Thermal Comfort an Aviation Topic?

Home , Cold Feet, Cold Feet (series 1), Cold Feet (series 2), Cold Feet (series 3), Cold Feet (series 4), Cold Feet (series 5)

German Social Accident Insurance 38th EAGOSH Meeting Institution for Transport and Traffic 6-7 May 2015

Thermal Comfort

An Aviation topic?

Thomas Sye

EAGOSH, 2015-05-07 Cold feet sensation on the flight deck of commercial aircraft

A possible prevention measure?

Sye T, EAGOSH 2015 2 Cold feet sensations in the flight deck of Airbus A 320/A 321 aircraft • Cold feet, caused by uncomfortable floor temperature • Large vertical air temperature gradient • Airbus A 320/A321 on medium haul-flights without underfloor heater, only

„even with sick socks and lined shoes both pilot‘s feet started to get numb“

Sye T, EAGOSH 2015 3 Possible causes • very low outside temperature at normal flight level (FL 350- 390): about - 60° C ( -76° F, 213 K) • assossiated with cooling of aircraft skin • lack of underfloor-heater (cost reduction)

• flight instruments with low or no heat emission

Sye T, EAGOSH 2015 4 Investigation

• The objectives were to evaluate the thermal local discomfort in the area of the pilot seat especially focusing on • Cold feet and warm head at the same time • Cold feet, caused by uncomfortable floor temperature Taking into account: DIN ISO 7730” "Ergonomics of the thermal environment - Analytical determination and interpretation of thermal comfort using calculation of the PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) indices and local thermal comfort criteria"

Sye T, EAGOSH 2015 5 Method • The thermal situation in the flight deck of 3 Airbus A 320/321 has been investigated on 6 medium – haul flights from Germany to Egypt and Teneriffa (Spain) and Fuerteventura (Spain) • 2 flights with under-floor heater (foot warmer) • 4 flights without under-floor heater (foot warmer)

• Measured (inflight, 4 - 5 hrs): • course of floor temperature near the pedals • vertical temperature profile at the pilots seat at three measuring points

Sye T, EAGOSH 2015 6 Measurement

Two measuring points at the pilots seat

Sye T, EAGOSH 2015 7 Measurement

3th measuring point near the pedals

Sye T, EAGOSH 2015 8 Results (floor temperature and resulting percentage of dissatisfied (PD)

aircraft without underfloor heater

°C und % (PD)

70 Airbus A 320 60 TFS - HAM, 22.02.2012 maximum floor temperature 50 22,6°C minimum floor temperature: 40 3,5°C minimum outdoor temperature 30 (static air temperature, SAT): -64°C FL max: 370 20

10 floor temperature pilots seat, left side 0 PD (percentage of dissatisfied, ISO 7730) :45 :15 :38 :00 :50 :15 :45 :54 :02 :40 :58 :10 :20 5 6 6 7 7 8 8 8 9 9 9 0 0 1 1 1 1 1 1 1 1 1 1 1 2 2

Sye T, EAGOSH 2015 9 Results (vertical temperature gradient) aircraft without underfloor heater

32 TFS - HAM 22.02.2012 27 A 320

min. temp. feet: 22 3,5° C (08:21 PM)

temperature ° C max. gradient 17 feet / head 19 K

7 head

hip 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 feet :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 :1 0 3 6 9 2 5 8 1 4 7 0 3 6 9 2 5 8 1 4 7 0 3 6 9 2 :2 :3 :4 :5 :1 :2 :3 :5 :0 :1 :3 :4 :5 :0 :2 :3 :4 :0 :1 :2 :4 :5 :0 :1 :3 3 3 3 3 4 4 4 4 5 5 5 5 5 6 6 6 6 7 7 7 7 7 8 8 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Sye T, EAGOSH 2015 10 Results (resulting percentage of dissatisfied (PD), ISO 7730, vertical temp. gradient) aircraft without underfloor heater TFS - HAM % 22.02.2012 Airbus A 320 120

100

0 Percentage of dissatified (PD), ISO 7730 :20:10:41:40:03:10:24:40:46:10:07:40:29:10:50:40:12:10:33:40:55:10:16:40:38:10:59:40:21:10 3 3 4 4 4 5 5 5 6 6 6 7 7 7 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Sye T, EAGOSH 2015 11 Results (floor temperature inflight)

aircraft with underfloor heater

°C

48 Airbus A 321, 47 DUS - FUE, 14.06.2012 maximum floor temperature 46 45,5°C 45 minimum floor temperature: 42,45°C 44 minimum outdoor temperature (static air temperature, SAT): -64°C 43 FL max: 330 42

41 floor temperature flight deck left 40

:31 :10 :35 :10 :30 :30 :00 :04 6 7 7 8 8 9 0 0 0 0 0 0 0 0 1 1

Sye T, EAGOSH 2015 12 Results (vertical temperature gradient) aircraft with underfloor heater 45,00

DUSDUS FUE - FUE 14.06.2012 40,00 Airbus14.06.2014 A321 D-ACSAAirbus A 321 Temp. (Min.) Füsse: min. temperature 21,72° C (07:47 Uhr) 35,00 feet 21,27°C (07:47 AM)

Temperaturentemperature° °CC 30,00

25,00

20,00 headFüsse hip Hüfte Kopf 15,00 feet

5 5 5 5 5 :35 25 15 05 :15 55 05 :5 1:45 2:55 7:35 3:25 4:35 5:45 0:25 1:35 6:15 50 0 1 :35:1 46: 5 :31:0 42: 5 0 1 38: 49 0 1 :33: 45: 5 :40 5: 6: 6: 6:24:056 6: 6: 7:08:457:19:557 7: 7: 8: 8: 8:26:5 8: 8: 9: 9: 9:22:4 9 9: 9: 0:07:250:18:35 1 1 10:29:4510

Sye T, EAGOSH 2015 13 Results (resulting percentage of dissatisfied (PD), ISO 7730, vertical temp. gradient) aircraft with underfloor heater DUS FUE % 14.06.2012 Airbus A 321 60

0 Percentage of dissatified (PD), ISO 7730 5:50:356:00:456:10:556:21:056:31:156:41:256:51:357:01:457:11:557:22:057:32:157:42:257:52:358:02:458:12:558:23:058:33:158:43:258:53:359:03:459:13:559:24:059:34:159:44:259:54:35 10:04:4510:14:5510:25:0510:35:15 Percentage of dissatified (PD), ISO 7730

Sye T, EAGOSH 2015 14 Discussion

Working as a pilot is • connected with high responsibility to flight safety • requires high concentration and attention • Due to the observed local thermal discomforts in the cockpit of the investigated commercial aircraft without underfloor heating a reduction in attention and concentration of the flight deck crew, especially during the takeoff and landing phase can not be excluded. This must be considered in the risk assessment

Sye T, EAGOSH 2015 15 Measures/ Recommendations

By use of auxiliary electrical heating systems (underfloor heater) an increase of working performance of the cockpit crew is possible. An increase of flight safety is to be expected and thereby a possible peril of passengers can be prevented.

Sye T, EAGOSH 2015 16 Thanks for listening! Questions?

Sye T, EAGOSH 2015 17