george.coy(at)gmail.com
Guest
|
 Posted: Mon Oct 18, 2010 10:59 am Post subject: Radial engine failures |
 |
|
I have flown a radial engine with no oil pressure for 40 minutes (over the North Atlantic). It was in a Russian AN-2. The engine was an ASH 62 engine (Russian Wright R-1820). We did not change the power setting and the engine continued to run and make power. As soon as the power setting was reduced, the engine wind milled for a bit then stopped. We made a successful landing at an airport in Iceland.
Examination of the engine found the oil cooler packed with fine metal chips. The front oil screen required a pry bar to be removed. It was packed with metal fines and included many chunks the size of a thumbnail. The cause of the oil loss was a faulty oil line. It was installed with a significant twist that slowly unscrewed the rubber to metal joint until it developed a leak. We noticed a loss of oil pressure about an hour before the oil pressure finally went to zero. During that time, the oil temp never changed until the we lost it all together. The cylinder head temp remained normal until the descent.
One significant difference was the fact that the AN2 had a “normal” propeller not an aerobatic prop. When the oil pressure was lost, it went to fine (cruise pitch). Thus we were able to keep going. The Yaks and other aerobatic aircraft propellers will go to coarse pitch upon loss of oil pressure. This significantly affects the ability to keep going.
Another time, I lost an oil plug in a Zlin 50 during local aerobatic practice. The oil pressure dropped and the prop went to full coarse pitch. It became necessary to dive to keep the airspeed in an acceptable range for a landing. Landed successfully with no further damage at the airport.
I have seen a seized M14P where the engine seized and the propeller shaft broke just inside the front bearing. The prop wind milled at a very high speed according to the pilot. He made a successful landing as well. The cause of the seizure was a connecting rod that was partially damaged by a hydraulic lock. It failed and caused others to jam and fail. It was a sudden seizure.
I was doing my final prep in a DC3 for my type rating and during an instrument approach (under the hood), the left engine did not “feel right”. There were no indications of any problems on the instruments, no abnormal vibrations, it just did not sound right. I broke off approach and landed. Turned out that one connecting rod had broken and the piston went to the top of the cylinder and stayed there. The remaining piece of connecting rod was short enough that it did not flail around and cause much other damage.
You can take what you want from my experiences, but I have learned to TRUST radial engines.
George Coy
CAS Ltd.
714 Airport Rd.
Swanton VT 05488
802-868-5633 off
802-363-5782 cell
george.coy(at)gmail.com (george.coy(at)gmail.com)
http://coyafct.com/
SKYPE george.coy
[quote][b]
| | - The Matronics Yak-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Yak-List |
|
|
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
