24 Apr 2014 |
Research article |
Aeronautics and Aerospace
Missed Approaches and Rejected Landings – Economic and Environmental Impact: Research Paper Introduction (RPI)




Header picture is from the authors: Substance CC license applies.
The approach and landing are ones of the most critical and demanding phases of a flight – both for the aircraft and the crew. The low altitude and speed ranges, characteristic for these phases of the flight, result in smaller safety margins relative to flight trajectory deviations, weather conditions, errors and malfunctions.
An approach and landing is conducted according to a navigation procedure that is specific for the runway and airport. This procedure, described by an area navigation chart (RNAV chart) elaborated by the regulatory authorities, specifies the flight path (the horizontal and vertical components of the flight trajectory) that has to be followed by an aircraft in order to have a safe separation from the terrain and the obstacles situated on the ground, and reach the runway threshold at the required altitude and with the required attitude. Additional guidance from the Air Traffic Controller (ATC) and / or Approach Controller (Approach) ensures a safe separation between successive aircrafts on approach/landing path and that the runway is available for landing (cleared from other aircrafts or obstacles).
During the approach and landing the flight trajectory, aircraft status (flight parameters and configuration), weather conditions (visibility, winds etc.) and external factors (separation from other aircrafts, runway clearance etc.) are closely monitored relative to their expected and acceptable status. If an issue that might pose a safety risk is identified, and the aircraft is considered capable to safely climb and fly, the approach or landing are aborted and the crew initiates a “Go Around” – an emergency climb to a safe altitude where the situation can be further assessed and corrective actions can be taken. An aborted approach is called “Missed Approach” and an aborted landing is called “Rejected Landing”.

Figure 1. – Example of possible aircraft flight trajectories during an approach and landing. Source [Img1]
The flight trajectory for the Go Around, corresponding to a Missed Approach or Rejected Landing, is executed according to a specific navigation procedure, called Missed Approach Procedure, included in the approach RNAV chart. It indicates the Lateral Navigation (LNAV) and Vertical Navigation (VNAV) profiles that ensure a safe separation between the aircraft and the obstacles on the ground and is not in conflict with the other aircrafts in the area. The Missed Approach Procedure includes a holding pattern, a circling flight trajectory that can be used either to assess the aircraft status and take the corrective actions or as a means to retain the aircraft in a safe area until it is possible to reintegrate it in the approach path traffic.
After the aircraft reaches the safe altitude, at the end of the Missed Approach Procedure, it follows the Air Traffic Controller (ATC) guidance during the flight on the holding pattern and back to the approach procedure starting point, for a new approach and landing. The aircraft’s flight trajectory during the missed approach procedure and the new approach and landing are predetermined, they are specific for the runway in use for landing. The only part of the flight trajectory that can change is the ATC vectoring segment (the length of the holding pattern and the flight segment from the holding pattern to the beginning of the new approach). Its length and flight trajectory (LNAV and VNAV profiles) are dependent upon the specific airport and runway for the new approach, air traffic conditions, weather etc.
The objective of the paper presented in this review is to evaluate the additional fuel burn and Green House Gas (GHG) emissions corresponding to a flight segment, determined by a missed approach decision, and to analyze the influence of the LNAV and VNAV profiles on the results. The study was conducted for a Boeing 737-400 (B734) aircraft at Seattle’s King County International Airport / Boeing Field runway 13R (BFI RWY 13R) and is based on the specific RNAV chart for BFI RWY 13R.

Figure 2 – Seattle’s King County International Airport / Boeing Field runway 13R – (BFI RWY 13R) RNAV approach procedure schematics ([1]). Source [Img1]

Figure 3 – Example of flight trajectory following a missed approach at BFI RWY 13R. Source [Img1]
The results indicate that the total length of the flight segment, determined by the missed approach procedure, is the main factor that affects the supplementary fuel burn and GHG emissions. For the evaluated aircraft model (Boeing 737-400), RNAV procedure for BFI RWY 13R and VNAV flight profiles, the missed approach flight segment with a 20 nautical miles holding pattern produces a supplementary 19.6 % fuel burn, 26.4 % carbon oxide (CO), 17.5 % nitrate oxides (NOx) and 32.5 % hydrocarbon (HC) emissions compared with a direct vectoring ATC segment. For an identical LNAV profile, the difference between the two VNAV profiles evaluated in the study is relatively small: 0.02 % for the fuel burn, 0.9 % for CO, 1.7 % for NOx and 7.5 % for HC emissions.
A comparison between the fuel burn and the GHG emissions for a flight segment corresponding to a missed approach, without holding pattern, performed by a Boeing 737-400 aircraft at BFI RWY 13R and standard flights of different total lengths is presented in Figure 4.

Figure 4 – Supplementary fuel burn and GHG emissions for a missed approach flight segment without holding pattern, at BFI RWY 13R, relative to reference flights. Source [Img1]
For a more comprehensive discussion about “Missed Approaches and Rejected Landings – Economic and Environmental Impact”, we invite you to read the following Research Paper, presented at the AIAA Aviation Technology, Integration, and Operations Conference in 2013 and submitted for publication in the Royal Aeronautical Society’s “The Aeronautical Journal”:
Dancila, R., Botez, R., Ford, S. “Fuel burn and emissions evaluation for a missed approach procedure performed by a B737-400” AIAA Aviation Technology, Integration, and Operations Conference, Los Angeles, CA, USA, 2013.
This study is part of the research conducted at Research Laboratory in Active Controls, Avionics and Aeroservoelasticity (LARCASE) in collaboration with CMC Electronics Esterline, in the field of flight trajectory optimization algorithms for Flight Management Systems. The results of these research activities were presented in conferences and published in specialized journals ([5], [6], [7], [8], [9], [10], [11], [12]).
For more information about the current projects and the research activity at LARCASE please visit the website.

Radu Ioan Dancila
Radu Dancila is a Ph.D. candidate at ÉTS and Research Assistant at the LARCASE conducting research in the field of flight trajectory optimization strategies and algorithms.
Program : Aerospace Engineering Automated Manufacturing Engineering
Research chair : Canada Research Chair for Aircraft Modeling and Simulation Technologies
Research laboratories : LARCASE – Aeronautical Research Laboratory in Active Control, Avionics and Aeroservoelasticity

Ruxandra Botez
Ruxandra Mihaela Botez is a Full Professor in the Systems Engineering Department at ÉTS. She specializes in modeling, simulation and control of aircraft, helicopters and autonomous flight systems and their experimental validation.
Program : Aerospace Engineering Automated Manufacturing Engineering
Research chair : Canada Research Chair for Aircraft Modeling and Simulation Technologies
Research laboratories : LARCASE – Aeronautical Research Laboratory in Active Control, Avionics and Aeroservoelasticity CIRODD- Centre interdisciplinaire de recherche en opérationnalisation du développement durable

Steven Ford
Steven Ford is a Platform & System Architect in the Cockpit Systems Integration group at Esterline CMC Electronics.
Research laboratories :
Field(s) of expertise :
Aeroservoelasticity Aeronautics Aeroelasticity Aerodynamics Flutter Flight Management System Flight Trajectories Optimisations ActiveControl Systems Unmanned Aerial System Modeling & Simulation Morphing Wing Modelling Helicopter Modelling & Simulation Aircraft Modelling & Simulation Flight Tests Flight Dynamics Flight Control Systems Finite Elements Vibrations Simulation & Control Technology Parameter Estimation Methods Fluid Structure Interactions Wind Tunnel Testing Certification of Helicopter Fight Dynamics Level D Neural Networks Methods Fuzzy Logic Methods
