Pilot Flying and Pilot Monitoring

On every multi-pilot flight deck one pilot flies and the other monitors. The pilot flying (PF) controls the flight path, speed and configuration, by hand or through the automation. The pilot monitoring (PM) watches what the aircraft and the PF are doing, compares it with what should be happening and speaks up when the two differ, while handling the radio, the checklists and the selections the PF asks for.

The split makes one pilot answerable for the flight path at every instant and frees the other to check it; two pilots each assuming the other is watching can be fatal. Accident investigators keep finding that the monitoring half of the bargain is where crews fail. Briefings and callouts in general are covered under crew coordination; this article looks at the two roles in detail.

Two roles, not two ranks

PF and PM are tasks, not positions. The commander decides, for each flight or sector, which pilot will handle the aircraft. The captain may therefore be PM while the first officer flies, and remains pilot-in-command throughout: the commander delegates the handling of the aircraft, not the command. On Air France 447 the captain was PNF for the takeoff; on Asiana 214 the trainee captain in the left seat was PF, while the instructor in the right seat was both pilot-in-command and PM.

Some decisions stay with the captain whoever flies. In Boeing's rejected takeoff procedure the left-seat pilot calls "REJECT" and carries out the stop. On the A320 the captain keeps a hand on the thrust levers until V1 and may decide to reject below 100 kt depending on the circumstances.

The name has changed with the thinking behind it. The FAA's advisory circular on standard operating procedures, AC 120-71, replaced pilot not flying (PNF) with pilot monitoring to stress that the second pilot's main job is monitoring, not simply not flying. PNF survives in some training material and in accident reports such as the BEA's on Air France 447. Licensing rules count the PF role too: under EASA's FCL.060, a pilot without an instrument rating may carry passengers at night as pilot-in-command only after at least one takeoff, approach and landing at night as pilot flying in the preceding 90 days.

Pilot flying duties

Boeing lists the PF's general responsibilities as taxiing, flight path and airspeed control, airplane configuration and navigation. Airbus reduces them, in normal operations, to two words: fly and navigate. In practice the PF:

• controls the aircraft directly or through the autopilot and autothrust; on Airbus aircraft a decision to fly by hand is agreed between both pilots;
• on the A320, makes the FCU selections while the autopilot is engaged; when flying by hand the PF asks the PM to make them, except that the PF may engage the autopilot and autothrust;
• operates the thrust levers, which on the A320 remain the PF's even when a procedure calls for moving one: the PF points to the lever, the PM confirms, and the PF moves it;
• calls for configuration changes such as "GEAR UP" or "FLAPS 15", which the PM selects;
• announces flight mode annunciator (FMA) changes, verifies and acknowledges the PM's callouts, and makes any callout the PM misses.

Airbus's first golden rule, "fly, navigate, communicate", in that order and with appropriate task sharing, sums up the PF's priorities, and its message for abnormal situations is simply to fly the aircraft. When something fails, the PF keeps flying while the PM works the problem; the two do not both turn to it.

Pilot monitoring duties

Boeing's list for the PM is checklist reading, communications, tasks asked for by the PF, and monitoring of taxiing, flight path, airspeed, airplane configuration and navigation. Airbus again uses two words: monitor the flight path, the navigation and the aircraft systems, and communicate with ATC, the cabin and the ground crew. The PM also:

• usually makes the FMS entries in flight on the Boeing 737, and any that must be made during taxi; the other pilot verifies each change before it is executed;
• cross-checks the PF's FMS preparation on the A320 page by page, in the order it was entered, so that both pilots hold the same picture of the departure;
• makes the standard callouts from the instruments, and a deviation call whenever a parameter passes the operator's limit;
• challenges the PF when necessary and, under Airbus's fourth golden rule, takes over when necessary.

In a non-normal situation on Airbus aircraft the PM reads and performs the ECAM actions or QRH procedure aloud and asks for the PF's confirmation before clearing each ECAM message, while the PF flies, navigates and takes over the radio. Critical actions are cross-checked by both pilots first; on the A320 in flight these include any action on an engine master lever, an IR mode selector, a guarded control or a circuit breaker. The 1989 Kegworth accident, in which the crew shut down the wrong engine, is the standard reminder of why. In recall maneuvers such as stall or upset recovery the roles narrow further: the PF flies, and the PM calls attitude, airspeed and altitude and any omitted action.

Task sharing by flight phase

Each operator's procedures fix who does what in each phase. The table gives representative tasks from the A320 and Boeing 737 procedures, with callouts in capitals.

