In response to requests from two users, I've added the Lycoming O-540-F and IO-580-B1A engines. While doing this, I discovered and fixed a minor bug with the Info screen's "Make It So" button. I also made a small change — if one exits the engine selector using the "Cancel" button, the selector will be reset to the current engine.

I fixed a problem with saving the % power setting, and did more code cleanup.

Following user requests, I've added the Lycoming IO-360-M1B engine. I've also added support for the new iPads, made a few minor aesthetic changes in the layout, did a whole mess of recoding, and did some general code cleanup.

I've added 11 engines in the Continental IO-550 family. I've also added the ability to separately select your preferred units for manifold pressure and altimeter setting. I also fixed a minor bug which could affect the equivalent sea level standard manifold pressure output, and did more coding cleanup.

I've corrected a reported problem with the information screens on the iPad Pro 10.5"

I've added an option to input % rated power and output the manifold pressure required, instead of inputting manifold pressure and outputting the power. To accomodate this new option for all the included engine models, I've had to change the maximum allowable manifold pressure from 32"Hg (1084 mb) to 31"Hg (1050 mb)., I've also fixed a bug, which could cause the app to freeze under an unlikely set of circumstances. Finally, I've made some more minor aesthetic changes.

I've added an additional 16 Continental engines in the -200, -240, -300 and A and C prefixed families. I've also added a Cancel button to the engine selector (a feature which I borrowed from my new AircraftPower S app). I've fixed a bug which could cause the app to crash when switching between Lycoming and Continental engines, and two other bugs which delayed the main screen from immediately responding to changes made in User Preferences. Finally, I've made a few minor aesthetic changes.

In response to numerous requests, I've begun to add Continental engines to AircraftPower. I've started with the Continental IO-360, O-470, IO-470 and IO-520 engine families, and will be adding more as I collect their data. To support the addition of another manufacturer, I've added a pop-up window at app start-up to remind users how to switch between engine manufacturers. I also fixed a minor bug that prevented the constant manifold pressure lines from displaying on the altitude charts of a few engines. "Under-the-hood," much of the code has been modified to accommodate a second engine manufacturer database, with a significant amount of general code clean-up.

In response to user suggestions, I've added five more variants of the IO-390 engine family. Preferences editing has been changed from being a "pop-up" on the Info screen to a new User Preferences screen which is accessed from the Info screen The user interface has been updated to provide compatibility with the latest iPads, including the new iPad Mini. An occasional aesthetic bug in the custom keypad's appearance was corrected. Other changes in this version are "under the hood" for compatibility with iPadOS 15.5, with minor debugging, and general coding clean-up.

Most of the changes in Version 2.2 are for compatibility with iPadOS 13. The most significant are those for iPadOS 13's Dark mode. Also, because of new screen space limitations, I decided to eliminate the option to have an edit window cleared when it's tapped (not a great loss since tapping the little gray "x" in the edit window will clear it). In response to a request from a user whose bird has turbo-normalized IO-360-C engines, I've added the ability for the user to input air temperatures up to 236F (120C), which may be useful for those with "after-market" turbochargers.

The most significant change is the addition of twenty-eight normally-aspirated engines in the -540 family to AircraftPower. Five IO-720 engine variants, the IO-390EXP experimental engine, and three more AEIO-320 and AEIO-360 engine variants have also been added. At the request of a user, I added the equivalent sea level standard manifold pressure as an optional output. Finally, I did some work "under the hood" to tune up the app a bit, and to fix a couple of bugs.

New features in Version 2.0 - The most significant change in Version 2.0 is the addition of support for landscape orientation. (However, AircraftPower remains a full-screen-only app.) The user has two choices for the landscape screen arrangement — the graphic on the left and the inputs on the right (the default), or vice versa for our left-handed friends. - The custom keypads have been improved, with added "smarts" including cursor control keys and a "restore" key, which restores the input window value to to what it was when tapped for editing. They also now play nicely with the iOS touch selection features. The keypads are tailored for each input; e.g., the user can't enter a negative pressure or rpm, nor a non-integer rpm, altitude or temperature. Finally, the user can select either a calculator-style keypad (top row: 7-8-9, the default) or a telephone-style keypad (top row: 1-2-3). - The user now has an option to have the input window cleared when it is tapped for editing. - The user can choose to input the indicated altitude instead of the pressure altitude (the default). If so, an input window for the altimeter setting appears. The altimeter setting and the indicated altitude are then used to calculate the pressure altitude, which is displayed in the graphic and used for the performance calculations. - I've also added three color indicators: First, when the percent of rated power is less than than 75%, the output power window has a light green background. I did this because I consider it to be inadvisable to lean above 75% rated power unless you can monitor each cylinder's exhaust gas temperature. Second, when the manifold pressure exceeds the ambient air pressure at the input pressure altitude, the operating point on the altitude side of the chart is surrounded by a yellow halo, shading to red when the manifold pressure exceeds the ambient air pressure by more than 3"Hg or 101 mb. I did this as an indicator that the input manifold pressure may be unrealistic unless your bird is very fast and has very good ram air recovery (At 150 kt IAS, the maximum possible ram recovery is a bit over 1"Hg or 35 mb). Third, when the sea level operating point is to the right of the limiting manifold pressure for continuous operation (not recommended), the sea level operating point is surrounded by a yellow halo. - Finally, there have been a lot minor tweaks "under the hood" to bring the code up to date for iOS 11.2, with backward compatibility to iOS 9.3. Earlier iOS versions are no longer supported.

Version 1.21 is mostly minor tweaks "under the hood" to bring the code up to date for iOS 9.3 and later. I've also reduced the height of the backspace/delete key on the custom keypad and added some "smarts" which should make it difficult to enter a non-number. Support for the iPad Pro is currently limited to full screen mode only. Earlier iOS versions are no longer supported.

A custom keypad has been added, so data entry may now be made using either vernier sliders or keypad.

New features: - Fifteen engines in the Lycoming O-235 and O-290 families have been added to the database. - The engine selection picker wheel has been changed from a single rotor to three — to select the engine type (O-, IO-, AIO-), family (235, 290, 320, 360) and variant (-A, -B, etc.) separately. As the number of engines in the database grows, this will be a more convenient way of selecting an engine. - The current state of the app is now preserved when the app is dismissed or shut down. - AircraftPower is now also compatible with iOS 6.1. - There are numerous changes “under the hood” which include significant code changes to increase flexibility and facilitate adding more types of engines. Bug fix: - A bug that prevented selection and display of the AIO-360 engine has been fixed.