View Full Version : Opinions on the Walter M601
7th Jul 2008, 19:15
Been looking at the Walter 601 and trying to understand why that engine hasn't been successful in the US.
Ok, it's a little bit heavier (like 20 lbs equipped) than a PT6, and yes it burns a bit more fuel than the PT6, but in a typical application you couldn't burn enough fuel in a lot of years to pay for the difference in cost ($70k) for new engine...
Is it the lack of support?
It seems that some AG fliers are using the engine with good results, I just want to understand why few others are using it and buying the PT6's...
9th Jul 2008, 08:21
Employer has fitted Walter M601 conversion to a 400GL Thrush, A/C has
flown approx 500hrs since with nil problems. A/C has similar performance
to a PT6-15 powered Thrush & is virtually the same to operate.
10th Jul 2008, 18:05
It isn't american made for starters. P&W have what, 5000% of the market for that category of turbine? Way back when the PT6 made its debut the Walther was on the wrong side of the iron curtain and it's a copy anyway isn't it...
Things may change slightly now that GE have indicated an interest in buying Walther to complete their line at the low end. But, like Microsoft, P&W have such a huge head start that they (GE) need to present a very serious value proposition to win PT6 drivers over me thinks.
Fuel economy will have alot more to do with "environmental economy" in the future so a small gain may be enough to offset a higher price.
It'll be interesting to watch the development of turbines in general. If this environment buzz holds on we should be flying many more turbines and pistons, as opposed to jets, in the future.. But, I doubt that'll happen.
10th Jul 2008, 19:06
Can any one tell me the typical fuel flow differences between these engines on ag ops.
I believe the -34 and Walter are about 200 litres an hour,is the G6 more fuel efficient,if so by how much?
11th Jul 2008, 06:37
A -34 powered Thrush burns about 220lph on spraying ops,the Walter slightly less.The -6 Garrett is the most economical using 175lph while delivering similar performance to the -34
11th Jul 2008, 08:58
To be precise, one has to distinguish M601D (or earlier versions) from M601E/F. D-s are less powerful, consume less fuel (150 lph on an L-410, though it would obviously be more in Ag operations), and are considerably cheaper to maintain (by 30-35%), but you won't find a new one except from someone's old stash. E-s and F-s are being officially produced, but I am not sure if Walter is really making new ones rather than selling its old stock. Generally, the demand nowadays somewhat exceeds the supply, driving the prices up.
11th Jul 2008, 11:51
I won't pretend to know about all L410 derivatives, but the company I work for has 2 L410 UVP E20s. The fuel flow is approx 150 KG per hour in the cruise, not litres per hour, and all four engines have returned this consistently over 6 months of use, looking at our engine monitoring logs. The are very reliable, although require some small time to idle before shutdown, which is believed to have been the cause of one combustion chamber failure recently diagnosed during routine maintenance. I have no experience of the PT6 to compare, but many have commented that our engines are quite noisy, especially on start up.
11th Jul 2008, 12:58
Mike, everything is correct: L-410UVP E-20 has the MTOW of 6600 kg and has the newer, more powerful M601E; 150 kgph sounds about right for these. M601D is the model used on the old (pre-1985) L-410UVP, which has three-blade props, no wingtip tanks, and MTOW just over 5700 kg (and there is a bulletin to lower the MTOW below 5700 to squeeze it into JAR-23 requirements instead of JAR-25 and not have to install TCAS/GPWS).
Oh yes, by the way - GE has just completed the acquisition of Walter.
11th Aug 2008, 16:19
As an update, and in contrast to my earlier claims of reliability, we're changing an engine today (ouch). The first indication that all was not well was that the ITT was 80 degrees higher than normal, and higher than the other engine. At first it was thought to be bleed valve failure, but on examination a hole in the engine casing of approx 2.5cm was found just in front of the bleed valve. Theories as to the cause abound locally, the most repeated of which is ingestion of some small foreign object, but I'd be interested to know of other suggestions/experience.