The approach calls are the clearest division of labor: the PM watches the altitude and calls the minima, while the PF looks for the visual references and decides. On final the PM also calls any excessive deviation in speed, pitch, bank, descent rate or path (see stabilized approach for the A320 limits).

Effective monitoring

Monitoring is not looking at the instruments; it is comparing them with an expectation. Active monitoring means the PM knows what the aircraft should do next, from the briefing, the clearance and the procedures, and checks that it does. Passive monitoring, glancing at displays with no prediction to test them against, lets slow drifts and silent mode changes pass, and people are poor at sustained watching of a system that is usually right. The FAA makes the same point about SOPs: when both pilots know what should happen, who does what and what will be said, any departure from the expected sequence becomes a visible cue.

Good monitoring rests on a few habits:

• Watch the FMA. It is the primary display of the modes actually engaged, which are not always the ones selected. Airbus's third golden rule requires the crew to monitor, announce, confirm and understand it at all times, and Boeing calls announcing FMA and thrust mode changes good CRM practice. The FMA callout is the PF's announcement of each new mode and the PM's confirmation (see flight deck automation).
• Use the standard callouts. The PM calls from instrument indications and the PF checks and acknowledges. If the PM misses a call the PF makes it; if an expected automatic callout does not sound, the PM makes it. A call the other pilot fails to make can be the first sign of subtle incapacitation.
• Be specific and immediate. A deviation call names the parameter and the amount, "sink 1,200" or "one dot low", and is made at once. Correcting the other pilot's slip silently removes their awareness of it and hides the weakness in the procedure.
• Cross-check entries. Routes and performance data are checked independently by both pilots, and a change is executed only after the other pilot has verified it.
• Keep the critical phases clear. Head-down work such as FMS entries is best done before taxi or when stopped. The FAA's sterile flight deck rule, 14 CFR 121.542, bans nonessential duties and conversation during taxi, takeoff, landing and all flight below 10,000 ft except cruise, so that nothing competes with monitoring when the margins are smallest.

View full schematic

Escalation is part of monitoring. Airbus asks the PM to communicate, to challenge the PF when necessary and to take over when necessary. The two-challenge rule sets a trigger: a pilot who does not respond appropriately to two clear challenges about a significant deviation is assumed to be incapacitated, and the other pilot takes control. Under most airline go-around policies either pilot may call "go around", and the PF complies without debate.

Transfer of control

Only one pilot flies at a time, so a handover must leave no doubt. Airbus uses two phrases and a reply. To give control, the pilot flying says "YOU HAVE CONTROL", and the other accepts with "I HAVE CONTROL" before taking up PF duties. To take control, a pilot says "I HAVE CONTROL", and the other replies "YOU HAVE CONTROL" before taking up PM duties. The FAA's Airplane Flying Handbook teaches a three-step positive exchange of flight controls, "You have the flight controls", "I have the flight controls", "You have the flight controls", with a visual check that the other pilot really is flying.

On the A320 family each sidestick sends its own order, and simultaneous inputs are added algebraically, up to the equivalent of one full deflection; both green SIDE STICK PRIORITY lights flash and a "DUAL INPUT" voice message sounds every 5 seconds. A pilot who must take over presses and holds the sidestick takeover pushbutton, which deactivates the other stick, triggers "PRIORITY LEFT" or "PRIORITY RIGHT" and lights a red arrow in front of the pilot losing authority. Held for 40 seconds, the priority latches until either pilot presses a pushbutton again. The callout goes with the button, never instead of it.

Control also changes hands by plan. In Airbus guidance, if the runway or intersection changes during taxi, the PF delegates the FMS update to the PM and, to cross-check the new takeoff data, either stops the aircraft or hands control to the other pilot. Taking off with performance data computed for another runway position is a serious error, and a planned handover keeps one pilot on the taxi while the other checks it.

Monitoring failures in accidents

Accident reports return to the same pattern: the information needed was displayed, and nobody was watching it. A 1994 NTSB safety study of 37 major accidents involving the flight crews of US air carriers between 1978 and 1990 found inadequate monitoring or challenging in 84 % of them.

More pilots do not guarantee more monitoring: Eastern 401 had three flight crew and Asiana 214 three pilots on the flight deck, and in both nobody was watching the parameter that mattered. For Colgan 3407 the NTSB named the failure to monitor airspeed against the rising low-speed cue as a contributing factor; for Asiana 214, inadequate monitoring of airspeed was part of the probable cause. The defenses are those described above: a clearly designated PF, a PM with an expectation to check against, every mode change spoken aloud, and a deviation called the moment it appears.

Library articles are written for study and exam preparation. They do not replace your aircraft's approved documentation, your operator's procedures or the regulations themselves.