Disclaimer: This is not intended to be a duplicate by any means and instead aims to address aspects of the 737’s performance and handling characteristics on landing specifically that are NOT covered by existing guides, or in more detail (triple checked and corrected for any inaccuracies found in the other ones, if applicable.)
Source
Right then, where should I start?
The 737… you either love it, or you hate it.
Whether you like it or not, it remains the most produced commercial airliner in the skies, and that popularity has certainly made its way into IF as well.
Unsurprisingly, there is no shortage of flying guides and tutorials for this aircraft out there; but having that said, one question still seems to remain for many, judging by my interactions with the community here on the IFC and elsewhere:
“How do I land the 737 properly?”
I will attempt to tackle this question to the best of my abilities in this topic - after nearly a month of intensive research, performance testing and analysis.
1. Introduction to the 737NG family
The 737NG lineup of passenger jetliners consists of six variants (ER variants included), three of which are present in IF:
- 737-700: The original variant launched in 1993, with a capacity of 149 passengers. MTOW: 70 080kg, MLW 58 604kg.
- 737-800: The most popular variant, launched in 1994, with room for 189 passengers. MTOW: 79 002kg, MLW 66 349kg.
- 737-900: A stretched 737-800 launched in 1997, but with the same capacity of 189 passengers due to an identical exit configuration to the 800. MTOW: 79 002kg, MLW 66 349kg; same as that of the 800.
These are important values, keep these in mind for later.
Please note that while the majority of liveries for the 737-900 in IF are that of the ER, the model itself (capacity, specifications etc.) are that of the standard -900. Performance-wise however, there are other quirks that I will go into more detail later.
2. [UNIVERSAL] Flap usage on approach and landing
With the 737NGs in IF coming in different sizes and weights, there are certainly differences in performance requirements and procedures between them. Nevertheless, there are similarities, owing to their design process, and for the purposes of this topic, I will covering those related to approach and landing procedures only as mentioned above, in unprecedented detail.
Let’s begin with flaps!
- Flap speed schedule/maneuvering speed: A successful approach and landing begins with proper planning. You should be thinking of extending your flaps as you incrementally reduce your speed during the approach - but when?
The answer lies in the maneuvering speed for each flap setting.
- Flaps UP: Vref 40 + 70kts
- Flaps 1: Vref 40 + 50kts
- Flaps 5: Vref 40 + 30kts
- Flaps 10: Vref 40 + 30kts
- Flaps 15: Vref 40 + 20kts
- Flaps 25: Vref 40 + 10kts
- Flaps 30: Vref 30 (you will be approaching slightly above this if your final landing configuration is 30)
- Flaps 40: Vref 40 (you will be approaching slightly above this if your final landing configuration is 40)
Now… what do you do with these speeds?
You select the next flap setting upon reaching the maneuvering speed of the current configuration.
For example, if I’m at Flaps 1 with a Vref40 of 140kts, I should be extending Flaps 5 at 140 + 50 = 190kts.
This extension should be made before slowing down to below the maneuvering speed for the existing flap setting (1 in this case.)
Flaps 2 is not used often, if at all, in normal operations so is excluded from this list.
It is not necessary to go through every single one of these configurations even so, most operators elect to conduct a simplified flap extension schedule (e.g. 1, 5, 15, 25, 30, etc.)
Note: Flap placard speeds are shown below the landing gear handle in the 737NG cockpit - they are the maximum allowable speeds for each flap setting (Vfe) but it is not recommended that you extend the flaps too close to the limit for each setting.
- FAQ: Flaps 30 or 40 for landing? There are two universally approved flap settings for landing the 737NG: 30 and 40.
- Flaps 30 is the most commonly used configuration for landing.
- Flaps 40 allows for a lower Vref, decreased landing distance, reduced body angle (and therefore more tail clearance on landing.)
- The benefits of Flaps 40 come at the expense of increased fuel consumption (due to greater drag), noise, (and from a personal perspective, the tendency to land harder.)
