time to use a particular resource and the impact its use will  have upon the safety of flight. For example, the assistance  of ATC may be very useful if a pilot becomes lost, but in  an emergency situation, there may be no time available to  contact ATC.  One of the most underutilized resources may be the  person in the right seat, even if the passenger has no flying  experience. When appropriate, the PIC can ask passengers  to assist with certain tasks, such as watching for traffic or  reading checklist items. The following are some other ways  a passenger can assist:  Also, the process of a verbal briefing (which can happen  whether or not passengers are aboard) can help the PIC in  the decision-making process. For example, assume a pilot  provides a lone passenger a briefing of the forecast landing  weather before departure. When the Automatic Terminal  Information Service (ATIS) is picked up, the weather  has significantly changed. The discussion of this forecast  change can lead the pilot to reexamine his or her activities  and decision-making.  [Figure 2-17]  Other valuable internal  resources include ingenuity, aviation knowledge, and flying  skill. Pilots can increase flight deck resources by improving  these characteristics.  When flying alone, another internal resource is verbal  communication. It has been established that verbal  communication reinforces an activity; touching an object  while communicating further enhances the probability an  activity has been accomplished. For this reason, many solo  pilots read the checklist out loud; when they reach critical  items, they touch the switch or control. For example, to  ascertain the landing gear is down, the pilot can read the  checklist. But, if he or she touches the gear handle during the  process, a safe extension of the landing gear is confirmed.  It is necessary for a pilot to have a thorough understanding  of all the equipment and systems in the aircraft being flown.  Lack of knowledge, such as knowing if the oil pressure  gauge is direct reading or uses a sensor, is the difference  between making a wise decision or poor one that leads to  a tragic error.  ATC and flight service specialists are the best external  resources during flight. In order to promote the safe, orderly  flow of air traffic around airports and, along flight routes, the  ATC provides pilots with traffic advisories, radar vectors,  and assistance in emergency situations. Although it is the  PIC’s responsibility to make the flight as safe as possible,  a pilot with a problem can request assistance from ATC.  [Figure 2-18]  For example, if a pilot needs to level off, be  Checklists are essential flight deck internal resources. They  are used to verify the aircraft instruments and systems are  checked, set, and operating properly, as well as ensuring  the proper procedures are performed if there is a system  malfunction or in-flight emergency. Students reluctant to  use checklists can be reminded that pilots at all levels of  experience refer to checklists, and that the more advanced the  aircraft is, the more crucial checklists become. In addition, the  pilot’s operating handbook (POH) is required to be carried on  board the aircraft and is essential for accurate flight planning  and resolving in-flight equipment malfunctions. However,  the most valuable resource a pilot has is the ability to manage  workload whether alone or with others.  Figure 2-17.  When possible, have a passenger reconfirm that critical  tasks are completed.  External Resources  Internal Resources  • Provide information in an irregular situation,  especially if familiar with flying. A strange smell or  sound may alert a passenger to a potential problem.  •  Confirm after the pilot that the landing gear is down.  •  Learn to look at the altimeter for a given altitude in a  descent.  •  Listen to logic or lack of logic.  Figure 2-18.  Controllers work to make flights as safe as possible.  2-23 