL FLOW warning. That is a distraction.

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David,

The High Manifold Pressure and High Fuel Flow alarms are covered in your POH emergency procedures and address conditions that have occurred in SR22T power loss accidents. The emergency procedures have been amended since a 2020 TPOH and address potential situations that resulted in partial loss of power/ surging during the takeoff/initial climb phase.

The CAS warnings and procedures are there for good reason. Several of these accidents could have been prevented had the pilots maintained adequate situational awareness during the takeoff roll when they might have safely aborted prior to rotation.

You might be aware of these already. I write because this is a guest forum and we don’t know who is reading it. Note that the original issue POH excerpt someone else posted above is out of date and is not applicable to your 2020 Perspective+ SR22T.

SR22T Power Loss Accidents

A few of these accidents were traced to inadvertent use of high boost/prime. That was mitigated by a software lockout. However, it was omitted from Perspective+ version .N1. You did not mention which software version you have.

In contrast, the Tuskegee accident (see NTSB report linked below) resulted from an improperly adjusted manifold pressure (slope) controller. The lowest fuel flow recorded in the power loss accidents was just 42.2 GPH, which seems why the HIGH FUEL FLOW warning triggers at 42. In the Tuskegee accident, the manifold pressure was over-boosted during the takeoff roll (which the pilot cliaimed he addressed by retarding the throttle - per the NTSB report) and peaked at 40.5" during initial climb. Fuel flow peaked at 48.1 GPH during initial climb. The aircraft then lost power at about 200 ft AGL, which led to a forced landing.

If interested, here is the link to the NTSB report on “Loss of Engine Power due to Excessive Fuel
Flow in Cirrus SR22T Aircraft”:
https://www.ntsb.gov/investigations/AccidentReports/Reports/AIR2204.pdf

SR22T (Perspective+) POH Emergency Procedure Excerpts

Here is the most recent Perspective+ SR22T POH revision page I could find on the Cirrus website. You should check with Cirrus directly and/or your maintenance provided to ensure your AFM/POH is up to date.

And here is an excerpt from the current online POH for the Perspective+ SR22T MAN PRESSURE Warning:

High fuel flow is a big deal and should be mitigated. A tenth or two MP excellence for a minute isn’t. I’m glad to hear you’re able to manage it without distraction.

Thanks. That really makes my day. :roll_eyes:

Sorry if I am repeating but still seeking clarity. There have been numerous fatalities according to an ntsb report I read for “excessive fuel flow” on take off with sr22T.

Some suspect accidental selection of high boost prime on take off but it is speculation on how the test happened.

It said:

The pilot should monitor fuel flow during takeoff. Fuel flow should never exceed 41 gallons per hour (GPH) at 36.5 inches of manifold pressure. Higher fuel flow rates may result in a rough running engine and/or loss of power

So since I would like to reduce the risk of dying on take off I’m obviously going to triple confirm fuel pump only on boost and if I see map warning that is an indication that engine getting too much fuel and to back off a little?

Rather back off a little than engine failure over fueling.

Thoughts?

David, you need to distinguish between MAP and fuel flow. I’ll defer to the experts, but here is my procedure - If my fuel flow is too high, I pull the mixture control back a little. That will reduce fuel flow. Reducing MAP (by pulling the power lever back a little) might reduce fuel flow some, but it will primarily reduce MAP (and the air in the fuel/air mixture going to the engine). By reducing the air (power lever) and not fuel (mixture control), you might actually enrich the fuel/air mixture going to your engine and make things worse. And btw, unless MAP is off the charts high (38+) or doesn’t come down to 37 or below by the time I level off (well after takeoff), I wouldn’t move the power lever away from full forward during takeoff and climb out.

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The NTSB report posted earlier referenced the 41 GPH trigger set by a 2018 service advisory (SA18-02). The service advisory came out while the first two power loss accidents were under investigation. Later, in 2020, Cirrus Aircraft published TPOH revision that set a 42 GPH high fuel flow trigger in a new emergency procedure.

A couple of thoughts (and please realize that we’re not presuming to offer instruction here - that should be provided by your CSIP or Cirrus Training Center Instructors):

  • Some of the power loss accident reports traced previous flights and noted that the aircraft engine data showed way out of spec. MAP/FF during several prior flights. (As Jim B discusses below, fuel flow is influenced by throttle travel. We saw data in a couple of these accidents that showed the TiT climb just before power loss, as Jim describes).

  • Without reviewing your engine data, it’s not possible to comment further on whether you have a temporary slight over-boost condition when oil is not completely warmed to normal operating temp. The POH emergency procedure for over-boost is clear. Now maybe some would argue that 0.1" over is not worrisome. But we’re on thin ice when we start to ignore CAS warnings and emergency procedure guidance without understanding.

  • Your note above adds that “Same thing anytime when I climb at full throttle I always have to back off ever so slightly”. That sounds like you’re getting excessive MAP even after oil is warmed to normal operating temperature. It might be an engine setup issue that a good A&P could diagnose by reviewing your engine data. Ask your service provider.

  • You could also reach out to Cirrus Aircraft at the number/e-mail on the website. See under “Need Aircraft Support?”