Microlighters

Hi Guys I am busy with a survey on crankshaft hours ,
please submit your hours as it will remain confidential - I want to supply stats to CAA as to how many hours the average crank has done as well as engine type
As example my plane a rebuilt engine - 582 -no new crank -removed the engine and replaced it at 1632 hours I flew it 250 hours
other 582 ex cheetah Rhino Park - 900 hours - every 300 hour inspection
no failures .
Leprachaun

Lep
Sorry for HiJack

What is situation with crank hrs today. If you have flown more than the suggested 150/300 hrs are you legal if you continue to fly?

As the law stands your crank has to be replaced at 300 hours !
I have been in touch with the powers to be plus the new inspectors who are still pretty lenient on the issue , but we need stats to "soften" them a bit .
They are adament that training aircraft will abide by the rules and others may get by with a crank inspection -
Now you know why I need some ammo , Leprachaun

My 503 in my old plane ZU-AUK did 575 hours by the time I sold it. Just before then (534hours) I did a crank test and the crank was within specification as were the pistons and rings. (wear limit on the gap is set to 1.0mm, mine was at 0.4mm after 534hours)

On average 503's in the Western Cape have been pushing 1000 to 1200 hours before replacement. But I don't have specifics

ZU-WYG (Challenger 503) is over 700 hours on the crank and still within specification

In the last 3 years in the Western Cape I have not heard of a single crank failure on a 503 or a 582.

Ask aviation engines to give you some stats regarding the sales of cranks vs the amount of motors they have sold over the last 10 years

Good luck on your quest Sir Leprechaun. "To measure is to know" (Lord Kelvin, 19th-century mathematical physicist.)

Lets get as much data as possible - our instructor fraternity should be able to contribute lots of history & will be an excellent source of stats. Also important will be to find out the consequences of the failures: safe landing, damage,injuries or death.

You have probably got them all but I would suggest analysing the data by A/C Type [Trike, Fixed Wing], Usage [Training, Social], Hours/year, Location [Coastal, Inland-High, Inland-Low], Oiling method [premix, injection], Decoke history, in addition to details of the failure.

While we are busy with this how about including data on engine outs and the reasons if known. A PM is on its way with my details.

503 DCDI = 600 hours and tests perfect. Never been opened. Also havent heard of any crank failures in the last three years.

503 DCDI done 650hrs inspection 120 hours ago on crank and was within specs

My old 503 single ignition had 880 hours with the same crank.
The other trike had a 503 duel motor with 815 hours with the same crank.
My 582 is now on 280 hours...

My 503 did 750 hours never opened till now. All the bits were well within spec. My last trike also 503 did about 600 hours. no problem with crank.

my 503 Hornet had 680 hrs when i sold it , the new owner wanted me to get it checked, opened at aviation engines no problems found

503 - 600 plus hours and still going strong

I cannot remember specifics, but the following is a true refelction of the facts at La Mercy Flight Park:

1. The school owned and operated about 10 microlight trikes, all fitted with Rotax 503 motors, during the 8 years of operation. All these machines did more than 600 hours per engine, with only 2 dekoke's done in those periods per engine. All trikes sold, and still flying today. One trike was fitted with a Rotax 582. This machine had a new crank fitted at 180 hours, and then did over 450 hours thereafter before it was sold. One particular 503 engine did 1 300 hours before we fitted a new shortblock. The original crank was still just fine.

2. All owners of trikes at La Mercy, and there were as many as 30+, never had crank failures of any kind. These privately owned trikes had engines with hours ranging from 100 to 1000. I sold them to almost all their owners, and was solely responsible for all AP work and maintenance.

3. In total the hours put onto these privately owned trikes, plus the school owned trikes, was approximately 16 000hours over the 8 year period.

4. All engine failures which occured, were as a result of non-crank related issues. These were as follows:

4.1 Water related problems on 582's
(a) Radiator cap came off
(b) insufficient water in radiator
(c) Thermostat failure
(d) radiator cap seal broken
(e) oil in water from rotary shaft, causing frothing of water and subsequent loss of cooling function causing overheating
(f) loss of circulation in old radiator

4.2 Rotary shaft seal related problems
4.3 Cold seizure on numerous occasions

4.4 fuel related problems
(a) water contamination
(b) blocked filter
(c) running out of fuel
(d) carb icing
(e) abrasion of fuel hose, causing loss of fuel flow


all the above led to engine failure in flight

No fatalities, nor even serious injuries occurred to any passengers or pilots of the aircraft engine failure mentioned above.

4.5 electrical failure
electrical failures did not cause emergency landings, as full operational functionality was maintained on remaining ignition circuit.

I trust the above will help you Alex.

Thanks and good luck.

Please note that I am NOT in favour of an AMENDED maintenance schedule, as that will always be a a contentious issue. I want any reference to a maintenance schedule as compulsory to be scrapped, and maintencance as the discretion of the owner and service industry.

Kind regards.

582 inspected at 470 hrs and still in spec.