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Military Aircraft

Volume 488: debated on Monday 23 February 2009

To ask the Secretary of State for Defence (1) how many air-to-air refuelling sorties were flown by the (a) Tornado and (b) Harrier fleets in the United Kingdom in each month of each of the last five financial years; (248571)

(2) what the rate of rejection of eco-engines from first line in the United Kingdom was in each week of each of the last five financial years;

(3) how much aviation fuel was transferred to the Tornado air defence and ground attack fleets during air-to-air refuelling operations in the United Kingdom in each week of each of the last five financial years;

(4) how much aviation fuel was used by the Tornado air defence and ground attack fleets in the United Kingdom in each week of each of the last five financial years;

(5) how much aviation fuel was consumed by the Harrier fleet in the United Kingdom in each week of each of the last five financial years;

(6) what the rate of rejection of RB 199 aero engines from first line was in the United Kingdom in each week of each of the last five financial years.

Mr. Bob Ainsworth: I will write to the hon. Member.

Substantive answer from Bob Ainsworth to David Lidington:

I undertook to write to you in answer to your six Parliamentary Questions on 19 January 2009, Official Report, column 1051W, requesting information about fuel consumption and engine rejection rates for the Harrier and Tornado fleets.

You asked for a range of detailed and specific information about fuel consumption, much of which is not held centrally in the format requested and could only be provided at disproportionate cost. However, you have since indicated that your main interest in asking about fuel consumption was to establish whether there is an unjustified increase in RAF flying patterns towards the end of a financial year, designed to ensure that all available fuel is consumed and to justify future fuel budgets. Relevant data are readily available showing the volume of fuel transferred on the ground and during air-to-air refuelling (AAR) with UK tankers, for the Harrier, Tornado GR4 and Tornado F3 fleets for each financial year. This indicates fuel consumption trends by month across financial years since 2005-06. Data prior to 2005-06 are not held centrally and could only be provided at disproportionate cost.

These data are set out in the following tables. To better show the trends they have also been presented in graphs for each financial year in an annex to this letter. It should be noted that the figures provided do not include fuel transferred from foreign tankers, for example during NATO exercises. They also do not include data for AAR consumption by 14 Squadron (Tornado GR4) based at RAF Lossiemouth, which are not available. Additionally, due to the relatively small level of consumption, figures for the Fast Jet Weapons Operational Evaluation Units are only recorded annually and so have not been included, as to do so would not assist in analysing any possible month on month trends. Because the figures which are missing are relatively small we do not consider them to be statistically significant.

Fuel transferred (million litres)

Tornado F3

Tornado GR4

Harrier GR7/9

2005-06

April

6.17

8.02

3.04

May

7.77

11.19

3.64

June

8.94

10.13

4.11

July

7.17

16.02

6.50

August

8.09

13.04

3.66

September

7.58

12.69

4.42

October

6.14

12.23

4.47

November

6.58

13.48

4.38

December

3.75

8.27

2.15

January

6.16

10.67

3.24

February

6.62

12.57

4.11

March

5.67

9.73

3.40

Total

80.64

138.04

47.12

2006-07

April

4.66

8.76

2.03

May

7.20

10.68

2.33

June

7.36

12.08

2.74

July

5.77

22.47

5.40

August

6.14

12.13

2.02

September

5.38

13.59

2.26

October

7.86

12.69

3.95

November

5.48

13.12

2.71

December

4.76

10.95

3.00

January

5.07

9.54

3.02

February

4.44

11.06

3.16

March

6.76

11.76

1.72

Total

70.88

148.83

36.51

2007-08

April

5.76

11.61

2.62

May

5.29

9.08

2.83

June

6.61

16.15

3.15

July

4.42

11.01

2.97

August

4.51

13.26

2.49

September

4.97

12.33

3.36

October

5.14

12.73

2.85

November

5.73

8.52

2.46

December

3.48

9.03

2.29

January

5.01

11.58

3.22

February

3.02

5.92

1.72

March

4.62

12.28

3.21

Total

58.56

133.50

33.17

As you can see, the data do not indicate a general upturn in fuel consumption in the final months of a financial year. Although this does occur in some cases, there are also some decreases at the end of financial years and peaks occurring at other times of the year. There are a number of reasons why flying rates may increase from December to March, including the improving weather and the fact that there is normally less flying in December and January, owing to traditional periods of leave. Flying may also increase in March because aircrew need to renew certain qualifications before the end of the training year, which coincides with the end of the financial year.

You also asked about the rejection from first line in the UK for the Pegasus and RB 199 engines in each week of the last five financial years. This data is available on a monthly basis for both engine types from 2005-06 only and is provided in the following table. It is to be expected that there will be a higher number of rejected RB 199 engines, due to the much larger size of the Tornado fleet (for example there are currently 210 Tornado F3 and GR4 and only 75 Harrier GR9 in the fleet) and the fact that that the Tornado is a dual-engine aircraft, whereas the Harrier only has one Pegasus engine. However, on average the rate of rejection for the three financial years works out at almost the same: 3.39 engines per 1000 flying hours for the Tornado RB 199 engine as opposed to 3.52 for the Harrier Pegasus engine.

An ‘engine rejection' occurs when it is deemed unserviceable and the necessary repair action cannot be carried out with the engine installed or is beyond the capability of the engineers on the squadron. Unserviceability may be caused by, among other things, physical damage to the engine, engine components becoming life expired, unsatisfactory vibration characteristics or poor performance.

Rejection rate of the RB 199 engine (fitted to the Tornado F3 and GR4) per 1000 flying hours

Rejection rate of the Pegasus engine (fitted to the Harrier GR7/9) per 1000 flying hours

2005-06

April

3.66

1.59

May

1.89

7.17

June

5.06

0.76

July

2.19

4.45

August

3.00

5.81

September

3.20

4.05

October

3.16

5.29

November

2.60

4.87

December

3.27

4.27

January

2.16

4.22

February

3.65

1.97

March

3.95

2.90

2006-07

April

3.19

2.22

May

3.63

8.37

June

3.31

1.54

July

5.07

4.77

August

2.79

2.83

September

2.24

3.17

October

3.24

2.14

November

3.74

1.37

December

2.92

4.80

January

3.82

5.22

February

2.55

1.87

March

4.23

1.64

2007-08

April

2.93

2.51

May

4.00

3.06

June

4.91

4.30

July

3.23

2.30

August

4.12

4.81

September

3.88

4.03

October

4.51

2.63

November

3.61

3.55

December

3.01

1.97

January

2.90

0.94

February

3.47

6.03

March

3.06

3.44

I hope this letter fully addresses your concerns.