Altitude Test — UN 38.3 T.1 / RTCA DO-160 Section 4 / IEC 60068-2-13

What Is Altitude?

The altitude test is a test in which the specimen is held at reduced air pressure for a defined period, evaluating leakage, deformation and loss of function. It represents aircraft cargo-hold or high-altitude conditions.

Purpose of Altitude

The purpose is to verify that products transported by air or operating at high altitude remain safe and functional at low pressure.

Which Products Is Altitude Applied To?

Lithium battery cells, modules and packs
Aerospace avionics units
Pressure-sensitive packaging
Electronic products shipped by air

In Which Sectors Is Altitude Used?

AerospaceSpaceDefenceElectronics

Standards Related to Altitude

UN 38.3 T.1
RTCA DO-160 Section 4
IEC 60068-2-13series of environmental testing methods test
MIL-STD-810 Method 500

Altitude Conditions

UN 38.3 T.1 pressure: 11.6 kPa or below
UN 38.3 T.1 duration: At least six hours
Temperature: 20 °C ± 5 °C in UN 38.3 T.1
Aerospace profile: Pressure and duration according to equipment category in RTCA DO-160

Equipment for Altitude

Vacuum chamber (pressure-controlled)
Pressure and temperature measurement system
Voltage and mass measurement (battery)
Function-monitoring rig

Sample Requirements for Altitude

The specimen must be fully charged in battery tests
Initial mass and voltage must be recorded
The number of specimens is defined in the standard
Connections must be checked on specimens requiring a seal

Duration of Altitude

At least six hours for UN 38.3 T.1; it may be longer according to the specification in aerospace profiles.

Altitude Procedure

1The specimen is identified, and its mass and voltage are recorded.
2The specimen is placed in the vacuum chamber.
3The pressure is reduced to the defined value.
4The conditions are maintained for the defined duration.
5The pressure is returned to ambient.
6Mass loss, leakage, deformation and voltage are assessed.

Altitude Acceptance Criteria

The acceptance criterion is defined in the applied standard. In UN 38.3 T.1, the typical criteria are that mass loss does not exceed the limit, that there is no leakage, gas release, fire or explosion, and that open-circuit voltage does not drop below a specified ratio.

Evaluation of Results

Mass loss is determined with a precision balance. Deformation and leakage are assessed by visual inspection.

Altitude Report

Applied standard and test number
Pressure, temperature and duration
Initial and final mass and voltage
Observations and photographs

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

UN 38.3 (air transport)
IATA Dangerous Goods Regulations
RTCA DO-160

Aerospace Testing — What Does This Testing Field Cover?

The section below describes the field that the Altitude test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Aerospace testing shows that equipment keeps working in the flight environment and provides evidence for the airworthiness file. In this family the acceptable probability of failure is several orders of magnitude lower than in other sectors; this directly determines the scope of testing and the certification burden.

The most distinctive feature of the field is TRACEABILITY. Which melt an aircraft part came from, in which heat treatment furnace and with which cycle it was processed, which operator made the weld and which inspector approved it are all recorded. The test report is one link in this chain; if the chain is broken, the report carries no value on its own.

Environmental qualification runs through RTCA DO-160, with categories selected according to the equipment's MOUNTING LOCATION in the aircraft. A device mounted on the cockpit panel and one mounted inside the wing pass the same section under different categories. When reading a DO-160 report it is therefore essential to know which sections were applied at which categories.

On the software and complex hardware side the approach changes entirely: the evidence is not testing but PROCESS ASSURANCE. DO-178C for software and DO-254 for complex electronic hardware define how the development process is to be run and which evidence is to be produced. Every step, from requirement to code, from testing of the code to coverage analysis, must be traceable. Testing software does not make it certifiable; the process record does.

A separate body of work applies on the material and special process side. AWS D17.1 is used for welding, SAE AMS 2750 for pyrometry in heat treatment and NAS 410 for non-destructive testing personnel. For special processes (heat treatment, coating, welding, NDT, bonding) NADCAP accreditation is effectively mandatory in the supply chain; without NADCAP it is not possible to sell parts to many OEMs.

On the quality system side the AS/EN 9100 series is used: 9100 for manufacturers, 9110 for maintenance organisations and 9120 for distributors. Without these certificates it is practically impossible to enter the aerospace supply chain, and audits are markedly more detailed than in other sectors.

Counterfeit part risk is a subject peculiar to the field. Separate standards and verification methods (visual inspection, X-ray, decapsulation and internal structure examination, XRF) are used to detect counterfeit or reworked parts in the electronic component supply chain.

Space applications add further layers: outgassing in vacuum, radiation tolerance, long-duration thermal vacuum cycling and assessment of single event effects.

Method groups in this field

Environmental qualification
RTCA DO-160 sections: temperature and altitude, vibration, shock, humidity, sand and dust, fungus, salt fog, fluid susceptibility, icing, lightning.
Electromagnetic
The EMC sections of DO-160; MIL-STD-461 and MIL-STD-704 power characteristics on military platforms.
Software and hardware assurance
DO-178C software life cycle and DO-254 hardware design assurance evidence; requirement traceability and coverage analysis.
Materials and welding
Welding qualification under AWS D17.1, mechanical testing of materials, metallography and non-destructive examination.
Special process control
SAE AMS 2750 pyrometry, coating and heat treatment process verification, preparation for NADCAP audits.
Space environment
Thermal vacuum cycling, outgassing, radiation tolerance and acoustic/vibration qualification.

Commonly confused in this field

There is no such document as a "DO-160 certificate"; DO-160 is a test specification and its output is a qualification report.
The selection of sections and categories comes from the customer's equipment specification; the laboratory cannot make that selection on its own.
DO-178C and DO-254 cannot be satisfied by testing; the evidence is the traceability of the development process.
An AS9100 certificate is not a product approval; it is a quality system certificate and part approval runs separately.
For special processes, work carried out without NADCAP is not accepted in the supply chain even when it is technically correct.
MIL-STD-810 and DO-160 are often confused: one is a military and the other a civil aviation specification, and their profiles differ.

Which decisions these results support

Airworthiness and TSO/ETSO files
Entry into the aerospace supply chain and supplier approval
Special process approval and NADCAP preparation
Determining the impact of a design change on qualification
Managing counterfeit part risk and component verification

Related Tests

Frequently Asked Questions About Altitude

Which test is mandatory for shipping lithium batteries by air?

The UN 38.3 test series is mandatory, and the T.1 altitude simulation is the first test in that series. A UN 38.3 test summary document is also required for shipment.