If something breaks, will something else be affected by it? 
What caused the failure? Is it something simple or something about to become catastrophic?
Where there is smoke, assume there is fire, land NOW. 
91.3 allows the pilot to break FAA regulations as needed to meet the emergency 
Post-incident/accident investigation process 
Land as soon as POSSIBLE vs. PRACTICAL. &quot;Possible&quot; is generally understood to be off-airport while &quot;practical&quot; is understood to be at the next suitable airport. However, 91.3 gives the pilot the ultimate authority and responsibility for the safety of that flight and to allow the pilot to make the decision and to do what is necessary to have an in-flight event conclude successfully. If the event was self-caused, there might be repercussions, but &quot;tis better to be tried by twelve than carried by six.&amp;rdquo;