- Flaps 40 is mainly used in these scenarios as a result:
- Steeper approaches (e.g. Marseilles/LFML 31R, with a 4.0 degree glideslope)
- ILS approaches in CAT II/III conditions (for better forward visibility)
- Short runways with limited landing distance (e.g. Congonhas/SBSP, Santos-Dumont (SBRJ)
Flaps 15 is not approved by JAA/EASA and CAAC; the FAA allows it but from what I've read this does not apply to all air carriers in the US. It is seldom used even in the operators that permit its use. For the purposes of this guide I will not be going into so much detail regarding the usage of Flaps 15 as a result.
Note: It is not recommended for both the speedbrakes and the flaps to be extended simultaneously; should this be a necessity for the given scenario, the flaps should not be extended past 15 whenever the spoilers are out.
3. [UNIVERSAL] Correcting for wind speed on final approach
This applies to all three variants of the 737NG in IF as well.
- Select a final approach speed of Vref + 5kts when the autothrottle is used. Sufficient wind and gust protection is available with the A/T active.
- If the A/T is disengaged or is planned to be disengaged sometime before landing, add 1/2 of the steady headwind component and full gust increment above the steady headwind speed to the Vref to obtain your approach speed.
- The approach speed after correction should not exceed Vref + 20 in the given configuration, or landing flap setting placard speed - 5, whichever is lower.
- DO NOT apply ANY correction if a tailwind is present. Maintain Vref + 5 on final approach.
For example:
I have a Vref of 137kts, with a headwind component of 16kts gusting 20kts.
My approach speed without A/T would be 137 + 16/2 + (20-16) = 149kts.
149 - 137 = 12, the correction is within limits.
4. [UNIVERSAL] Crosswind landing technique
- The maximum crosswind component allowed for landing on a runway of minimum 45m width is 40kts. Dry runway figure quoted because that’s all we have in IF.
- Method: There are three approved crosswind landing techniques for the 737NG: Touchdown in crab, de-crab in flare and sideslip (wing-low.)
The second method has largely been covered in the official Infinite Flight tutorial here, I would recommend checking that out first.
Touching down in a crab is largely the same as the above method but instead of applying opposite rudder to align the nose with the runway heading, you land in the crab maintained throughout approach and apply rudder after the main gear touches down to get back onto the centerline. Ensure adequate rudder and upwind aileron are applied after touchdown to maintain directional control.
Note: While sideslip is in fact an approved method of landing the 737 in real life (basically involving a crab during initial approach and transitioning to align with the centerline before the flare by applying opposite rudder and aileron at the same time), I do not recommend its use in IF, a) due to its complexity and b) because the aircraft responds fairly strangely to this combination of control inputs after some testing I did.
5. [REVISED AND TESTED] Realistic landing profiles for the 737-700
Enough with all the theory then. How about let’s see what a landing would look like in practice - let’s kick the easy one out of the way first:
Vref for Flaps 30 and 40 up to MLW, all weights in kgs x 1000 (metric tons)
| Weight, kgs x 1000 | Vref 30 | Vref 40 |
|---|---|---|
| 58 | 133 | 131 |
| 56 | 130 | 128 |
| 54 | 128 | 126 |
| 52 | 125 | 123 |
| 50 | 123 | 121 |
| 48 | 121 | 119 |
| 46 | 118 | 116 |
| 44 | 116 | 114 |
| 42 | 113 | 111 |
| 40 | 111 | 109 |
6. [REVISED AND TESTED] Realistic landing profiles for the 737-800*
Standard 737-800
Vref for Flaps 30 and 40 up to MLW, all weights in kgs x 1000 (metric tons)
| Weight, kgs x 1000 | Vref 30 | Vref 40 |
|---|---|---|
| 66 | 149 | 142 |
| 64 | 147 | 140 |
| 62 | 144 | 137 |
| 60 | 142 | 135 |
| 58 | 140 | 132 |
| 56 | 137 | 129 |
| 54 | 135 | 127 |
| 52 | 132 | 124 |
| 50 | 129 | 122 |
| *45 | *122 | *115 |
| *40 | *115 | *108 |
*Simbrief data started showing discrepancies with real world Vref tables below 50t, the latter of which only showed 5t increments.
