Cessna 421 Dual Engine Failure


#1

Experience is what you get as a result of not having any! Annual Flight Safety training kept me from becoming overwhelmed… and an angel on my wing!

brettgodfrey.com/aviation.html


#2

My neighbor just purchased a 421, (she also owns an Ovation, luck girl).

So did anyone tell you why the engine came back even though it was left left at full rich? Was it a result of a lower altitude, ie more air to help the mixture? Why did one come back and not the other?

God forbid, if it ever happens again, would you try different mixture settings as part of your restart checklist? Would you, in another engine out situation, leave the good engine alone until you knew you had the field in light of the loss of power on throttle reduction?

Sorry for all the questions, and glad you are OK.


#3

Incredible Brett, thanks for sharing. Well done sir!


#4

Our thoughts and prayers are with the family of those killed in Demopolis, Alabama.


#5

great story-thanks-I was biting my nails all the way down.


#6

Brett, your report made me remember this:

stoenworks.com/Last%20flight%20o … 0Xray.html

Although I shouldn’t be saying this as a C172 driver without instrument rating, it seems to me that they should adapt multi-engine training.

Kind regards,
Holger


#7

Thanks to everyone who read my story. Unfortunately, my airplane is now for sale (fresh annual 08/2012). The link no longer contains the story, but information about N421CX.


#8

I’m a new member and saw your post although the story has been removed. The first time I experienced the same thing in a 421C was on climb to FL180. I lost one engine and while sorting that out lost the other. It happened again on a few occasions and I found by experience that it does not occur if the electric fuel pumps are not used during climb. Rich Cut was the term used to describe over fuelling the engine in a changing environment during climb. Apparently given the right set of circumstances the excess fuel causes combustion failure and consequent loss of power.


#9

Thanks for the post! You may read my story in the January 2012 issue of Flying Magazine - I Learned About Flying From That “Worst Case Scenario”.


#10

Having followed this thread since its inception, I would strongly recommend that anyone with the privilage to fly 300 or 400 series Cessnas to google S.B. MEB 88-3 and read it several times and understand it! The Conquest guys may disregard. I believe the gist of this service letter is the root cause of the double engine failure described by the originator of this thread and the loss of the fictious 5378Xray narrated in the link. This service letter, in my opinion, should have been an A.D., if only to standardize the fleet. The result of selecting high (armed) boost pump on modified versus non-modified airplanes was dramatic and more than once, fatal. The beginning of this service letter was brought about by the undiagnosed failure of the fuel pressure switches and the inability to actually get high boost should the engine driven pump fail. The primer system, masking the failed fuel pressure switch, was part of the culprit, but the end result was the loss of airplanes. The failure of the switch in the closed mode resulted in an immediate over rich mixture and was thus an apparent failure to be addressed. The moral of the story is to know thy systems and at least understand the ramifications of service letters if they are not complied with. A large part of turbine powered airplane inspections is dedicated to the functionality checks of silent but redundant systems. Piston airplanes of old don’t have quite the urgency of these systems in their maintenance manuals, so RTFB is the word (os so) of the day. Read the f-----g book.


#11

Missed a spot in my last reply. Any time metal comes out of an oil filter, that engine comes off to determine where it came from and more importantly, what damage resulted from oil contamination due to metal. Refer to the link about the last flight of5376Xray on this thread. Not to shoot the messenger, but there were several Oh Duh moments leading up to the not quite but apparently inevitable. For the uninitiated, turbine powered airplanes are the pinnacle of the fleet and thus their pilots, the reality is that there is nothing more complex and requiring the need for proper engine management than a heavy, high-performance piston twin. Nuff said.


#12

Hi, I’m a new guy here. I can’t read the article, but two month ago i crushes my 414 chancellor due a engine failure while i was on training with my instructor.

After crush, the plane was on fire, me and my instructor were burns in arms, face and oth parts of the body. I tell you this due can be some recurrent in this model (the good engine was not able to fly the plane).

Regards!


#13

[From author of article linked below] The 88-3 conversion had been made on my plane. That was not what caused the first engine failure at FL230. Rather, it was a defective aneroid. The engine flooded when I reduced power. The second engine failure at 8,000 was the combined result of a mal-adjustment of the upper limit fuel setting and having gone to full rich when the first engine failed. “Everything full rich” on failure of one engine is what I was taught—throttle, props and mixture full forward, etc., with fuel pump from low to high on the failed engine if the earlier measures do not produce a restart. Leaning to attempt a restart is listed in the Cessna manual, but the manual does not elaborate on the reason for this last step, which I had not been taught at Flight Safety. The manual and Flight Safety both omit any detailed consideration of the point that the Continental engine can flood, particularly at altitude, if adjustments are off. Leaning to attempt a restart is the essential final step that Cessna pilots must keep in mind. I suggested to Flight Safety that they should add this to their syllabus, but sadly enough, they’ve discontinued Cessna 400 series training programs.

—Brett Godfrey
(Link to main article: godlap.com/Articles/Flying%2 … rticle.pdf)


#14

The intention of my post on this thread was not to question the skills of the author. Indeed, the fact that you may describe this scenario is a tribute to your skills, training, and cool head in a life threatening situation. The intent was to inform others that GTSIO-520’s are very mixture critical engines and even more so with increased altitude. The failure of the fuel pump aneroid on the first engine failure makes perfect sense. Rich-out was the result and probably unavoidable no matter the training level or experience of the pilot. The reversion to trained responses lead to the loss of the second as was pointed out by the author. Any time one moves the mixture control to full rich and then selects high boost (post MEB 88-3) one will be rewarded with a windmilling propeller at altitude. It’s a given. Flight Safety teaches the Cessna emergency procedure and everything forward was as incorrect when it was published as it is now. These engines require a mechanic who truly knows the fuel system and its components to properly rig one (2). If you have split throttles, mixtures, or fuel flows are split on engine acceleration, or the fuel flow at takeoff power is above the red line and you have to lean it on takeoff, find a more knowledgeable 400 series mechanic and be willing to pay for his time. The essence is that these engines are very intolerant of excessively rich or lean mixtures. Why do you think they are so finnicky to start when hot. The sweet spot grows smaller with altitude!


#15

Hi Brett that must have been a nightmare!! Are you giving up on flying after that one? Seen the plane and hanger for sale on your site? Possibly time for a turbine?