PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   The Pacific: General Aviation & Questions (https://www.pprune.org/pacific-general-aviation-questions-91/)
-   -   PA-31 Check lists (https://www.pprune.org/pacific-general-aviation-questions/643254-pa-31-check-lists.html)

megan 22nd Oct 2021 03:23

Dipsticks? Why have I become the subject of discussion?

lucille 22nd Oct 2021 21:10

Paper checklists, all the better to wrap your Swiss Cheese sandwiches in.

MakeItHappenCaptain 23rd Oct 2021 07:17


Originally Posted by Office Update (Post 11128695)
On a Chieftain its the C/R engines.

C R A P. Nothing to do with engine rotation. Navajo’s have TIO’s on both sides and have the same dipstick setup. Purely due to dihedral.

ps. On the topic of checklists, make sure your Phase 1 checks for engine failure after takeoff have the engine being feathered BEFORE cleaning up the gear. (It’s in the manual if you need to check.)

Sam Asama 24th Oct 2021 08:20


Originally Posted by MakeItHappenCaptain (Post 11130976)
the engine being feathered

Pretty aggressive and antagonist responses to others. Then you talk about "feathering" a piston engine"?



43Inches 24th Oct 2021 09:02

The Navajo manual is written in typical Piper fashion of the time with the expanded explanation key to understanding the procedure. The reasoning for the propeller to be feathered prior to gear retraction is that it allows for the aircraft being at rotation and still on or near the ground, it also offers the fastest reduction in drag over the gear cycling up (on one hydraulic pump). We are assuming Piper used a very long runway for certification, so that the engine failed at rotation, you are rolling along not getting airborne, but now feather the propeller, see if it gets airborne, is it climbing, now retract the gear. Pretty sure in that same time and space you could have just closed the throttles and stayed on the ground. Which is what it basically says to do for most short field options until speed above 104 KIAS. Its going to be a few scary seconds if its barely climbing and those flipper doors open.

Every time I see someone refer to phase 1 checks for Navajos, makes me think its going in for maintenance.

There are also C/R Navajos, called Navajo CRs, who would've thunk.

Capt Fathom 24th Oct 2021 09:51

No need to comment at all. The OP has not been back to the thread they started 6 days ago. Obviously not that interested.

Big Pistons Forever 24th Oct 2021 17:08


Originally Posted by 43Inches (Post 11131494)
The Navajo manual is written in typical Piper fashion of the time with the expanded explanation key to understanding the procedure. The reasoning for the propeller to be feathered prior to gear retraction is that it allows for the aircraft being at rotation and still on or near the ground, it also offers the fastest reduction in drag over the gear cycling up (on one hydraulic pump). We are assuming Piper used a very long runway for certification, so that the engine failed at rotation, you are rolling along not getting airborne, but now feather the propeller, see if it gets airborne, is it climbing, now retract the gear. Pretty sure in that same time and space you could have just closed the throttles and stayed on the ground. Which is what it basically says to do for most short field options until speed above 104 KIAS. Its going to be a few scary seconds if its barely climbing and those flipper doors open.
.

The last company I worked for that flew Ho's taught a fly away from the EFALO procedures. I put a quick end to that. The new procedure was in the event of an engine failure before the aircraft was at VYse, with a positive rate of climb and with the gear up, the only action the pilot was to take was to close both throttles and land/crash straight ahead. After VYse/positive rate/gear up, the pilot identified /verified/and feathered the failed engine and then assessed the aircrafts actual flight profile. At that point the choice was either continue or close both throttles and take your lumps.

Sadly the accident statistics for piston twin low EFALO accidents where the takeoff was continued is a very sad compilation of smoking holes next to the runway....

Sorry for the thread drift but I still see too many pilots who think they can fly away from an EFALO on a grossed out piston twin on a hot day.

43Inches 24th Oct 2021 22:24

I have to agree that's sensible, if the gear is down, you should only be a few feet in the air, land, and if you hit anything it will be low speed and in control. I know some that taught the gear handle as the 'go' signal, leave gear down until no more usable runway, then retract, at that point it's go, if one fails, stop if its still down. Any continuation below blue line in a light twin is going to involve some long acceleration level or loss of height to regain quickly. This used to be something I'd get a pilot to demonstrate, at a safe altitude, no where near VMCA or Stall BTW. And with instructors while the engine was feathered so they got a real appreciation for why not to get slow, I'd always do a significant single engine (one feathered) sequence to demonstrate to instructors how to get maximum performance in the real situation, 3-5 deg bank, importance of drag management, etc.


Sorry for the thread drift but I still see too many pilots who think they can fly away from an EFALO on a grossed out piston twin on a hot day.
The thread was cast adrift from the first post, it's now mid ocean with Wilson for company. At least it's still relating to Navajos.

In a side note I have noticed in past sim practices on turboprops when faced with a performance issue I just adopted the 5 degs bank. Where a lot of others try to fly wings level and fit the flight directors, the performance difference was quite noticeable. Especially with a failed auto-feather or such, being able to get a few feet climb while the FO manually feathers, while wings level needing a huge amount more rudder and significant less climb if any.

extreme P 25th Oct 2021 02:05


Originally Posted by Capt Fathom (Post 11131519)
No need to comment at all. The OP has not been back to the thread they started 6 days ago. Obviously not that interested.

OP actually seemed quite interested in the material I provided for him after a PM.

He was very appreciative and I found him to be a complete gentleman.

