# NAC-DFD® Decelerometer — NAC-DFD Decelerometer

> NAC-DFD Decelerometer (iPhone/iPad app by Neubert Aero Corp.)

- Source: https://appshunter.io/ios/app/nac-dfd-decelerometer/id6478895830 (this page in markdown: same URL + `.md`)
- Developer: [Neubert Aero Corp](https://appshunter.io/developer/1785752651)
- Category: Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 13.0 · 3 MB
- Languages: English
- Released: 2024-10-29
- Data updated: 2026-06-05
- User reviews in markdown: https://appshunter.io/ios/app/nac-dfd-decelerometer/id6478895830/reviews.md

## What is NAC?

Terms of Service: https://airportnac.com/terms-and-conditions/

EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

NAC-Dynamic Friction Decelerometer (NAC-DFD®)

The NAC-DFD® is an electronic friction testing device designed for airport runways. This 3-axis mobile iOS™ application enables airport operators to "spot-check" contaminated surfaces during winter runway operations.

Key Features:

Accurate Measurements: Records vehicle braking values by measuring the "g" force or lock-wheel braking action during qualified tests.

Automated Reporting: Automatically generates final reports segmented into runway thirds: "touchdown," "midfield," and "rollout."

Comprehensive Data Recording: Captures all necessary data, including time, date, operator, and assigned user ID.

Versatile Contaminant Selection: Allows operators to choose from 14 different contaminant types for reporting runway conditions during winter operations.

Easy Data Export: Supports exporting results using the standard print function.

Additional Information:

The NAC-DFD® assists airport operators in assessing the effectiveness of friction-enhancing treatments by indicating trends in runway friction levels. It is approved by the Federal Aviation Administration, as listed in Advisory Circular 150/5200-30C, Appendix 3.

Note: For continued testing, a subscription is required.

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| U.S. Region | $199.00 | per year |



## Version history (last 5 releases)

### 2.68 — 2025-01-25

* Updated app description to clarify subscription requirements for continued testing.
* Added a subscription page screenshot for improved transparency.

### 2.65 — 2024-11-24

Added the "Restore Purchases" link to the Subscription page.

Sandbox user:
username: egadams
password: jan02@Th



Guideline 3.1.2 - Business - Payments - Subscriptions
Issue Description


The submission still did not include all the required information for apps offering auto-renewable subscriptions. Apps offering auto-renewable subscriptions must include all of the following required information in the binary:

1.) Problem
- Title of auto-renewing subscription, which may be the same as the in-app purchase product name
1.) Solution
The "Yearly Subscription" label clearly appears above the cost of the subscription

2. Problem
- Length of subscription
2. Solution
The length of the subscription is clearly one year.

3. Problem
- Price of subscription, and price per unit if appropriate
3. Solution
The price of the yearly subscription is clearly shown as "$0.99"

4. Problem
- Functional links to the privacy policy and Terms of Use (EULA)
4. Solution
The links to the privacy policy AND the Apple EULA are included in the subscription dialog.

5. Problem
The app metadata must also include functional links to the privacy policy and Terms of Use (EULA).
5. The "App Privacy" link on the left hand of the Airport_Project Distribution page includes a valid link to the parent websites privacy policy.  The Terms of Use (EULA) are not custom and the radio button is selected for that.

Next Steps


Update the app's binary to include the following required information:

1. Problem
- A functional link to the privacy policy
1. Solution
A functional link appears in the subscription dialog above the EULA link.

2. Problem
Update the app's metadata to include the following required information:


- A functional link to the Terms of Use (EULA). If you are using the standard Apple Terms of Use (EULA), include a link to the Terms of Use in the App Description. If you are using a custom EULA, add it in App Store Connect.

2. Solution
A functional link to the Apple EULA has been included in the subscription dialog.  The radio button to use Apple's EULA has been selected.


If any of these solutions are unacceptable, please let me know in your rejection letter.  Please let me know which part of it is unacceptable so that I can focus on fixing what is wrong.

### 1.2 — 2024-10-30

Removed In-App subscription.  Added Subscriptions and yearly_subscription inside that.  Set price to .99.

### 1.1 — 2024-10-30

Added yearly subscription.  App checks subscription at start up.

### 1.0 — 2024-10-29

No release notes.

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## Related topics

[dfd project](https://appshunter.io/ios/topics/dfd-project)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-05.*