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update info

of the B737 PRH app

The contents of the app are updated on a regular basis when appropriate and free of charge. Besides technical issues like bug fixes, updates are triggered by changes in the regulations or when additional information becomes available in order to be even more explanatory and/or to clarify the various performance subjects. If you have any suggestion to improve this app, it would be highly appreciated if you want to contact us about it.


Update 3.3 - july 2023

  • Chapter Takeoff Thrust Reduction and Obstacle Clearance Requirement expanded with text and figures.

  • Added full screen option in TOOLS.

  • Solved some iOS 16 bugs.

Update 3.2.2 - may 2023

  • The OUTPUT of the Landing Distance & Brake Cooling calculator TOOL now also displays per autobrake setting the speeds where the Caution zone and Fuse Plug Melt Zone will be entered regarding brake cooling.

  • Some text changes and layout adjustments.

Update 3.2 - feb 2023

  • Expanded the Landing Distance & Brake Cooling Calculator and Go-Around & Climb Gradient calculator tools with B737 Classic (B733/B744) and B738-SFP2 data, together with an input redesign for better overview between CL/NG/MAX types.

  • Improved the interactive V1 range tool for better understanding.

  • Figures added regarding missed approach gradients for clarification.

  • Minor text adjustments.

  • iOS16 optimizations.

Update 3.1.4 - jun 2022

  • Added the option in the Landing Distance & Brake Cooling Calculator tool to display unfactored distances (minus the 15% regulatory requirement). In the same tool it is now also possible to select an approach speed based on VREF additive below 5kts. Lowest selectable VREF Additive is 0kts (was 5kts).


Update 3.1.3 - jun 2022

  • Added the option to purchase a lifetime membership for the app (or for only the TOOLS section, only available for early customers (before update 2.0)).


Update 3.1 - feb 2022

  • The Landing Distance & Brake Cooling calculator as well as the Go-around Climb Gradient & Limit Weight calculator have been redesigned and now remember your latest input.

  • All sections/chapters can now be collapsed at once for beter overview.

  • Some text corrections and minor bug fixes.


Update 3.0 (.1) - feb 2022

  • Complete rebuild from the ground up to support the latest iOS15 features

    • fold/unfold sections for better overview and easier navigation

    • enlarge figures

    • improved search function in either all chapters or your current chapter

    • overall improved user experience

  • Added NEW tool: Interactive V1 Range visualization.

  • Fixed an issue where some wind components in the Wind Components tool were not displayed correctly.

Update 2.4.5 - jan 2022

  • Added NEW tool: Runway Condition Report (GRF) Decoder according the new Global Reporting Format (GRF).

  • Fixed a (iOS15) issue where the various parameters in the Landing Distance and Brake Cooling Calculator did not scroll correctly.

Update 2.4.4 / 5 / 6 - nov 2021

  • GRF data implemented and renamed chapter 'Braking Performance Data' into 'Runway Surface Condition' with sub-chapters 'Runway Condition Reporting' and 'Runway Friction Parameters'.

  • Tools selector bars coloured for better contrast.

  • Minor adjustments.

Update 2.4.3 - oct 2021

  • Fixed an issue where some users reported that some tools would crash after update to iOS 15.


Update 2.4.1 / 2.4.2 - april 2021

  • Minor adjustments


Update 2.4 - april 2021

  • Added NEW tool: Go-Around Gradient and Limit Weight Calculator for various B737-types

  • Option in settings to change the pressure unit (hPa/"Hg)

  • Chapter "Return To Land (RTL) Requirement" added, applicable to B737MAX

Update 2.3 - february 2021

  • Added NEW tool: Landing Distance Calculator (integrated in the Brake Cooling calculator) for various B737-types

  • Option in settings to change the distance unit (m/ft) and temperature unit (C/F)

  • Content update

Update 2.2 - december 2020

  • Added NEW tool: Brake Cooling Calculator for B737-700 and B737-800 with carbon brakes

Update 2.1 - november 2020

  • Added NEW chapter: "Descent" under Enroute Performance

  • Added NEW tool: Wind component and approach speed calculator


Update 2.0.4 - august 2020

  • Minor content correction and bug fixes

Update 2.0.1/ 2.0.2 / 2.0.3 - july 2020

  • Issue regarding subscription fixed

UPDATE 2.0 july 2020 - MAJOR technical and content update

  • Completely redesigned user interface with a modernized look and feel, with

    • new logo

    • vastly improved search functionally

    • iPhone support

    • dark mode capability

    • useful interactive tools to decode MOTNE / SNOWTAM and to calculate actual runway stop margin.

  • Content update:

    • latest regulations implemented

    • added procedures and remarks regarding computerized performance tools

    • new chapter Double Derate

    • new chapter Braking Performance Data

    • added info regarding passenger oxygen requirements

    • added various clarifying FMC pictures

november 2019 - technical and content update

  • Content update

  • Bug fixes and UI improvements

june 2019 - technical update

  • Fix to properly re-scale chapter content

  • Fixed an issue when some customer have not received content update

may 2019 - content update

  • Expanded go-around climb gradient info in applicable chapters

  • Expanded chapter 'Enroute Cruise Altitude' with step climb considerations

  • Adjusted landing dispatch performance flowchart

  • Additional remarks regarding wind, line up loss, EMAS/RESA, Vmbe, oxygen requirement, recommended brake cooling schedule, FAS, landing climb limit weight

  • Various text changes and additives throughout the app for clarification and extra info

july 2016 - content update

  • Remarks added regarding recommended brake cooling schedule, quick turnaround, VR increase in x-wind conditions

  • Additional V1-range info added in chapter 'Balanced Takeoff'

  • Added definitions according ICAO annex 6

april 2015 - content update

  • All EASA regulation quotes are now references to the new European Commission Regulation 965/2012, which replaced EU-OPS as per october 2014. Chapter 'Legend' and 'References' changed accordingly.

  • Added chapter 'Takeoff Flap Setting'

  • Added remarks with respect to TALPA-ARC recommendartions regarding landing performance data.

  • Added some ICAO PAN-OPS and Annex 6 quotes

  • Chapters 'Driftdown', 'Derated Takeoff Thrust', 'Assumed Temperature Reduced Thrust' and 'Glossary' expanded

  • Editorial text changes for clarification

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