Traffic_Is_Er_Was 25th Oct 2021 03:18


Originally Posted by Peter Fanelli (Post 11128704)
It's so the same dipstick can be used in either engine. That way only one dipstick had to be manufactured for the aircraft.
It's all about the angle the engines are at when mounted on the wing as opposed to say the Aztec where the engines are mounted level.
Direction of rotation has nothing to do with it. If I remember correctly the Seneca is the same, that's the original Seneca not the Seneca II and above.

But which side do you read?? Are they marked left and right?? Is it Left from the the front, or Left from the rear?? What if someone swaps dipsticks?? What if somebody put the dipstick in backwards?? The possibilities for catastrophe are endless! :E

43Inches 25th Oct 2021 03:21

Stick it in ya eye, if it's stings and goes blurry with oil, then there's enough for flight.

mustafagander 25th Oct 2021 09:25

Surely we all think it through before setting power for T/O.
I was taught, on the PA31-350 Chieftain, to decide on an altitude depending on D/A etc at which I would attempt to fly away, otherwise close both throttles and land again. Something along the lines of 200ft, clean, failed engine identified and feathered and 110Kts for most flights. Yep, there's a gap - good luck. Of course if we had a C414AW with the RAM VII mods, it's much easier!

43Inches 25th Oct 2021 11:46

To be fair to the Navajo, only 1 out of 20 fatal accidents in Australia was an engine failure on take off, and that aircraft was close to 400kg overweight and it landed and all but one evacuated. Most accidents for type are IMC mishandling related, either loss of control or CFIT en-route, approach or circling to land. After weather, fuel system management including running the aux tanks dry and not switching is the next main cause of accident. So the talk of safety issues around take-off is really misplaced as the chance of an accident in that phase is one of the less likely events. In fact just as many King-Air variants have crashed on take off for similar reasons, showing power-plant has little to do with it.

That's one fatal (overweight) EFATO for a type that has flown a hell of a lot of hours and sectors in Australia since the 1970s.

By George 25th Oct 2021 20:43

A good friend of mine was killed on the 30th March 1978 in Chieftain VH-MBK with an engine failure on take-off at Melbourne airport. The Mahogany Mk1 drivers took over a year to claim he prematurely shut down an engine with some power still available. Peter B only had seconds to decide. A hole in the top of one piston pressurised the crankcase which blew the oil dipstick out of its filler. The escaping oil subsequently torched on the turbo-charger outlet creating the impression of a fire. (which was visible from the ground). Peter secured the engine but slowly descended into the trees clipping a wing tip which dislodged the wing root and a fuel line. He survived the crash but was unable to escape the flash fire. An accident that has haunted me for years. He was also slightly overweight, 60 odd kilos by memory. The simple fact of light piston twins is they are not designed to perform to the four segments of performance that protects the heavy iron.

As for checklists, in the years I flew them 'TMPFISCH' was how we operated, coupled with a good knowledge of the cockpit layout and a good scan. In single pilot operations I felt this gave you a better feeling of being in the loop than reading from a hand held card while trying to fly. Flying schools with their two page checklists for a Beechcraft Duchess, just to start the engines will disagree. In two pilot operations and sophisticated turbine aeroplanes checklists are vital along with a good scan pattern.

The other problem with light twins is a relatively high VMCA. The Twin Comanche (PA30, not the PA39) has a higher VMCA than a Fokker Friendship. This is why Piper started to mess around with left and right engines.

43Inches 25th Oct 2021 21:51

Yes, familiar with that accident. There was a few factors that led to the aircraft not being able to maintain height. One was being overweight and the second the left engine was not capable of delivering full power as the density controllers were set incorrectly limiting power to a maximum of 330hp. 20HP doesn't sound like a lot, but when you only have marginal performance to start with every horse counts. I've mentioned correct setting of density controllers in regard to PA-31s numerous times previously and this accident is one of the reasons why.

The 65kg overload was only worked out on available evidence and could have been more as nothing was available to weigh post accident unlike in the case of VH-POC, out of Portland. However overload is still overload, you cut into those tiny margins by any amount and you are living on borrowed time.

It was unfortunate the circumstance that led the pilot to believe it was a fire and would probably have been the same assumption for most. Trying to then push a circuit and land at very low level at night was always going to be a very tall order even if everything did not conspire against him, which it did that evening. If it was a straight failure, no other maintenance issue and he attempted to fly straight ahead and climb he may have been able to squeeze some performance out of it even with the overload.

I have to say I intentionally left that one out of my tally due to the complicated nature of it not being a straight forward engine failure.

That being said if you take out all the weather related and fuel related fatal accidents you are left with 5 out of 20 related to mechanical performance of which most were complex situations where either both engines suffered some form of degredation, MZK and MBK, were overloaded MBK(again) and POC or there was some form of miss-handling in flight DAP and PGW.

All other engine failures and incidents have either made it safely back to terra firma or resulted in low injuries. I know a number of engine failures on type in Australia that have simply landed and the problem resolved, I have been in two of them, one with 10 PoB occurring at 200ft after take-off. We were 100kg under max weight with actual weights used and the aircraft performed fine for a circuit and return.

Big Pistons Forever 26th Oct 2021 02:40

I had an EFATO in a Ho, 38 lbs under gross going through 1000 ft. Bad news was the choice was go back for the NDB circle to land at barely minimums to my departure airport, or fly 100 miles over the mountains on one engine to the nearest airport. I chose the approach back to the departure airport. It worked OK, but could definitely be categorized as a “significant emotional event”.

The part that made my head explode was that 2 other pilots had put a total of 6 litres of oil in the engine over the the last 4 flight hours. The last 2 litres was added before my last flight because the other Pilot thought he was being “helpful”, but of course didn’t think it was noteworthy enough to tell me :mad:


All times are GMT. The time now is 09:39.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.