**Standard B738 speeds above. Some B738s are fitted with a SFP (Short Field Performance) package that allows for reduced approach and landing speeds as a result of some modifications to the airframe. These modifications, bar the increased ground spoiler deflection to 60 degrees, are not present in the 3D model in IF but I personally find it easier to land with SFP speeds. For Infinite Flight purposes, I would just put it down to personal preference regarding which to use - I recommend trying out both sets of speeds first.
737-800SFP
Vref for Flaps 30 and 40 up to MLW, all weights in kgs x 1000 (metric tons)
| Weight, kgs x 1000 | Vref 30 | Vref 40 |
|---|---|---|
| 65 | 147 | 139 |
| 60 | 141 | 133 |
| 55 | 134 | 127 |
| 50 | 128 | 121 |
| 45 | 121 | 114 |
Apologies for the lack of more values - SFP data is comparatively difficult to find and I only managed to find tables in increments of 5 000kg.
7. [REVISED AND TESTED] Realistic landing profiles for the 737-900**
OK. Here is where it gets messy…
Even though the 737-900 in IF is technically a non-ER as I mentioned above, it is mainly used for the purposes of the ER and guess what, lands better with ER speeds!
I will include figures for both the ER and the non-ER for the purposes of this, but please note that non-ER data has been exceptionally hard to find and there will be fewer values given. However, for the purposes of Infinite Flight, I would highly recommend using the ER speeds.
737-900ER (recommended)
Vref for Flaps 30 and 40 up to 71t, all weights in kgs x 1000 (metric tons)
| Weight, kgs x 1000 | Vref 30 | Vref 40 |
|---|---|---|
| **71 | 149 | 144 |
| **69 | 147 | 142 |
| 66 | 143 | 138 |
| 64 | 141 | 136 |
| 62 | 138 | 133 |
| 60 | 136 | 131 |
| 58 | 134 | 129 |
| 56 | 131 | 126 |
| 54 | 129 | 124 |
| 52 | 126 | 121 |
| 50 | 124 | 119 |
**Values above 66t for this aircraft exceed its maximum landing weight of 66 349kg in IF. The MLW of the 737-900ER in real life is 71 350kg.
737-900 (non-ER)
| Weight, kgs x 1000 | Vref 30 | Vref 40 |
|---|---|---|
| 66 | 151 | 141 |
Having looked practically everywhere for more information on the non-ER B739, figures for MLW were all I managed to find - but this doesn’t matter so much as after having tested both the ER and non-ER speeds, the former seemed to work much better - using the non-ER speeds just resulted in a very long float in any case.
8. Final tips and tricks to ensure a smoother experience
- Do not pull back the thrust all at once at 30ft. A gradual, smooth thrust reduction to idle starting between 20-30ft and finishing just prior to touchdown will ensure a smoother landing. Pay attention especially on the longer variants and if Flaps 40 is used.
- Do not flare excessively - this will either lead to a float and long landing, or a tailstrike may occur (tailstrike risk increases with the longer variants so take extra care.)
- On a standard 3-degree glideslope, the sink rate on final approach below 1000ft AGL should not exceed -1000fpm - a go-around would be the best course of action in case the descent rate surpasses this.
FAQ
- Can I use Flaps 25 for landing? Nope, 25 is not an approved setting for landing on the Boeing 737. See Section 2 for more information.
- What exactly is Vref? Vref is the reference landing speed for an aircraft at a given mass - it is usually 1.3 times the stall speed at landing configuration.
This topic is not intended to discredit the hard work of other community members who have made guides focusing on other aspects of the 737 or an overview of the aircraft; nor is it equivalent to rendering those simply “wrong” or “invalid”. Instead, this is only meant to be a presentation of my research and findings that I felt other users could benefit from in one way or another - in fact I would highly encourage any of you to correct any mistakes I have made, or missed in the making of this guide for this very reason.
So… that’s it for now! I hope you found this hyper-detailed guide useful; for other aspects of 737 flying you can refer to a huge variety of other sources, both on the IFC and elsewhere, many of which I used as sources myself (which I will link below.)
Simbrief (for performance calculations, would highly recommend!)
737 Airplane Characteristics for Airport Planning
FAA Reference Codes and Approach Speeds for Boeing Aircraft
PPRuNe (for more insight into wider real world aviation)
Happy flying!