A couple years back I had about a 100 percent pass rate on Multi-Engine checkrides. However, things have changed. Most of the experienced instructors have moved on leaving the training to newer, lower time multiengine instructors. While I'm not trying to beating up the newer MEI's, I have noticed my pass rate has dropped a little.
One of the biggest problems has been a loss of control of the airplane during engine out operation. Most of the time this happens when the applicant allow the airspeed to bleed off to an unsafe level at which point I have to intervene. Rather than write a long winded explanation on what happen, lets just put more emphasis on maintaining at or above Vyse during engine out operations. If you can hold altitude at or above Vyse great, do that. If you lose an engine during departure, lower the nose and maintain Vyse. don't let it go below it trying to make the airplane climb. If you are shooting an instrument approach, and you need to arrest a descent, remember to add power when you raise the nose.
Another issue has been identifying the inoperative engine. Dead foot, Dead engine works. Don't use the engine instruments. Several applicants got confused on which engine failed and attempted to feather a working engine.
I have had a couple of applicants read from a book on how to do each maneuver. You need to know how to fly basic maneuvers from memory. Reading from a book on how to do slow flight, Steep turns, the Vmc demo or stall procedures is not acceptable. Notice the ACS uses the wording "To determine that the applicant exhibits satisfactory knowledge, risk management, and skills
associated with....." and "The applicant demonstrates the ability to:" This means the pilot knows how to do each maneuver. (Up until just recently, I have never seen this. 99.9% of multi-engine applicant know how to fly their airplane and do each maneuver from memory.) Please note, this is not to imply that an applicant is to memorize the aircraft checklists and then do them from memory. I am talking about knowing how to conduct a maneuver, for example steep turns, from memory.
Please review the Private and Commercial ACS for the required maneuvers for the muti-engine rating. There have been some changes from the old PTS.